Indian Patents
Title of Invention

COMBINATION WEIGHER AND WEIGHING SYSTEM USING THE SAME
Abstract A combination weigher of the present invention comprises a first combination weigher unit including a left inner chute (6a), an outer chute (7a), collecting hoppers (8a, 9a), weighing hoppers (4) and memory hoppers (5) which are disposed above the left chutes (6a, 7a), and a second combination weigher unit including a right inner chute (6b), an outer chute (7b), collecting hoppers (8b, 9b), weighing hoppers (4) and memory hoppers (5) which are disposed above the right chutes (6b, 7b), and a control unit (20) configured to control the entire combination weigher. The control unit (20) performs a combination process for each combination weigher unit and causes weighing hoppers (4) and memory hoppers (5) which make up of discharge combinations determined in respective combination processes to discharge the objects to be weighed in an inward direction and an outward direction alternately, and to cause the two collecting hoppers to alternately discharge the objects to be weighed according to the discharge, in each combination weigher unit.
Full Text DESCRIPTION
COMBINATION WEIGHER AND WEIGHING SYSTEM USING THE SAME
Technical Field
[0001] The present invention relates to a combination weigher and a weighing system
which feed to a packaging machine or the like, objects to be weighed which have been
weighed.
Background Art
[0002] Objects to be weighed, such as detergents and confectionary, which have been
weighed to have specified weight by a combination weigher, are typically packaged by a
packaging machine. A schematic construction of a first conventional example of such a
combination weigher which weighs the objects to be weighed is shown in Fig. 13.
[0003] The combination weigher of Fig. 13 is configured such that a control unit 30
controls an operation of the entire combination weigher and performs combination
calculation. The combination weigher is constructed in such a manner that a center
base body (body) 11 is disposed at a center of the combination weigher, and a dispersion
feeder 1 having a conical shape is mounted io an upper part of the center base body 11 to
radially disperse objects to be weighed supplied from an external supplying device by
vibration. Around the dispersion feeder 1, linear feeders 2 are provided to transfer the
objects to be weighed which have been sent from the dispersion feeder 1 into respective
feeding hoppers 3 by vibration. A plurality of feeding hoppers 3 and weighing hoppers
4 are disposed below the linear feeders 2 and are arranged in a circular shape in such a
manner that each feeding hopper 3 and each weighing hopper 4 correspond to the
associated one of the linear feeders 2. The feeding hopper 3 receives the objects to be
weighed which have been sent from the linear feeder 2, and opens its gate to feed the
objects to be weighed to the weighing hopper 4 located therebelow when the weighing
hopper 4 becomes empty. The weighing hopper 4 is attached with a weight sensor 41
such as a load cell. The weight sensor 41 measures weight of the objects to be weighed

inside the weighing hopper 4. The control unit 30 performs combination calculation to
determine a combination made up of hoppers which will discharge the objects to be
weighed, from the plurality of weighing hoppers 4. The weighing hoppers 4
corresponding to the combination discharge the objects to be weighed onto a collecting
chute 12. The collecting chute 12 is disposed below the weighing hoppers 4. The
objects to be weighed which have been discharged from the weighing hoppers 4 slide
down on the collecting chute 12 and are held in a collecting hopper 13 provided at a
discharge outlet in a bottom part of the collecting chute 12. Thereafter, the objects to be
weighed are sent out to a packaging machine which is not shown. While manufacturing
package bags, the packaging machine charges the objects to be weighed which have been
discharged from the combination weigher into the package bags and packages them.
[0004] In order to enable the combination weigher to be adapted to a high-speed
operated packaging machine, it is necessary to provide a collecting hopper 13 at a
discharge outlet of the collecting chute 12 so that the objects to be weighed are
discharged in a state where they are lumped together, and to shorten a discharge cycle
time. To this end, conventionally, the number of weighing hoppers was increased to a
certain degree to configure so that a double shift operation is carried out rather than a
single shift operation, thereby reducing the discharge cycle time taken for the single shift
operation by half. The single shift operation is carried out in a configuration in which,
for example, a total number of the weighing hoppers 4 is set to ten, the number of the
weighing hoppers 4 selected to make up of a combination is set to four, the combination
calculation is performed once within one weighing cycle time, the weighing hoppers 4
perform discharge operation once within one weighing cycle time, and the collecting
hopper 13 performs discharge operation with respect to the packaging machine once
within one weighing cycle time. In order to achieve weighing precision substantially as
high as that in the single shift operation when the double shift operation is carried out,
the number of the weighing hoppers 4 is increased by four so that a total number of them
is fourteen and the number of the weighing hoppers 4 selected to make up of the

combination is set to four. And, the combination calculation is performed once in every
1/2 of one weighing cycle time, weighing hoppers 4 making up of a combination selected
in the combination calculation discharge the objects to be weighed, and according to the
discharge, the collecting hopper 13 discharges the objects to be weighed. That is, the
combination calculation is performed twice within one weighing cycle time, the
weighing hoppers 4 performs the discharge operation twice within one weighing cycle
time, and the collecting hopper 13 performs the discharge operation with respect to the
packaging machine twice within one weighing cycle time. This makes it possible to
improve productivity within a specified time period (the total number of times the
combination weigher discharges the objects to be weighed to the packaging machine) and
hence to adapt the combination weigher to the high-speed operated packaging machine.
[0005] However, even when the conventional combination weigher shown in Fig. 13
is configured to carry out the double shift operation, a batch length of the objects to be
weighed which have been discharged from the weighing hoppers 4 and slide on the
collecting chute 12 is not reduced. For this reason, a distance between the batches of
the objects to be weighed discharged from the weighing hoppers 4 selected to make up of
a previous combination and the objects to be weighed discharged from the weighing
hoppers 4 selected to make up of a subsequent combination is insufficiently large and the
objects to be weighed in the previous and subsequent combinations are likely to be mixed,
making it difficult to carry out the double shift operation at a specified operation speed.
To solve this problem, two collecting chutes may be provided as shown in Fig. 14.
[0006] Fig. 14(a) is a schematic partial cross-sectional view showing a second example
of the conventional combination weigher as viewed from laterally. Fig. 14(b) is a
schematic view of collecting chutes (inner chute and outer chute) and weighing hoppers
of the combination weigher as viewed from above. The combination weigher is
configured in such a manner that a lower chute is incorporated into the combination
weigher disclosed in a patent document 1 to discharge objects to be weighed into a
packaging machine having one inlet.

[0007] In the combination weigher, two collecting chutes, i.e., an inner chute 6 and an
outer chute 7 are provided, and each weighing hopper 4 has two gates (not shown) to be
able to discharge objects to be weighed selectively to the inner chute 6 or the outer chute
7 which is located therebelow. In addition, a collecting hopper 8 is provided at an
discharge outlet 6e in a bottom part of the inner chute 6 to hold and discharge the objects
to be weighed, and a collecting hopper 9 is provided at an discharge outlet 7e in a bottom
part of the outer chute 7 to hold and discharge the objects to be weighed. Furthermore,
one lower chute 10 is provided below the two collecting hoppers 8 and 9 to feed the
objects to be weighed which have been discharged from the collecting hoppers 8 and 9
into one inlet of the packaging machine. A control unit 31 controls an operation of the
entire combination weigher and performs combination calculation. The combination
weigher is configured to carry out the double shift operation in such a manner that the
weighing hoppers 4 selected sequentially to make up of the combinations discharge the
objects to be weighed alternately to the inner chute 6 and the outer chute 7 and the
collecting hopper 8 and the collecting hopper 9 alternately discharge the objects to be
weighed to the lower chute 10. Thereby, the objects to be weighed are discharged twice
frum the discharge outlet 10e of the lower chute 10 within one weighing cycle time. So,
productivity within a specified time period can be improved. Also, since the weighing
hoppers 4 discharge the objects to be weighed to each of the inner chute 6 and the outer
chute 7 only once within one weighing cycle time, a sufficient distance is provided
between the batches of the objects to be weighed which are discharged previously and
the objects to be weighed which are discharged subsequently on each of the chutes.
[0008] In cases where the combination weigher is not equipped with the lower chute
10, two packaging machines or a twin-inlet packaging machine having two inlets are/ is
disposed below the combination weigher, and the objects to be weighed which have been
discharged from the collecting hoppers 8 and 9 are fed into the associated packaging
machine inlets. In this case, by the double shift operation, the objects to be weighed are
discharged once to each of the two packaging machine inlets within one weighing cycle

time. That is, the objects to be weighed are discharged twice in total within one
weighing cycle time irrespective of the presence or absence of the lower chute 10. Thus,
productivity within a specified time period can be improved.
Patent document 1 Japanese Laid-Open Patent Application Publication No. Sho.
57-125322
Patent document 2 Japanese Examined Patent Application Publication No. Hei. 8 -
1395
Disclosure of the Invention
Problems to be Solved by the Invention
[0009] However, in the configuration of Fig. 14, the outer chute 7 is disposed so that
the objects to be weighed which have been discharged from the weighing hopper 4
located closer to the collecting hopper 8 of the inner chute 6 to the outer chute 7 are
transferred to the collecting hopper 9 through the outside of the periphery of the inner
chute 6. Therefore, the collecting chute consisting of the outer chute and the inner
chute is complicated in structure.
[0010] In addition, since the collecting hoppers 8 and 9 respectively provided at the
inner chute 6 and the ouier chuie 7 are positioned distant from a center of a circle formed
by arrangement of the weighing hoppers 4, a distance over which the objects to be
weighed are transferred from the weighing hopper 4 to the collecting hopper 8 and
inclination of the chute 6 is varied significantly, and a distance over which the objects to
be weighed are transferred from the weighing hopper 4 to the collecting hopper 9 and
inclination of the chute 7 is varied significantly, depending on the position of the
weighing hopper 4 with respect to the collecting hopper 8 or 9. For this reason, there is
a significant variation in time when the objects to be weighed which have been
transferred on the chute 6 or 7 reach the collecting hopper 8 or 9. In particular, since
the objects to be weighed which have been discharged from the weighing hopper 4
located closer to the collecting hopper 8 of the inner chute 6 to the outer chute 7 are
transferred to the collecting hopper 9 through the outside of the periphery of the inner

chute 6, they reach at a time that is much later than a time when the objects to be
weighed which have been discharged from the weighing hopper 4 located closer to the
collecting hopper 9 reach the collecting hopper 9. As a result, there is a significant
variation in the time when the objects to be weighed reach the collecting hopper 9.
Thus, there is a significant variation in the time when the objects to be weighed which
have been discharged simultaneously from the plurality of weighing hoppers 4 to the
inner chute 6 or to the outer chute 7 reach the collecting hopper 8 or 9, and time that
lapses from when a tip part of the batch of the objects to be weighed reach the collecting
hopper 8 or the collecting hopper 9 until a tail part of the batch of the objects to be
weighed reach the collecting hopper 8 or to the collecting hopper 9 is long. In this case,
also, a sufficient distance is unable to be provided between the batches of the objects to
be weighed which are discharged onto the collecting chute 6 or 7 previously and the
objects to be weighed which are discharged onto the collecting chute 6 or 7 subsequently
and they are likely to be mixed, unless an operation speed is set slow, depending on
characteristic of the objects to be weighed, for example, if the objects to be weighed are
bulky (bulk density is low). As a result, the combination weigher is unable to operate at
a high Speed.
[0011] The present invention has been made to solve the above described problem,
and an object of the present invention is to provide a combination weigher and a
weighing system which are equipped with collecting chutes having a relatively simple
structure, and are able to operate at a high speed irrespective of characteristics of almost
all objects to be weighed.
Means for Solving the Problem
[0012] To achieve the above described objective, a combination weigher of the
present invention comprises a combination hopper line formed by a plurality of
combination hoppers which are arranged in a circular-arc shape having a central angle of
approximately 180 degrees or smaller and are fed with objects to be weighed, the
plurality of combination hoppers being each configured to be able to discharge the

objects to be weighed selectively in an inward direction which is toward a center of the
circular-arc shape or in an outward direction which is an opposite direction of the inward
direction; an inner chute which is disposed below the combination hopper line and has an
upper end portion of a circular-arc shape conforming to the shape of the combination
hopper line, the inner chute being configured to gather the objects to be weighed which
have been discharged in the inward direction from the combination hoppers and to
discharge the objects to be weighed from a discharge outlet provided at a bottom part
thereof; an outer chute which is disposed along outside of the inner chute, the outer chute
being configured to gather the objects to be weighed which have been discharged in the
outward direction from the combination hoppers and to discharge the objects to be
weighed from a discharge outlet provided at a bottom part thereof; a first collecting
hopper which is provided at the discharge outlet of the inner chute to hold and discharge
the objects to be weighed which have been discharged from the discharge outlet of the
inner chute; a second collecting hopper which is provided at the discharge outlet of the
outer chute to hold and discharge the objects to be weighed which have been discharged
from the discharge outlet of the outer chute; a combination calculation means which is
configured to determine a first discharge combination and a second discharge
combination each of which is made up of combination hoppers in which a combination
weight value which is a total of weights of the objects to be weighed which have been
fed to the combination hoppers is within an allowable range with respect to a target
weight value; and a control means which is configured to cause the combination hoppers
making up of the first discharge combination to discharge the objects to be weighed in
the inward direction and to cause the combination hoppers making up of the second
discharge combination to discharge the objects to be weighed in the outward direction,
and is configured to cause the first collecting hopper holding the objects to be weighed
which have been discharged from the combination hoppers making up of the first
discharge combination to discharge the objects to be weighed and to cause the second
collecting hopper holding the objects to be weighed which have been discharged from the

combination hoppers making up of the second discharge combination to discharge the
objects to be weighed.
[0013] In such a configuration, since the inner chute is disposed to correspond to the
combination hopper line of the circular-arc shape having a central angle of approximately
180 degrees or smaller, and the outer chute is disposed along outside of the inner chute,
the collecting chutes (inner chute and outer chute) can be made to have a relatively
simple structure. In addition, it becomes possible to shorten and substantially equalize
a distance over which the objects to be weighed which have been discharged from the
combination hoppers to the inner chute are transferred to the associated collecting hopper
and a distance over which the objects to be weighed which have been discharged from
the combination hoppers to the outer chute are transferred to the associated collecting
hopper. Irrespective of the characteristics of almost all the objects to be weighed, the
objects to be weighed which have been discharged from the combination hoppers can be
gathered to the associated collecting hoppers in a short time. Therefore, the collecting
chutes can be made to have a relatively simple structure, and the combination weigher is
able to operate at a high speed irrespective of the characteristics of almost all the objects
to be weighed.
[0014] The combination calculation means may be configured to repeatedly perform a
combination process in which combination calculation is performed based on the weights
of the objects to be weighed which have been fed to the combination hoppers to
determine one combination made up of the combination hoppers in which a combination
weight value is within the allowable range with respect to the target weight value and to
determine the combination as an optimal combination; and the combination calculation
means may be configured to repeatedly perform the combination process n (plural
number) times in such a manner that, the combination calculation is performed based on
weights of objects to be weighed which have been fed to combination hoppers which do
not make up of an optimal combination determined in a previous combination process, in
a subsequent combination process, and may be configured to determine optimal

combinations determined sequentially in the combination process performed repeatedly
as the first discharge combination and the second discharge combination alternately; the
control means may be configured to cause the combination hoppers making up of the
first discharge combination and the combination hoppers making up of the second
discharge combination to alternately discharge the objects to be weighed and to cause the
first collecting hopper and the second collecting hopper to alternately discharge the
objects to be weighed, based on the first discharge combination and the second discharge
combination alternately determined by the combination calculation means; and wherein
the objects to be weighed which have been discharged from the first collecting hopper
and the objects to be weighed which have been discharged from the second collecting
hopper may be fed to the same packaging machine inlet.
[0015] In such a configuration, since the combination process can be performed n
times and the objects to be weighed can be discharged to the same packaging machine
inlet n times within one operation cycle time (e.g., one weighing cycle time),
productivity (the number of times the objects to be weighed are discharged from the
combination weigher to the packaging machine) within a specified time period can be
improved. In addition, since the objects to be weighed inside the combination hoppers
are discharged to the inner chute and to the outer chute alternately for the respective
discharge combinations determined sequentially, that is, the objects to be weighed are
discharged from the combination hoppers to the inner chute and to the outer chute only
n/2 times within one operation cycle time, a sufficient distance can be provided between
the batches of the objects to be weighed which are discharged previously and the objects
to be weighed which are discharged subsequently on each of the chutes, even when the
combination weigher carries out a high-speed-operation. In the case of n = 2, a double
shift operation takes place, while in the case of n = 3, a triple shift operation takes place.
[0016] The combination calculation means may be configured to repeatedly perform a
combination process in which combination calculation is performed based on the weights
of the objects to be weighed which have been fed to the combination hoppers to

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determine one combination made up of the combination hoppers in which a combination
weight value is within the allowable range with respect to the target weight value and to
determine the combination as an optimal combination; and the combination calculation
means may be configured to repeatedly perform the combination process n (plural
number) times in such a manner that, the combination calculation is performed based on
weights of objects to be weighed which have been fed to combination hoppers which do
not make up of an optimal combination determined in a previous combination process, in
a subsequent combination process, and may be configured to determine optimal
combinations determined sequentially in the combination process performed repeatedly
as the first discharge combination and the second discharge combination alternately; the
control means may be configured to cause the combination hoppers making up of the
first discharge combination and the combination hoppers making up of the second
discharge combination to alternately discharge the objects to be weighed and to cause the
first collecting hopper and the second collecting hopper to alternately discharge the
objects to be weighed, based on the first discharge combination and the second discharge
combination alternately determined by the combination calculation means; and wherein
the objects to be weighed which have been discharged from the first collecting hopper
and the objects to be weighed which have been discharged from the second collecting
hopper may be fed to different packaging machine inlets.
[0017] In such a configuration, since the combination process can be performed n
times and the objects to be weighed can be discharged to each of the two packaging
machine inlets n/2 times within one operation cycle time (e.g., one weighing cycle time),
the objects to be weighed can be discharged n times in total, and thus, productivity
within a specified time period can be improved. In addition, since the objects to be
weighed inside the combination hoppers are discharged to the inner chute and to the
outer chute alternately for the respective discharges determined sequentially, that is, the
objects to be weighed are discharged from the combination hoppers to the inner chute
and to the outer chute n/2 times within one operation cycle time, a sufficient distance can

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be provided between the batches of the objects to be weighed which are discharged
previously and the objects to be weighed which are discharged subsequently on each of
the chutes, even when the combination weigher carries out a high-speed operation. In
the case of n = 2, double shift operation takes place, while in the case of n = 3, triple
shift operation takes place.
[0018] The combination calculation means may be configured to perform a
combination process in which combination calculation is performed based on the weights
of the objects to be weighed which have been fed to the combination hoppers to
determine two combinations which do not include the same combination hoppers and in
which combination weight values obtained in the combination calculation are within the
allowable range with respect to the target weight value, one of the two combinations may
be determined as the first discharge combination and the other of the two combinations is
determined as the second discharge combination; wherein the control means may be
configured to cause the combination hoppers making up of the first discharge
combination and the combination hoppers making up of the second discharge
combination which have been determined by the combination calculation means to
discharge the objects to be weighed simultaneously, and to cause the first collecting
hopper and the second collecting hopper to discharge the objects to be weighed
simultaneously; and wherein the objects to be weighed which have been discharged from
the first collecting hopper and the objects to be weighed which have been discharged
from the second collecting hopper may be fed to different packaging machine inlets.
[0019] In such a configuration, since the objects to be weighed can be discharged once
from each of the first and second collecting hoppers, within one operation cycle time
(e.g., one weighing cycle time) which is a time taken from when two discharge
combinations are determined until subsequent two discharge combinations are
determined, productivity within a specified time period can be improved. In addition,
since the objects to be weighed inside the combination hoppers making up of one of the
two discharge combinations determined simultaneously are discharged to the inner chute

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and the objects to be weighed inside the combination hoppers making up of the other
discharge combination are discharged to the outer chute, that is, the objects to be
weighed are discharged from the combination hoppers to each of the inner chute and to
the outer chute only once within one operation cycle time, a sufficient distance can be
provided between the batches of the objects to be weighed which are discharged
previously and the objects to be weighed which are discharged subsequently on each of
the chutes, even when the combination weigher carries out a high-speed operation.
Furthermore, since the two discharge combinations which will discharge the objects to be
weighed within one operation cycle are determined simultaneously, weights of the
objects to be weighed of all the combination hoppers can be used in the combination
calculation for determining the two discharge combinations. As a result, combination
weighing precision for the objects to be weighed which are discharged can be improved
as a whole.
[0020] The combination hopper line may include two lines which are upper and lower
combination hopper lines, combination hoppers forming the upper combination hopper
line may be weighing hoppers which weigh weights of the objects to be weighed which
have been fed to the weighing hoppers and combination hoppers forming the lower
combination hopper line may be memory hoppers which are provided to respectively
correspond to the weighing hoppers and are fed with the objects to be weighed which
have been weighed in the weighing hoppers; wherein the weighing hoppers may be each
configured to be able to discharge the objects to be weighed selectively to the
corresponding memory hopper or to the outer chute, and the memory hopper may be
configured to be able to discharge the objects to be weighed selectively to the inner chute
or to the outer chute; and wherein the combination calculation means may be configured
to determine a first discharge combination such that a weighing hopper and a
corresponding memory hopper are included in the first discharge combination when the
weighing hopper is selected to make up of the first discharge combination.
[0021] In such a configuration, since the weighing hoppers and the memory hoppers

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arranged at upper and lower positions are equipped as the combination hoppers, the
number of weight values used in the combination calculation can be increased so that
combination weighing precision can be improved, without increasing a diameter of a
circular-arc shape formed by arrangement of the combination hoppers.
[0022] A weighing system of the present invention comprises a plurality of weighing
units each of which includes a combination weigher according to claim 1, the plurality of
weighing units being configured such that combination hopper lines corresponding to the
plurality of weighing units are continuously arranged and combination hoppers
corresponding to the plurality of weighing units are arranged in a circular shape.
[0023] In this case, there are provided P (P : plural number) combination hopper lines
having P circular-arc shaped hopper lines into which a combination hopper group made
up of a plurality of combination hoppers for discharging the objects to be weighed
selectively in the inward direction which is toward a center of the circle shape formed by
arrangement of the hoppers or in the outward direction which is the opposite direction
thereof are divided, P inner chutes and P outer chutes disposed to respectively
correspond to the combination hopper lines, P first collecting hoppers provided at
discharge outlets of the inner chutes and P second collecting hoppers provided at
discharge outlets of the outer chutes. Each weighing unit may be configured to include
combination calculation means and control means in addition to the combination hopper
line, the inner chute, the outer chute, the first collecting hopper, and the second collecting
hopper which are associated with each other. In this case, the combination calculation
means of the respective weighing units may be integrated into one combination
calculation means. Also, control means of the respective weighing units may be
integrated into one control means.
[0024] In the weighing system of the present invention, a plurality of combination
weighers (weighing units) of the present invention are equipped, and therefore
advantages similar to those of the combination weigher of the present invention are
achieved in each weighing unit.

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[0025] Combination calculation means in each of the weighing units may be
configured to repeatedly perform a combination process in which combination
calculation is performed based on the weights of the objects to be weighed which have
been fed to the combination hoppers within the weighing unit to determine one
combination made up of combination hoppers in which a combination weight value is
within an allowable range with respect to a target weight value and to determine the
combination as an optimal combination; and the combination calculation means in each
of the weighing units may be configured to repeatedly perform the combination process
n (plural number) times in such a manner that, the combination calculation is performed
based on weights of objects to be weighed which have been fed to combination hoppers
which do not make up of an optimal combination determined in a previous combination
process, in a subsequent combination process, and may be configured to determine
optimal combinations determined sequentially in the combination process performed
repeatedly as the first discharge combination and the second discharge combination
alternately; the control means in each of the weighing units may be configured to cause
the combination hoppers making up of the first discharge combination and the
combination hoppers making up of the second discharge combination to alternately
discharge the objects to be weighed and to cause the first collecting hopper and the
second collecting hopper within the weighing unit to alternately discharge the objects to
be weighed, based on the first discharge combination and the second discharge
combination alternately determined by the combination calculation means within the
weighing unit; and the objects to be weighed which have been discharged from the first
collecting hopper and from the second collecting hopper belonging to the same weighing
unit may be fed to the packaging machine inlet, and the objects to be weighed which
have been discharged from the first collecting hopper and from the second collecting
hopper belonging to different weighing units are fed to different packaging machine
inlets.
[0026] In such a configuration, since the combination process can be performed n

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times and the objects to be weighed can be discharged to the same packaging machine
inlet n times within one operation cycle time (e.g., one weighing cycle time) in each
weighing unit, productivity (the number of times the objects to be weighed are
discharged from the combination weigher to the packaging machine) within a specified
time period can be improved. In addition, since the objects to be weighed inside the
combination hoppers are discharged to the inner chute and to the outer chute alternately
for the respective discharge combinations determined sequentially, that is, the objects to
be weighed are discharged from the combination hoppers to the inner chute and to the
outer chute only n/2 times within one operation cycle time, a sufficient distance can be
provided between the batches of the objects to be weighed which are discharged
previously and the objects to be weighed which are discharged subsequently on each of
the chutes, even when the combination weigher carries out a high-speed operation. In
the case of n = 2, the double shift operation takes place, while in the case of n = 3, the
triple shift operation takes place.
[0027] A total number of the weighing units may be an even number. The
combination calculation means in each of the weighing units may be configured to
perform a combination process in which combination calculation is performed based on
the weights of the objects to be weighed which have been fed to the combination hoppers
within the weighing unit to determine two combinations which do not include the same
combination hoppers and in which combination measured values obtained in the
combination calculation are within an allowable range with respect to a target weight
value and to determine the two combinations as the first discharge combination and the
second discharge combination; wherein the control means in each of the weighing units
may be configured to perform an internal discharge process for causing the combination
hoppers making up of the first discharge combination determined by the combination
calculation means within the weighing unit and the combination hoppers making up of
the second discharge combination determined by the combination calculation means to
discharge the objects to be weighed simultaneously, and an external discharge process for

16
causing the first collecting hopper and the second collecting hopper to discharge the
objects to be weighed simultaneously; wherein two weighing units including
combination hopper lines arranged adjacent each other may be predetermined as a pair
unit, the objects to be weighed which have been discharged from one of the first
collecting hopper and the second collecting hopper of the weighing units forming the pair
unit are fed to one of a pair of packaging machine inlets corresponding to the pair unit,
and the objects to be weighed which have been discharged from the other collecting
hopper are fed to the other packaging machine inlet; and wherein each of the weighing
units may be configured to repeatedly perform a series of processes including the
combination process, the internal discharge process and the external discharge process,
with a time difference of substantially 1/2 of one operation cycle time that lapses from
when an external discharge process in the weighing unit is terminated until a subsequent
external discharge process in the weighing unit starts, between the two weighing units
forming the pair unit.
[0028] In such a configuration, since the objects to be weighed can be discharged once
from each of the first and second collecting hoppers, within one operation cycle time
(e.g., one weighing cycle time) in each weighing unit, productivity within a specified
time period can be improved. In addition, the objects to be weighed can be fed twice
within one operation cycle time to each of the two packaging machine inlets respectively
corresponding to the two weighing units of the pair unit, the weighing system is able to
be adapted to the packaging machine operated at a high speed. Furthermore, since the
objects to be weighed inside the combination hoppers making up of one of the two
discharge combinations determined simultaneously are discharged to the inner chute and
the objects to be weighed inside the combination hoppers making up of the other
discharge combination are discharged to the outer chute in each weighing unit, that is, the
objects to be weighed are discharged once from the combination hoppers to the inner
chute and to the outer chute within one operation cycle time, a sufficient distance can be
provided between the batches of the objects to be weighed which are discharged

17
previously and the objects to be weighed which are discharged subsequently on each of
the chutes, even when the combination weigher carries out a high-speed operation.
Moreover, since the two discharge combinations which will discharge the objects to be
weighed within one operation cycle time are determined simultaneously, the weights of
the objects to be weighed of all the combination hoppers within each weighing unit can
be used in the combination calculation for determining two discharge combinations. As
a result, combination weighing precision for the objects to be weighed which are
discharged can be improved as a whole.
[0029] The combination calculation means in each of the weighing units may be
configured to perform a first process in which the combination calculation is performed
based on the weights of the objects to be weighed which have been fed to the
combination hoppers within the weighing unit to determine, as optimal combinations,
combinations made up of combination hoppers in which combination weight values are
within the allowable range with respect to the target weight value, and to determine
optimal combination sets each of which is formed by combining two optimal
combinations which do not include the same combination hoppers; and a second process
in which for each of the optimal combination sets, a total of absolute values of
differences between combination weight values of the optimal combinations included in
the optimal combination set and the target weight value are calculated to select one
optimal combination set in which the total of the absolute values of the differences is
smallest, and one of two optimal combinations included in the selected optimal
combination set is determined as the first discharge combination and the other optimal
combination is determined as the second discharge combination.
[0030] In such a configuration, combination weighing precision for the objects to be
weighed which are discharged from the combination hoppers making up of the respective
discharge combinations can be improved as a whole.
[0031] The combination calculation means in each of the weighing units may be
configured to perform a first process in which the combination calculation is performed

18
based on weights of the objects to be weighed which have been fed to the combination
hoppers within the weighing unit to determine, as allowable combinations, combinations
made up of combination hoppers in which combination weight values are within the
allowable range with respect to the target weight value, m (m: plural number) allowable
combinations are selected, as first optimal combinations, from the allowable
combinations, by giving priority to allowable combinations in which absolute values of
differences between combination weight values and the target weight value are smaller,
one allowable combination is selected as a second optimal combination from allowable
combinations made up of combination hoppers obtained by excluding the combination
hoppers belonging to each of the first optimal combinations, and m optimal combination
sets each of which is made up of corresponding first and second optimal combinations
are determined; and a second process in which for each of the optimal combination sets,
a total of absolute values of differences between combination weight values of the first
and second optimal combinations and the target weight value is calculated to select one
optimal combination set in which the total of the absolute values of the differences is
smallest, one of the first and second optimal combinations included in the selected
optimal combination is determined as the first discharge combination and the other of the
first and second optimal combinations is determined as the second discharge
combination.
[0032] In such a configuration, combination weighing precision for the objects to be
weighed which are discharged from the combination hoppers making up of the respective
discharge combinations can be improved as a whole.
[0033] The combination calculation means in each of the weighing units may be
configured to perform the combination calculation based on the weights of the objects to
be weighed which have been fed to the combination hoppers within the weighing unit to
determine, as allowable combinations, combinations made up of the combination hoppers
in which combination weight values are within the allowable range with respect to the
target weight value, to select as a first optimal combination one allowable combination in

19
which an absolute value of difference between a combination weight value and the target
weight value is smallest, from the allowable combinations, to select one allowable
combination as a second optimal combination from allowable combinations made up of
combination hoppers obtained by excluding the combination hoppers belonging to the
first optimal combination, by giving priority to allowable combinations in which absolute
values of differences between combination weight values and the target weight value are
smaller, and to determine that one of the first and second optimal combinations is the
first discharge combination and the other of the first and second optimal combinations is
the second discharge combination.
[0034] In such a configuration, combination weighing precision for the objects to be
weighed which are discharged from the combination hoppers making up of the respective
discharge combinations can be improved as a whole.
The combination calculation means in each of the weighing units may be
configured to perform a combination process in which combination calculation is
performed based on the weights of the objects to be weighed which have been fed to the
combination hoppers within the weighing unit to determine two combinations which do
not include the same combination hoppers and in which combination weight values
obtained in the combination calculation are within the allowable range with respect to the
target weight value, one of the two combinations is determined as the first discharge
combination and the other of the two combinations is determined as the second discharge
combination; wherein the control means in each of the weighing units may be configured
to perform an internal discharge process for causing the combination hoppers making up
of the first discharge combination determined by the combination calculation means
within the weighing unit and the combination hoppers making up of the second discharge
combination determined by the combination calculation means to discharge the objects to
be weighed simultaneously, and an external discharge process for causing the first
collecting hopper and the second collecting hopper to discharge the objects to be
weighed simultaneously; and wherein the plurality of weighing units may be configured

20
to perform a series of processes including the combination process, the internal discharge
process and the external discharge process at the same timings, and to feed the objects to
be weighed which have been discharged simultaneously from the first collecting hopper
and from the second collecting hopper of the plurality of weighing units to different
packaging machine inlets.
[0035] In such a configuration, since the objects to be weighed can be discharged once
from the first and second collecting hoppers of the plurality of weighing units within one
operation cycle time (e.g., one weighing cycle time), productivity within a specified time
period can be improved. For example, in cases where k (k : plural number) weighing
units are equipped, the objects to be weighed can be fed simultaneously into (2 X k)
packaging machine inlets within one operation cycle time, the weighing system is able to
be adapted to a packaging machine which packages (2 X k) sets of objects to be
weighed simultaneously. In addition, since the objects to be weighed inside the
combination hoppers making up of one of the two discharge combinations determined
simultaneously are discharged to the inner chute and the objects to be weighed inside the
combination hoppers making up of the other discharge combination are discharged to the
outer chute in each weighing unit, that is, the objects to be weighed are discharged from
the combination hoppers to the inner chute and to the outer chute once within one
operation cycle time, in each weighing unit, a sufficient distance can be provided
between the batches of the objects to be weighed which are discharged previously and
the objects to be weighed which are discharged subsequently on each of the chutes, even
when the weighing system carries out a high-speed operation. Furthermore, since the
two discharge combinations which will discharge the objects to be weighed within one
operation cycle time are determined simultaneously, weights of the objects to be weighed
of all the combination hoppers within the respective weighing units can be used in the
combination calculation for determining the two discharge combinations. As a result,
combination weighing precision for the objects to be weighed which are discharged can
be improved as a whole.

21
The combination hopper line of the plurality of weighing units may include two
lines which are upper and lower combination hopper lines, combination hoppers forming
the upper combination hopper line are weighing hoppers which weigh weights of the
objects to be weighed which have been fed to the weighing hoppers, combination
hoppers forming the lower combination hopper line are memory hoppers which are
provided to respectively correspond to the weighing hoppers and are fed with the objects
to be weighed which have been weighed in the weighing hoppers; the weighing hoppers
may be each configured to be able to discharge the objects to be weighed selectively to
the corresponding memory hopper or to the outer chute, and the memory hoppers may be
each configured to be able to discharge the objects to be weighed selectively to the inner
chute or to the outer chute; and wherein the combination calculation means in each of the
weighing units is configured to determine a first discharge combination such that a
weighing hopper and a corresponding memory hopper are included in the first discharge
combination when the weighing hopper is selected to make up of the first discharge
combination.
[0036] In such a configuration, since the weighing hoppers and the memory hoppers
arranged at upper and lower positions are equipped as the combination hoppers, the
number of weight values used in the combination calculation can be increased so that
combination weighing precision can be improved, without increasing a diameter of the
circular shape formed by arrangement of the combination hoppers.
Effects of the Invention
[0037] The present invention has the above described configuration, and provides a
combination weigher and a weighing system which are equipped with collecting chutes
with a relatively simple structure and are capable of operating at a high speed
irrespective of characteristics of almost all the objects to be weighed.
The above and further objects, features and advantages of the present invention
will more fully be apparent from the following detailed description of preferred
embodiments with accompanying drawings.

22
Brief Description of the Drawings
Fig. 1 (a) is a schematic partial cross-sectional view of a combination weigher
according to an example 1 of an embodiment 1 of the present invention, as viewed from
laterally, Fig. l(b) is a schematic view of collecting chutes, weighing hoppers, and
memory hoppers of the combination weigher as viewed from above, and Fig. l(c) is a
schematic view of lower chutes of the combination weigher as viewed from above;
Fig. 2 is a timing chart showing a double shift operation of the combination
weigher of the example 1 of the embodiment 1 of the present invention;
Fig. 3 is a timing chart showing a triple shift operation of the combination
weigher of the example 1 of the embodiment 1 of the present invention;
Fig. 4 (a) is a schematic view of collecting chutes, weighing hoppers and memory
hoppers of a combination weigher according to an example 2 of the embodiment 1 of the
present invention, as viewed from above, and Fig. 4(b) is a schematic view of a lower
chute of the combination weigher as viewed from above;
Fig. 5 (a) is a schematic partial cross-sectional view of a combination weigher
according to an example a of an embodiment 2 of the present invention, as viewed from
laterally, Fig. 5(b) is a schematic view of collecting chutes, weighing hoppers, and
memory hoppers of the combination weigher as viewed from above, and Fig. 5(c) is a
schematic view of the lower chute of the combination weigher as viewed from above;
Fig. 6 is a flowchart showing a procedure of a first combination process in the
combination weigher according to the embodiment 2 of the present invention;
Fig. 7 is a timing chart showing an operation of a combination weigher according
to the example a of the embodiment 2 of the present invention;
Fig. 8 is a flowchart showing a procedure of a second combination process in the
combination weigher according to the embodiment 2 of the present invention;
Fig. 9 (a) is a schematic view of collecting chutes, weighing hoppers and memory
hoppers of a combination weigher according to an example b of the embodiment 2 of the

23
present invention, as viewed from above, and Fig. 9(b) is a schematic view of a lower
chute of the combination weigher as viewed from above;
Fig. 10 is a timing chart showing an operation of a combination weigher according
to an example c of the embodiment 2 of the present invention;
Fig. 11 (a) is a cross-sectional view showing a schematic construction according to
an example of a packaging machine disposed below the combination weigher according
to the example c of the embodiment 2 of the present invention and Fig. ll(b) is a
schematic plan view of the packaging machine as viewed from above;
Figs. 12(a), 12(b), and 12(c) are schematic views showing another examples of
hoppers for use in the combination weighers according to the embodiments 1 and 2 of the
present invention;
Fig. 13 is a schematic partial cross-sectional view of a combination weigher
according to a first conventional example as viewed from laterally; and
Fig. 14(a) is a schematic partial cross-sectional view of a combination weigher
according to a second conventional example as viewed from laterally, and Fig. 14(b) is a
schematic view showing collecting chutes and weighing hoppers of the combination
weigher as viewed from above.
Description of Reference Numerals
[0039] 1 dispersion feeder
2 linear feeder
3 feeding hopper
4 weighing hopper
5 memory hopper
6a, 6b, 6c, 6d inner chute
7a, 7b, 7c, 7d outer chute
8a, 8b, 8c, 8d inner chute collecting hopper
9a, 9b, 9c, 9d outer chute collecting hopper

24
10a, 10b, 10c, 10d lower chute
11 center base body
20 control unit
Best Mode for Carrying Out the Invention
[0040] Hereinafter, preferred embodiments of the present invention will be described
with reference to the drawings.
[0041] (Embodiment 1)
[Example 1 of Embodiment 1]
Fig. 1 (a) is a schematic partial cross-sectional view of a combination weigher
(weighing system) according to an example 1 of an embodiment 1 of the present
invention, as viewed from laterally, Fig. l(b) is a schematic view of collecting chutes
(inner chutes and outer chutes), weighing hoppers, and memory hoppers of the
combination weigher as viewed from above, and Fig. l(c) is a schematic view of a lower
chute of the combination weigher as viewed from above.
[0042] As shown in Fig. l(a), the combination weigher is constructed in such a manner
that a center base body (body) 11 is disposed at a center of the combination weigher and
supported by four legs (not shown), and a dispersion feeder 1 having a conical shape is
mounted to an upper part of the center base body 11 to radially disperse objects to be
weighed supplied from an external supplying device by vibration. Around the
dispersion feeder 1, a plurality of linear feeders 2 are provided to transfer the objects to
be weighed sent from the dispersion feeder 1 into respective feeding hoppers 3 by
vibration. A plurality of feeding hoppers 3, a plurality of weighing hoppers 4 and a
plurality of memory hoppers 5 are disposed below the linear feeders 2 and are arranged
in a circular shape around the center base body 11 in such a manner that each feeding
hopper 3, each weighing hopper 4, and each memory hopper 5 correspond to the
associated one of the linear feeders 2. The dispersion feeder 1, the linear feeders 2, the
feeding hoppers 3, the weighing hoppers 4 and the memory hoppers 5 are mounted to the
center base body 11. Inside the center base body 11, drive units therefor (vibration

25
device for the dispersion feeder 1 and the linear feeders 2, gate opening and closing
devices for the feeding hoppers 3, the weighing hoppers 4 and the memory hoppers 5,
etc) are accommodated. Each weighing hopper 4 is attached with a weight sensor 41
such as a load cell which measures a weight of the objects to be weighed inside the
weighing hopper 4. The weight sensors 41 are accommodated inside the center base
body 11 along with the drive units. Each weight sensor 41 outputs a measured value to
a control unit 20. Each memory hopper 5 is disposed below and in an inward direction
of the corresponding weighing hopper 4. When the memory hopper 5 becomes empty,
the weighing hopper 4 feeds the objects to be weighed to the memory hopper 5. The
inward direction refers to a direction toward a center of a circle shape formed by
arrangement of the weighing hoppers 4 and the memory hoppers 5, and its opposite
direction refers to an outward direction. Below the memory hoppers 5 arranged in the
circular shape, two inner chutes 6a and 6b formed by dividing in two a chute of a
substantially inverted cone frustum shape are disposed, and outer chutes 7a and 7b are
disposed along outside of the inner chutes 6a and 6b to respectively correspond to the
inner chutes 6a and 6b.
[0043] Each weighing hopper 4 is provided with two gates (not shown) to be able to
selectively discharge the objects to be weighed to the corresponding memory hopper 5 or
to the outer chute 7a or 7b located therebelow. To be more specific, each weighing
hopper 4 is provided with the gate (hereinafter referred to as "inner gate") for
discharging the objects to be weighed to the memory hopper 5 and the gate (hereinafter
referred to as "outer gate") for discharging the objects to be weighed to the outer chute 7a
or 7b. Each memory hopper 5 is provided with two gates (not shown) to be able to
selectively discharge the objects to be weighed to the inner chute 6a or 6b or to the outer
chute 7a or 7b located therebelow. To be more specific, each memory hopper 5 is
provided with the gate (hereinafter referred to as "inner gate" for discharging the objects
to be weighed to the inner chute 6a or 6a and the gate (hereinafter referred to as "outer
gate") for discharging the objects to be weighed to the outer chute 7a or 7b. In Fig. l(a),

26
within a circle 21, the substantially actual shapes of the weighing hopper 4 and the
memory hopper 5 are schematically shown, and the shapes of the inner gate 22 and the
outer gate 23 are schematically shown.
[0044] In the example 1, all the weighing hoppers 4 and memory hoppers 5 arranged in
a circular shape are divided into two groups A and B, and the two inner chutes 6a and 6b
are provided to respectively correspond to the two groups A and B, and the two outer
chutes 7a and 7b are provided to respectively correspond to the two groups A and B.
The inner chutes 6a and 6b have upper ends a circular-arc shape to conform to the shape
(circular-arc shape) formed by arrangement of the hoppers of the corresponding groups A
and B. Discharge outlets 6ae and 6be are provided at bottom parts of the inner chutes
6a and 6b which are closer to the center of the circular-arc shape. Collecting hoppers 8a
and 8b are provided at the bottom part discharge outlets 6ae and 6be, respectively to hold
and discharge the objects to be weighed. The outer chutes 7a and 7b disposed along the
outside of the inner chutes 6a and 6b have upper edges of a circular-arc shape.
Discharge outlets 7ae and 7be are provided at bottom parts of the outer chutes 7a and 7b
which are closer to the center of the circular-arc shape. Collecting hoppers 9a and 9b
are provided at the bottom part discharge cutlets 7ae and 7be, respectively to hold and
discharge the objects to be weighed.
[0045] A first combination weigher unit includes the weighing hoppers 4 and the
memory hoppers 5 in the group A, the linear feeder 2, the feeding hopper 3, the inner
chute 6a, the outer chute 7a and the collecting hoppers 8a and 9a disposed to correspond
to the group A. A second combination weigher unit includes the weighing hoppers 4
and the memory hoppers 5 in the group B, the linear feeder 2, the feeding hopper 3, the
inner chute 6b, the outer chute 7b and the collecting hoppers 8b and 9b disposed to
correspond to the group B.
[0046] Below the collecting hoppers 8a and 9a of the first combination weigher unit, a
lower chute 10a is disposed to receive the objects to be weighed which have been
discharged from the collecting hoppers 8a or 9a and discharge them from a bottom part

27
discharge outlet 10ae. Likewise, below the collecting hoppers 8b and 9b of the second
combination weigher unit, a lower chute 10b is disposed to receive the objects to be
weighed which have been discharged from the collecting hoppers 8b or 9b and discharge
them from a bottom part discharge outlet 10be.
[0047] Below the lower chutes 10a and 10b of the combination weigher, two packaging
machines (not shown) or a twin-inlet packaging machine (not shown) having two inlets
into which the objects to be weighed are fed are disposed. The objects to be weighed
which have been discharged from the discharge outlet lOae of the lower chute 10a and
from the discharge outlet lObe of the lower chute 10b are respectively fed into different
packaging machine inlets (first and second packaging machine inlets) and are charged
into package bags for packaging. Thus, in the present example, the objects to be
weighed which have been discharged from the collecting hoppers 8a or 9a in the first
combination weigher unit are fed into the first packaging machine inlet through the lower
chute 10a, and the objects to be weighed which have been discharged from the collecting
hoppers 8b or 9b in the second combination weigher unit are fed into the second
packaging machine inlet through the lower chute 10b.
[0048] In the present example, the control unit 20 controls the first combination
weigher unit and the second combination weigher unit so that each of the first
combination weigher unit and the second combination weigher unit operates as a single
combination weigher.
[0049] The control unit 20 includes a control means and a combination calculation
means for each combination weigher unit to control the operation of the entire
combination weigher and to perform a combination process to determine a combination
(discharge combination) made up of the weighing hoppers 4 and the memory hoppers 5
which will discharge the objects to be weighed, for each of the first and second
combination weigher units. In the combination process, the combination calculation is
performed based on measured values (measured values obtained using the weight sensors
41) of the weights of the objects to be weighed inside the weighing hoppers 4 and the

28
memory hoppers 5 to determine one combination made up of the weighing hoppers 4 and
the memory hoppers 5 in which a combination measured value (= combination weight
value) which is a total of the measured values is within an allowable range
(predetermined weight range) with respect to a target weight value to determine it as an
optimal combination. The measured values of the objects to be weighed inside the
memory hopper 5 for use in this combination process are measured values obtained using
the weight sensors 41 in the weighing hoppers 4 located thereabove. If the number of
combinations in which the measured values are within the allowable range with respect
to the target weight value is plural, a combination in which, for example, a total
measured value (combination measured value) is closest to the target weight value (or a
combination whose measured value coincides with the target weight value, if any), i.e., a
combination in which an absolute value of a difference between the total measured value
and the target weight value is smallest, is determined as an optimal combination. In the
embodiment 1, the optimal combination is a discharge combination. In the combination
weigher, the target weight value and the allowable range with respect to the target weight
value are predetermined. The allowable range is determined such that the target weight
value is a lower limit value and a value larger than the target weight value is an upper
limit value, for example. By way of example, when the target weight value is set to
400g, the lower limit value of the allowable range is set to 400g which is equal to the
target weight value, and the upper limit value of the allowable range is set to 420g which
is larger than the target weight value. Alternatively, the allowable range may be
determined such that a value smaller than the target weight value is set as the lower limit
value and the upper limit value is not set (In this case, the upper limit value may be
assumed to be infinite). In cases where the allowable rage with respect to the target
weight value is set to a range which is not smaller than the target weight value, that is,
the lower limit value of the allowable range is set to a value equal to the target weight
value, an absolute value of a difference between the combination measured value which
is a total of the measured values of the optimal combinations and the target weight value

29
is equal to a value (difference) obtained by subtracting the target weight value from the
combination measured value.
[0050] Hereinafter, the weighing hoppers 4 and the memory hoppers 5 are collectively
referred to as combination hoppers 4 and 5 when they are not distinguished from each
other.
[0051] An outline of the operation of the combination weigher configured as described
above will be first described.
[0052] The objects to be weighed are supplied from the external supplying device to
the dispersion feeder 1. The dispersion feeder 1 feeds the objects to be weighed to the
feeding hopper 3 through the linear feeder 2. The feeding hopper 3 feeds the objects to
be weighed to the weighing hopper 4. The weight sensor 41 measures the weight of the
objects to be weighed which have been fed into the weighing hopper 4, and sends the
measured value to the control unit 20. The objects to be weighed whose weight has
been measured in the weighing hopper 4 are supplied to the memory hopper 5 located
therebelow if the memory hopper 5 is empty. The above described combination process
is performed for each combination weigher unit to determine the discharge combinations
(optimal combinations). Then, the combination hoppers 4 and 5 selected to make up of
the discharge combination discharge the objects to be weighed. When the objects to be
weighed are held in the weighing hopper 4 located above the memory hopper 5 which is
empty, the weighing hopper 4 feeds the objects to be weighed to the memory hopper 5.
The feeding hopper 3 feeds the objects to be weighed to the weighing hopper 4 which is
empty. The linear feeder 2 feeds the objects to be weighed to the feeding hopper 3
which is empty.
[0053] In present embodiment, the combination process is performed sequentially for
each combination weigher unit, and the combination hoppers 4 and 5 selected to make up
of the discharge combinations discharge the objects to be weighed. A discharge
direction in which the combination hoppers 4 and 5 discharge the objects to be weighed
is switched for each discharge combination determined in the combination process. To

30
be more specific, the combination hoppers 4 and 5 discharge the objects to be weighed
alternately to the inner chutes 6a or 6b and to the outer chute 7a or 7b for respective of
discharge combinations sequentially determined. According to the discharge, the inner
chute collecting hopper 8a or 8b and the outer chute collecting hoppers 9a or 9b
alternately discharge the objects to be weighed. For example, when the combination
process is repeated for the first combination weigher unit, the combination hoppers 4 and
5 determined in respective combination processes discharge the objects to be weighed
alternately to the inner chute 6a and to the outer chute 7a. In the combination process
for determining the discharge combination for discharging the objects to be weighed to
the inner chute 6a, the weighing hopper 4 is selected to make up of the discharge
combination only when the corresponding memory hopper 5 disposed therebelow is
selected together. In this case, the weighing hopper 4 and the memory hopper 5 open
their inner gates to discharge the objects to be weighed in such a manner that the objects
to be weighed are discharged from the weighing hopper 4 to the inner chute 6a through
the inside of the memory hopper 5. In the combination process for determining the
discharge combination for discharging the objects to be weighed to the inner chute 6a,
the memory hopper 5 can be selected freely to make up of the discharge combination.
In the combination process for determining the discharge combination for discharging the
objects to be weighed to the outer chute 6a, the weighing hopper 4 and the memory
hopper 5 can be selected freely to make up of the discharge combination. The same
applies to the second combination weigher unit.
[0054] Subsequently, an operation of the first and second combination weigher units
which takes place when the first and second combination weigher units are configured to
carry out the double shift operation will be described in detail. In the double shift
operation, by setting the number of weighing hoppers 4 and the number of memory
hoppers 5 to nine or ten in each of the groups A and B, and by setting the number of the
combination hoppers 4 and 5 which will be selected in the combination process (the
number of combination hoppers 4 and 5 which will be selected to make up of the optimal

31
combination) to four in each of the groups A and B, high combination weighing precision
is obtained. The phrase "the number of combination hoppers 4 and 5 which will be
selected in the combination process is set to four" means that the linear feeder 2 and
others are configured to operate so that a target feed amount of the objects to be weighed
which are fed from each feeding hopper 3 to the weighing hopper 4 once becomes
substantially 1/4 of a target weight value.
[0055] Fig. 2 is a timing chart showing the double shift operation carried out by each
combination weigher unit in the combination weigher according to the example 1 of
present embodiment.
[0056] One operation cycle time Tw in each combination weigher unit is, for example,
a time period taken to accomplish a procedure in which immediately after a discharge
combination has been determined in a combination process in a previous operation cycle,
weighing hoppers 4 selected to make up of the discharge combination (when these
weighing hoppers 4 are selected to make up of the discharge combination) discharge the
objects to be weighed, the objects to be weighed are subsequently fed to these weighing
hoppers 4 making up of the discharge combination, time for stabilizing the weight
sensors 41 lapses, the weight sensors 41 measure the weights of the objects to be
weighed inside these weighing hoppers 4, and thereafter a combination process is
performed to determine a discharge combination. One weighing cycle time is, for
example, a time period taken to accomplish a procedure in which weighing hoppers 4
selected to make up of a discharge combination determined in a combination process in a
previous operation cycle (when these weighing hoppers 4 are selected to make up of the
discharge combination), start to discharge the objects to be weighed, the objects to be
weighed are subsequently fed to these weighing hoppers 4 making up of the discharge
combination, time for stabilizing the weight sensors 41 lapses, the weight sensors 41
measure the weights of the objects to be weighed inside these weighing hopper 4, and
thereafter a combination process is performed to determine a discharge combination.
Therefore, one weighing cycle time is equal to one operation cycle time Tw in a case

32
where an allowance time, a wait time, etc, which lapses from when a discharge
combination is determined in a combination process until hoppers selected to make up of
the discharge combination start to discharge the objects to be weighed is zero. It is
desired that one operation cycle time Tw be equal to one weighing cycle time to make
the combination weigher carry out a high-speed operation. Therefore, in present
embodiment, the one operation cycle time Tw is set equal to or substantially equal to one
weighing cycle time.
[0057] The double shift operation in each combination weigher unit is carried out in
such a manner that a combination process is performed once in every Tw/2 time and
combination hoppers 4 and 5 making up of an optimal combination selected in the
combination process discharge the objects to be weighed. The combination process in
the double shift operation is performed in such a manner that combination calculation is
performed using measured values (weight values) of the objects to be weighed of the
combination hoppers 4 and 5 holding the objects to be weighed whose weight values
have been measured by the weight sensors 41 in each combination weigher unit to select
one combination made up of the combination hoppers 4 and 5 in which a total measured
value is within a specified weight range and to determine it as an optima) combination,
and measured values of all the combination hoppers 4 and 5 are used in combination
calculation in two continuous combination processes. In each combination weigher unit,
the combination hoppers 4 and 5 making up of optimal combinations sequentially
selected resulting from the combination processes repeated once in every Tw/2 time
discharge the objects to be weighed alternately to the inner chute 6a or 6b and to the
outer chute 7a or 7b for respective of the optimal combinations, and according to the
discharge, the collecting hopper 8a or 8b and the collecting hopper 9a and 9b alternately
discharge the objects to be weighed. Thereby, the objects to be weighed are discharged
from each combination weigher unit to the packaging machine twice within one
operation cycle time Tw. In this case, one discharge cycle time Tdl for each
combination weigher unit is equal to 1/2 of one operation cycle time Tw. One

33
discharge cycle time Td1 is equal to one packaging cycle time Tp1 for the packaging
machine. Whereas the measured values of all the combination hoppers 4 and 5 in each
combination weigher unit are used in combination calculation in two continuous
combination processes, the measured values of all the combination hoppers 4 and 5 are
not necessarily used. For example, in cases where the total number of the combination
hoppers 4 and 5 is large in each combination weight unit, the measured values of all the
combination hoppers 4 and 5 are sometimes not used in combination calculation in two
continuous combination processes, if the number of measured values used is limited in
one combination calculation, that is, the number is predetermined.
[0058] Receiving, for example, a feed command signal from the packaging machine, as
an input, the control unit 20 causes the inner chute collecting hopper 8a or 8b to open its
gates to discharge the objects to be weighed to the packaging machine in response to the
feed command signal (time t1). And, the control unit 20 causes the combination
hoppers 4 and 5 selected to make up of the optimal combinations to open their inner
gates based on the operation timing of the gate of the collecting hopper 8a or 8b to
discharge the objects to be weighed from the combination hoppers 4 and 5 to the inner
chute 6a or 6b (time tl). Receiving a subsequent feed command signal as an input, the
control unit 20 causes the outer chute collecting hopper 9a or 9b to open its gate to
discharge the objects o be weighed to the packaging machine in response to the feed
command signal (time t2). And, the control unit 20 causes the combination hoppers 4
and 5 selected to make up of the optimal combinations to open their outer gates based on
the operation timing of the gate of the collecting hopper 9a or 9b to discharge the objects
to be weighed from the combination hoppers 4 and 5 to the outer chute 7a or 7b (time t2).
Then, receiving a subsequent feed command signal as an input, the control unit 20 causes
the inner chute collecting hopper 8a or 8b to open its gate to discharge the objects to be
weighed to the packaging machine in response to the feed command signal, and causes
the combination hoppers 4 and 5 selected to make up of the optimal combinations to
open their inner gates to discharge the objects to be weighed from the combination

34
hoppers 4 and 5 to the inner chute 6a or 6b (time t3). Thereafter, the similar operation
is repeated.
[0059] In the operation shown in Fig. 2, the objects to be weighed which have been
discharged from the combination hoppers 4 and 5 by opening the inner gates at time t1
are gathered to and held in the inner chute collecting hopper 8a or 8b before time t3, and
the collecting hopper 8a or 8b opens its gate to discharge the objects to be weighed to the
packaging machine at time t3. Likewise, the objects to be weighed which have been
discharged from the combination hoppers 4 and 5 by opening their outer gates at time t2
are gathered to and held in the outer chute collecting hopper 9a or 9b before time t4, and
the collecting hopper 9a or 9b opens its gate to discharge the objects to be weighed to the
packaging machine at time t4.
[0060] As described above, the combination hoppers 4 and 5 making up of the optimal
combinations discharge the objects to be weighed to the inner chute 6a or 6b and to the
outer chute 7a or 7b alternately, and according to the discharge, the inner chute collecting
hopper 8a or 8b and the outer chute collecting hopper 9a or 9b alternately discharge the
objects to be weighed to the packaging machine. Whereas in the operation of Fig. 2, the
opening and closing timings of the gate of the collecting hopper 8a or 8b are the same as
the opening and closing timings of the inner gates of the combination hoppers 4 and 5
and the opening and closing timings of the gate of the collecting hopper 9a or 9b are the
same as the opening and closing timings of the outer gates of the combination hoppers 4
and 5, these are merely exemplary. For example, the control unit 20 may control the
opening and closing timings of the gates of the combination hoppers 4 and 5 based on the
opening and closing timings of the gates of the collecting hoppers 8a, 8b, 9a and 9b to
make the opening and closing timings of the gates different.
[0061] By causing each combination weigher unit to perform the double shift operation
as described above, each combination weigher unit is able to discharge the objects to be
weighed to the packaging machine once in every Tw/2 time at a speed twice as high as
that of the single shift operation. This makes it possible to improve productivity (the

35
total number of times the combination weigher discharges the objects to be weighed to
the packaging machine) within a specified time period, and thus to adapt the combination
weigher to the packaging machine operated at a high speed.
[0062] Subsequently, an operation of each combination weigher unit taking place when
the combination weigher unit is configured to carry out a triple shift operation will be
described in detail. In the triple shift operation, by setting the number of weighing
hoppers 4 and the number of memory hoppers 5 respectively to eleven or twelve in each
of the groups A and B, and by setting the number of the combination hoppers 4 and 5
which will be selected in the combination process to four in each of the groups A and B,
high combination weighing precision is obtained.
[0063] Fig. 3 is a timing chart showing the triple shift operation carried out by each
combination weigher unit in the combination weigher according to the example 1 of the
present embodiment.
[0064] The triple shift operation in each combination weigher unit is carried out in such
a manner that a combination process is performed once in every Tw/3 time and the
combination hoppers 4 and 5 making up of an optimal combination selected in the
combination process discharge the objects to be weighed. The combination process in
the triple shift operation is performed in such a manner that for each combination
weigher unit, combination calculation is carried out using measured values (weight
values of the objects to be weighed) of the combination hoppers 4 and 5 holding the
objects to be weighed whose weight values have been measured by the weight sensors 41
to select one combination made up of the combination hoppers 4 and 5 in which a total
measured value is within a predetermined weight range and to determine it as an optimal
combination, and measured values of all the combination hoppers 4 and 5 are used in
combination calculation in three continuous combination processes. In each
combination weigher unit, the combination hoppers 4 and 5 making up of optimal
combinations sequentially selected resulting from repetitive combination processes
performed once in every Tw/3 time discharge the objects to be weighed alternately to the

36
inner chute 6a or 6b and to the outer chute 7a or 7b for respective of the optimal
combinations, and according to the discharge, the collecting hopper 8a or 8b and the
collecting hopper 9a or 9b alternately discharge the objects to be weighed. Thereby, the
objects to be weighed are discharged from each combination weigher unit to the
packaging machine three times within one operation cycle time Tw. In this case, one
discharge cycle time Td2 for each combination weigher unit is equal to 1/3 of one
operation cycle time Tw. One discharge cycle time Td2 is equal to one packaging cycle
time Tp2 of the packaging machine. Whereas in each combination weigher unit, the
measured values of all the combination hoppers 4 and 5 are used in combination
calculation in three continuous combination processes, the measured values of all the
combination hoppers 4 and 5 are not necessarily used. For example, in cases where
the total number of the combination hoppers 4 and 5 is large in each combination weight
unit, the measured values of all the combination hoppers 4 and 5 are sometimes not used
in combination calculation in continuous three combination processes, if the number of
measured values used in one combination calculation is limited, that is, the number is
predetermined.
[0065] Receiving, for example, a feed command signal from the packaging machine, as
an input, the control unit 20 causes the inner chute collecting hopper 8a or 8b to open its
gate to discharge the objects to be weighed to the packaging machine in response to he
feed command signal (time t11). And, the control unit 20 causes the combination
hoppers 4 and 5 selected to make up of the optimal combinations to open their inner
gates based on the operation timing of the gate of the collecting hopper 8a or 8b to
discharge the objects to be weighed to the inner chutes 6a or 6b (time t11). Receiving a
subsequent feed command signal as an input, the control unit 20 causes the outer chute
collecting hopper 9a or 9b to open its gate to discharge the objects to be weighed to the
packaging machine in response to the feed command signal (time t12). And, the control
unit 20 causes the combination hoppers 4 and 5 selected to make up of the optimal
combinations to open their outer gates based on the operation timing of the gate of the

37
collecting hopper 9a or 9b to discharge the objects to be weighed to the outer chute 7a or
7b (time t12). Then, receiving a subsequent feed command signal as an input, the
control unit 20 causes the inner chute collecting hopper 8a or 8b to open its gate to
discharge the objects to be weighed to the packaging machine, and causes the
combination hoppers 4 and 5 selected to make up of the optimal combinations to open
their inner gates to discharge the objects to be weighed to the inner chute 6a or 6b, in
response to the feed command signal (time t13). Thereafter, the similar operation is
repeated.
[0066] In the operation shown in Fig. 3, the objects to be weighed which have been
discharged from the combination hoppers 4 and 5 by opening their inner gates at time t11
are gathered to and held in the inner chute collecting hopper 8a or 8b before time t13,
and the collecting hopper 8a or 8b opens its gate to discharge the objects to be weighed
to the packaging machine at time t13. Likewise, the objects to be weighed which have
been discharged from the combination hoppers 4 and 5 by opening the outer gates at time
t12 are gathered to and held in the inner chute collecting hopper 9a or 9b before time t14,
and the collecting hopper 9a or 9b opens its gate to discharge the objects to be weighed
to the packaging machine at time t14.
[0067] As described above, the combination hoppers 4 and 5 selected to make up of the
optimal combinations every time combination calculation is performed, discharge the
objects to be weighed to the inner chute 6a or 6b and to the outer chute 7a or 7b
alternately, and according to the discharge, the inner chute collecting hopper 8a or 8b and
the outer chute collecting hopper 9a or 9b alternately discharge the objects to be weighed
to the packaging machine. Whereas in the operation of Fig. 3, the opening and closing
timings of the gate of the collecting hopper 8a or 8b are the same as the opening and
closing timings of the inner gates of the combination hoppers 4 and 5 and the opening
and closing timings of the gate of the collecting hopper 9a or 9b are the same as the
opening and closing timings of the outer gates of the combination hoppers 4 and 5, these
are merely exemplary. For example, the control unit 20 may control the opening and

38
closing timings of the gates of the combination hoppers 4 and 5 based on the opening and
closing timings of the gates of the collecting hopper 8a, 8b, 9a or 9b to make the opening
and closing timings of the gates different.
[0068] By causing each combination weigher unit to perform the triple shift operation
as described above, each combination weigher unit discharges the objects to be weighed
to the packaging machine once in every Tw/3 time at a speed three times as high as that
of the single shift operation. This makes it possible to improve productivity within a
specified time period, and thus to adapt the combination weigher to the packaging
machine operated at a high speed.
[0069] Whereas the control unit 20 executes control to cause the first and second
combination weigher units to operate at same timings as illustrated in the timing charts of
Figs. 2 and 3, it may alternatively execute control to cause the first and second
combination weigher units to operate at different timings. In this case, for example, the
control unit 20 may be configured to receive a feed command signal corresponding to the
first combination weigher unit as an input and a feed command signal corresponding to
the second combination weigher unit as an input, from the packaging machine, and to
control the operation of each combination weigher unit based on the associated feed
command signal.
[0070] Since in the example 1, each combination weigher unit is configured in such a
manner that the inner chute 6a or 6b is disposed to correspond to the group A or B of the
combination hoppers 4 and 5 arranged in a circular-arc shape (semi-circular shape in the
example 1) having a central angle of approximately 180 degrees or smaller, and the outer
chute 7a or 7b is disposed along outside of the inner chute 6a or 6b, the collecting chutes
(inner chute and outer chute) can be made to have a relatively simple structure, and the
distance over which the objects to be weighed which have been discharged from the
combination hoppers 4 and 5 to the inner chute 6a or 6b are transferred and the distance
over which the objects to be weighed which have been discharged from the combination
hoppers 4 and 5 to the outer chute 7a or 7b are transferred to the collecting hopper 9a or

39
9b can be made short and substantially equal. Irrespective of the characteristics of
almost all objects to be weighed, the objects to be weighed which have been discharged
from the combination hoppers 4 and 5 can be gathered to the associated collecting hopper
9a or 9b in a short time. Therefore, a structure of the collecting chutes can be made
relatively simple, and the combination weigher is able to operate at a high speed
irrespective of the characteristics of almost all the objects to be weighed. In addition,
each combination weigher unit is able to carry out the double shift operation or the triple
shift operation without slowing the operation speed.
[0071 ] [Example 2 of Embodiment 1]
Fig. 4 (a) is a schematic view of collecting chutes (inner chutes and outer
chutes), weighing hoppers and memory hoppers of a combination weigher (weighing
system) according to an example 2 of the embodiment 1 of the present invention, as
viewed from above, and Fig. 4(b) is a schematic view of lower chutes of the combination
weigher as viewed from above.
[0072] In the example 1 shown in Fig. 1, two combination weigher units are equipped,
while in the present example, three combination weigher units are equipped. In the
present example, as in the example 1, the center base body 11, the dispersion feeder 1,
the linear feeders 2, the feeding hoppers 3, the weighing hoppers 4 attached with the
weight sensors 41, and the memory hoppers 5, are equipped, and are identical in
configuration to those of the example 1. Therefore, explanation therefor is omitted.
[0073] In the example 2, all the weighing hoppers 4 and memory hoppers 5 are divided
into three groups A, B, and C, and combination weigher units are equipped to
respectively include the three groups A, B, and C and to respectively correspond to the
groups A, B, and C. So, three inner chutes 6a, 6b, and 6c are equipped to respectively
correspond to the three groups A, B, and C. Collecting hoppers 8a, 8b, and 8c are
respectively provided at bottom part discharge outlets 6ae, 6be, and 6ce of the inner
chutes 6a, 6b, and 6c to hold and discharge the objects to be weighed. Three outer
chutes 7a, 7b, and 7c are provided to respectively correspond to the three groups A, B,

40
and C. Collecting hoppers 9a, 9b, and 9c are provided at bottom part discharge outlets
7ae, 7be, and 7ce of the outer chutes 7a, 7b, and 7c to hold and discharge the objects to
be weighed. Hereinafter, a combination weigher unit including the group A is referred
to as a first combination weigher unit, a combination weigher unit including the group B
is referred to as a second combination weigher unit, and a combination weigher unit
including the group C is referred to as a third combination weigher unit.
[0074] Below the collecting hoppers 8a and 9a of the first combination weigher unit, a
lower chute 10a is provided to receive the objects to be weighed which have been
discharged from the collecting hopper 8a or 9a and to discharge the objects to be weighed
from a bottom part discharge outlet 10ae thereof. Likewise, below the collecting
hoppers 8b and 9b of the second combination weigher unit, a lower chute 10b is provided
to receive the objects to be weighed which have been discharged from the collecting
hopper 8b or 9b and to discharge the objects to be weighed from a bottom part discharge
outlet 10be thereof. Likewise, below the collecting hoppers 8c and 9c of the third
combination weigher unit, a lower chute 10c is provided to receive the objects to be
weighed which have been discharged from the collecting hopper 8c or 9c and to
discharge the objects to be weighed from a bottom part discharge outlet 10ce thereof.
[0075] Below the lower chutes 10a, 10b and 10c of the combination weigher, three
packaging machines (not shown) or a packaging machine (not shown) having three inlets
into which the objects to be weighed are fed are disposed. The objects to be weighed
which have been discharged from the discharge outlet 10ae of the lower chute 10a, the
discharge outlet 10be of the lower chute 10b, and the discharge outlet 10ce of the lower
chute 10c are fed into different inlets (first to third packaging machine inlets) and are
charged into package bags for packaging. Thus, in the present example, the objects to
be weighed which have been discharged from the collecting hopper 8a or 9a in the first
combination weigher unit are fed into the first packaging machine inlet through the lower
chute 10a, the objects to be weighed which have been discharged from the collecting
hopper 8b or 9b in the second combination weigher unit are fed into the second

41
packaging machine inlet through the lower chute 10b, and the objects to be weighed
which have been discharged from the collecting hopper 8c or 9c in the third combination
weigher unit are fed into the third packaging machine inlet through the lower chute 10c.
[0076] The control unit 20 (see Fig. 1(a)) is equipped, which controls an operation of
the entire combination weigher of the present example and performs a combination
process to determine a combination (discharge combination) made up of the weighing
hoppers 4 and the memory hoppers 5 which will discharge the objects to be weighed for
each of the first, second, and third combination weigher units. The combination process
for each combination weigher unit is identical to that of the example 1.
[0077] The other configuration is identical to that of the example 1 and will not be
further described.
[0078] In the example 2, each combination weigher unit may be configured to carry out
the double shift operation and the triple shift operation as in the example 1.
[0079] The timing charts of the first and second combination weigher units are similar
to those of Fig. 2, for example, and the timing chart of the third combination weigher unit
is similar to those of the first and second combination weigher units, in the configuration
to cause the first, second and third combination weigher units to carry out the double
shift operation.
[0080] The timing charts of the first and second combination weigher units are similar
to those of Fig. 3, for example, and the timing chart of the third combination weigher unit
is similar to those of the first and second combination weigher units, in the configuration
to cause the first, second and third combination weigher units to carry out the triple shift
operation.
[0081] The combination weigher of the example 2 differs from the combination
weigher of the example 1 in the number of combination weigher units equipped, and is
able to achieve advantages similar to those of the combination weigher of the example 1.
[0082] Whereas the control unit 20 executes control to cause the first, second and third
combination weigher units to operate at same timings as described above in the above

42
operation, as in the case of the example 1, it may alternatively execute control to cause
the first, second and third combination weigher units to operate at different timings. In
this case, for example, the control unit 20 may be configured to receive a feed command
signal corresponding to the first combination weigher unit as an input, a feed command
signal corresponding to the second combination weigher unit as an input, and a feed
command signal corresponding to the third combination weigher unit as an input, from
the packaging machine, and to control the operation of each combination weigher unit
based on the associated feed command signal.
[0083] As in the configuration of the example 1 in which the two combination weigher
units are equipped and as in the configuration of the example 2 in which the three
combination weigher units are equipped, four or more combination weigher units may be
equipped.
[0084] It should be noted that, whereas in the embodiment 1, each combination
weigher unit is configured to carry out the double shift operation and the triple shift
operation, it may be configured to carry out the single shift operation with a low
operation speed (discharge speed), as a matter of course. When each combination
weigher unit is configured to carry out the single shift operation, combination calculation
is performed once within the one operation cycle time Tw, the combination hoppers 4
and 5 perform the discharge operation once within the one operation cycle time Tw, and
the collecting hoppers perform the discharge operation with respect to the packaging
machine once within the one operation cycle time Tw. In this case, one discharge
cycle time of the combination weigher is equal to the one operation cycle time Tw.
[0085] (Embodiment 2)
[Example a of embodiment 2]
Fig. 5 (a) is a schematic partial cross-sectional view of a combination weigher
(weighing system) according to an example a of an embodiment 2 of the present
invention, as viewed from laterally, Fig. 5(b) is a schematic view of collecting chutes
(inner chutes and outer chutes), weighing hoppers, and memory hoppers of the

43
combination weigher as viewed from above, and Fig. 5(c) is a schematic view of lower
chutes of the combination weigher as viewed from above.
[0086] As shown in Fig. 5(c), the combination weigher according to the example a of
the present embodiment is configured in such a manner that two lower chutes 10a and
10b are disposed below four collecting hoppers 8a, 8b, 9a and 9b, the collecting hoppers
8a and 9b are provided with gates (not shown) to be able to discharge the objects to be
weighed to the lower chute 10a, and the collecting hoppers 8b and 9a are provided with
gates (not shown) to be able to discharge the objects to be weighed to the lower chute
10b. The objects to be weighed which have been discharged to the lower chute 10a or
10b are discharged from the associated discharge outlet 10ae or 10be, respectively. The
other configuration is identical to that of the example 1 of the embodiment 1 shown in
Fig. 1, and will not be further described. Nonetheless, in the example a of the present
embodiment, the combination process performed by the control unit 20 and operation
timings are different from those of the example 1 of the embodiment 1. In the example
a, as in the example 1, the first combination weigher unit includes the weighing hoppers
4 and the memory hoppers 5 in the group A, and the associated components
corresponding to the group A, and the second combination weigher unit includes the
weighing hoppers 4 and the memory hoppers 5 in the group B and the associated
components corresponding to the group B.
[0087] Below the lower chutes 10a and 10b of the combination weigher, two packaging
machines (not shown) or a twin-inlet packaging machine (not shown) having two inlets
into which the objects to be weighed are fed are disposed. The objects to be weighed
which have been discharged from the discharge outlet 10ae of the lower chute 10a and
the discharge outlet lObe of the lower chute 10b are respectively fed into the different
packaging machine inlets (first and second packaging machine inlets) and are charged
into package bags for packaging. Thus, in the present example, the objects to be
weighed which have been discharged from the collecting hopper 8a in the first
combination weigher unit and from the collecting hopper 9b in the second combination

44
weigher unit are fed into the first packaging machine inlet through the lower chute 10a,
while the objects to be weighed which have been discharged from the collecting hopper
9a in the first combination weigher unit and from the collecting hopper 8b in the second
combination weigher unit are fed into the second packaging machine inlet through the
lower chute 10b.
[0088] The control unit 20 includes a control means and a combination calculation
means for each combination weigher unit to control the operation of the entire
combination weigher and to perform a combination process to determine a combination
(discharge combination) made up of the weighing hoppers 4 and the memory hoppers 5
which will discharge the objects to be weighed, for each of the first and second
combination weigher units. In the combination process, the combination calculation is
performed based on measured values (measured values obtained using the weight sensors
41) of the weights of the objects to be weighed inside the weighing hoppers 4 and the
memory hoppers 5 to select two combinations made up of the weighing hoppers 4 and
the memory hoppers 5 in which a combination measured value (= combination weight
value) which is a total of the measured values is within an allowable range
(predetermined weight range) with respect to a target weight value and to determine them
as discharge combinations. The measured values of the objects to be weighed inside the
memory hoppers 5 for use in this combination process are measured values obtained
using the weight sensors 41 in the weighing hoppers 4 located thereabove. The
combination process will be described in detail.
[0089] Hereinafter, the weighing hoppers 4 and the memory hoppers 5 are collectively
referred to as combination hoppers 4 and 5 when they are not particularly distinguished
from each other.
[0090] An outline of the operation of the above configured combination weigher will
be first described.
[0091] The objects to be weighed are supplied from the external supplying device to
the dispersion feeder 1. The dispersion feeder 1 feeds the objects to be weighed to the

45
feeding hopper 3 through the linear feeder 2. The feeding hopper 3 feeds the objects to
be weighed to the weighing hopper 4. The weight sensor 41 measures the weight of the
objects to be weighed which have been fed into the weighing hopper 4, and sends the
measured value to the control unit 20. The objects to be weighed whose weight has
been measured in the weighing hopper 4 are supplied to the memory hopper 5 located
therebelow if the memory hopper 5 is empty. The control unit 20 performs the
combination process to determine two discharge combinations simultaneously for each
combination weigher unit. Then, the combination hoppers 4 and 5 selected to make up
of the two discharge combinations in each combination weigher unit discharge the
objects to be weighed. If the objects to be weighed are held in the weighing hopper 4
located above the memory hopper 5 which is empty, the weighing hopper 4 feeds the
objects to be weighed to the empty memory hopper 5. The feeding hopper 3 feeds the
objects to be weighed to the empty weighing hopper 4. The linear feeder 2 feeds the
objects to be weighed to the empty feeding hopper 3.
[0092] In the above configuration, in each combination weigher unit, discharge
directions in which the combination hoppers 4 and 5 making up of the two discharge
combinations determined simultaneously in the combination process are made different.
To be specific, in each combination weigher unit, the combination hoppers 4 and 5
making up of one of the two discharge combinations are caused to discharge the objects
to be weighed to the inner chute (6a or 6b) and simultaneously, the combination hoppers
4 and 5 making up of the other discharge combination discharge the objects to be
weighed to the outer chute (7a or 7b). In addition, the inner chute collecting hopper (8a
or 8b) and the outer chute collecting hopper (9a or 9b) are caused to discharge the objects
to be weighed simultaneously. For example, in the two discharge combinations of the
first combination weigher unit, the weighing hopper 4 is selected to make up of the
discharge combination for discharging the objects to be weighed to the inner chute 6a,
only when the corresponding memory hopper 5 disposed therebelow is selected together.
In this case, the weighing hopper 4 and the memory hopper 5 open their inner gates to

46
discharge the objects to be weighed in such a manner that the objects to be weighed are
discharged from the weighing hopper 4 onto the inner chute 6a through inside of the
memory hopper 5. To make up of the discharge combination for discharging the objects
to be weighed to the inner chute 6a, the memory hopper 5 may be selected freely. To
make up of the discharge combination for discharging the objects to be weighed to the
outer chute 6a, the weighing hopper 4 and the memory hopper 5 may be selected freely.
The same applies to the second combination weigher unit.
[0093] Subsequently, the combination process of the present embodiment will be
described in detail. Fig. 6 is a flowchart showing the combination process of an
arbitrary combination weigher unit of the present embodiment. For the first and second
combination weigher units, the combination process shown in steps S1 to S4 is
performed.
[0094] In step S1, combination calculation is performed using measured values of the
objects to be weighed which have been fed to all the combination hoppers 4 and 5 in the
arbitrary combination weigher unit to select combinations in which a combination
measured value which is a total of measured values is within an allowable range with
respect to a target weight value and to determine them as optimal combinations.
[0095] In step S2, an optimal combination set (pair of optimal combinations) formed
by combining two optimal combinations which include different combination hoppers 4
and 5 is determined. In the present embodiment, if weighing hoppers 4 are selected to
make up of both of the two optimal combinations to be combined and the memory
hoppers 5 corresponding to the selected weighing hoppers 4 are not selected, the two
optimal combinations are excluded from the optimal combination set (are not selected for
the optimal combination set). Therefore, in cases where weighing hoppers 4 are
included in the two optimal combinations composing the optimal combination set, the
memory hopper 5 corresponding to the selected weighing hopper 4 is always selected to
make up of at least one optimal combination.
[0096] In step S3, for each optimal combination set, absolute values of differences

47
between combination measured values of respective optimal combinations composing
the optimal combination set and a target weight value are calculated and a total of the
absolute values of the differences is calculated. The absolute values of the differences
between the combination measured values and the target weight value mean absolute
values obtained by subtracting the target weight value from the combination measured
values or by subtracting the combination measured values from the target value, and are
zero or positive values.
[0097] In step S4, one optimal combination set in which the total of the absolute values
of the differences calculated in step S3 is smallest is selected, and one of the two optimal
combinations composing the set is determined as the discharge combination (first
discharge combination) for discharging the objects to be weighed to the inner chute (6a
or 6b), and the other of the two optimal combinations is determined as the discharge
combination (second discharge combination) for discharging the objects to be weighed to
the outer chute (7a or 7b). If a weighing hopper 4 is selected to make up of one of the
two optimal combinations composing the selected optimal combination set, and a
memory hopper 5 corresponding to the selected weighing hopper 4 is not selected, the
optimal combination is determined as the second discharge combination for discharging
the objects to be weighed to the outer chute, and the other optimal combination is
determined as the first discharge combination for discharging the objects to be weighed
to the inner chute. If an optimal combination which includes a weighing hopper 4 but
does not include a memory hopper 5 corresponding to the selected weighing hopper 4 is
not included in a selected optimal combination set, any predetermined method may be
employed to determine which of the two optimal combinations as the first discharge
combination or the second discharge combination. For example, serial numbers may be
assigned to the memory hoppers 5, an optimal combination including a memory hopper 5
with a smallest number may be determined as the first discharge combination, and the
other optimal combination may be determined as the second discharge combination, or
vice versa. Alternatively, the first and second optimal combinations may be determined

48
according to the magnitude of the combination measured value. For example, an
optimal combination with a larger combination measured value may be determined as the
first combination and an optimal combination with a smaller combination measured
value may be determined as the second combination, or vice versa. In a further
alternative, the optimal combination with the larger combination measured value and the
optimal combination with the smaller combination measured value may be alternately
determined as the first and second discharge combinations, every time combination
process is performed.
[0098] Whereas in steps S3 and S4, for each optimal combination set, the total of the
absolute values of the differences between the combination measured values of the
respective optimal combinations and the target weight value is calculated, and the
optimal combination set in which the total of the absolute values of the differences is
smallest is selected to determine the two discharge combinations, the total of squares of
the absolute values of the differences between the combination measured values of the
respective optimal combinations and the target weight value, may be calculated, and an
optimal combination set in which a total of the squares of the differences is smallest may
be selected to determine it as two discharge combinations, for each optimal combination
set.
[0099] As described above, two discharge combinations are determined in one
combination process. In the example a, as in the configuration to cause the
combination weigher to carry out the double shift operation in the example 1 of the
embodiment 1, by setting the number of weighing hoppers 4 and the number of memory
hoppers 5 respectively to nine or ten in each of the groups A and B, and by setting the
number of the combination hoppers 4 and 5 which would be selected in the combination
process to make up of one optimal combination set in the combination process to four,
high combination weighing precision is obtained.
[0100] Fig. 7 is a timing chart showing the operation of the combination weigher
according to the example a of the present embodiment.

49
[0101] One operation cycle time TW in each combination weigher unit is, for example,
a time period taken to accomplish a procedure in which immediately after two discharge
combinations have been determined in a combination process in a previous operation
cycle, weighing hoppers 4 selected to make up of these two discharge combinations
(when the weighing hoppers 4 are selected to make up of the discharge combinations)
discharge the objects to be weighed, the objects to be weighed are subsequently fed to the
weighing hoppers 4 making up of these discharge combinations, time for stabilizing the
weight sensors 41 lapses, the weight sensors 41 measure the weights of the objects to be
weighed inside these weighing hoppers 4, and thereafter next combination process is
performed to determine two discharge combinations. One weighing cycle time is, for
example, a time period taken to accomplish a procedure in which weighing hoppers 4
selected to make up of two discharge combinations determined in a combination process
in a previous operation cycle (when the weighing hoppers 4 are selected to make up of
the discharge combinations), start to discharge the objects to be weighed, the objects to
be weighed are subsequently fed to the weighing hoppers 4 making up of the two
discharge combinations, time for stabilizing the weight sensors 41 lapses, the weight
sensors 41 measures the weights of the objects to be weighed inside these weighing
hoppers 4, and thereafter next combination process is performed to determine two
discharge combinations. Therefore, one weighing cycle time is equal to one operation
cycle time Tw in a case where an allowance time, a wait time, etc, which lapses from
when two discharge combinations are determined in a combination process until hoppers
selected to make up of the two discharge combinations start to discharge the objects to be
weighed, is zero. It is desired that the operation cycle time Tw be equal to one
weighing cycle time to carry out high-speed operation. Therefore, in present
embodiment, the one operation cycle time Tw is equal to or substantially equal to one
weighing cycle time.
[0102] In the example a, the operation of the first combination weigher unit and the
operation of the second combination weigher unit take place at timings with Tw/2 time

50
difference, but are similar. For each combination weight unit, a combination process is
performed to determine two discharge combinations once in every Tw time and the
combination hoppers 4 and 5 making up of the two discharge combinations determined in
the combination process discharge the objects to be weighed simultaneously. In
addition, the inner chute collecting hopper (8a or 8b) and the outer chute collecting
hopper (9a or 9b) discharge the objects to be weighed simultaneously once in every Tw
time. Thereby, in each combination weigher unit, the objects to be weighed making up
of two discharge combinations are fed to the packaging machine within one operation
cycle time Tw. In this case, one discharge cycle time Td3 in each combination weigher
unit is equal to one operation cycle time Tw and is twice as long as one packaging cycle
time Tp1 of the packaging machine.
[0103] Receiving, for example, a feed command signal from the packaging machine, as
an input, the control unit 20 causes the inner chute collecting hopper 8a and the outer
chute collecting hopper 9a in the first combination weigher unit, for example, to open
their gates simultaneously to discharge the objects to be weighed to the packaging
machine, in response to the feed command signal (time t1). And, the control unit 20
causes the combination hoppers 4 and 5 selected to make up of one of the discharge
combinations to open their inner gates based on the operation timings of the gates of the
collecting hoppers 8a and 9a to discharge the objects to be weighed to the inner chute 6a
and causes the combination hoppers 4 and 5 selected to make up of the other discharge
combination to open their outer gates based on the operation timings of the gates of the
collecting hoppers 8a and 9a to discharge the objects to be weighed to the outer chute 7a
(time tl). Receiving a subsequent feed command signal as an input, the control unit 20
causes the inner chute collecting hopper 8b and the outer chute collecting hopper 9b in
the second combination weigher unit to open their gates simultaneously to discharge the
objects to be weighed to the packaging machine (time t2). And, the control unit 20
causes the combination hoppers 4 and 5 selected to make up of one of the discharge
combinations to open their inner gates based on the operation timings of the gates of the

51
collecting chutes 8b and 9b to discharge the objects to be weighed to the inner chute 6b
and causes the combination hoppers 4 and 5 selected to make up of the other discharge
combination to open their outer gates based on the operation timings of the gates of the
collecting hoppers 8b and 9b to discharge the objects to be weighed to the outer chute 7b
(time t2). The above operation is repeated every time the feed command signal is
received as the input (time t3, time t4, time t5).
[0104] In the operation shown in Fig. 7, the objects to be weighed which have been
discharged from the combination hoppers 4 and 5 by opening the inner gates in the first
combination weigher unit at time t1 are gathered to and held in the inner chute collecting
hopper 8a before time t3, and the collecting hopper 8a opens its gate to feed the objects
to be weighed in the collecting hopper 8a to the first packaging machine inlet through the
lower chute 10a at time t3. Likewise, the objects to be weighed which have been
discharged from the combination hoppers 4 and 5 by opening the outer gates in the first
combination weigher unit at time tl are gathered to and held in the outer chute collecting
hoppers 9a before time t3, and the collecting hopper 9a opens its gate to feed the objects
to be weighed in the collecting hopper 9a to the second packaging machine inlet through
the lower chute 10b at time t3.
[0105] The objects to be weighed which have been discharged from the combination
hoppers 4 and 5 by opening the inner gates in the second combination weigher unit at
time t2 are gathered to and held in the inner chute collecting hopper 8b before time t4,
and the collecting hopper 8b opens its gate to feed the objects to be weighed in the
collecting hopper 8b to the second packaging machine inlet through the lower chute 10b
at time t4. Likewise, the objects to be weighed which have been discharged from the
combination hoppers 4 and 5 by opening the outer gates in the second combination
weigher unit at time t2 are gathered to and held in the outer chute collecting hopper 9b
before time t4, and the collecting hopper 9b opens its gate to feed the objects to be
weighed in the collecting hopper 9b to the first packaging machine inlet through the
lower chute 10a at time t4.

52
[0106] Whereas in the operation of Fig. 7, the opening and closing timings of the gates
of the inner chute collecting hopper and the outer chute collecting hopper are the same as
the opening and closing timings of the inner gate and the outer gate of the combination
hoppers in each combination weigher unit, these are merely exemplary. For example,
the control unit 20 may control the opening and closing timings of the inner gate and the
outer gate of the combination hoppers based on the opening and closing timings of the
gates of the collecting hoppers to make the opening and closing timings of the gates
different between the collecting hoppers and the combination hoppers.
[0107] By causing the two combination weigher units to operate in the manner as
described above, the objects to be weighed are fed to each of the two packaging machine
inlets once in every Tw/2 time. Therefore, the objects to be weighed are discharged
twice to each of the two packaging machine inlets within the one operation cycle time
Tw. As a result, productivity (total number of times the combination weigher discharge
the objects to be weighed to the packaging machine) within a specified time period can
be improved.
[0108] In the example a of the present embodiment, each combination weigher unit is
configured in such a mariner that the inner chute 6a or 6b is disposed to respectively
correspond to the group A or B of the combination hoppers 4 and 5 arranged in a
circular-arc shape (semi-circular shape in the example a) having a central angle of
approximately 180 degrees or smaller, and the outer chute 7a or 7b is disposed along
outside of the inner chute 6a or 6b, as in the example 1 of the embodiment 1. So, the
collecting chutes (inner chute and outer chute) can be made to have a relatively simple
structure, and the distance over which the objects to be weighed which have been
discharged from the combination hoppers 4 and 5 to the inner chute 6a or 6b are
transferred and the distance over which the objects to be weighed which have been
discharged from the combination hoppers 4 and 5 to the outer chute 7a or 7b are
transferred to the collecting hopper 9a or 9b can be made short and substantially equal.
Irrespective of the characteristics of almost all objects to be weighed, all of the objects to

53
be weighed which have been discharged from the combination hoppers 4 and 5 can be
gathered to the associated collecting hoppers 9a or 9b in a short time. Therefore, a
structure of the collecting chutes can be made to have a relatively simple structure, and
the combination weigher is able to operate at a high speed irrespective of the
characteristics of almost all objects to be weighed. In addition, each combination
weigher unit is able to select two combinations of the objects to be weighed and perform
discharge operation of the two combinations within the one operation cycle time Tw
without slowing the operation speed.
[0109] Furthermore, since in the combination process (first combination process)
shown in the flowchart of Fig. 6, an optimal combination set in which the total of the
absolute values of the differences between the combination measured values of the
respective optimal combinations and the target weight value is smallest is selected and
the two optimal combinations composing the optimal combination set are determined as
the discharge combinations, combination weighing precision for the discharged objects
to be weighed can be improved as a whole.
[0110] The first combination process shown in the flowchart of Fig. 6 may be replaced
by a second combination process or a third combination process to be described below
[0111] First, the second combination process will be described. Fig. 8 is a flowchart
showing the combination process for an arbitrary combination weigher unit in the present
embodiment. In the first and second combination weigher units, the combination
process shown in steps S11 to S15 is performed.
[0112] In step S11, combination calculation is performed using measured values of the
objects to be weighed which have been fed to all the combination hoppers 4 and 5 in an
arbitrary combination weigher unit to select combinations in which a combination
measured value which is a total of the measured values is within an allowable range with
respect to a target weight value and to determine them as allowable combinations. The
process in step Sll is the same as the process of step S1 of Fig. 6, and the optimal
combinations determined in step S1 correspond to the allowable combinations

54
determined in step S11.
[0113] In step S12, predetermined m (m: plural number), for example ten allowable
combinations are selected from all the allowable combinations by giving priority to those
in which absolute values of difference between combination measured values and the
target weight value are smaller, and the selected allowable combinations are determined
as first optimal combinations.
[0114] In step S13, one allowable combination is selected from allowable combinations
made up of the combination hoppers 4 and 5 obtained by excluding the combination
hoppers 4 and 5 making up of an arbitrary first optimal combination from all the
combination hoppers 4 and 5 in the combination weigher unit, by giving priority to a
combination in which an absolute value of a difference between a combination measured
value and the target weight value is smaller, and the selected allowable combination is
determined as a second optimal combination corresponding to the arbitrary first optimal
combination. In the same manner, second optimal combinations respectively
corresponding to m first optimal combinations are determined. In this manner, the
second optimal combinations respectively corresponding to m first optimal combinations
are determined, and m optimal combination sets each consisting of the associated first
optimal combination and second optimal combination are determined. It should be
noted that in the present embodiment, when weighing hoppers 4 are selected to make up
of two combinations consisting of a first optimal combination and an allowable
combination which is a candidate of the associated second optimal combination but
memory hoppers 5 corresponding to the selected weighing hoppers 4 are not selected, the
allowable combination is not selected as the second optimal combination. Therefore,
when the weighing hoppers 4 are selected to make up of two optimal combinations
composing an optimal combination set, the memory hopper 5 corresponding to the
selected weighing hopper 4 is always selected to make up of at least one optimal
combination.
[0115] In step S14, for each optimal combination set, absolute values of differences

55
between combination measured values of the first and second optimal combinations
composing the optimal combination set and the target weight value are calculated and a
total of the absolute values of the differences is calculated.
[0116] In step S15, one optimal combination set in which the total of the absolute
values of the differences calculated in step S14 is smallest is selected, one of the two
optimal combinations composing the optimal combination set is determined as a
discharge combination (first discharge combination) for discharging the objects to be
weighed to the inner chute (6a or 6b) and the other optimal combination is determined as
the discharge combination (second discharge combination) for discharging the objects to
be weighed to the outer chute (7a or 7b). If a weighing hopper 4 is selected to make up
of one of the two optimal combinations composing the selected optimal combination set
but a memory hopper 5 corresponding to the selected weighing hopper 4 is not selected,
the optimal combination is determined as the second discharge combination for
discharging the objects to be weighed to the outer chute and the other optimal
combination is determined as the first discharge combination for discharging the objects
to be weighed to the inner chute. If an optimal combination which includes a weighing
hopper 4 but does not include a memory hopper 5 corresponding to the selected weighing
hopper 4 is not included in a selected optimal combination set, any specified method may
be employed to determine which of the two optimal combinations is the first discharge
combination or the second discharge combination. For example, serial numbers may be
assigned to the memory hoppers 5, an optimal combination including the memory hopper
5 with a smallest number may be determined as the first discharge combination, and the
other optimal combination may be determined as the second discharge combination, or
vice versa. Alternatively, the first and second optimal combinations may be determined
according to the magnitude of the combination measured values. For example, an
optimal combination with a larger combination measured value may be determined as the
first discharge combination and an optimal combination with a smaller combination
measured value may be determined as the second discharge combination, or vice versa.

56
In a further alternative, the optimal combination with the larger combination measured
value and the optimal combination with the smaller combination measured value may be
alternately determined as the first and second discharge combinations, every time the
combination process is performed.
[0117] Whereas in steps S14 and S15, for each optimal combination set, the total of the
absolute values of the differences between the combination measured values of the
respective optimal combinations and the target weight value is calculated, and one
optimal combination set in which the total of the absolute values of the differences is
smallest is selected to determine it as the two discharge combinations, a total of squares
of differences between the combination measured values of the respective optimal
combinations and the target weight value, may be calculated, and one optimal
combination set in which the total of the squares of the differences is smallest is selected
to determine it as two discharge combinations, for each optimal combination set.
[0118] Subsequently, the third combination process will be described. The third
combination process is performed for the first and second combination weigher units as
described below.
[0119] In the third combination process, combination calculation is performed using
measured values of the objects to be weighed which have been fed to all the combination
hoppers 4 and 5 in an arbitrary combination weigher unit to select combinations in which
a combination measured value which is a total of measured values is within an allowable
range with respect to a target weight value and to determine them as allowable
combinations. One allowable combination in which an absolute value of a difference
between a combination measured value and the target weight value is smallest is selected
from all the allowable combinations and is determined as the first optimal combination.
[0120] Then, one allowable combination is selected from allowable combinations
consisting of combinations made up of the combination hoppers 4 and 5 remaining after
excluding the combination hoppers 4 and 5 making up of the first optimal combination
from all the combination hoppers 4 and 5 in the combination weigher unit, by giving

57
priority to a combination in which an absolute value of a difference between a
combination measured value and a target weight value is smaller, and the selected
allowable combination is determined as a second optimal combination. It should be
noted that in present embodiment, when weighing hoppers 4 are selected to make up of
two combinations consisting of a first optimal combination and an allowable
combination which is a candidate of the associated second optimal combination but a
memory hopper 5 corresponding to the selected weighing hopper 4 is not selected, the
allowable combination is not selected as the second optimal combination. Therefore,
when the weighing hoppers 4 are selected to make up of both of first and second optimal
combinations, the memory hopper 5 corresponding to the selected weighing hopper 4 is
always selected to make up of at least one optimal combination.
[0121] Then, one of the first and second optimal combinations is determined as the
discharge combination (first discharge combination) for discharging the objects to be
weighed to the inner chute and the other is determined as the discharge combination
(second discharge combination) for discharging the objects to be weighed to the outer
chute. If a weighing hopper 4 is selected to make up of one of the two optimal
combinations but a memory hopper 5 corresponding to the selected weighing hopper 4 is
not selected, the optimal combination is determined as the second discharge combination
for discharging the objects to be weighed to the outer chute and the other optimal
combination is determined as the first discharge combination for discharging the objects
to be weighed to the inner chute. If the first optimal combination and the second
optimal combination are not a combination which includes a weighing hopper 4 but does
not include a memory hopper 5 corresponding to the selected weighing hopper 4, any
specified method may be employed to determine which of the two optimal combinations
is the first discharge combination or second discharge combination, as in the case of the
second combination process.
[0122] In cases where the allowable range with respect to the target weight value is set
to not less than the target weight value, i.e., a lower limit value of the allowable range is

58
equal to the target weight value in the first, second, and third combination processes, an
absolute value of a difference between a combination measured value of an optimal
combination or an allowable combination and the target weight value is equal to a value
(difference) obtained by subtracting the target weight value from the combination
measured value. In this case, therefore, the operation in which the total of the absolute
values of the differences between the combination measured values of the respective
optimal combinations and the target weight value is calculated in step S3 in Fig. 6 and in
step S14 in Fig. 8, is equivalent to the operation in which the total of the differences is
calculated by subtracting the target weight value from the combination measured values
of the respective optimal combinations.
[0123] In cases where a lower limit value of the allowable range is equal to the target
weight value, the steps S3 and S4 in Fig. 6 and the steps S14 and 15 in Fig. 8 may be
replaced by steps in which a total of combination measured values of two optimal
combinations composing each optimal combination set is calculated, one optimal
combination set in which the calculated total is smallest may be selected, and two
optimal combinations composing the optimal combination set may be determined as first
and second discharge combinations. In this case, also, two discharge combinations
which are the same as those resulting from the steps S3 and S4 and the steps S14 and S15
are determined.
[0124] Since the above described first, second or third combination process is
performed for each combination weigher unit to determine the two discharge
combinations which will discharge the objects to be weighed once in every one operation
cycle time Tw, weights of the objects to be weighed inside of all the combination
hoppers 4 and 5 within each combination weigher unit can be used in the combination
calculation for determining the two discharge combinations. As a result, combination
weighing precision for the objects to be weighed which are discharged can be improved
as a whole.
[0125] In the second combination process, a plurality of first optimal combinations are

59
determined under an extended selection condition for the first optimal combination, the
second optimal combinations respectively corresponding to the first optimal
combinations are determined, and the two optimal combinations in which the total of
combination measured values is smallest are selected from among them, in the third
combination process. This means that the use of the second combination process can
improve as a whole combination weighing precision for the objects to be weighed which
are discharged rather than the use of the third combination process. Furthermore, since
the optimal combination set in which the total of the absolute values of the differences
between the combination measured values of the two optimal combinations and the target
weight value is smallest is selected from the optimal combination sets each of which is
formed by combining two optimal combinations selected from all the optimal
combinations, combination weighing precision for the objects to be weighed which are
discharged can be further improved as a whole.
[0126] In addition, the calculation amount decreases in the order of the first
combination process, the second combination process, and the third combination process,
and time taken for the combination processes can be decreased in this order.
[0127] Whereas in the example a, the collecting hopper 8a and the collecting hopper
9b are configured to discharge the objects to be weighed to the lower chute 10a and the
collecting hopper 9a and the collecting hopper 8b are configured to discharge the objects
to be weighed to the lower chute 10b, one of the collecting hopper 8a and the collecting
hopper 9a in the first combination weigher unit may be configured to discharge the
objects to be weighed to the lower chute 10a, the other collecting hopper 8a or 9a may be
configured to discharge the objects to be weighed to the lower chute 10b, one of the
collecting hopper 8b and the collecting hopper 9b in the second combination weigher
unit may be configured to discharge the objects to be weighed to the lower chute 10a and
the other collecting hopper 8b or 9b may be configured to discharge the objects to be
weighed to the lower chute 10b.
[0128] [Example b of embodiment 2]

60
Fig. 9 (a) is a schematic view of collecting chutes (inner chutes and outer
chutes), weighing hoppers and memory hoppers of a combination weigher (weighing
system) according to an example b of the embodiment 2 of the present invention, as
viewed from above, and Fig. 9(b) is a schematic view of a lower chute of the
combination weigher as viewed from above.
[0129] Whereas in the example a shown in Fig. 5, two combination weigher units are
equipped, four combination weigher units are equipped in the present example. In the
present example, as in the example a, the center body 11, the dispersion feeder 1, the
linear feeders 2, the feeding hoppers 3, the weighing hoppers 4 attached with the weight
sensors 41, and the memory hoppers 5, are equipped as shown in Fig. 5(a), and are
identical in configuration to those of the example a. Therefore, explanation therefor is
omitted.
[0130] In the example b, all the weighing hoppers 4 and memory hoppers 5 are divided
into four groups A, B, C, and D and combination weigher units are equipped to
respectively include the four groups A, B, C, and D and to respectively correspond to the
groups A, B, C, and D. So, four inner chutes 6a, 6b, 6c, and 6d are provided to
respectively correspond to the four groups A, B, C and D, Collecting hoppers 8a. 8b. 8c.
and 8d are respectively provided at bottom part discharge outlets 6ae, 6be, 6ce and 6de of
the inner chutes 6a, 6b, 6c, and 6d to hold and discharge the objects to be weighed.
Four outer chutes 7a, 7b, 7c and 7d are provided to respectively correspond to the four
groups A, B, C, and D. Collecting hoppers 9a, 9b, 9c and 9d are respectively provided
at bottom part discharge outlets 7ae, 7be, 7ce, and 7de of the outer chutes 7a, 7b, 7c, and
7d to hold and discharge the objects to be weighed. Hereinafter, a combination weigher
unit including the group A is referred to as a first combination weigher unit, a
combination weigher unit including the group B is referred to as a second combination
weigher unit, a combination weigher unit including the group C is referred to as a third
combination weigher unit, and a combination weigher unit including the group D will be
referred to as a fourth combination weigher unit.

61
[0131] Below the collecting hopper 9a of the first combination weigher unit and the
collecting hopper 9b of the second combination weigher unit, the lower chute 10a is
provided, and the objects to be weighed which have been discharged from the collecting
hoppers 9a or 9b are discharged from the discharge outlet 10ae through the lower chute
10a. Below the collecting hopper 8a of the first combination weigher unit and the
collecting hopper 8b of the second combination weigher unit, the lower chute 10b is
provided, and the objects to be weighed which have been discharged from the collecting
hoppers 8a and 8b are discharged from the discharge outlet 10be through the lower chute
10b. Below the collecting hopper 8c of the third combination weigher unit and the
collecting hopper 8d of the fourth combination weigher unit, the lower chute 10c is
provided, and the objects to be weighed which have been discharged from the collecting
hoppers 8c and 8d are discharged from the discharge outlet 10ce through the lower chute
10c. Below the collecting hopper 9c of the third combination weigher unit and the
collecting hopper 9d of the fourth combination weigher unit, the lower chute 10d is
provided, and the objects to be weighed which have been discharged from the collecting
hoppers 9c and 9d are discharged from the discharge outlet 10de through the lower chute
10d.
[0132] Below the lower chutes 10a, 10b, 10c and 10d of the combination weigher, four
packaging machines (not shown) or a packaging machine (not shown) having four inlets
into which the objects to be weighed are fed are disposed. The objects to be weighed
which have been discharged from the discharge outlet 10ae of the lower chute 10a, the
discharge outlet 10be of the lower chute 10b, the discharge outlet 10ce of the lower chute
10c, and the discharge outlet 10de of the lower chute 10d are respectively fed into the
different packaging machine inlets (first to fourth packaging machine inlets) and are
charged into package bags for packaging. Thus, in the present example, the objects to
be weighed which have been discharged from the collecting hopper 9a in the first
combination weigher unit and the collecting hopper 9b in the second combination
weigher unit are fed into the first packaging machine inlet through the lower chute 10a,

62
and the objects to be weighed which have been discharged from the collecting hopper 8a
in the first combination weigher unit and the collecting hopper 8b in the second
combination weigher unit are fed into the second packaging machine inlet through the
lower chute 10b. Also, the objects to be weighed which have been discharged from the
collecting hopper 8c in the third combination weigher unit and from the collecting
hopper 8d in the fourth combination weigher unit are fed into the third packaging
machine inlet through the lower chute 10c, and the objects to be weighed which have
been discharged from the collecting hopper 9c in the third combination weigher unit and
from the collecting hopper 9d in the fourth combination weigher unit are fed into the
fourth packaging machine inlet through the lower chute 10d
[0133] The control unit 20 (see Fig. 5(a)) is equipped to control an operation of the
entire combination weigher of the present example and to perform a combination process
to determine a combination (discharge combination) made up of the weighing hoppers 4
and the memory hoppers 5 which will discharge the objects to be weighed for each of the
first, second, third and fourth combination weigher units. The combination process for
each combination weigher unit is identical to that of the example a.
[0134] The other configuration is identical to that of the example a and will not be
further described. In the present example b, as in the example a, by setting the number
of the weighing hoppers 4 and the memory hoppers 5 to nine or ten in each of the groups
A, B, C, and D and by setting the number of weighing hoppers 4 and memory hoppers 5
which would be selected to form one optimal combination in the combination process to
four, high combination weighing precision is obtained.
[0135] In the example b, operation timings are taken for each pair of two combination
weigher units arranged adjacent each other. In the present example, the first
combination weigher unit and the second combination weigher unit form a pair and the
third combination weigher unit and the fourth combination weigher unit form a pair.
[0136] The timing charts for the first combination weigher unit and the second
combination weigher unit are similar to those of, for example, Fig. 7, and the timing

63
charts for the third combination weigher unit and the fourth combination weigher unit are
similar to those for the first combination weigher unit and the second combination
weigher unit. That is, the pair of the first and second combination weigher units and the
pair of the third and fourth combination weigher units in the present example may be
configured to operate as in the first and second combination weigher units in the example
a, and description therefor will be omitted. It should be noted that the pair of the first
and second combination weigher units and the pair of the third and fourth combination
weigher units in the present example may be controlled based on different feed command
signals. That is, it is necessary to set Tw/2 time difference between the operation
timings for the two combination weigher units forming each pair as shown in Fig. 7, but
any special correlation need not be made between the operation timings for the two pairs.
[0137] The combination weigher according to the example b is identical to the
combination weigher according to the example a except for the number of pairs of the
combination weigher units, and is able to achieve advantages similar to those of the
combination weigher of the example a.
[0138] In the example a, the configuration in which the two combination weigher
units(one pair of combination weigher units) are equipped, and in the example b. the
configuration in which the four combination weigher units(two pairs of combination
weigher units) are equipped. In the same manner, combination weigher units of even
number which is six or more (three or more pairs of combination weigher units) may be
equipped.
[Example c of Embodiment 2]
A combination weigher (weighing system) according to an example c of the
embodiment 2 of the present invention is configured in such a manner that the two
lower chutes 10a and 10b are omitted from the example a shown in Fig. 5 and the
four collecting hoppers 8a, 8b, 9a, and 9b are respectively able to discharge the
objects to be weighed in the same direction, for example, in a straight-downward
direction. The other configuration is identical to that of the example a and will not

64
be described. Hereinafter, description will be given with reference to Fig. 5 (in the
example c, the lower chutes 10a and 10b are omitted as described above).
In the example c, a first combination weigher unit including the group A
consisting of the weighing hoppers 4 and the memory hoppers 5 and a second
combination weigher unit including the group B consisting of the weighing hoppers 4
and the memory hoppers 5 are configured to operate at the same timings and the four
collecting hoppers 8a, 8b, 9a, and 9b are configured to discharge the objects to be
weighed simultaneously. As in the example a, for the first and second combination
weigher units, the first combination process, the second combination process, or the
third combination process is performed to determine two discharge combinations
simultaneously.
Fig. 10 is a timing chart showing the operation of the combination weigher
according to the example c.
[0139] Whereas in the example a, the first combination weigher unit and the
second combination weigher unit operate with a time difference of Tvv/2 time as
shown in Fig. 7, they operate at the same timings in the example c. In this case, one
discharge cycle time Td3 for each combination weigher unit is equal to one operation
cycle time Tw. The one discharge cycle time Td3 is equal to one packaging cycle
time Tp3 for the packaging machine.
[0140] A combination process for determining two discharge combinations
simultaneously is performed once in every Tw time for each combination weigher
unit, and the combination hoppers 4 and 5 making up of the two discharge
combinations determined in the combination process discharge the objects to be
weighed simultaneously once in every Tw time in each combination weigher unit.
In addition, in each combination weigher unit, the inner chute collecting hopper (8a
or 8b) and the outer chute collecting chopper (9a or 9b) discharge the objects to be
weighed simultaneously once in every Tw time. The operation of each combination
weigher unit is similar to that of the example a and will not be further described in

65
detail.
Below the combination weigher, four packaging machines (not shown) or a
packaging machine having four inlets (not shown) into which the objects to be
weighed are fed are disposed. The objects to be weighed which have been
discharged simultaneously from the four collecting hoppers 8a, 8b, 9a, and 9b are fed
into different packaging machine inlets (first to fourth packaging machine inlets) and
are packaged in the packaging machine(s).
The combination weigher according to the example c is identical to the
combination weigher according to the example a except for timings when the
combination weigher units operate and the packaging machine inlets toward which the
objects to be weighed are discharged, and is able to achieve advantages similar to those
of the combination weigher of the example a.
By causing the two combination weigher units to operate at the same timings as
in the example c, the objects to be weighed are fed into each of the four packaging
machine inlets once in every Tw time. Since the objects to be weighed are discharged
once to each of the four packaging machine inlets within the one operation cycle time Tw,
productivity within a specified time period can be improved.
One example of the packaging machine having the four packaging machine
inlets is shown in Fig. 11. Fig. 11 (a) is a schematic cross-sectional view showing a
vacuum packaging machine and Fig. ll(b) is a schematic plan view of the packaging
machine as viewed from above.
In the packaging machine, funnels 51 are respectively disposed under the four
collecting hoppers 8a, 8b, 9a, and 9b of the combination weigher. In this case, the
funnels 51 are packaging machine inlets. It should be noted that openings of package
bags or package containers manufactured or used in the packaging machine are
packaging machine inlets into which the objects to be weighed are fed, depending on the
type of the packaging machine.
[0141] In the packaging machine, first, a forming part 52 suctions and heats a

66
resin-made film drawn from a roll to manufacture four package containers 55
simultaneously. The resin-made film forming the package containers 55 is held by a
conveyor means such as a belt conveyor which is not shown and is conveyed
intermittently in a direction indicated by an arrow 56. Receiving, for example, a feed
command signal from the packaging machine as an input, the combination weigher
discharges the objects to be weighed simultaneously from the four collecting hoppers 8a,
8b, 9a, and 9b. The objects to be weighed are fed to the package containers 55 through
the associated funnels 51. Receiving, for example, a discharge completion signal, from
the combination weigher, and being ready for conveying the resin-made firm, the
packaging machine conveys subsequent four package containers 55 to under the four
funnels 51 and stops. The packaging machine sends a feed command signal to the
combination weigher. Thereby, the four package containers 55 are fed with the objects
to be weighed simultaneously, and then are conveyed to a lid seal part 53. In the lid
sealing part 53, a resin-made film is bonded to upper surfaces of the package containers
55 to close the openings of the package containers 55. Thereafter, in a cutting part (not
shown) positioned in a subsequent stage of the lid seal part 53, the resin-made film is cut
for each package container 55 or each set of four package containers 55.
Another example of the packaging machine adapted to the combination weigher
according to the example c, may be a package bag supply type packaging machine
configured in such a manner that separate four package bags are conveyed to locations
under the four collecting hoppers 8a, 8b, 9a, and 9b simultaneously, the objects to be
weighed which have been discharged from these collecting hoppers are fed into openings
of the package bags through funnels or the like, and thereafter the openings of the
package bags are sealed. Still another example of the packaging machine may be
configured in such a manner that one or two resin-made films are drawn out from a roll
and is subjected to heat treatment and pressurization treatment so that four package bags
connected to each other are manufactured simultaneously, these package bags are
transported to locations under the collecting hoppers 8a, 8b, 9a, and 9b, objects to be

67
weighed which have been discharged from these collecting hoppers are fed into openings
of the package bags through funnels and the like, thereafter, the openings of the package
bags are sealed, and the resin-made films are separated by cutting for each package bag.
A still another example of the packaging machine may be a packaging line configured in
such a manner that each set of four resin-made package containers manufactured in
advance (e.g., package containers which are formed by separating the package containers
55 in Fig. 11) are sequentially put on a belt conveyor and are transported to locations
under the four collecting hoppers 8a, 8b, 9a, and 9b, and the openings of the package
containers are closed by the resin-made film or the like after the combination weigher
feeds the objects to be weighed to the four package containers simultaneously.
[0142] In cases where the conventional combination weigher shown in, for example,
Fig. 13 is used to discharge four sets of the objects to be weighed as in the example c, the
following configurations (1) to (3) may be employed.
[0143] (1) Four combination weighers are configured to operate at the same operation
timings so that each combination weigher discharge one set of objects to be weighed,
thus discharging four sets of objects to be weighed simultaneously.
[0144] (2) Two combination weighers and a sorting discharge apparatus are used, and
the two combination weighers are configured to operate at the same timings and carry out
the double shift operation. In this case, each combination weigher discharges one set of
objects to be weighed once in every 1/2 of one operation cycle time Tw. Therefore, two
sets of objects to be weighed are discharged from the whole of the two combination
weighers once in every Tw/2 time, and four sets of objects to be weighed are discharged
therefrom within Tw time. In this case, the sorting discharge apparatus is required to
individually receive the four sets of objects to be weighed which are discharged within
Tw time and to discharge them to the packaging machine simultaneously. For example,
four discharge hoppers (first to fourth discharge hoppers) are arranged in a straight line
shape under collecting hoppers 13 (Fig. 13) of the two combination weighers, and the
sorting discharge apparatus is constituted by the two collecting hoppers 13 and the four

68
discharge hoppers. One of the two collecting hoppers 13 is configured to be able to
discharge the objects to be weighed to the first discharge hopper and to the second
discharge hopper alternately, while the other collecting hopper 13 is configured to be able
to discharge the objects to be weighed to the third discharge hopper and to the fourth
discharge hopper alternately. The four discharge hoppers are configured to discharge
the objects to be weighed to the packaging machine simultaneously, when these four
discharge hoppers hold the objects to be weighed.
(3) One combination weigher and one sorting apparatus are used.
Combination calculation is performed once in every Tw/4 time. Weighing hoppers 4
making up of a combination selected in the combination calculation discharge the objects
to be weighed, and according to the discharge, the collecting hopper 13 discharges the
objects to be weighed (hereinafter this operation is referred to as "fourth shift operation").
In this case, one set of objects to be weighed are discharged from the combination
weigher once in every Tw/4 time, and therefore four sets of objects to be weighed are
discharged within Tw time. In this case, also, the sorting discharge apparatus is
required to individually receive four sets of objects to be weighed which are discharged
within Tw time and to discharge them to the packaging machine simultaneously, as in the
above (2) case, although its configuration is different. To form the sorting discharge
apparatus used in this case, for example, the sorting discharge apparatus described in the
above (2) case may be altered to have two stages.
In the configuration of the above (1) case, because of the need for the four
combination weighers, equipment cost increases. In the configuration of the above (2)
case, because of the need for the two combination weighers and the expensive sorting
discharge apparatus, equipment const increases. In the configuration of the above (3)
case, because of the need for the sorting discharge apparatus which has a more complex
structure and is more expensive than in the above (2) case, equipment const increases.
Furthermore, the double shift operation in the configuration of the above (2) case and the
fourth shift operation in the configuration of the above (4) case may arise a problem that,

69
since each combination weigher has only one collecting chute 12 (Fig. 13), a distance
between the batches of the objects to be weighed which are discharged from the
weighing hoppers 4 selected in a previous combination onto the collecting chute 12 and
the objects to be weighed which are discharged from the weighing hoppers 4 selected in a
subsequent combination onto the collecting chute 12 becomes insufficiently large,
depending on characteristics of the objects to be weighed, making high-speed operation
difficult.
[0145] In contrast to these configurations, the combination weigher of the example c, is
able to operate at a high speed irrespective of characteristics of almost all the objects to
be weighed and without substantially increasing equipment cost.
[0146] Whereas in the configuration c, the combination weigher equipped with the two
combination weigher units has been described, it may alternatively be equipped with
three or more combination weigher units in the same manner. For example, in cases
where the combination weigher is equipped with three combination weigher units, six
collecting hoppers 8a, 8b, 8c, 9a, 9b, and 9c are equipped as shown in Fig. 4(a) to
discharge the objects to be weighed simultaneously from the six collecting hoppers. In
this case, in the packaging machine, for example, in the packaging machine shown in Fig.
11, six package containers 55 are manufactured simultaneously and are conveyed, and
the objects to be weighed are fed to the package containers 55 through the associated
funnels 51. In this case, since the six collecting hoppers are not aligned as shown in Fig.
4(a), the six funnels 51 are shape-changed to be able to guide the objects to be weighed
to the six package containers 55 which are aligned. For example, the funnels 51 may be
shape-changed in such a manner that an upper part receiver opening of each funnel 51 is
located under the associated collecting hopper, and a pipe portion forming a lower part of
the funnel 51 is made slightly longer so that a lower end of the pipe portion is located
immediately above the associated package container 55.
Whereas in the first and second embodiments, the weighing hoppers 4 and the
memory hoppers 5 arranged in a circular shape are divided into a plurality of groups and

70
one combination weigher is equipped with combination weigher units respectively
corresponding to the plurality of groups, a combination weigher (circular-arc shaped
combination weigher) consisting of a combination weigher unit corresponding to one
group may be used, for example. One example of this is a combination weigher which
includes the dispersion feeder 1, the first combination weigher unit corresponding to the
group A and the lower chute 10a in the configuration 1 shown in Fig. 1 and is configured
to carry out the double shift operation or the triple shift operation. In this case, the
feeding hoppers 3, the weighing hoppers 4 and the memory hoppers 5 are arranged in a
semi-circular shape, and according to the shape, the linear feeder 2 is disposed.
Therefore, the shape of the dispersion feeder 1 for feeding the objects to be weighed to
the linear feeder 2 is changed. In this case, the combination weigher is configured
substantially in a semi-circular shape (sector form having a central angle of
approximately 180 degrees) as viewed from above. Likewise, a combination weigher
which includes the dispersion feeder 1, the first combination weigher unit corresponding
to the group A and the lower chute 10a in the configuration 2 shown in Fig. 4 and is
configured to carry out the double shift operation or the triple operation, may be shaped
in a sector form having a central angle of approximately 120 degrees as viewed from
above. The objects to be weighed which have been discharged from these combination
weighers having the sector form are fed into one package machine inlet through the
lower chute 10a. Also, the lower chute 10a may be omitted from the above
configuration and the objects to be weighed which have been discharged from the two
collecting hoppers 8a and 9a (e.g., see Fig. 1) of the first combination weigher unit may
be fed into different two packaging machine inlets. In the above configuration, the
double shift operation or the triple shift operation may be replaced by any of the first,
second, and third combinations processes and the operation described in the embodiment
2, and the objects to be weighed which have been discharged from the two collecting
hoppers 8a and 9a (e.g., see Fig. 1) of the first combination weigher unit may be fed into
two different packaging machine inlets without providing the lower chute 10a. The

71
above described combination weigher is equipped with only the combination weigher
unit corresponding to one group (e.g., group A in Fig. 1, group A in Fig. 4, or group A in
Fig. 9, etc) made up of the combination hoppers 4 and 5 and is configured in such a
manner that the feeding hoppers 3, the weighing hoppers 4, and the memory hoppers 5
are arranged in a circular-arc shape having a central angle of approximately 180 degrees
or smaller.
[0147] In the examples of the embodiments 1 and 2, and the above described
circular-arc shaped combination weigher, required lower chutes (10a, 10b, 10c, and lOd)
may be equipped in the packaging machine.
[0148] Whereas in the examples of the embodiments 1 and 2, and the above described
circular-arc shaped combination weigher, the weighing hoppers 4 and the memory
hoppers 5 located obliquely therebelow are illustrated as the combination hoppers fed
with the objects to be weighed whose measured values are used in the combination
calculation, these combination hoppers are merely exemplary. Figs. 12(a), 12(b), and
12(c) are plan views schematically showing hoppers such as combination hoppers
according to another examples. In Figs. 12(a), 12(b), and 12(c), an inner chute 6X
corresponds to the inner chutes 6a and 6b and others in Figs. 1 and 5 and the ouier chute
7X corresponds to the outer chutes 7a and 7b and others in Figs. 1 and 5. Each
weighing hopper 4 shown in Figs. 12(a), 12(b), and 12(c) is attached with one weight
sensor 41 (see Figs. 1 and 5).
[0149] For example, as shown in Fig. 12(a), each weighing hopper 4 may be
configured to have two chambers (weighing chambers) 4a and 4b which are respectively
fed with the objects to be weighed and a memory hopper 5 having two chambers
(accommodating chambers) 5a and 5b respectively corresponding to the weighing
chambers 4a and 4b of the weighing hopper 4 may be provided obliquely below each
weighing hopper 4. The two weighing chambers 4a and 4b of each weighing hopper 4
may be arranged side by side substantially in the same direction as the direction in which
the plurality of weighing hoppers 4 are arranged, and the two accommodating chambers

72
5a and 5b of each memory hopper 5 may be arranged side by side substantially in the
same direction as the direction in which the plurality of memory hoppers 5 are arranged.
In this case, the feeding hopper 3 is configured to be able to discharge the objects to be
weighed selectively to the weighing chamber 4a or to the weighing hopper 4b of the
weighing hopper 4. The weighing chamber 4a of the weighing hopper 4 is configured
to be able to discharge the objects to be weighed selectively to the accommodating
chamber 5a of the memory hopper 5 or to the outer chute 7X, while the weighing
chamber 4b of the weighing hopper 4 is configured to be able to discharge the objects to
be weighed selectively to the accommodating chamber 5b of the memory hopper 5 or to
the outer chute 7X. The two accommodating chambers 5a and 5b of the memory
hopper 5 are each configured to be able to discharge the objects to be weighed selectively
to the inner chute 6A or to the outer chute 7X. The combination calculation is
performed using weights (measured values) of the objects to be weighed inside the
weighing chambers 4a and 4b of each weighing hopper 4 and weights (measured values)
of the objects to be weighed inside the accommodating chambers 5a an 5b of each
memory hopper 5, and the weighing chambers 4a and 4b and the accommodating
chambers 5a and 5b are candidates io be selecied io make up of a discharge combination.
In each weighing hopper 4, when one weighing chamber, for example, weighing chamber
4a holds the objects to be weighed, the weight sensor 41 measures the weight of the
objects to be weighed inside the weighing chamber 4a. Then, when the other weighing
chamber 4b is fed with the objects to be weighed, the weight sensor 41 measures a total
weight of the objects to be weighed inside the two weighing chambers 4a and 4b. The
control unit 20 (see Figs. 1 and 5) calculates the weight (measured value) of the objects
to be weighed inside the weighing chamber 4b by subtracting the weight of the objects to
be weighed inside the weighing chamber 4a from the total weight of the objects to be
weighed inside the two weighing chambers 4a and 4b. As the measured values of the
objects to be weighed inside the accommodating chambers 5a and 5b, measured values
obtained by measurement and calculation in the weighing chambers 4a and 4b of the

73
weighing hopper located thereabove are used. In this case, if the weighing chamber 4a
or 4b is selected to make up of a discharge combination for discharging the objects to be
weighed to the inner chute 6X, the corresponding accommodating chamber 5a or 5b is
selected simultaneously. For example, when the corresponding weighing chamber 4a
and accommodating chamber 5a are selected simultaneously, the objects to be weighed
inside the weighing chamber 4a are discharged to the inner chute 6X through the
accommodating chamber 5a.
[0150] As shown in Fig. 12(b), each weighing hopper 4 may be configured to have
two weighing chambers 4a and 4b without providing the memory hopper 5. The two
weighing chambers 4a and 4b of each weighing hopper 4 may be arranged side by side
substantially in the same direction as the direction in which the plurality of weighing
hoppers 4 are arranged. In this case, the feeding hopper 3 is configured to be able to
discharge the objects to be weighed selectively to the weighing chamber 4a or to the
weighing hopper 4b of the weighing hopper 4. The two weighing chambers 4a and 4b
of the weighing hopper 4 may be configured to be able to discharge the objects to be
weighed selectively to the inner chute 6A or to the outer chute 7X. The combination
calculation is performed using ihe weights (measured values) of the objects to be
weighed inside the weighing chambers 4a and 4b of each weighing hopper 4 and the
weighing chambers 4a and 4b are candidates to be selected to make up of a discharge
combination. The weights of the objects to be weighed inside the weighing chambers
4a and 4b are calculated in the same manner as that of Fig. 12(a).
[0151] As shown in Fig. 12(c), each memory hopper 5 may be configured to have two
accommodating chambers 5a and 5b. The two accommodating chambers 5a and 5b of
each memory hopper 5 may be arranged side by side substantially in the same direction
as the direction in which the plurality of memory hoppers 5 are arranged. Herein, the
feeding hopper 3 (see Figs. 1 and 5) for feeding the objects to be weighed to the
weighing hopper 4 is not illustrated. In this case, the weighing hopper 4 is configured
to be able to discharge the objects to be weighed selectively to the accommodating

74
chamber 5a or to the accommodating chamber 5b of the memory hopper 5 and is
configured not to discharge the objects to be weighed to the inner chute 6X and to the
outer chute 7X. The two accommodating chambers 5a and 5b of the memory hopper 5
are each configured to be able to discharge the objects to be weighed selectively to the
inner chute 6X or to the outer chute 7X. The combination calculation is, for example,
performed using the weights (measured values) of the objects to be weighed inside the
accommodating chambers 5a and 5b of each memory hopper 5, and the accommodating
chambers 5a and 5b are candidates to be selected to make up of a discharge combination
but the weighing hopper 4 does not participate in a combination. As the weights of the
objects to be weighed inside the accommodating chambers 5a and 5b, weights measured
in the weighing hopper 4 located thereabove are used. The weighing hopper 4 is able to
participate in a combination provided that the weighing hopper 4 and the accommodating
chamber 5a or 5b of the corresponding memory hopper 5 are selected simultaneously.
For example, when the weighing hopper 4 and the accommodating chamber 5a of the
corresponding memory hopper 5 are selected to make up of a discharge combination
simultaneously, the objects to be weighed inside the weighing hopper 4 are discharged
onto the inner chute 6X or onto the outer chute 7X through the accommodating chamber
5a.
[0152] In addition to the above, the configuration of the hoppers such as the
combination hoppers or the like may be changed in various ways. In the configuration
shown in the examples of the embodiments 1 and 2, in which the weighing hoppers 4 and
the memory hoppers 5 are equipped, two measured values for use in combination
calculation are obtained for each weight sensor 41 attached on the associated weighing
hopper 4. In the configuration shown in Fig. 12(a), four measured values for use in
combination calculation are obtained for each weight sensor 41. In the configuration
shown in Fig. 12(b), two measured values for use in combination calculation are obtained
for each weight sensor 41. In the configuration shown in Fig. 12(c), two measured
values for use in combination calculation are obtained for each weight sensor 41 when

75
the weighing hoppers 4 do not participate in a combination, while three measured values
for use in combination calculation are obtained for each weight sensor 41 when the
weighing hoppers 4 participate in a combination. With these hopper configurations,
efficient use of the weight sensors 41 which are expensive is achieved. In addition,
without increasing a diameter of a circle along which the combination hoppers are
arranged, the number of measured values for use in the combination calculation can be
increased so that combination weighing precision is improved.
[0153] Moreover, in the above described embodiments 1 and 2, the control unit 20 is
not limited to being configured as the single control apparatus, but instead may be
configured to include a plurality of control apparatuses disposed in a distributed manner,
and these control apparatuses may co-operate to control the operation of the combination
weigher.
Numerous modifications and alternative embodiments of the invention will
be apparent to those skilled in the art in view of the foregoing description.
Accordingly, the description is to be construed as illustrative only, and is provided
for the purpose of teaching those skilled in the art the best mode of carrying out the
invention. The details of the structure and/or function may be varied substantially
without departing from the spirit of the invention.
Industrial Applicability
[0154] A combination weigher and a weighing system of the present invention are
useful as a combination weigher, a weighing system and others which are coupled to a
packaging machine operated at a high speed or a twin-type packaging machine, etc.

76
CLAIMS
[1] A combination weigher comprising:
a combination hopper line formed by a plurality of combination hoppers which are
arranged in a circular-arc shape having a central angle of approximately 180 degrees or
smaller and are fed with objects to be weighed, the plurality of combination hoppers
being each configured to be able to discharge the objects to be weighed selectively in an
inward direction which is toward a center of the circular-arc shape or in an outward
direction which is an opposite direction of the inward direction;
an inner chute which is disposed below the combination hopper line and has an
upper end portion of a circular-arc shape conforming to the shape of the combination
hopper line, the inner chute being configured to gather the objects to be weighed which
have been discharged in the inward direction from the combination hoppers and to
discharge the objects to be weighed from a discharge outlet provided at a bottom part
thereof;
an outer chute which is disposed along outside of the inner chute, the outer chute
being configured to gather the objects to be weighed which have been discharged in the
outward direction from the combination hoppers and to discharge the objects to be
weighed from a discharge outlet provided at a bottom part thereof;
a first collecting hopper which is provided at the discharge outlet of the inner chute
to hold and discharge the objects to be weighed which have been discharged from the
discharge outlet of the inner chute;
a second collecting hopper which is provided at the discharge outlet of the outer
chute to hold and discharge the objects to be weighed which have been discharged from
the discharge outlet of the outer chute;
a combination calculation means which is configured to determine a first discharge
combination and a second discharge combination each of which is made up of
combination hoppers in which a combination weight value which is a total of weights of

77
the objects to be weighed which have been fed to the combination hoppers is within an
allowable range with respect to a target weight value; and
a control means which is configured to cause the combination hoppers making up
of the first discharge combination to discharge the objects to be weighed in the inward
direction and to cause the combination hoppers making up of the second discharge
combination to discharge the objects to be weighed in the outward direction, and is
configured to cause the first collecting hopper holding the objects to be weighed which
have been discharged from the combination hoppers making up of the first discharge
combination to discharge the objects to be weighed and to cause the second collecting
hopper holding the objects to be weighed which have been discharged from the
combination hoppers making up of the second discharge combination to discharge the
objects to be weighed.
[2] The combination weigher according to claim 1,
wherein the combination calculation means is configured to repeatedly perform a
combination process in which combination calculation is performed based on the weights
of the objects to be weighed which have been fed to the combination hoppers to
determine one combination made up of the combination hoppers in which a combination
weight value is within the allowable range with respect to the target weight value and to
determine the combination as an optimal combination; and
the combination calculation means is configured to repeatedly perform the
combination process n (plural number) times in such a manner that, the combination
calculation is performed based on weights of objects to be weighed which have been fed
to combination hoppers which do not make up of an optimal combination determined in a
previous combination process, in a subsequent combination process, and is configured to
determine optimal combinations determined sequentially in the combination process
performed repeatedly as the first discharge combination and the second discharge
combination alternately;

78
the control means is configured to cause the combination hoppers making up of the
first discharge combination and the combination hoppers making up of the second
discharge combination to alternately discharge the objects to be weighed and to cause the
first collecting hopper and the second collecting hopper to alternately discharge the
objects to be weighed, based on the first discharge combination and the second discharge
combination alternately determined by the combination calculation means; and
wherein the objects to be weighed which have been discharged from the first
collecting hopper and the objects to be weighed which have been discharged from the
second collecting hopper are fed into the same packaging machine inlet.
[3] The combination weigher according to claim 1,
wherein the combination calculation means is configured to repeatedly perform a
combination process in which combination calculation is performed based on the weights
of the objects to be weighed which have been fed to the combination hoppers to
determine one combination made up of the combination hoppers in which a combination
weight value is within the allowable range with respect to the target weight value and to
determine the combination as an optimal combination; and
the combination calculation means is configured to repeatedly perform the
combination process n (plural number) times in such a manner that, the combination
calculation is performed based on weights of objects to be weighed which have been fed
to combination hoppers which do not make up of an optimal combination determined in a
previous combination process, in a subsequent combination process, and is configured to
determine optimal combinations determined sequentially in the combination process
performed repeatedly as the first discharge combination and the second discharge
combination alternately;
the control means is configured to cause the combination hoppers making up of the
first discharge combination and the combination hoppers making up of the second
discharge combination to alternately discharge the objects to be weighed and to cause the

79
first collecting hopper and the second collecting hopper to alternately discharge the
objects to be weighed, based on the first discharge combination and the second discharge
combination alternately determined by the combination calculation means; and
wherein the objects to be weighed which have been discharged from the first
collecting hopper and the objects to be weighed which have been discharged from the
second collecting hopper are fed into different packaging machine inlets.
[4] The combination weigher according to claim 1,
wherein the combination calculation means is configured to perform a combination
process in which combination calculation is performed based on the weights of the
objects to be weighed which have been fed to the combination hoppers to determine two
combinations which do not include the same combination hoppers and in which
combination weight values obtained in the combination calculation are within the
allowable range with respect to the target weight value, one of the two combinations is
determined as the first discharge combination and the other of the two combinations is
determined as the second discharge combination;
wherein the control means is configured to cause the combination hoppers making
up of the first discharge combination and the combination hoppers making up of the
second discharge combination which have been determined by the combination
calculation means to discharge the objects to be weighed simultaneously, and to cause the
first collecting hopper and the second collecting hopper to discharge the objects to be
weighed simultaneously; and
wherein the objects to be weighed which have been discharged from the first
collecting hopper and the objects to be weighed which have been discharged from the
second collecting hopper are fed into different packaging machine inlets.
[5] The combination weigher according to claim 1,
wherein the combination hopper line includes two lines which are upper and lower

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combination hopper lines, combination hoppers forming the upper combination hopper
line are weighing hoppers which weigh weights of the objects to be weighed which have
been fed to the weighing hoppers and combination hoppers forming the lower
combination hopper line are memory hoppers which are provided to respectively
correspond to the weighing hoppers and are fed with the objects to be weighed which
have been weighed in the weighing hoppers;
wherein the weighing hoppers are each configured to be able to discharge the
objects to be weighed selectively to the corresponding memory hopper or to the outer
chute, and the memory hoppers are each configured to be able to discharge the objects to
be weighed selectively to the inner chute or to the outer chute; and
wherein the combination calculation means is configured to determine a first
discharge combination such that a weighing hopper and a corresponding memory hopper
are included in the first discharge combination when the weighing hopper is selected to
make up of the first discharge combination.
[6] A weighing system comprising:
a piuraiity of weighing units each of which includes a combination weigher
according to claim 1, the plurality of weighing units being configured such that
combination hopper lines corresponding to the plurality of weighing units are
continuously arranged and combination hoppers corresponding to the plurality of
weighing units are arranged in a circular shape.
[7] The weighing system according to claim 6,
wherein combination calculation means in each of the weighing units is
configured to repeatedly perform a combination process in which combination
calculation is performed based on weights of the objects to be weighed which have been
fed to the combination hoppers within the weighing unit to determine one combination
made up of combination hoppers in which a combination weight value is within an

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allowable range with respect to a target weight value and to determine the combination as
an optimal combination; and
the combination calculation means in each of the weighing units is configured to
repeatedly perform the combination process n (plural number) times in such a manner
that, the combination calculation is performed based on weights of objects to be weighed
which have been fed to combination hoppers which do not make up of an optimal
combination determined in a previous combination process, in a subsequent combination
process, and is configured to determine optimal combinations determined sequentially in
the combination process performed repeatedly as the first discharge combination and the
second discharge combination alternately;
the control means in each of the weighing units is configured to cause the
combination hoppers making up of the first discharge combination and the combination
hoppers making up of the second discharge combination to alternately discharge the
objects to be weighed and to cause the first collecting hopper and the second collecting
hopper within the weighing unit to alternately discharge the objects to be weighed, based
on the first discharge combination and the second discharge combination alternately
determined by the combination calculation means within the weighing unit; and
wherein the objects to be weighed which have been discharged from the first
collecting hopper and from the second collecting hopper belonging to the same weighing
unit are fed to the same packaging machine inlet, and the objects to be weighed which
have been discharged from the first collecting hopper and from the second collecting
hopper belonging to different weighing units are fed to different packaging machine
inlets.
[8] The weighing system according to claim 6,
wherein a total number of the weighing units is an even number;
wherein the combination calculation means in each of the weighing units is
configured to perform a combination process in which combination calculation is

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performed based on the weights of the objects to be weighed which have been fed to the
combination hoppers within the weighing unit to determine two combinations which do
not include the same combination hoppers and in which combination weight values
obtained in the combination calculation are within an allowable range with respect to a
target weight value and to determine the two combinations as the first discharge
combination and the second discharge combination;
wherein the control means in each of the weighing units is configured to perform
an internal discharge process for causing the combination hoppers making up of the first
discharge combination determined by the combination calculation means within the
weighing unit and the combination hoppers making up of the second discharge
combination determined by the combination calculation means to discharge the objects to
be weighed simultaneously, and an external discharge process for causing the first
collecting hopper and the second collecting hopper to discharge the objects to be
weighed simultaneously;
wherein two weighing units including combination hopper lines arranged adjacent
each other are predetermined as a pair unit, the objects to be weighed which have been
discharged from one of the first collecting hopper and the second hopper of the
weighing units forming the pair unit are fed to one of a pair of packaging machine inlets
corresponding to the pair unit, and the objects to be weighed which have been discharged
from the other collecting hopper are fed to the other packaging machine inlet; and
wherein each of the weighing units is configured to repeatedly perform a series of
processes including the combination process, the internal discharge process and the
external discharge process, with a time difference of substantially 1/2 of one operation
cycle time that lapses from when an external discharge process in the weighing unit is
terminated until a subsequent external discharge process in the weighing unit starts, the
time difference being set between the two weighing units forming the pair unit.
[9] The weighing system according to claim 8,

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wherein the combination calculation means in each of the weighing units is
configured to perform:
a first process in which the combination calculation is performed based on the
weights of the objects to be weighed which have been fed to the combination hoppers
within the weighing unit to determine, as optimal combinations, combinations made up
of combination hoppers in which combination weight values are within the allowable
range with respect to the target weight value, and to determine optimal combination sets
each of which is formed by combining two optimal combinations which do not include
the same combination hoppers; and
a second process in which for each of the optimal combination sets, a total of
absolute values of differences between combination weight values of the optimal
combinations included in the optimal combination set and the target weight value are
calculated to select one optimal combination set in which the total of the absolute values
of the differences is smallest, and one of two optimal combinations included in the
selected optimal combination set is determined as the first discharge combination and the
other optimal combination is determined as the second discharge combination.
[10] The weighing system according to claim 8,
wherein the combination calculation means in each of the weighing units is
configured to perform:
a first process in which the combination calculation is performed based on
weights of the objects to be weighed which have been fed to the combination hoppers
within the weighing unit to determine, as allowable combinations, combinations made up
of combination hoppers in which combination weight values are within the allowable
range with respect to the target weight value, m (m: plural number) allowable
combinations are selected, as first optimal combinations, from the allowable
combinations, by giving priority to allowable combinations in which absolute values of
differences between combination weight values and the target weight value are smaller,

84
one allowable combination is selected as a second optimal combination from allowable
combinations made up of combination hoppers obtained by excluding the combination
hoppers belonging to each of the first optimal combinations, and m optimal combination
sets each of which is made up of corresponding first and second optimal combinations
are determined; and
a second process in which for each of the optimal combination sets, a total of
absolute values of differences between combination weight values of the first and second
optimal combinations and the target weight value is calculated to select one optimal
combination set in which the total of the absolute values of the differences is smallest,
one of the first and second optimal combinations included in the selected optimal
combination set is determined as the first discharge combination and the other of the first
and second optimal combinations is determined as the second discharge combination.
[11] The weighing system according to claim 8,
wherein the combination calculation means in each of the weighing units is
configured to perform:
the combination calculation based on the weights of the objects to be weighed
which have been fed to the combination hoppers within the weighing unit to determine,
as allowable combinations, combinations made up of the combination hoppers in which
combination weight values are within the allowable range with respect to the target
weight value, to select as a first optimal combination one allowable combination in
which an absolute value of difference between a combination weight value and the target
weight value is smallest, from the allowable combinations, to select one allowable
combination as a second optimal combination from allowable combinations made up of
combination hoppers obtained by excluding the combination hoppers belonging to the
first optimal combination, by giving priority to allowable combinations in which absolute
values of differences between combination weight values and the target weight value are
smaller, and to determine that one of the first and second optimal combinations is the

85
first discharge combination and the other of the first and second optimal combinations is
the second discharge combination.
[12] The weighing system according to claim 6,
wherein the combination calculation means in each of the weighing units is
configured to perform a combination process in which combination calculation is
performed based on the weights of the objects to be weighed which have been fed to the
combination hoppers within the weighing unit to determine two combinations which do
not include the same combination hoppers and in which combination weight values
obtained in the combination calculation are within the allowable range with respect to the
target weight value, one of the two combinations is determined as the first discharge
combination and the other of the two combinations is determined as the second discharge
combination;
wherein the control means in each of the weighing units is configured to perform
an internal discharge process for causing the combination hoppers making up of the first
discharge combination determined by the combination calculation means within the
weighing unit and the combination hoppers making up of the second discharge
combination determined by the combination calculation means to discharge the objects to
be weighed simultaneously, and an external discharge process for causing the first
collecting hopper and the second collecting hopper to discharge the objects to be
weighed simultaneously; and
wherein the plurality of weighing units are configured to perform a series of
processes including the combination process, the internal discharge process and the
external discharge process at the same timings, and to feed the objects to be weighed
which have been discharged simultaneously from the first collecting hopper and from the
second collecting hopper of the plurality of weighing units to different packaging
machine inlets.

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[13] The weighing system according to claim 6,
wherein the combination hopper line of the plurality of weighing units includes
two lines which are upper and lower combination hopper lines, combination hoppers
forming the upper combination hopper line are weighing hoppers which weigh weights
of the objects to be weighed which have been fed to the weighing hoppers, combination
hoppers forming the lower combination hopper line are memory hoppers which are
provided to respectively correspond to the weighing hoppers and are fed with the objects
to be weighed which have been weighed in the weighing hoppers; the weighing hoppers
are each configured to be able to discharge the objects to be weighed selectively to the
corresponding memory hopper or to the outer chute, and the memory hoppers are each
configured to be able to discharge the objects to be weighed selectively to the inner chute
or to the outer chute; and
wherein the combination calculation means in each of the weighing units is
configured to determine a first discharge combination such that a weighing hopper and a
corresponding memory hopper are included in the first discharge combination when the
weighing hopper is selected to make up of the first discharge combination.

A combination weigher of the present invention comprises a first combination
weigher unit including a left inner chute (6a), an outer chute (7a), collecting hoppers (8a,
9a), weighing hoppers (4) and memory hoppers (5) which are disposed above the left
chutes (6a, 7a), and a second combination weigher unit including a right inner chute (6b),
an outer chute (7b), collecting hoppers (8b, 9b), weighing hoppers (4) and memory
hoppers (5) which are disposed above the right chutes (6b, 7b), and a control unit (20)
configured to control the entire combination weigher. The control unit (20) performs a
combination process for each combination weigher unit and causes weighing hoppers (4)
and memory hoppers (5) which make up of discharge combinations determined in
respective combination processes to discharge the objects to be weighed in an inward
direction and an outward direction alternately, and to cause the two collecting hoppers to
alternately discharge the objects to be weighed according to the discharge, in each
combination weigher unit.

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Patent Number 270629
Indian Patent Application Number 1937/KOLNP/2008
PG Journal Number 02/2016
Publication Date 08-Jan-2016
Grant Date 05-Jan-2016
Date of Filing 14-May-2008
Name of Patentee KAWANISHI SHOZO
Applicant Address 7-39, KURAKUEN YONBAN-CHO NISHINOMIYA-SHI, HYOGO
Inventors:
# Inventor's Name Inventor's Address
1 KAWANISHI SHOZO 7-39, KURAKUEN YONBAN-CHO, NISHINOMIYA-SHI, HYOGO 662-0088
PCT International Classification Number G01G 19/387
PCT International Application Number PCT/JP2006/324549
PCT International Filing date 2006-12-08
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2005-358515 2005-12-13 Japan
2 2006-043524 2006-02-21 Japan