Title of Invention

MOLDING DEVICE

Abstract A molding device, comprising a first molding tool (10) a link motion control element (12) to and moving said molding tool between an opening position and a closing position, said ink motion control element having a rotation body (26) with a slot guide (24) on an external circumferential side thereof, having an actuating member (30) engaged by said slot guide and having a slide component (32) operable in conjunction with said actuating member, rotation of said slot guide from one end area to another end area and vice versa displacing said slide component and said molding tool by longitudinal displacement of said actuating member between said opening and closing positions of said molding tool; a drive (14) coupled to and actuating said rotation body; and adjusting means (44) on said slide component for varying a maximum closing force of said molding tool, each of said adjusting means being an energy accumulator.
Full Text FIELD OF THE INVENTION:
The invention relates to molding devices in general and to a molding device for forming
plastic containers in particular.
BACKGROUND AND PRIOR ART:
Processes and molding devices for production of containers are known in the prior art (DE
199 26 329 A1, US 3,883,186 and US 3,877,861), ones in which a hose of plasticized plastic
material is extruded into a molding mechanism, one end of the hose is closed by heat sealing and
the hose is expanded by generation of a pneumatic pressure gradient acting on the hose and
applied to the molding wall of the molding mechanism consisting of two opposite molding tools
for form the container. The plastic container is then filled under sterile conditions into the
molding mechanism by way of an appropriate charging mandrel and, after the charging mandrel
has been removed, is hermetically sealed, a specific head geometry being formed. For the
purpose of forming the plastic container proper, in which fluid is later stored, two container
molding jaws may be moved toward each other by hydraulic drive means in order to obtain a
closing position and away from each other into one of their opening positions.
The head geometries to be generated by the two separately actuatable head jaws regularly
also comprise the neck component of the plastic container, including one in the form of ampules,
which, closed by a head piece by way of a separation point, may be opened for a fluid removal
process as soon as the head piece is separated by way of a separation point from a toggle piece
molded on it and in this way removed from the plastic container proper.
Such processes have been disclosed in a plurality of embodiments and are widely used in
packing systems for liquid or paste products, for example, in the disclosed bottlepack 7 system
The hydraulic drive systems regularly employed in practical applications for the respective
feed movement of the molding tool present problems in that any leakage may result in fouling
with the fluid, something which results in problems especially when the molding machines are
used for plastic containers in the pharmaceutical and food packaging spheres and in medical
technology in general. The maintenance cost is also increased and the hydraulic drive systems do
not reach the desired or high cycle frequencies for mass production for the sake of precise
positioning; of the molding tools for shaping of containers.
OBJECT OF THE INVENTION:
On the basis of this prior art the object of the invention is to create a molding device for moving
at least one molding tool, a tool making it possible to apply modern drive concepts, such as ones
in the form of electric or pneumatic drives, the maintenance cost of which is reduced and which
permit especially high rates of output of goods to be produced, such as plastic containers, along
with high positioning accuracy for the molding tools. The object as thus formulated is attained by
means of a molding device with the characteristics as disclosed hereunder.
DESCRIPTION OF THE INVENTION:
In the molding device claimed for the invention a link motion control element is provided for
moving at least one molding tool, especially one for generation of container geometries in plastic
containers; this element moves the respective molding tool to a closing position at least for mold,
the link motion control element being actuatable by a drive. On the basis of the link motion
control element a novel drive and movement concept is presented for the respective molding
tool, one which makes it possible to dispense with hydraulic drive means entirely and by
preference to employ an electric or pneumatic drive as the drive means. The link motion control
element in question may, however, continue to be actuated conventionally by
means of a hydraulic drive if the respective application appears to call for it and rigid
requirements have not been set for sterile filling or clean room qualities.
The molding device claimed for the invention with drivable link motion control element
for a closing movement with the molding device permits uniform, safe, and position-accurate
driving of the respective molding tool and entails only a minor maintenance effort. The link
motion control elenent may be employed to execute a plurality of opening and closing processes
in rapid sequence; with the molding device claimed for the invention this results in high output
of goods to be produced, in particular those in the form of blow-molded plastic containers filled
under sterile conditions.
In one pref srred embodiment of the device claimed for the invention the link motion
control element has a slot guide positioned on the exterior circumference on a body of rotation
actuatable by a drive. By preference provision is also made such that there is engaged in the slot
guide an actuating member which operates in conjunction with a slide component and such that,
during rotation of he slot guide from one of its end positions to its other end position and vice
versa, the slide component with molding tool which may be associated with it may be displaced
with the molding tool by way of the actuating member which my be moved longitudinally in this
manner from a closing position to an opening position of the mold shaped by the respective
molding tool and vice versa. Safe and precise positioning control is achieved as a result, along
with clearly defined specific closing forces specified by the link motion control element.
In another especially preferred embodiment of the molding device claimed for the
invention, the max imum closing force for the molding tool may be specified by way of central
adjusting means on the slide component means preferably in the form of an energy accumulator.
Pressure spring elements, such as ones in the form of disk springs or the like, are suitable for use
as energy accumulators. Independently of the closing force of the link motion control element
which is applied, this force may be appreciably limited, and the reliability of shaping thereby
increased, by way of the adjusting means. It has been found in configuration of the molding
device to be especially cost-effective to mount the body of rotation together with the drive so as
to be stationary on a machine frame in relation to which the slide component may move back and
forth along its rail guide. A rigid machine configuration is achieved for the slide component and
for the molding device as a whole and obstacles in operation are reliably eliminated on the basis
of the rail guide in question.
In another especially preferred embodiment of the molding device claimed for the
invention, the molding tools mounted opposite each other may be moved by a single link motion
control element syachronously by way of a common driving component. By preference
provision is also rrade such that at least four link motion control elements positioned in pairs,
one opposite the ether, may be driven by gearing actuatable by the drive and the common drive
component. As a result, a total of four molding tools with mold geometries mounted in sequence
may be actuated in pairs operating together synchronously for shaping and mold opening
processes in order to produce several container geometries.
In one preferred embodiment provision is also made as protection from collision such
that a monitoring i ssembly monitors the position of the link motion control element, at least with
respect to the position of the molding tool in its closing position, but preferably also in its
opening position.
It has also been found to be favorable for obstacle-free operation in one preferred
embodiment of the molding device claimed for the invention for the path equation for the slot
guide of the body of rotation to be executed as a Bestehom sinoid.
The device claimed for the invention will be described in detail below with reference to
an exemplary embodiment illustrated in the drawing, in which not drawn to scale
Brief description of the accompaying drawing:
FIG. 1 presents a top view of the molding device as a whole;
FIG. 2 an enlarged section of FIG. 1 representing the upper left segment of the latter;
FIG. 3 the development of the path geometry of a link motion control element mounted
on a body of rotation and having slot guides such as the path geometry applied in
the nolding device shown in FIGS. 1 and 2.
First a part of the molding device as a whole for moving a molding tool 10 will be
described with reference to the upper left segment of the illustration in FIG. 1 and FIG. 2. On its
free front side the molding tool 10 has trough-like recesses (not shown) which form mold halves
for generation of container geometries for plastic containers (not shown), including ones in the
form of ampules. For the purpose of generating the respective container geometries the molding
tool 10 operates in conjunction with a corresponding molding tool 10a with correspondingly
shaped recesses (not shown), the two molding tools 10, 10a being in the closed molding position
shown in FIG. 1, in which position the free front surfaces of the molding tools 10, 10a meet
along a closing separation line I -I.
For the purpose of moving the respective molding tool 10, 10a use is made of a link
motion control element designated as a whole as 12 which may be driven by means of a centrally
mounted drive 14. For the sake of simplicity there is shown in FIG. 1 only the spline shaft of the
drive which may be coupled to the driven shaft of an electric motor, such as one in the form of
an electric stepping; motor, and permits driving of the link motion control element 12. For this
purpose the spline shaft 14 is rotatably mounted by way of bearings 16 in a machine frame 18
and has a drive gear 20 on its one free side facing the molding tool 10. The drive gear 20 in
question meshes with a driven gear 22 of the link motion control element 12. The link motion
control element 12 has a slot guide 24 which is positioned on the external circumference side on
a body of rotation 26 which may be powered by drive 14 and which is essentially cylindrical in
configuration. The respective slot guide 24 has two path or curve segments 28 resulting from
development of the body of rotation 26 as show in FIG. 3. The respective path curve of a curve
segment 28 obeys a path equation for a Bestehorn sinoid. The respective body of rotation 26
with its path curve segments 28 need not be configured to be identical for the molding tool 10a to
the body of rotation 26 for the molding tool 10. In this instance slight adaptations may be
necessary with respect to the control curve pattern. However, the bodies of rotation 26 of the
two mold halves 10, 10a are in other respects essentially the same.
An actuating member 30 in the form of a cam follower engages the slot guide 24 with its
two path curve segments 28. The actuating member 30 in question is mounted rotatably on
opposite sides of a slide component 32 so that, as the body of rotation 26 with its slot guide 24
rotates, uniform advance in the direction of closing of the molding tools 10, 10a is ensured, along
with uniform reset) ing movement into a corresponding opening position, the respective rearward
position being indicated by a broken-line circle at the top left in FIG. 1 and in FIG. 2. When the
slot guide 24 rotates from one of its end areas 34 to the other end area 36 of a path curve segment
28, the slide component 32 may be displaced longitudinally in one direction of movement and in
the other direction when the body of rotation rotates in the opposite direction. Consequently, the
maximum path of travel which may be reached for the slide component 32 thus is determined by
the longitudinal axial distance between the end areas 34, 36 opposite each other of two different
path curve segment 28 of a slot guide 24 of a body of rotation 26.
The slide component 32 has on its frontal side facing the molding tool 10 a guide
component 38 on which the respective molding tool 20 may be mounted so as to be replaceable
and on the edge side the guide component 38 is mounted so that it may be displaced axially in
the longitudinal direction along two rail guides 40, the ends of the rail guides ,40 being
appropriately mounted in the machine frame 18. In addition, the guide component 38 is retained
so that it may be displaced longitudinally in a displacement component 42 of the slide
component in a dirjction in parallel with the rail guides 40, the displacement component 42
resting on adjusting means 44 in the form of a disk spring package which functions as a
compression spring. In this way the maximum closing force for the molding tool 10 may be
determined by way of the adjusting means 44 so that a reliably operating shaping process is
made possible.
In the line c of sight to FIG. 1 a drive component 46 in the form of a drive shaft is mounted
at the top in paralle 1 with the upper rail guide 40. At both ends of the drive shaft 46 a crown gear
48, 48a is connected to this shaft, so that, as the body of rotation 26 moves by way of the drive
shaft 14, the driven gear 22 meshes with the crown gear 48, thereby driving the drive shaft 46,
which in turn trans nits the driving power by way of the crown gear 48a on the opposite side to
the following driven gear 22 of the body of rotation 26 following in the drive chain.
Consequently, the molding tools 10, 10a mounted opposite each other may be actuated and
moved in pairs by a single link motion control element 12 with drive 14, by way of the common
drive component 46. Hence, molding tools 10, 10a move synchronously into their opening
position and into treir closing position along the closing separation line I -I.
As is also to be seen in the illustration in FIG. 1, four link motion control elements 12
positioned opposite: each other in pairs may thus be actuated in the drive direction appropriate for
back-and-forth movement of the slide components 32 of the molding device by way of the gears
operated by the drive 14 and consisting of gears 20, 22 and 48, 48a. The respective drive is very
accurate and permits precise positioning of the respective molding tool 10, 10a for a molding
process. In addition, the molding tools 10 opposite each other in one line may be connected to
each other on one side, but may also be separated from each other, that which has been stated
also applying correspondingly to molding tools 10a mounted opposite each other.
As is also to be seen in FIG. 2, a monitoring assembly 50 is provided. It is spring-loaded
and may be displaced longitudinally from its locking position illustrated in FIG. 2 into a release
position, preferably from the exterior by way of an actuator, in particular one in the form of a
pneumatic cylinder or the like. The body of rotation 26 accordingly has on the external
circumference side a first recess 52 which corresponds to the closing position of the molding
tools 10, 10a. If looking occurs in this locking position, that is, if parts of the monitoring
assembly 50 are engaged in the associated recess 52 in the body of rotation 26, it is made certain
that a locking position has been assumed along the closing separation line I -I by the molding
tools 10, 10a and flat the machine control unit then recognizes that a reliable molding process is
possible. If as a result of an error the position in question is not assumed, the monitoring
assembly 50 ascertains this and the molding process could be halted without damage to the
molding device. The reset opening position area for the molding tools 10, 10a may also be
monitored synchronously by way of the monitoring assembly 50, by means of a recess (not
shown) positioned diametrically opposite recess 52. In addition, the drive shaft 46 is mounted on
the end side so as to be rotatable, by way of additional bearings 54 in the machine frame 18.
The configuration of the molding device as described makes it possible to reach very high
cycle speeds in production of molded containers of a plastic material, along with very high
machining accuracy, in view of the specifiable accuracy of positioning of the molding tools 10,
10a, with respect both to their closing position and to movement apart into their opening position
for the production mold. The molding device is very rigidly configured from the viewpoint of its
structural design, so that precise actuation of the moving parts is ensured, while the molding
device may be very cost-effectively produced and maintained because of the equivalent parts
employed.
I CLAIM:
1. A molding device, comprising:
a first molding tool (10);
a link motion control element (12) to and moving said molding tool between
an opening and a closing position, said link motion control element
having a rotation body (26) with a slot guide (24) on an external
circumferential side thereof, having an actuating member (30) engaged
by said slot guide and having a slide component (32) operable in
conjunction with said actuating member, rotation of said slot guide
from one end area to another end area and vice versa displacing said
slide component and said molding tool by longitudinal displacement of
said actuating member between said opening and closing positions
of said molding tool;
a drive (14) coupled to and actuating said rotation body; and adjusting means
(44) on said slide component for varying a maximum closing force of said
molding tooi; each of said adjusting means being an energy accumulator.
2. A molding device as claimed in claim 1, wherein said rotation body is
mounted stationary with said drive on a machine frame (18) relative to said
slide component; and said slide component is movable back and forth
along rail guide (40).
3. A molding device as claimed in claim 1, wherein a second molding tool
(10a) is mounted opposite said first molding tool and is coupled to and
moved by a second link motion control element synchronously by a
common drive component as a pair with said first molding tool.
4. A molding device as claimed in claim 3, wherein third and fourth
molding tools are mounted opposite one another and are coupled to and
moved as a pair by third and fourth link motion control elements,
respectively synchronously by gearing operated by said drive and said
common drive component with said first and second molding tools.
5. A molding device as claimed in claim 1, wherein a monitoring assembly
(50) is coupled to said link control element to monitor positions thereof
relative to positioning of said molding tool in said closing position.
6. A molding device as claimed in claim 1, wherein said guide slot
extends along a path defined by a Bestehom sinoid.
7. A molding device as claimed in claim 1, wherein said drive is stepping
electric motor.
8. A molding device as claimed in claim 1, comprising first and second
molding tools (10,10a) mounted opposite one another as a first pair; third
and fourth molding tools mounted opposite one another as a second
pair;
first and second link motion control elements coupled to and moving said
first and second molding tools, respectively, opposite each other as said
first pair synchronously between opening positions and closing positions;
third and fourth link motion control elements coupled to and moving said
third and fourth molding tools, respectively, opposite each other as said
second pair synchronously between opening positions and closing
positions;
a drive and a common drive component coupled to and actuating by
gearing said link motion control element.
9. A molding device as claimed in claim 8, wherein each said link motion
control element has a rotation body with a slot guide on an external
circumferential side thereof.
10. A molding device as claimed in claim 9, wherein an actuating member
is engaged by each said slot guide and has a slide component operable in
conjunction with each said actuating member, rotation of each said slot
guide from one end area to another end area and vice versa displacing
the respective slide component and the respective molding tool by
longitudinal displacement of the respective actuating member between said
opening and closing positions of the respective molding tool.
11. A molding device as claimed in claim 8, wherein said rotation bodies
are mounted stationary with said drive on a machine frame (13) relative to
said slide components; and
each said slide component is movable back and forth along a rail guide (40).
12. A molding device as claimed in claim 8, wherein said guide slot
extends along a path defined by a Bestehorn sinoid.
13. A molding device as claimed in claim 8, wherein said drive is a
stepping electric motor.
14. A molding device, comprising:
a first molding tool;
a link motion control element coupled to and moving said molding tool
between an opening position and a closing position, said link motion
control element having rotation body with a slot guide on an external
circumferential side thereof, said guide slot extending along a path defined
by a Bestehorn sinoid; and
a drive coupled to and actuating said rotation body.
15. A molding device as claimed in claim 14, wherein an actuating
member is engaged by said slot guide and has a slide component
operable in conjunction with said actuating member, rotation of said slot
guide from one end area to another end area and vice versa displacing said
slide component and said molding tool by longitudinal displacement of said
actuating member between said opening and closing positions of said
molding tool.
16. A molding device as claimed in claim 14, wherein said rotation body is
mounted stationary with said drive on a machine frame relative to said slide
component; and
said slide component is movable back and forth along a rail guide.
17. A molding device as claimed in claim 14, wherein a monitoring
assembly is coupled to said link control element to monitor positions
thereof relative to positioning of said molding tool in said closing
position.
18. A molding device as claimed in claim 14, wherein said drive is a
stepping electric motor.
A molding device, comprising a first molding tool (10) a link motion control
element (12) to and moving said molding tool between an opening position
and a closing position, said ink motion control element having a rotation
body (26) with a slot guide (24) on an external circumferential
side thereof, having an actuating member (30) engaged by said slot
guide and having a slide component (32) operable in conjunction with
said actuating member, rotation of said slot guide from one end area
to another end area and vice versa displacing said slide component and
said molding tool by longitudinal displacement of said actuating
member between said opening and closing positions of said molding tool;
a drive (14) coupled to and actuating said rotation body; and adjusting
means (44) on said slide component for varying a maximum closing force of
said molding tool, each of said adjusting means being an energy accumulator.

Documents:


Patent Number 223800
Indian Patent Application Number 01754/KOLNP/2005
PG Journal Number 39/2008
Publication Date 26-Sep-2008
Grant Date 23-Sep-2008
Date of Filing 05-Sep-2005
Name of Patentee HANSEN, BERND
Applicant Address TALSTRASSE 22-30, 74429, SULZBACH-LAUFEN
Inventors:
# Inventor's Name Inventor's Address
1 HANSEN, BERND TALSTRASSE 22-30, 74429, SULZBACH-LAUFEN
PCT International Classification Number B29C 49/56
PCT International Application Number PCT/EP2004/000531
PCT International Filing date 2004-01-23
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 103 17 711.6 2003-04-17 Germany