Title of Invention	A SPINNING MACHINE WITH MEANS FOR CONTACTLESS MONITORING AND MEASURING OF LOW PRESSURE
Abstract	Described is a spinning machine having a plurality of spinning positions, each of which comprises a vacuum-operated condensing zone for condensing a fibre strand. The low pressure is generated by a number of fans, whereby each of the fans are arranged to a number of spinning positions. Each fan comprises a monitoring device, which monitors an operating parameter of the fan relating to the low pressure. The operating parameter monitored by the monitoring device is the rotational fan speed, which can be measured by non-contact operating sensors.

Title of Invention

A SPINNING MACHINE WITH MEANS FOR CONTACTLESS MONITORING AND MEASURING OF LOW PRESSURE

Abstract

Described is a spinning machine having a plurality of spinning positions, each of which comprises a vacuum-operated condensing zone for condensing a fibre strand. The low pressure is generated by a number of fans, whereby each of the fans are arranged to a number of spinning positions. Each fan comprises a monitoring device, which monitors an operating parameter of the fan relating to the low pressure. The operating parameter monitored by the monitoring device is the rotational fan speed, which can be measured by non-contact operating sensors.

Full Text	2 BACKGROUND AND SUMMARY OF THE INVENTION Spinning machine having a number of spinning positions The present invention relates to a spinning machine having a plurality of spinning positions, each of which comprises a vacuum-operated condensing zone for condensing a fibre strand, also comprising a number of fans which generate the low pressure and which are arranged to a number of spinning positions, whereby each fan comprises a monitoring device, to which an operating parameter of the fan relating to the low pressure is assigned. A spinning machine of this type is prior art in German published patent application 103 48 225 A1. In the case of this spinning machine, each fan is driven by a drive belt, whose tension level is an indicator of sufficient low pressure. A tension roller is assigned to each drive belt, which, in the case of a decrease in tension, changes its position in the drive belt, thus activating a switch. The known arrangement is based on previous findings that the power consumption of a fan is proportional to the drawn out volume flow. In the case of a blockage in the components carrying the suction air, a lower volume flow is drawn out, which results in reduced power consumption and thus inevitably to a reduction in the tension of the respective drive belt. Experience in the field has shown that clogging, however, often does not occur in the components carrying the suction air to the fan, but rather in the fans and in particular at the fan wheel itself. Clogging of this kind results in sluggish running of the fan wheel, which is not recognized by the known monitoring device because the power consumption of the fan does not decrease and therefore the tension of the drive belt does not decrease. It is an object of the present invention to create a monitoring device for a fan of a spinning machine of the above mentioned type, which monitoring device can detect a drop in low pressure in the condensing zone caused by the sluggish running of the fan wheel. This object has been achieved in that the parameter monitored by the monitoring device is the rotational fan speed. 3 The present invention is based on previous findings that in the case of clogging in the fan or at the fan wheel itself, the fan shaft becomes sluggish and can only be rotated by applying increased levels of power. The fan shaft is slowed down and the volume flow drawn out by the fan wheel decreases. The required level of low pressure is therefore no longer present in the condensing zone. The monitoring of the fan speed according to the present invention is not only suitable for belt-driven fans, but also for single motor-driven fans. Such single motor-driven fans are known in German patent application 199 33 747 A1. In addition to the advantage of being able to detect sluggish running of the fan wheel, the monitoring device according to the present invention can also establish if there is clogging in the components carrying the suction air to the fan. In the case of such clogging, a decrease in fan speed is not the cause of a lower volume flow, but rather a decrease in cross section caused by the clogging. The decreasing volume flow effects a reduced power consumption of the fan, whereby the fan speed increases, in particular in the case of single motor-driven fans. A monitoring of the fan speed is significantly simpler to carry out than a direct measuring and monitoring of the low pressure, as low pressure sensors are complicated to adjust. It is advantageous to equip the monitoring device with sensors, which can monitor the fan speed without contact and thus without any additional friction losses. These sensors can hereby be assigned to the fan wheel or to the fan shaft. If the sensors are assigned to the fan shaft, it is advantageous to arrange to the monitoring device a signal transmitter which is stationarily fixed to the fan shaft, which signal transmitter generates a signal which changes proportionally in relation to the fan speed. BRIEF DESCRIPTION OF THE DRAWINGS These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings wherein: Figure 1 is a partly intersectional side view of a drafting unit of a spinning position comprising a condensing zone arranged thereto, and also comprising a fan 4 generating a low pressure and driven by drive belts, together with a monitoring device, Figure 2 is a view in the direction of the arrow II of Figure 1 of the condensing zones of a number of spinning positions each belonging to one suction channel and one fan, whereby several components, in particular the drafting unit, are omitted. The spinning machine, preferably a ring spinning machine, shown only partly in Figures 1 and 2, consists of a number of machine sections 1, 2 arranged in machine longitudinal direction. To such a machine section 1, 2, four spinning positions 3 to 6, for example, are arranged, whereby the number of spinning positions can be much larger. A known drafting unit 7 is provided for each spinning position, to which a condensing zone 8 is arranged downstream thereof, the design of which said condensing zone being optional. Each drafting unit 7 comprises a number of roller pairs, in the present case three roller pairs 9, 10 and 11, which comprise in the known way a driven lower cylinder extending in machine longitudinal direction as well as a pressure roller arranged to each spinning position. A sliver or roving 12 is fed to each drafting unit 7 in feed direction A, which sliver or roving 12 is then drafted to the desired degree of fineness. Directly downstream of the last roller pair 11, the so-called front roller pair of the drafting unit 7, a drafted but still twist-free fibre strand 13 is present. This fibre strand 13 travels through the above mentioned condensing zone 8 and is hereby bundled, so that the fibre strand 13 is narrower and less hairy with overall improved utilization of material, which results ultimately in a greater tensile strength. The condensing zone 8 is bordered by a nipping line 14 on its exit side, from which nipping line 14 onwards the thread to be spun receives its spinning twist. The thread 15 is fed in delivery direction B to a twist device (not shown) for example a ring spindle. The nipping line 14 acts as a twist block in relation to the spinning twist. A profile tube 15 is arranged to the condensing zones 8 of a number of spinning positions 3 to 6, which profile tube 16 extends along a machine section 1 and forms a suction channel. On the upper side of the profile tube 16, one suction slit 17 is 5 applied per spinning position 3 to 6, which suction slit 17 extends essentially in transport direction of the fibre strand 13 and reaches almost to the nipping line 14. As can be seen in Figure 2, a profile tube 16 is also arranged to the machine section 2. In each spinning position, a relatively narrow transport belt 18 is assigned to the respective condensing zone 8, which transport belt 18 covers the suction slit 17 and is designed to be air-permeable. The transport belt 18 can advantageously be a thin woven belt having very fine pores. The profile tube 16 is designed on its outer contour as a sliding surface for the transport belt 18, whereby the latter surrounds the profile tube 16 closely and runs on the profile tube 16. A nipping roller 19 serves to drive the transport belt 18, which nipping roller 19 forms, together with the profile tube 16, the nipping line 14 mentioned above. The nipping roller 19 is driven in a way not shown and drives in turn the transport belt 18 by means of friction. Each profile tube 16 comprises a suction opening 20, so that one suction opening 20 is available per machine section 1, in the present case for the spinning positions 3 to 6. The profile tube 16 is connected to a flexible suction tube or suction conduit 21. One fan 22 is arranged to each suction conduit 21, which generates the required vacuum. The individual fans 22 are each driven by means of a drive belt 24. One drive pulley 25 is provided per machine section 1, 2 for the drive belt 24. The individual drive pulleys 25 are affixed to a drive shaft 26 which extends continuously in machine longitudinal direction and is driven, for example, from the headstock of the spinning machine. A spring-loaded tension roller 32 can hereby be arranged to each drive belt 24. It has already been explained that the condensing of the individual fibre strands 13 serves to improve the quality of the spun thread 15. A prerequisite of this process is that the condensing effect on the fibre strands 13 at the individual condensing zones 8 is identical. As the condensing zones 8 operate with low pressure, it is of great importance that the low pressure at the individual condensing zones 8 remains as constant as possible, and in particular, does not decrease. A decrease in low pressure at a condensing zone 8 can occur, for example when in the area of one of 6 the components conveying the suction air from the condensing zone 8 to the fan 22, for example the profile tube 16 or the suction conduit 21, clogging occurs and the drawn out volume flow decreases. Very often a blockage occurs in the fan 22 itself. Dust and fibre ends can hereby become deposited in between the fan wheel and the housing of the fan 22 and thus result in sluggish running of the fan wheel. The fan wheel can no longer move freely and comes into contact with the trash deposits when it passes by. The fan wheel is slowed down and its rotational speed decreases. The reduced fan speed reduces the fan's suctioning capacity, and this leads to a reduced low pressure in the condensing zones 8. For this reason a monitoring device 27 is arranged to each fan, which monitoring device 27 can be activated in order to avoid an operational disturbance due to insufficient low pressure in the condensing zone 8. It is provided in accordance with the present invention that the monitoring device 27 monitors the fan speed. A deviation from the nominal fan speed is hereby always an indication that the level of low pressure in the condensing zone 8 has changed. The rotational speed of the fan is thus an indicator of the level of low pressure. Every change in speed can be analysed by a control device 28 and the relevant measures taken. These measures can range from switching on a warning signal for the attention of a machine operator, to shutting down the relevant spinning position via the control device 28. It is hereby advantageous when the monitoring device 27 comprises sensors 29 which monitor the fan speed without contact, said sensors 29 being connectable to the control device 28. The control device 28 comprises hereby a set value for the fan speed and compares this constantly with the actual value delivered by the sensor 29. It is advantageous when a signalling device 30 is assigned to the control device 28, which signalling device 30 can be designed in the form of warning lights or light emitting diodes which signal the current operational status to the machine operator. It can hereby be advantageous, depending on the dimensions of the deviations between the actual value and the set value, for the signalling device 30 to give different warnings. For example, in the case of a minimal drop below the set value, a yellow warning signal could be given, while in the case of increasing blockage and drop in the fan speed below an adjustable limit, a red warning light could be given. The machine operator can then react and take steps accordingly to eliminate the fault. Correct fan speed could be shown by means of a green light. 7 It can be provided that each fan 22 comprises a control device 28 and a signalling device 30. Alternatively, a central machine control system, to which a central signalling device is assigned, can just as well carry out the monitoring of the fans 22. In an embodiment of the present invention it is provided that a signal transmitter 31 stationarily fixed to the fan shaft 23, is assigned to the monitoring device 27. The assessment of the fan speed by the sensor 29 is made possible in a simple way. 8 CLAIMS: 1. A spinning machine having a plurality of spinning positions (3, 4, 5, 6) each of which comprises a vacuum-operated condensing zone (8) for condensing a fibre strand (13), also comprising a number of fans (22) which generate the low pressure and which are arranged to a number of spinning positions (3, 4, 5, 6), whereby each fan (22) comprises a monitoring device (27), to which an operating parameter of the fan relating to the low pressure is assigned, wherein the parameter monitored by the monitoring device (27) is the rotational fan speed. 2. A spinning machine according to claim 1, characterized in that the monitoring device (27) comprises a sensor (29) which assesses the fan speed in a non- contact manner. 3. A spinning machine according to claim 1 and 2, characterized in that a signal transmitter (31), stationary fixed to the fan shaft (23), is assigned to the monitoring device (27).

Full Text

2 BACKGROUND AND SUMMARY OF THE INVENTION
Spinning machine having a number of spinning positions
The present invention relates to a spinning machine having a plurality of spinning positions, each of which comprises a vacuum-operated condensing zone for condensing a fibre strand, also comprising a number of fans which generate the low pressure and which are arranged to a number of spinning positions, whereby each fan comprises a monitoring device, to which an operating parameter of the fan relating to the low pressure is assigned.
A spinning machine of this type is prior art in German published patent application 103 48 225 A1. In the case of this spinning machine, each fan is driven by a drive belt, whose tension level is an indicator of sufficient low pressure. A tension roller is assigned to each drive belt, which, in the case of a decrease in tension, changes its position in the drive belt, thus activating a switch. The known arrangement is based on previous findings that the power consumption of a fan is proportional to the drawn out volume flow. In the case of a blockage in the components carrying the suction air, a lower volume flow is drawn out, which results in reduced power consumption and thus inevitably to a reduction in the tension of the respective drive belt.
Experience in the field has shown that clogging, however, often does not occur in the components carrying the suction air to the fan, but rather in the fans and in particular at the fan wheel itself. Clogging of this kind results in sluggish running of the fan wheel, which is not recognized by the known monitoring device because the power consumption of the fan does not decrease and therefore the tension of the drive belt does not decrease.
It is an object of the present invention to create a monitoring device for a fan of a spinning machine of the above mentioned type, which monitoring device can detect a drop in low pressure in the condensing zone caused by the sluggish running of the fan wheel.
This object has been achieved in that the parameter monitored by the monitoring device is the rotational fan speed.

3
The present invention is based on previous findings that in the case of clogging in the fan or at the fan wheel itself, the fan shaft becomes sluggish and can only be rotated by applying increased levels of power. The fan shaft is slowed down and the volume flow drawn out by the fan wheel decreases. The required level of low pressure is therefore no longer present in the condensing zone.
The monitoring of the fan speed according to the present invention is not only suitable for belt-driven fans, but also for single motor-driven fans. Such single motor-driven fans are known in German patent application 199 33 747 A1.
In addition to the advantage of being able to detect sluggish running of the fan wheel, the monitoring device according to the present invention can also establish if there is clogging in the components carrying the suction air to the fan. In the case of such clogging, a decrease in fan speed is not the cause of a lower volume flow, but rather a decrease in cross section caused by the clogging. The decreasing volume flow effects a reduced power consumption of the fan, whereby the fan speed increases, in particular in the case of single motor-driven fans.
A monitoring of the fan speed is significantly simpler to carry out than a direct measuring and monitoring of the low pressure, as low pressure sensors are complicated to adjust.
It is advantageous to equip the monitoring device with sensors, which can monitor the fan speed without contact and thus without any additional friction losses. These sensors can hereby be assigned to the fan wheel or to the fan shaft. If the sensors are assigned to the fan shaft, it is advantageous to arrange to the monitoring device a signal transmitter which is stationarily fixed to the fan shaft, which signal transmitter generates a signal which changes proportionally in relation to the fan speed.
BRIEF DESCRIPTION OF THE DRAWINGS
These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings wherein:
Figure 1 is a partly intersectional side view of a drafting unit of a spinning position comprising a condensing zone arranged thereto, and also comprising a fan

4
generating a low pressure and driven by drive belts, together with a monitoring device,
Figure 2 is a view in the direction of the arrow II of Figure 1 of the condensing zones of a number of spinning positions each belonging to one suction channel and one fan, whereby several components, in particular the drafting unit, are omitted.
The spinning machine, preferably a ring spinning machine, shown only partly in Figures 1 and 2, consists of a number of machine sections 1, 2 arranged in machine longitudinal direction. To such a machine section 1, 2, four spinning positions 3 to 6, for example, are arranged, whereby the number of spinning positions can be much larger.
A known drafting unit 7 is provided for each spinning position, to which a condensing zone 8 is arranged downstream thereof, the design of which said condensing zone being optional.
Each drafting unit 7 comprises a number of roller pairs, in the present case three roller pairs 9, 10 and 11, which comprise in the known way a driven lower cylinder extending in machine longitudinal direction as well as a pressure roller arranged to each spinning position.
A sliver or roving 12 is fed to each drafting unit 7 in feed direction A, which sliver or roving 12 is then drafted to the desired degree of fineness. Directly downstream of the last roller pair 11, the so-called front roller pair of the drafting unit 7, a drafted but still twist-free fibre strand 13 is present. This fibre strand 13 travels through the above mentioned condensing zone 8 and is hereby bundled, so that the fibre strand 13 is narrower and less hairy with overall improved utilization of material, which results ultimately in a greater tensile strength. The condensing zone 8 is bordered by a nipping line 14 on its exit side, from which nipping line 14 onwards the thread to be spun receives its spinning twist. The thread 15 is fed in delivery direction B to a twist device (not shown) for example a ring spindle. The nipping line 14 acts as a twist block in relation to the spinning twist.
A profile tube 15 is arranged to the condensing zones 8 of a number of spinning positions 3 to 6, which profile tube 16 extends along a machine section 1 and forms a suction channel. On the upper side of the profile tube 16, one suction slit 17 is

5
applied per spinning position 3 to 6, which suction slit 17 extends essentially in transport direction of the fibre strand 13 and reaches almost to the nipping line 14.
As can be seen in Figure 2, a profile tube 16 is also arranged to the machine section 2.
In each spinning position, a relatively narrow transport belt 18 is assigned to the respective condensing zone 8, which transport belt 18 covers the suction slit 17 and is designed to be air-permeable. The transport belt 18 can advantageously be a thin woven belt having very fine pores. The profile tube 16 is designed on its outer contour as a sliding surface for the transport belt 18, whereby the latter surrounds the profile tube 16 closely and runs on the profile tube 16. A nipping roller 19 serves to drive the transport belt 18, which nipping roller 19 forms, together with the profile tube 16, the nipping line 14 mentioned above. The nipping roller 19 is driven in a way not shown and drives in turn the transport belt 18 by means of friction.
Each profile tube 16 comprises a suction opening 20, so that one suction opening 20 is available per machine section 1, in the present case for the spinning positions 3 to 6. The profile tube 16 is connected to a flexible suction tube or suction conduit 21.
One fan 22 is arranged to each suction conduit 21, which generates the required vacuum.
The individual fans 22 are each driven by means of a drive belt 24. One drive pulley 25 is provided per machine section 1, 2 for the drive belt 24. The individual drive pulleys 25 are affixed to a drive shaft 26 which extends continuously in machine longitudinal direction and is driven, for example, from the headstock of the spinning machine. A spring-loaded tension roller 32 can hereby be arranged to each drive belt 24.
It has already been explained that the condensing of the individual fibre strands 13 serves to improve the quality of the spun thread 15. A prerequisite of this process is that the condensing effect on the fibre strands 13 at the individual condensing zones 8 is identical. As the condensing zones 8 operate with low pressure, it is of great importance that the low pressure at the individual condensing zones 8 remains as constant as possible, and in particular, does not decrease. A decrease in low pressure at a condensing zone 8 can occur, for example when in the area of one of

6
the components conveying the suction air from the condensing zone 8 to the fan 22, for example the profile tube 16 or the suction conduit 21, clogging occurs and the drawn out volume flow decreases. Very often a blockage occurs in the fan 22 itself. Dust and fibre ends can hereby become deposited in between the fan wheel and the housing of the fan 22 and thus result in sluggish running of the fan wheel. The fan wheel can no longer move freely and comes into contact with the trash deposits when it passes by. The fan wheel is slowed down and its rotational speed decreases. The reduced fan speed reduces the fan's suctioning capacity, and this leads to a reduced low pressure in the condensing zones 8. For this reason a monitoring device 27 is arranged to each fan, which monitoring device 27 can be activated in order to avoid an operational disturbance due to insufficient low pressure in the condensing zone 8.
It is provided in accordance with the present invention that the monitoring device 27 monitors the fan speed. A deviation from the nominal fan speed is hereby always an indication that the level of low pressure in the condensing zone 8 has changed. The rotational speed of the fan is thus an indicator of the level of low pressure. Every change in speed can be analysed by a control device 28 and the relevant measures taken. These measures can range from switching on a warning signal for the attention of a machine operator, to shutting down the relevant spinning position via the control device 28. It is hereby advantageous when the monitoring device 27 comprises sensors 29 which monitor the fan speed without contact, said sensors 29 being connectable to the control device 28.
The control device 28 comprises hereby a set value for the fan speed and compares this constantly with the actual value delivered by the sensor 29. It is advantageous when a signalling device 30 is assigned to the control device 28, which signalling device 30 can be designed in the form of warning lights or light emitting diodes which signal the current operational status to the machine operator. It can hereby be advantageous, depending on the dimensions of the deviations between the actual value and the set value, for the signalling device 30 to give different warnings. For example, in the case of a minimal drop below the set value, a yellow warning signal could be given, while in the case of increasing blockage and drop in the fan speed below an adjustable limit, a red warning light could be given. The machine operator can then react and take steps accordingly to eliminate the fault. Correct fan speed could be shown by means of a green light.

7
It can be provided that each fan 22 comprises a control device 28 and a signalling device 30. Alternatively, a central machine control system, to which a central signalling device is assigned, can just as well carry out the monitoring of the fans 22.
In an embodiment of the present invention it is provided that a signal transmitter 31 stationarily fixed to the fan shaft 23, is assigned to the monitoring device 27. The assessment of the fan speed by the sensor 29 is made possible in a simple way.

8 CLAIMS:
1. A spinning machine having a plurality of spinning positions (3, 4, 5, 6) each of
which comprises a vacuum-operated condensing zone (8) for condensing a
fibre strand (13), also comprising a number of fans (22) which generate the
low pressure and which are arranged to a number of spinning positions (3, 4,
5, 6), whereby each fan (22) comprises a monitoring device (27), to which an
operating parameter of the fan relating to the low pressure is assigned,
wherein the parameter monitored by the monitoring device (27) is the
rotational fan speed.
2. A spinning machine according to claim 1, characterized in that the monitoring
device (27) comprises a sensor (29) which assesses the fan speed in a non-
contact manner.
3. A spinning machine according to claim 1 and 2, characterized in that a signal
transmitter (31), stationary fixed to the fan shaft (23), is assigned to the
monitoring device (27).

Documents:

00531-kol-2006 -abstract.pdf

00531-kol-2006 -description (complete).pdf

00531-kol-2006-assignment.pdf

00531-kol-2006-claims.pdf

00531-kol-2006-correspondence others.pdf

00531-kol-2006-correspondence.pdf

00531-kol-2006-drawings.pdf

00531-kol-2006-form-26.pdf

00531-kol-2006-form1.pdf

00531-kol-2006-form3.pdf

00531-kol-2006-form5.pdf

00531-kol-2006-from2.pdf

00531-kol-2006-priority document.pdf

531-KOL-2006-(07-08-2012)-ANNEXTURE TO FORM-3.pdf

531-KOL-2006-(07-08-2012)-EXAMINATION REPORT REPLY RECIEVED.PDF

531-KOL-2006-(07-08-2012)-OTHERS.pdf

531-KOL-2006-(14-11-2012)-ABSTRACT.pdf

531-KOL-2006-(14-11-2012)-ASSIGNMENT.pdf

531-KOL-2006-(14-11-2012)-CLAIMS.pdf

531-KOL-2006-(14-11-2012)-CORRESPONDENCE-1.pdf

531-KOL-2006-(14-11-2012)-CORRESPONDENCE.pdf

531-KOL-2006-(14-11-2012)-DESCRIPTION (COMPLETE).pdf

531-KOL-2006-(14-11-2012)-DRAWINGS.pdf

531-KOL-2006-(14-11-2012)-FORM-1.pdf

531-KOL-2006-(14-11-2012)-FORM-13.pdf

531-KOL-2006-(14-11-2012)-FORM-2.pdf

531-KOL-2006-(14-11-2012)-FORM-5.pdf

531-KOL-2006-(14-11-2012)-FORM-6.pdf

531-KOL-2006-(14-11-2012)-OTHERS.pdf

531-KOL-2006-(14-11-2012)-PETITION UNDER RULE 137.pdf

531-KOL-2006-CORRESPONDENCE.pdf

531-kol-2006-form 18.pdf

abstract-00531-kol-2006.jpg

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Patent Number

263911

Indian Patent Application Number

531/KOL/2006

PG Journal Number

48/2014

Publication Date

28-Nov-2014

Grant Date

27-Nov-2014

Date of Filing

01-Jun-2006

Name of Patentee

MASCHINENFABRIK RIETER AG.

Applicant Address

Klosterstrasse 208406 Winterthur

Inventors:

#	Inventor's Name	Inventor's Address
1	Wolfgang LEHNER	Friedho fstrasse 60 D-73054 Elsllngen/flls
2	Ralf MECHEL	Hohensteinstrasse 4 D-73079 Sussen

PCT International Classification Number

D01H4/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	10 2005 030 273.4	2005-06-21	Germany