GB2459561A

GB2459561A - Monitoring apparatus for a moving fibre sliver at a drafting system of a textile machine

Info

Publication number: GB2459561A
Application number: GB0907126A
Authority: GB
Inventors: Pedro Corrales
Original assignee: Truetzschler GmbH and Co KG
Current assignee: Truetzschler GmbH and Co KG
Priority date: 2008-04-28
Filing date: 2009-04-24
Publication date: 2009-11-04
Anticipated expiration: 2029-04-24
Also published as: BRPI0901036A2; CN101570907B; JP5368164B2; BRPI0901036B1; DE102008021218A1; GB2459561B; CH698818B1; CH698818A2; JP2009263858A; CN101570907A; BRPI0901036B8; IT1397502B1; ITMI20090610A1; GB0907126D0

Abstract

A monitoring device 12 for a moving fibre sliver 7 comprises a deflecting element 12b, which is arranged to be deflected by the tensioned fibre sliver. Movement of the deflecting element upon loss of tension is monitored and may initiate a switching operation or produce an inductive pulse (figure 5). A tube 16 may have a slot receiving a number of deflecting elements each corresponding to a sliver. The tube may have one pole of a voltage source connected to it and the other pole may be connected to a counter-element 12a. When under tension the sliver maintains a gap "a" and upon loss of tension the deflecting element closes the gap completing the electrical circuit. Alternatively, movement of the deflecting element may cause an inductive pulse. The deflecting element may be a leaf spring or may have a compression spring (20, figure 4) located at one end. Preferably the monitoring device is used at a drafting system of a textile machine, for example, a draw frame, card, combing machine or the like, and is arranged in the vicinity of or within a device for feeding at least one fibre sliver 7 to the drafting system to detect breakage of the sliver.

Description

S

Monitoring apparatus for at least one moving fibre sliver at a drafting system of a textile machine The invention relates to a monitoring apparatus for at least one moving fibre sliver at a drafting system of a textile machine, for example, a draw frame, card, combing machine or the like.

In a draw frame, the fibre slivers are removed from cans and fed via a feed device to the roller pair on the feed table of the drafting system. The feed device is located in a section upstream of the feed table of a drafting system. The cans containing the fibre sliver to be processed are placed on both sides or on just one side of the feed device. The fibre sliver of each can is drawn perpendicularly upwards out of the can and diverted by the feed device through about 90° towards the draw frame. The fibre slivers of all cans are guided parallel to one another by the feed device. During transport of the fibre slivers beiiig offered up to the draw frame, individual fibre slivers may break. This is mostly attributable to coiling-related faults in the sliver. For that purpose, a monitoring de.vice is arranged in the transport path of the fibre sliver, which detects arid signals a sliver breakage.

The signal for a sliver breakage causes the draw frame to stop, so that the operator is able to join the broken sliver ends before they enter the draw frame. The monitoring device can be arranged inside the feed device or between the feed device and the draw frame. In addition, the fibre slivers may come to a halt. In the event of sliver breakage or stoppage, the fibre slivers lose tension. At high feed speeds of the fibre sliver, the problem arises that not every sliver breakage is reliably detected by the monitoring device. At the high feed speeds of the fibre sliver, it may happen that the sliver end, owing to its relatively low weight, does not fall to a depth on a level with the monitoring path until after it has passed the monitoring device, e.g. a light barrier, so that the falling sliver end cannot trigger a signal. In such a case, the sliver end passes through the weighting or contact rollers at the draw frame intake and is detected as a sliver breakage only at that point. This has the disadvantage that it is impossible to join the sliver ends any more, rather, a new sliver starting end has to be threaded in. This is considerably more time-consuming that joining the sliver ends before they enter the draw frame.

It is an aim of the invention to produce a monitoring apparatus which avoids or mitigates the said disadvantages, which is especially simple and allows reliable monitoring in a short time in the event of sliver breakage or stoppage of the fibre sliver.

The present invention provides a monitoring apparatus for at least one moving fibre sliver at a drafting system of a textile machine, comprising a feed device for feeding at least one fibre sliver to the drafting system and a monitoring device for monitoring the moving fibre sliver, the monitoring device being arranged in the vicinity of or within the feed device and comprising a deflecting element positioned f or being in contact, in operation, with the moving fibre sliver and which is so arranged that it is deflected when the fibre sliver is tensioned and that in the event of loss of tension of the fibre sliver it is able to initiate a switching operation.

Because the deflecting element directly detects the loss in tension of the fibre sliver through contact with the fibre sliver, quick and reliable monitoring is achievable in a simple manner. This furthermore allows the efficiency of the textile machine to be increased, by virtue of quick and safe shutdown being achievable in the event of sliver breakage or stoppage of the at least one fibre sliver.

Advantageously, the deflecting element is resiliently tensionable. Advantageously, the deflecting element is at least partially metallic. In one embodiment, the deflecting element is arranged to be lifted by the tensioned fibre sliver with respect to a non-moving

I

counter-element. In one advantageous embodiment, the deflecting element and the counter-element form a switching device. Preferably, the switching device is capable of initiating an electrical pulse on movement of the deflecting element.

In certain embodiments, the deflecting element is in the form of a leaf spring. It may be advantageous for the deflecting element to be convexly curved. It is preferred that the contact area of the deflecting element with the fibre sliver is smooth.

Preferably, the tensioned fibre sliver resiliently biases the deflecting element. The deflecting element is, for example, arranged to be biased by inherent resiliency.

In certain embodiments, the deflecting element and the counter-element co-operate as a contact switch. In other embodiments, the deflecting element and the counter-element may co-operate as a contactless switch.

The contactless switch may be a measuring device, for example, a proximity initiator. Preferably, the measuring device comprises an inductive proximity switch.

It is preferred that a movement is arranged to be initiated by loss of tension of the fibre sliver. The loss of tension may occur, for example, by stoppage of at least one fibre sliver, or through tearing or breakage of at least one fibre sliver. In certain embodiments, the switching device may be connected to a shut-off device of the machine.

Advantageously, the deflecting element, for example, a leaf spring, and the counter-element are connected to a voltage source. Advantageously, the counter-element is at least partially metallic.

Where there is a plurality of slivers, it is preferred that the monitoring device comprises a plurality of deflecting elements, for example, leaf springs, which may be mounted on a holding element, for example, a tube or the like. Preferably, a deflecting element is present for each fibre sliver.

S

In some embodiments, the deflecting elements are arranged between the feed device and the drafting system.

Advantageous, the deflecting element, for example, leaf spring, and the counter-element are electrically insulated with respect to one another. Advantageously, on loss of tension the fibre sliver is deflected downwards by gravity.

In one embodiment, the deflecting element is spring-loaded.

The invention also provides monitoring apparatus for at least one moving fibre sliver at a drafting system of a textile machine, for example, a draw frame, card, combing machine of the like, using a monitoring element positioned in contact with the moving fibre sliver, the monitoring apparatus being arranged in the vicinity of or within a device for feeding at least one fibre sliver to the drafting system, wherein the monitoring element for the fibre sliver comprises a deflecting element, which is arranged to be deflected by the tensioned fibre sliver and in the event of loss of tension of the fibre sliver is able to initiate a switching operation.

Certain illustrative embodiments of the invention will now be described in detail with reference to the accompanying drawings, in which: Fig. la is a schematic side view of a feed table and drafting system of a draw frame with a first embodiment of the apparatus according to the invention, Fig. lb is a plan view of the feed table and drafting system of Fig. la, Fig. 2a is a side view of the first embodiment of the apparatus according to the invention, with tensioned fibre sliver and tensioned leaf spring, one end region of which is out of contact with the counter-element, Fig. 2b is a side view of the apparatus of Fig. 2a, but with the fibre sliver not under tension (sagging down) and leaf spring not under tension, the end region of the leaf spring being in contact with the counter-element, Fig. 3 shows a second embodiment in which the other end region of the leaf spring is in contact with the counter-element, and with the leaf spring and the counter-element connected to a voltage supply source, Fig. 4 shows a third embodiment with a spring-loaded deflecting element, and Fig. 5 shows a fourth embodiment of the apparatus according to the invention with a contactiess switch, where an inductive displacement sensor is associated with the leaf spring.

Referring to the side view in Fig. la, there is shown the feed region 1, the supply region 2, the drafting system 3 and the sliver deposition region 4 of a draw frame, for example, a draw frame TD 02 made by Trützschler GmbH & Co. KG of Mônchengladbach, Germany. In the feed region 1, three spinning cans 5a to 5c (round cans) of a draw frame are arranged in two rows (see Fig. ib) beneath the sliver feed table 6 (creel), and the feed slivers 7a to 7c are drawn off over sliver diverting elements 8a to 8c, for example, diverting rollers, diverting bars or the like, and supplied to the drafting system 3. Fibre slivers 7a to 7c are lifted from the spinning cans 5a to 5c and guided on the feed table 6 to the drafting system 3.

After passing through the drafting system 3, the drawn fibre sliver 7' enters the revolving plate of a can coiler 4 and is deposited in coils in the delivery can. The feed table 6 extends as far as the draw frame over the region of the entire sliver feed apparatus. By means of the fibre sliver feed apparatus a fibre sliver 7 is fed from each spinning can 5 to the draw frame. In the region of each sliver diverting element Ba, Bc there is a guide element for guiding the fibre slivers 7. The letter A denotes the running direction of the fibre slivers 7a, 7b

S

and 7c. At the delivery end of the feed table 6 there is a guide device for the fibre slivers 7a to 7f, comprising a horizontal bar 10 of cylindrical cross-section, to the rear side of which eight cylinders ha to llh are attached. The axes of the cylinders ha to hf are vertically aligned and the distance between the cylinder barrels of the cylinders ha to lih is sufficiently large for a fibre sliver 7a to 7f to be able to pass through without its passage being impaired. In this way, guide channels open at the top are formed for the fibre slivers 7a to 7f, that is, the cylinders ha to iih function as guide elements. The monitoring device 12 according to the invention is arranged downstream of the feed table 6 and upstream of the drafting system 3.

As shown in Fig. lb, on each side of the feed table 6 a row of three spinning cans 5 (not shown) are set up parallel to one another. In operation, respective fibre slivers 7 can be drawn simultaneously from all six spinning cans 5. Alternatively, operation can be such that fibre sliver 7 is drawn off on one side only, for example, from the three spinning cans 5a to 5c, whilst on the other side the three spinning cans Sd to 5f are being exchanged.

Furthermore, on each side of the feed table 6 there are three sliver diverting elements Ba, 8b, 8c and 8d, 8e, 8f respectively, arranged one behind the other in the direction of working A. Respective pairs of sliver diverting elements 8a and 8d, 8b and 8e and 8c and 8f are arranged coaxiahly with respect to one another. The length of the fibre slivers 7 in the feed region 1 decreases from the inside outwards. As shown in Fig. la and Fig. lb, the fibre slivers 7a to 7f run from the feed table 6 of the feed region 1 over the guide arrangement (bars 10, cylinders ha to lie) beneath the monitoring apparatus 12, through the sliver funnel 14 and through the drafting.

system 3, a web guide 15, a sliver funnel with take-off rollers and a revolving plate 4.1 into the can 4.2.

In Fig. lb, the underneath rollers III, II, I of the drafting system 3 are shown. According to Fig. lb. in the region between the sliver diverting elements 8 and the monitoring apparatus 12 the composite fibre sliver comprising six fibre slivers 7 is subject to a feed creel tension, and in the region between the monitoring apparatus 12 and the feed rollers comprising lower roller, III and the corresponding upper roller of the drafting system 3 the composite fibre sliver comprising six fibre slivers 7 is subject to a transport tension.

Associated with each fibre sliver 7a to 7f is a deflecting element 12, comprising a common counter-element 12a and six deflecting elements in the form of leaf springs 12b1 to 12b6. In operation, the tensioned fibre slivers 7a to 7f according to Fig. 1 press from below against the leaf springs 12b1 to 12b6 and deflect these upwards, causing the leaf springs 12b1 to 12b6 to be tensioned and to exert pressure on the fibre slivers 7a to 7f. Whenthe fibre slivers 7a to 7t are not under tension, the force exerted by the slivers pressure on the leaf springs 12b1 to l2b6 decreases or ceases completely (the fibre slivers 7a to 7t sag down), the result being that the leaf springs l2b1 to 12b6 relax and return substantially or completely to their relaxed starting position (compare Figs 2a and 3) . In practice, one or more than one fibre sliver may break or otherwise cease to be tensioned and the corresponding leaf spring or leaf springs will relax and return to their starting positions whilst the remaining leaf springs continue to be in the upwardly deflected position.

In the embodiment of Figs 2a and 2b, a monitoring element 12 for a fibre sliver 7 comprises the common counter-element 12a and an individual deflecting element in the form of a leaf spring l2b. The counter-element is in the form of a multi-sided tube or a portion of a cylinder barrel open at one side, and consists of, for example, sheet metal. The leaf spring l2b is convexly curved and at each end region has a respective extension piece 12 and 122. The extension pieces l2 and 122 project approximately at right angles from the leaf spring body.

S

The extension piece 122 projects into a continuous slot in a tube 16 and is secured there. The tube 16 holds all leaf springs 12b1 to 12b6 jointly. Between the open end of the extension piece l2 and the electrically conductive inner surface of the counter element 12a, there is a gap a, as shown in Fig. 2a. In operation, the tensioned fibre material 7 presses the leaf spring 12b in the direction of, that is, against the outer lateral surface of the tube 16 and thus lifts the extension piece towards the counter-element 12a. In the event of a sliver breakage, the tension in the fibre sliver 7 decreases, and the sliver sags down, as shown in Fig. 2b. The leaf spring 12b therefore springs into its relaxed starting position again, that is, away from the tube 16. The free end of the extension piece l2 presses on the electrically conductive inner lateral surface of the counter-element 12a and by touch -as a contact switch -closes an electric circuit (the electrical circuit may for example be analogous to that shown in Fig.3.) In the embodiment of Fig. 3, an electric circuit comprising a voltage source 17, a switching device 18, for example, an off switch for the machine, and a contact switch is provided. The contact switch consists of the leaf spring 12b and the metal tube 16 on the one hand and the counter-element 12a on the other hand. In the example shown, the contact switch is closed by contact of the region 123 of the leaf spring 12b -situated in the vicinity of the extension piece 122 -with the counter-element l2a. The fibre sliver 7 is not under tension, so that the leaf spring 12b has lost its tension. One pole of the voltage source is applied to the tube 16 and hence to all leaf springs 12b1 to l2b6. The other pole of the voltage source 17 is applied to the counter-element l2a.

The tube 16 and the counter-element 12a are electrically insulated with respect to one another.

In a further embodiment shown in Fig. 4, the deflecting element 12b comprises a metal sheet or the like, one end region 124 of which is spring-loaded, for example, by a compression spring 20, which is supported at a fixed counter-abutment 21.

In the embodiment of Fig. 5, a contactiess switch is associated with the leaf spring 12b. For that purpose, an inductive displacement sensor 19 comprising a plunger coil l9. and plunger motor 192 is associated with the extension piece l2, and is electrically connected to a control device (riot shown) , for example, the machine control. In the example illustrated, in operation the leaf spring 12b is tensioned. In the event of a sliver breakage, and corresponding relaxation of the leaf spring 12b, the plunger coil 192 emits an electrical pulse.

An inductive proximity switch, a light sensor, or the like may also be used as contactless switch.

In the embodiments described there are six leaf springs. It will be appreciated that there may be a different number of slivers, for example more than six slivers, in which case a corresponding higher (or, if appropriate, lower) number of leaf springs will normally be provided.

The apparatus according to the invention can be used both on a draw frame without levelling, for example, the TrUtzschler TD 02, and also on an autoleveller draw frame, for example, the TrQtzschler TD 03.

In operation, the contact force of the tensioned fibre sliver on the resiliently biased leaf spring is greater than the counter-force on the fibre sliver, so that the leaf spring yields.

Claims

Claims 1. A monitoring apparatus for at least one moving fibre sliver at a drafting system of a textile machine, comprising a feed device for feeding at least one fibre sliver to the drafting system and a monitoring device positioned for monitoring the moving fibre sliver, the monitoring device being arranged in the vicinity of or within the feed device and comprising a deflecting element positioned for being in contact, in operation, with the moving fibre sliver and which is so arranged that it is deflected when the fibre sliver is tensioned and that in the event of loss of tension of the fibre sliver it is able to initiate a switching operation.
2. An apparatus according to claim 1, in which the deflecting element is resiliently tensionable.
3. An apparatus according to claim 1 or claim 2, in which the deflecting element is at least partially metallic.
4. An apparatus according to any one of claims 1 to 3, in which the deflecting element is arranged to be moved by the tensioned fibre sliver with respect to a non-moving counter-element.
5. An apparatus according to any one of claims 1 to 4, in which the deflecting element and the counter-element form a switching device.
6. An apparatus according to claim 5, in which the switching device is capable of initiating an electrical pulse on movement of the deflecting element.
7. An apparatus according to any one of claims 1 to 6, in which the deflecting element is in the form of a leaf spring.
8. An apparatus according to any one of claims 1 to 7, in which the deflecting element is convexly curved.
9. An apparatus according to any one of claims 1 to 8, in which the contact area of the deflecting element with the fibre sliver is smooth.
10. An apparatus according to any one of claims 1 to 9, in which the tensioned fibre sliver resiliently biases the deflecting element.
11. An apparatus according to any one of claims 1 to 10, in which the deflecting element is arranged to be biased by inherent resiliency.
12. An apparatus according to any one of claims 1 to 11, in which the deflecting element and the counter-element co-operate as a contact switch.
13. An apparatus according to any one of claims 1 to 12, in which the deflecting element and the counter-element co-operate as a contactless switch.
14. An apparatus according to any one of claims 1 to 13, in which the contactless switch is a measuring device.
15. An apparatus according to claim 13, in which the measuring device comprises a proximity initiator.
16. An apparatus according to claim 14 or claim 15, in which the measuring device comprises an inductive proximity switch.
17. An apparatus according to any one of claims 1 to 16, in which the arrangement is such that a movement of the deflecting element is initiated by loss of tension of the fibre sliver.
18. An apparatus according to any one of claims 1 to 17, in which the arrangement is such that a loss of tension occurs by stoppage of at least one fibre sliver.
19. An apparatus according to any one of claims 1 to 18,.in which the arrangement is such that a loss of tension occurs through tearing or breakage of at least one fibre sliver.
20. An apparatus according to any one of claims 1 to 19, in which the monitoring device is connected to a shut-off device of the machine.
21. An apparatus according to any one of claims 1 to 20, in which the deflecting element and a counter-element with respect to which it is moveable are connected to a voltage source.
22. An apparatus according to claim 21, in which the counter-element is at least partially metallic.
23. An apparatus according to any one of claims 1 to 22, in which the monitoring device comprises a plurality of deflecting elements.
24. An apparatus according to claim 23 or 24, in which the deflecting elements are mounted on a holding element.
25. An apparatus according to claim 23 or claim 24, which the deflecting elements are leaf springs, which are mounted on a common holding element.
26. An apparatus according to any one of claims 1 to 25, in which a deflecting element is present for each fibre sliver.
27. An apparatus according to any one of claims 1 to 26, in which the or each deflecting element is arranged between the feed device and the drafting system.
28. An apparatus according to any one of claims 1 to 27, * in which the or each deflecting element and a counter-element with respect to which it is moveable are electrically insulated with respect to one another.
29. An apparatus according to any one of claims 1 to 28, in which the arrangement is such that, on loss of tension, the fibre sliver is deflected downwards by gravity.
30. An apparatus according to any one of claims 1 to 29, in which the or each deflecting element is spring-loaded.
31. A monitoring apparatus for at least one moving fibre sliver at a drafting system of a textile machine, for example, a draw frame, card, combing machine of the like, using a monitoring element positioned in contact with the moving fibre sliver, the monitoring apparatus being arranged in the vicinity of or within a device for feeding at least one fibre sliver to the drafting system, wherein the monitoring element for the fibre sliver comprises a deflecting element, which is arranged to be deflected by the tensioned fibre sliver and in the event of loss of tension of the fibre sliver is able to initiate a switching operation.S
32. An apparatus for monitoring a fibre sliver in a feed arrangement for a drafting system of a textile machine, the apparatus being substantially as described herein with reference to and as illustrated by any of Figs. la and lb, 2a and 2b and 3 to 5.
33. A method of monitoring a fibre sliver being fed from a feed arrangement to a drafting system of a textile machine, comprising feeding the fibre sliver under tension through a feed device in which a deflecting element is deflected by the tensioned fibre sliver, on loss of sliver tension permitting a movement of said deflecting element from said deflected position, and monitoring for a said movement.
34. A method according to claim 32, in which a signal indicating loss of tension is generated and provided to the machine control.