GB2076436A - An improved weft yarn supply device and method of weft yarn supply - Google Patents

Abstract

A device and a method for controlling the supply of yarn to be woven as weft in a woven fabric which causes a yarn draw off means to be actuated by a control means itself operated by pattern chain 10, so that during each pick of a first period of time yarn is supplied for weaving as weft and so that during each pick of a second period of time a smaller quantity of yarn is supplied for weaving as weft or warp. By the invention a pocketed tape can be produced with pockets spaced along the tape thus representing a considerable saving in yarn over prior art pocketed tape with a continuous row of pockets. <IMAGE>

Description

SPECIFICATION An improved weft yarn supply device and method of weft yarn supply This invention concerns a weft yarn supply device and method of weft yarn supply primarily, although not exclusively, for use in a loom to control the amount of weft yarn fed to a weft inserter during weaving of a fabric.

It is known that in for example a needleloom fabric it is necessary to retain the successively inserted weft loops at their ends remote from the point at which they enter the warp shed in order that, upon retraction of the weft inserting means, the first inserted weft loop is retained in the shed.

A commonly used means for retaining the weft loops is to knit them together using a latch needle.

One of the essential factors in such a loom is that the latch needle always retains a loop of weft yarn on its shank during the weaving process in order that a continuous chain of knitted loops can be produced. Should the loop of weft yarn be "lost" from the latch needle it is not possible to continue to weave the fabrtic effectively since there is then no means of producing a knitted stitch and thus no means for preventing the withdrawal of a first inserted weft loop from a warp shed as the weft inserter is withdrawn from the shed prior to a shed change.

Ther are, therefore, circumstances in which, of necessity considerably more weft yarn is used than is actually required. One example of such a circumstance exists in the production on a needleloom of a pocketed curtain heading tape being for example a single row of pockets along the tape. In the past it has always been thought necessary to produce a continuous row of pockets on a face of a base fabric. In use, however, only a relatively small number of those pockets are required for the insertion of curtain suspension hooks and thus the weaving of a continuous row of such pockets necessarily entails the use of a greater amount of weft than is actually essential for providing a useful heading tape. In those instances in which the curtain heading tape has more than one row of pockets the quantity of weft used unnecessarily is even greater.

According to the invention there is provided a device for controlling the supply of yarn to be woven as weft in a woven fabric, said device comprising control means, yarn drawing means actuated by said control means, said yarn drawing means being adapted to draw yarn from a supply and forward said yarn for weaving, pattern control means for controlling operation of said control means so as to actuate said yarn drawing means during each pick of a first period of time to supply a quantity of yarn for weaving as weft and so as to actuate said yarn drawing means during each pick of a second period of time to supply a smaller quantity of yarn for weaving as weft or warp.

The invention also provides a method for controlling the supply of yarn to be woven as weft in a woven fabric, said method comprising operating a yarn drawing means through the action of control means actuated by pattern control means so as to draw a quantity of yarn from a yarn supply and forward said yarn for weaving as weft during each pick of a first period of time and so as to draw a smaller quantity of yarn for weaving as weft or warp during each pick of a second period of time.

The invention will now be described further, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a schematic illustration of a weft yarn supply device; Fig. 2 is a diagrammatic illustration of one form of pocketed curtain heading tape that can be provided using the weft yarn supply device of Fig. 1; Fig. 3 is a diagrammatic plan view of a part of a loom comprising a further embodiment of the invention; Fig. 4 is a view similar to Fig. 3 showing formation of a pocket in a first row in a tape; Fig. 5 is a view similar to Fig. 3 showing formation of a pocket in a second row in the tape; and Fig. 6 is a diagrammatic plan view of a part of a loom comprising another embodiment of the invention for forming pockets in two or more rows in a tape at the same time.

In the following description the production of a pocketed curtain heading tape in which there is a single row of pockets formed along the length of the tape, the pockets being formed at spacedapart intervals on one face of a body portion of the tape will be described but this is not intended to restrict the invention to the production of this type of tape only.

Thus, in its simplest form as illustrated a weft yarn supply device comprises a pattern chain 10 on which there are cam links 11 and 12, the links 11 being of "low" profile and, in use, adapted not to impart any movement from a datum position of a pivoted lever 13 referred to below. The links 12 have a "high" profile and, in use, are adapted to cause the lever 1 3 to rise from the datum position and then return to it. The pivoted lever 13 is provided intermediate its ends with a cam follower 14 which bears on the pattern chain 10 and is held in position in contact with the cam links 11, 12 of the chain 10 by means of a spring 15. The pivot point for the lever 1 3 is at one side of the cam follower 14 and is in the form of a pivot pin 1 6.In the region of the end of the lever 13 which extends from the cam follower and away from the pivot pin 1 6 are a number of spaced-apart holes 17, 1 7a, 1 7b (while three such holes are shown there may be more or less than three). Under the influence of the pattern chain 10 the lever 1 3 can thus pivot about pin 1 6 from the full line position to a lifted position, shown in broken line. A link 18 is pivotally connected to the lever 1 3 by means of a pivot pin 19 and thus link 1 8 is pivotally connected at its other end to, for example, a sprag clutch operating lever 20.The pivotal connection of the link 1 8 to the operating lever 20 is by means of a pivot pin 21 which can be secured in position at any point within the length of an elongate pin receiving slot 22 formed in the free end region of the lever 20.

As shown the link 1 8 is pivotally connected to the lever 13 at the hole 1 7 remote from the cam follower 14 and to the operating lever 20 at that end of the slot 22 remote from the free end of the lever 20. It will be appreciated however that the link 1 8 can be connected to the lever 1 3 at any one of the holes and that the other end of the link 1 8 can be secured at any position between the ends of the slot 22.

The operating lever 20 is secured to one part of a sprag clutch 23 (or like mechanism) and the other part is secured to a shaft 24 upon which is secured a pulley 25, or sprocket, which is wrapped by a belt 26, or chain, which also wraps a pulley 27, or sprocket, part on a shaft 28 which latter serves to operate a yarn drawing device (not shown) arranged to draw yarn from a source and feed it to a weft inserter of the loom.

In use, the device operates in the following manner. As each cam 11, 12 of the pattern chain arrives at the cam follower 14, the lever 1 3 will either be pivoted slightly from a datum position (when a cam 11 contacts the follower 14) or will be pivoted through a substantial arc about pin 1 6 (when a cam 12 contacts the follower 14). Upon being pivoted by the action of a cam 12 the lever will move to the broken line position and the link 18 will move the operating lever 20 to the broken line position. This in turn will operate the sprag clutch 23 to rotate the shaft 24, which in turn rotates the pulleys 25 to move the belt 26, turn the pulley 27 to rotate the shaft 28 and thus operate the yarn drawing and feeding device to feed a predetermined quantity of yarn to the weft inserter.The lever, link and pulley arrangement is so constructed than when a cam 12 moves the lever sufficient weft yarn will be fed to the weft inserter to enable a pocket forming pick to be produced. When the lever is only moved slightly only sufficient weft yarn is fed to the weft inserter to produce a short pick (say equal to two or three warp yarn spacings). Thus when the device is fitted to a curtain heading tape weaving needleloom equipped with one other weft inserter a fabric like that shown diagrammatically in Fig. 2 can be woven.

Referring to Fig. 2 it will be seen that the curtain heading tape comprises a body fabric 29 (woven using a body fabric weft inserter) which operates in the normal manner to insert picks from the edge A of the fabric. A latch needle will limit these loops (or a catch thread) in known manner along edge B of the fabric, and longitudinally spaced apart pockets 30. It is to be noted that draw cords (not shown) would also normally be provided. The device above described serves to feed weft yarn to a second weft inserter which is used to produce pockets 30. If it is assumed that there are to be pockets 30 of twelve pick width separated by sixty picks then the pattern chain of the device will have thirteen cams 12 and fifty nine cams 11.Thus to commence weaving a pocket 30 of the first of the cams 12 operates the lever 1 3 and its associated mechanism as described above and sufficient weft yarn is fed to the weft inserter to produce the first pick of the pocket 30. The weft inserter enters the pocket warp shed from side A' and the inserted loop is knitted at the side B1 of the pocket. The next eleven consecutive picks are formed in an identical manner and are interlaced with pocket warp yarns.

When the thirteenth cam 1 2 operates the lever the pocket warp shedding is such that the weft loop is not interlaced with the warp and thus a floating length of weft yarn 31 is formed. On operation of the lever 1 3 by the first of the cams 11 only sufficient weft is fed to the weft inserter to produce a pick of short length and this becomes located at position C. This pick may only be interfaced with, say three warp yarns. This pick is knitted by the latch needle as in fact are the following fifty eight picks to produce a line of knitting 32 extending along the body 29 of the fabric until the position for the next pocket 30 is reached. At this time the first cam 12 is again operative and thus a single floating yarn 33 is formed (due to the shedding of the pocket warp yarns).

In practice the floating weft yarns 31 and 33 may be cut off as weaving progresses so that in the finished fabric that are not present.

It will be appreciated that due to the small amount of pocket weft yarn required to produce the line of knitted stiches 32 considerable savings can be made when compared with a curtain heading tape in which there are continuous sideby-side pockets along the whole length of the tape.

In practice, as often happens there are unused heald control levers and in this case the lever 1 3 could be one of such levers.

The invention is not restricted to the details set out above. For example, it is often necessary to provide two (or more) rows of pockets along the length of the body fabric of a curtain heading tape.

In the case in which there is a need to provide two rows of such pockets two devices of the kind described above are used, again if possible using two unused shedding levers of the loom for actuating the weft feeding devices required to provide the two pocket forming weft inserters with weft. In this case the pockets of one row may be lateraliy offset from the pockets of the other row.

To achieve this the shedding of the pocket warp yarns, and the actuation of the weft supply devices would be suitably controlled by (a) the pattern cam chains of the heald control levers and (b) the pattern cam chains of the weft supply operating devices.

The possibility also exists of using a two lever system for operating a weft supply device. In this arrangement there would be one lever 13 adapted to operate a first sprag clutch 23 to cause the weft supply to provide, say, sufficient weft to produce a pocket pick. This lever would be controlled by a pattern chain in which there are "high" lift cams 12 and "no lift" cams only. The second lever 1 3 would operate its sprag clutch to cause the weft supply to operate to provide short lengths of weft for weaving and knitting between the pockets.

This lever would be controlled by a pattern chain in which there are "low" lift cams and "no lift" cams only.

From the above it will be clear that for a three pocket tape, that is a tape being three rows of pockets along its length a further device of either the single lever or two lever kind will be required, together with, of course, an additional weft supply device, weft inserter and knitting needle.

The embodiment of Fig. 2 requires a separate weft supply and weft inserter for each pocket in the case where two or more rows of pockets are to be formed. A much more simple arrangement by which a tape having two or more rows of pockets can be produced will now be described with reference to Fig. 3, which illustrates a loom equipped with latched needles 40, 42, located in line with the right hand edge (as viewed in the drawing) of rows 44 and 46 respectively of pockets to be formed in tape 48 being woven on the loom. A warp end 50 which lies at the left hand side of the row of pockets 44 is arranged to be lifted by the heald to a position intermediate the pocket-forming warp shed where it is picked up by a weft inserter in the form of a forked rapier 52. The forked rapier carries the warp end 50 across the loom in the manner of a weft as shown in Fig. 4.The supply of sufficient yarn being obtained, for example, by means of a mechanism as described with reference to Fig. 1. As the warp end is drawn across the loom it engages against a deflector 54 adjacent to, and on the left hand side of latched needle 40. The position of the deflector 54, is adjusted so that yarn 50 is laid in the hook of the latched needle 40 and prevented from being engaged by latched needle 42.

The rapier 52 returns to the position shown in Fig. 3 and the above described cycle is repeated for a sufficient number of picks to form a pocket.

In each pick the latched needle 40 forms a stitch with the loop of yarn 50 formed in the preceding pick. At the completion of the last pocket forming pick the warp end 50 is no longer lifted by the heald into a position where it is engaged by the rapier but instead forms part of the shed for weaving the body of the tape as indicated by the dotted line 50'.

At a predetermined interval after completion of a pocket in row 44 warp yarn 60 which lies along the left hand edge of the second row of pockets 46 is lifted by the heald to a position where it is engaged by rapier 52 as it traverses across the loom from left to right. The rapier 52 carries warp 60 between a pocket forming shed (not shown) and lays it in the hook of latched needle 42, Fig 5.

A similar sequence of operation follows as has been described with reference to Figs. 3 and 4 until a pocket has been formed in row 46. As with warp ends 50, the warp ends 60 when not in use as a weft for forming pockets in row 46 forms part of the tape body as shown in dotted lines 60'.

It will be apparent from the foregoing that pocketed tape formed as described with reference to Figs. 3 to 5 have a rather neater appearance than that of the embodiment of Fig. 2. This is because there are no loops 31 and 33 nor is there a line of stitches 32 between the pockets. As mentioned the inclusion of the warp ends 50 and 60 between the pockets in the body of the tape gives the tape body a uniform appearance.

Moreover the use of only one warp end as a weft for the pockets of each row makes virtually no apparent difference to the uniform appearance of the tape body at the mouth of the pockets, that is to say at the left hand sides thereof.

As explained above yarn 50 and 60 at the right hand side of their respective pockets are secured by forming stitches beween each pick and the succeeding pick with the aid of latched needles 40 and 42. At the completion of the last pocketforming pick the yarn 50 or 60 reverts from its role as a pocket forming weft to that of a warp end for the tape body. The normal tension applied to the warp end may not be sufficient adequately to reduce the size of the last loop formed on the latched needle during the last pocket forming pick.

It may, therefore, be desirable to apply a small shogging movement to the warp ends 50 or 60 at the moment of completion of the last pick so that that last loop aforesaid is reduced in size and does not mar the appearance of the product.

The shogging movement can be achieved by any appropriate means, for example by means of a member which engages the yarn and jerks it at the desired moment. Such a member may have its movements controlled by a spare shedding or other lever on the loom.

The sequence of operations as described with reference to Figs. 3 to 5 produces a tape in which the pockets in one row are staggered in relation to the pockets of the other row. It is possible, however, to produce pockets in two or more rows which are in register with each other or which are partially staggered. As can be seen in Fig. 6 if the warp ends 50 and 60 are lifted simultaneously to the middle of pocket-forming sheds for pockets in rows 44 and 46, then both yarns are engaged by the rapier as it moves across the loom from left to right. Yarn 50 is laid in the hook of latched needle 40 and prevented from dropping into the hook of latched needle 42 by virtue of the deflector 54. At the same time yarn 60 is laid in the hook of latched needle 42. In this way the pockets of both rows can be formed so that they are precisely aligned transversely of the tape or so that they overlap transversely to whatever extent desired.

Although the invention and its mode of operation has been described in relation to the production of curtain heading tape pockets the invention is not restricted to this use only. For example when weft patterning effects are required in needleloom fabrics the device of Fig.1 (or devices) described can be used with suitable modifications to the pattern control chain (or chains).

Claims (36)

1. A device for controlling the supply of yarn to be woven as weft in a woven fabric, said device comprising control means, yarn drawing means actuated by said control means, aid yarn drawing means being adapted to draw yarn from a supply and forward said yarn for weaving, pattern control means for controlling operation of said control means so as to actuate said yarn drawing means during each pick of a first period of time to supply a quantity of yarn for weaving as weft and so as to actuate said yarn drawing means during each pick of a second period of time to supply a small quantity of yarn for weaving as weft or warp.

2. A device as claimed in Claim 1, wherein the pattern control means comprises a pattern chain having high and low profile links corresponding to the first and second period of time respectively.

3. A device as claimed in Claim 2, wherein the control means comprises a follower adapted to follow the profile of links in said pattern chain.

4. A device as claimed in Claim 3, wherein the control means also comprises a linkage between the follower and the yarn drawing means.

5. A device as claimed in Claim 4, wherein the said linkage is adjustable so as to vary the quantity of yarn drawn from the supply by the yarn drawing means upon actuation of the control means.

6. A loom comprising a device as claimed in any preceding claim, said loom including at least one weft inserter, the supply of yarn to said inserter being controlled by said device.

7. A loom as claimed in Claim 6 wherein the yarn supplied to said weft inserter is a warp yarn end whereby said warp yarn end is woven as weft during said first period of time and is woven as warp during said second period of time.

8. A loom as claimed in Claim 6 or Claim 7, comprising a plurality of different yarn supply devices for supplying different yarns to said weft inserter for weaving at transversely different locations across the loom, each yarn supply being controlled by said device.

9. A loom as claimed in Claim 8, wherein different yarns are supplied to the weft inserter for weaving at different times.

10. A loom as claimed in Claim 8, wherein different yarns are supplied to the weft inserter for weaving at substantially the same time.

11. A loom as claimed in any of Claims 8 to 10, wherein deflector means is provided to deflect all but one yarn out of engagement with weft securing means disposed in at least one of said different locations.

12. A loom as claimed in any of Claims 7 to 11, wherein means is provided for imparting tension to the said warp yarn end at substantially the end of the first period of time.

13. A loom as claimed in Claim 6, wherein the yarn supplied to weft insert is a separate supply of weft yarn.

14. A method for controlling the supply of yarn to be woven as weft in a woven fabric, said method comprising operating a yarn drawing means through the action of control means actuated by pattern control means so as to draw a quantity of yarn from a yarn supply and forward said yarn for weaving as weft during each pick of a first period of time and so as to draw a smaller quantity of yarn for weaving as weft or warp during each pick of a second period of time.

15. A method as claimed in Claim 14 wherein the pattern control means comprises a pattern chain having a high and low profile links corresponding to the first and second periods of time respectively.

16. A method as claimed in Claim 15, wherein the control means comprises a follower adapted to follow the profile of links in said pattern chain.

1 7. A method as claimed in Claim 16, wherein the control means comprises a linkage between the follower and the yarn drawing means.

18. A method as claimed in Claim 17, wherein the linkage is adjustable so as to vary the quantity of yarn drawn from the supply by the yarn drawing means upon actuation of the control means.

19. A method as claimed in any of Claims 14 to 18, wherein yarn is supplied by said yarn drawing means to a weft inserter comprised in a loom.

20. A method as claimed in Claim 19, wherein yarn is supplied by said yarn drawing means to said weft inserter only during said first period of time.

21. A method as claimed in Claim 20, wherein the yarn supplied to said weft inserter is a warp yarn end, said warp yarn end being woven as weft during said first period of time and woven as warp during said second period of time.

22. A method as claimed in Claim 19 or Claim 20, wherein a plurality of different yarns are supplied to said weft inserter for weaving at transversely different locations across the loom.

23. A method as claimed in Claim 22, wherein different yarns are supplied to the weft inserter for weaving at different times.

24. A method as claimed in Claim 23, wherein different yarns are supplied to the weft inserter for weaving at substantially the same time.

25. A method as claimed in Claim 24, wherein all but one of the yarns supplied to the weft inserter are deflected out of engagement with weft securing means disposed in at least one of said different locations.

26. A method as claimed in any of Claims 19 to 25 wherein tension is applied to the said warp end at substantially the end of the first period of time.

27. A method as claimed in Claim 19, wherein yarn is supplied to said inserter from a separate supply of weft yarn.

28. A method as claimed in Claim 27, wherein the yarn from said supply is woven as weft during said second period of time.

29. A woven fabric produced by the method as claimed in any of Claims 14 to 28.

30. A pocketed woven fabric produced by the method as claimed in any of Claims 14 to 28 wherein the weft in the pockets being the yarn supplied during said first period of time.

31. A pocketed woven fabric as claimed in Claim 30, including two or more longitudinal rows of pockets.

32. A pocketed woven fabric as claimed in Claim 31 wherein the pockets in one row are staggered transversly in relation to pockets in another row.

33. A pocketed woven fabric as claimed in Claim 31, wherein the pockets in one row are transversely aligned with the pockets in another row.

34. A device for controlling the supply of yarn substantially as described herein with reference to Fig. 1 of the accompanying drawings.

35. A method for controlling the supply of yarn substantially as described herein.

36. Pocketed woven fabric as claimed in Claim 30 substantially as described herein.