GB1576726A

GB1576726A - Selvedges in woven fabrics

Info

Publication number: GB1576726A
Application number: GB3468776A
Authority: GB
Original assignee: Bonas Machine Co Ltd
Current assignee: Bonas Machine Co Ltd
Priority date: 1976-08-20
Filing date: 1976-08-20
Publication date: 1980-10-15
Also published as: CH619008A5; FR2362226A1; DE2727290C2; DE2727290A1

Abstract

On the side facing away from the weft-insertion side, the fabric (11) has a selvedge, on which a first catch thread (8) retains the inserted weft-thread loops and a second catch thread (9) prevents a loosening of the first catch thread (8). The first catch thread (8) is drawn through each successively inserted weft-thread loop, in order to form a first series of stitches. The second catch thread (9) is drawn only through selected stitches of the first catch thread (8), in order to form a second series of stitches simultaneously with the selected stitches of the first catch thread (8). The second series of stitches can be produced with any stitch or with alternating stitches of the first catch thread (8). The first and the second catch thread (8 and 9) are guided through guide members (6 and 7), the first guide members (6) being moved, whenever the weft-inserting needle (1) is moved to insert a weft-thread loop, into a position in which they guide the first catch thread (8) into the path of movement of the insertion needle (1). <IMAGE>

Description

(54) IMPROVEMENTS IN SELVEDGES IN WOVEN FABRICS (71) We, BONAS MACHINE COMPANY LIMITED, a British Company of Grangewood Hall, Netherseal, Burton-on-Trent, Staffordshire DE12 8BQ, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention concerns the formation of selvedges in woven fabrics and in particular the formation of selvedges on fabrics woven using a weft inserter needle, rapier or the like to insert weft in the form of loops.

For the sake of convenience fabrics woven in the manner just referred to will be called needleloom fabrics.' The formation of a selvedge on a needleloom fabric is well known and can be achieved in any one of numerous different processes. For example, the successive weft loops can be knitted together using a latch needle to produce a chain stitch selvedge.

Alternatively a so-called catch thread can be knitted through otherwise unconnected weft loops to form a chain stitch selvedge.

Both of these processes have the disadvantage that the selvedge can be unravelled. It is also possible, and known, to produce a selvedge in which both the weft loops and a catch thread are knitted together to produce a selvedge which is more difficult to unravel but which has, for some end uses of the fabric, the disadvan tage of producing an unacceptably bulky selvedge.

Various other forms of knitted selvedee have been proposed, for example, knitting together the weft loops and one of a number of catch threads, the catch threads being knitted in alternating sequence, knitting together in alternating or other sequence two or more catch threads without the simultaneous knitting of the weft loops. In the first form just referred to the selvedge, while being difficult to unravel is bulky and in the second form the selvedge is relatively easy to unravel providing the catch threads are pulled in the correct sequence.

It is an object of the present invention to produce a knitted selvedge in a needleloom fabric which is difficult to unravel and at the same time does not have the disadvantage of excessive bulk.

Thus according to the present invention there is provided a selvedge for a needleloom fabric comprising a first catch thread arranged to be drawn through the weft loops to form a series of chain stitches to retain loops of weft at the side of the fabric opposite to that from which they were inserted and a second catch thread arranged to form a series of chain stitches through the first catch thread only substantially to prevent the first catch thread from being unravelled.

Preferably the second catch thread is appreciably finer than the first catch thread.

The invention will now be described further, by way of example, with reference to several practical forms thereof and the accompanying drawings in which: FIG. 1 shows diagrammatically parts of a needleloom relevant to the invention, a few warp yarns to illustrate shed formation and a portion of a woven fabric.

FIGS, 2, 3 and 4 are views similar to FIG. 1 showing different stages of a selvedge stitch formation.

FIG. 5 is a diagrammatic side elevation of a needleloom.

FIGS. 6 to 9 are views somewhat similar to FIGS. 1 to 4 showing a modification.

FIG. 10 is a view somewhat similar to FIG. 1 showing a further modification.

FIG. 11 is a view somewhat similar to FIG. 1 showing a still further modification, and FIG. 12 shows, on a very much enlarged scale, a part of a woven fabric and the selvedge stitch formation.

As shown, particularly in FIGS. 1 to 4 of the drawings the parts of one form of needleloom required to produce a fabric and a knitted selvedge includes a weft inserter 1 for inserting a weft 4 into a warp shed S, a knitting needle 2 having a latch 2a and a reed 3. These elements are well known. In addition, in the arrangements being described there are provided catch thread guide elements 6 and 7 through which pass respectively a first catch thread 8 and a second catch thread 9. The weft inserter 1 has an eye la at its free end through which passes the weft 4, and, as is usual a plurality of warp yarns 5 pass between dents 3a of the reed 3. Beyond the fell woven fabric 11 passes around and between control rollers 1 la from the loom to be wound onto a reel (not shown) or fed into a collecting can C, see FIG. 7.

The warp yarns referred to are conveniently supplied from a beam B located rearwardly of heald frames H (of which only two are shown for simplicity).

Linkages L shown in chain line on FIG. 5, are provided for the weft inserter 1, knitting needle 2, reed 3, heald frames H and catch thread guide elements 6, 7 are provided and these linkages L, within the loom body LB, are operatively associated with an operating mechanism which conveniently is in the form of a series of control cams (not shown).

With reference to FIGS 1 to 4 in particular, it will be seen that, to make a selvedge stitch in accordance with the invention the latch needle 2, as shown in FIG. 1 first moves alongside the fabric 11 in the direction of arrow A towards the reed 3 with the latch 2a in the open position. During this movement loops of the catch threads 8 and 9 located in the hook of the needle 2 pass from the hook of the needle 2 onto its shank (see FIG. 2). During the initial forward movement of the latch needle 2 the weft inserter 1 has laid a loop of weft 4 into the warp shed S. The hook of the latch needle at its extreme forward position, as shown in FIG. 2 has passed through the weft loop to engage the catch thread 8 which has been moved by its guide 6 into a position such that it can be positively engaged.The catch thread 9 is positioned to lie in front of the weft loop (that is between it and the fell) and after the latch needle hook has passed this catch thread to reach its extreme forward position the catch thread guide 7 moves to position the thread 9 in the line of movement of the hook of the now retracting latch needle before the latch 2a is closed and after it has drawn the catch thread 8 through the loop of weft A as explained below. Conveniently the guides 6 and 7 are, as stated above, controlled for movement by cams carried by the loom main shaft.Continued retraction of the latch needle as indicated in FIGS. 3 and 4 by the arrow R causes the previously formed loops on its shank to close the latch 2a to allow the hook of the needle to pass through these loops (as shown in FIG. 3) to draw the just hooked catch threads 8 and 9 through the previously formed loops (as shown in FIG. 4) to form a chain stitch.

The weft inserter 1 moves out of the warp shed as the chain stitch is being formed.

The cycle of movements is now ready to recommence after the warp shed has been changed by movement of the heald frames H. As can be seen from FIG. 12 only one of the two catch threads 8, 9 is actually passed through the weft loops to retain them. This catch thread, namely catch thread 8, is conveniently finer than the weft.

The catch thread 9 may be appreciably finer than catch thread 8 since it serves simply to enwrap the catch thread 8 to prevent unravelling.

By use of the above described process it is possible, using a needleloom of substantially standard form, to produce a nonbulky selvedge which for all practical purposes is not capable of being unravelled.

During the formation of the knitted stitches.

and by virtue of the different characteristics, such as tension and thread diameter, the second catch thread 9 tends, as the stitches are cast-off, to enwrap and 'strangle' the first catch thread 8.

While we have illustrated catch thread guides 6 and 7 in the form of levers controlled for movement from cams on the loom main shaft, one at least of the guides can, in fact, consist of co-operating means mounted on an adjacent pair of heald frames of the loom so that one of the catch threads can be 'shed' to cause it to be correctly positioned to be engaged by the hook of the latch needle, such an arrangement is shown in FIGS. 6 to 9 on which parts identical to those of FIGS. ] to 4 are indicated by like reference numerals. Only the modified parts will be referred to in detail. As can be seen the guide 6 for catch thread 8 is retained and in place of the guide 7 the catch thread 9 is controlled by operating pins 12 and 13 mounted on two adjacent heald frames H.

The knitted stitch formation is identical to that described above but the catch thread during the stitch formation is first controlled by the pin 1 3 which, starting from the position shown in FIG. 6 is 'shed' as follows.

During forward movement of the weft insertion needle 1 through the shed the thread 9 is held by the pin 13 of heald frame H in such a position that the latch needle 2 can pass above it and the weft inserting needle can pass below it as shown in FIGS. 6 and 7. The catch thread 8 is, at this part of the cycle, positioned by the guide 6 to be engaged by the hook of the latch needle 2 (see FIG. 7). Upon the commencement of the return movement of the latch needle 2 and retraction of the weft insertion needle 1 the positions of the heald frames start to reverse their relative positions thus that frame H carrying pin 13 is being lowered and frame H carrying pin 12 is being raised.This causes thread 9 to be moved into the path of the hook of the retracting latch needle to be engaged thereby before, as shown in FIG. 8, the latch 2a is closed as the previously formed loops pass off the shank of the needle 2.

The thread 9, as the pins 12, 13 pass each other (see FIGS. 8 and 91 is then brought under the control of the pin 12 to be raised so that at the next weft insertion the thread 9 is held in position to lie above the path of the weft insertion needle 1 and below the path of the latch needle 2, that is the thread 9 is again in the position shown in FIG. 6 but is now held in this position by pin 12. The weft insertion and knitting cycle now recommences.

As shown in FIG. 10 it is possible to provide an arrangement in which one thread guide is fixed in position and the other is movable. In this arrangement, elements identical to those of FIG. 1 have been given the same reference numerals as are used in FIG. 1.

Thus the modification consists in providing a fixed guide 14 for the catch thread 9. This guide 14 is conveniently fixed to a part of the loom body LB. The position of the fixed guide 14 is such that the catch thread 9 will lie in the path of movement of the hook of the latch needle 2. The catch thread 8 is provided with a movable guide 15, one end of which is pivotally attached to a fixed mounting block 16 carried by the loom body LB. Adjacent the mounting Mock 15 and secured to the guide 15 is an attachment block 16a to which is pivotally connected one end of a connecting link 17, the other end of which is pivotally connected to a control link L which extends through the loom body LB.

Also visible in this figure is the end region of one of the control links L for the reed 3.

This latter control link L projects, as can be seen through a slot 18 in the loom body LB. The control link L and connecting link 17 are so arranged as to cause, in use, the end of the guide 15 carrying the catch thread 8 to be moved in an arcuate path indicated by the double headed arrow 19 thus to enable the catch thread 8 to be moved into and out of the path of movement of the hook of the latch needle 2.

The arrangement shown in FIG. 11 is a modification of that shown in FIG. 10 in that the fixed guide 14 is dispensed with and there is provided a catch thread guide consisting of two arms 20 and 21 carried by a common pivotally mounted bar 22.

The bar 22 is pivotally mounted on a mounting block 16 and is provided with an attachment block 16a identical to that shown in FIG. 10. Movement of the two arms 20, 21 is indicated by the double headed arrow 19S. The disposition of the free ends of the arms 20, 21 is such that the catch thread 8 carried by arm 20 and the catch thread 9 carried by the arm 21 will be moved to enable the latch needle 2 to form knitted stitches identical to those described above.

Other variations and modifications falling within the scope of the invention defined by the appended claims can be envisaged. For example, it is possible to effectively prevent unravelling of the selvedge without knitting the second catch thread 9 each time a stitch is formed with catch thread 8, one ,possibility lies in the knitting of catch thread 9 with alternate stitches of catch thread 8, other possibilities do, of course, existi. In a further modification the fabric may be woven using more than one weft if desired. Alternatively a fabric having multi-ply regions such as a curtain heading tape having a pocketed face or faces can be woven. In a further alternative using a needle loom having weft inserters which enter the warp shed from each side thereof, in predetermined sequence, it is possible for both selvedges to be produced as described above.

If desired the arrangement described in relation to FIGS. 6 to 9 can be varied by providing an extra heald in the adjacent heald frames H, in this case the pins 12, 13 are not required. In a still further alternative both catch threads can either be controlled by pins on the heald frames L or by providing extra healds in the heald frames.

WHAT WE CLAIM IS:- 1. A selvedge for a needleloom fabric comprisina a first catch thread arranged to be drawn through the weft loops to form a series of chain stitches to retain loops of weft at the side of the fabric opposite to that from which they were inserted and a second catch thread arranged to form a series of chain stitches through the first catch thread only substantially to prevent the first catch thread from being unravelled.

2. A selvedge as claimed in claim 1 in which the first catch thread only is drawn through successively formed weft loops to

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. frame H in such a position that the latch needle 2 can pass above it and the weft inserting needle can pass below it as shown in FIGS. 6 and 7. The catch thread 8 is, at this part of the cycle, positioned by the guide 6 to be engaged by the hook of the latch needle 2 (see FIG. 7). Upon the commencement of the return movement of the latch needle 2 and retraction of the weft insertion needle 1 the positions of the heald frames start to reverse their relative positions thus that frame H carrying pin 13 is being lowered and frame H carrying pin 12 is being raised. This causes thread 9 to be moved into the path of the hook of the retracting latch needle to be engaged thereby before, as shown in FIG. 8, the latch 2a is closed as the previously formed loops pass off the shank of the needle 2. The thread 9, as the pins 12, 13 pass each other (see FIGS. 8 and 91 is then brought under the control of the pin 12 to be raised so that at the next weft insertion the thread 9 is held in position to lie above the path of the weft insertion needle 1 and below the path of the latch needle 2, that is the thread 9 is again in the position shown in FIG. 6 but is now held in this position by pin 12. The weft insertion and knitting cycle now recommences. As shown in FIG. 10 it is possible to provide an arrangement in which one thread guide is fixed in position and the other is movable. In this arrangement, elements identical to those of FIG. 1 have been given the same reference numerals as are used in FIG. 1. Thus the modification consists in providing a fixed guide 14 for the catch thread 9. This guide 14 is conveniently fixed to a part of the loom body LB. The position of the fixed guide 14 is such that the catch thread 9 will lie in the path of movement of the hook of the latch needle 2. The catch thread 8 is provided with a movable guide 15, one end of which is pivotally attached to a fixed mounting block 16 carried by the loom body LB. Adjacent the mounting Mock 15 and secured to the guide 15 is an attachment block 16a to which is pivotally connected one end of a connecting link 17, the other end of which is pivotally connected to a control link L which extends through the loom body LB. Also visible in this figure is the end region of one of the control links L for the reed 3. This latter control link L projects, as can be seen through a slot 18 in the loom body LB. The control link L and connecting link 17 are so arranged as to cause, in use, the end of the guide 15 carrying the catch thread 8 to be moved in an arcuate path indicated by the double headed arrow 19 thus to enable the catch thread 8 to be moved into and out of the path of movement of the hook of the latch needle 2. The arrangement shown in FIG. 11 is a modification of that shown in FIG. 10 in that the fixed guide 14 is dispensed with and there is provided a catch thread guide consisting of two arms 20 and 21 carried by a common pivotally mounted bar 22. The bar 22 is pivotally mounted on a mounting block 16 and is provided with an attachment block 16a identical to that shown in FIG. 10. Movement of the two arms 20, 21 is indicated by the double headed arrow 19S. The disposition of the free ends of the arms 20, 21 is such that the catch thread 8 carried by arm 20 and the catch thread 9 carried by the arm 21 will be moved to enable the latch needle 2 to form knitted stitches identical to those described above. Other variations and modifications falling within the scope of the invention defined by the appended claims can be envisaged. For example, it is possible to effectively prevent unravelling of the selvedge without knitting the second catch thread 9 each time a stitch is formed with catch thread 8, one ,possibility lies in the knitting of catch thread 9 with alternate stitches of catch thread 8, other possibilities do, of course, existi. In a further modification the fabric may be woven using more than one weft if desired. Alternatively a fabric having multi-ply regions such as a curtain heading tape having a pocketed face or faces can be woven. In a further alternative using a needle loom having weft inserters which enter the warp shed from each side thereof, in predetermined sequence, it is possible for both selvedges to be produced as described above. If desired the arrangement described in relation to FIGS. 6 to 9 can be varied by providing an extra heald in the adjacent heald frames H, in this case the pins 12, 13 are not required. In a still further alternative both catch threads can either be controlled by pins on the heald frames L or by providing extra healds in the heald frames. WHAT WE CLAIM IS:-

1. A selvedge for a needleloom fabric comprisina a first catch thread arranged to be drawn through the weft loops to form a series of chain stitches to retain loops of weft at the side of the fabric opposite to that from which they were inserted and a second catch thread arranged to form a series of chain stitches through the first catch thread only substantially to prevent the first catch thread from being unravelled.

form a series of chain stitches, the second catch thread being formed simultaneously into chain stitches with selected chain stitches of the first catch thread.

3. A selvedge as claimed in claims 1 or 2 in which the first and second catch threads are formed into chain stitches at each successively formed weft loop.

4. A selvedge as claimed in claims 1 or 2 in which the second catch thread is formed into chain stitches with alternate chain stitches of the first catch thread.

5. A selvedge as claimed in any one of claims 1 to 4 in which the second catch thread is of appreciably finer yarn than the first catch thread.

6. The method of producing a selvedge for a needleloom fabric as claimed in any one of claims 1 to 5 including the steps of forming successive warp sheds from a plurality of warp threads, inserting a loop of weft into each of the sheds, drawing a first catch thread through each successively inserted weft loop to produce a first series of chain stitches, and drawing a second catch thread through selected chain stitches of the first catch thread only to form a second series of chain stitches simul taneously with the selected chain stitches of the first catch thread to prevent the first catch thread from being unravelled.

7. The method as claimed in claim 6 including the step of forming the second series of chain stitches with every chain stitches of the first catch thread.

8. The method as claimed in claim 6 including the step of forming the second series of chain stitches with alternate chain stitches of the first catch thread.

9. The method as claimed in any one of claims 6, 7 or 8 including the step of in serting the weft loops through the suc- cessively formed warp sheds using a weft inserter, positioning the first catch thread in the path of movement of a latch needle hook, reciprocating the latch needle along side that edge of the fabric opposite to that at which the weft loops are inserted into the shed thereby to produce a first series of chain stitches for each weft loop, posi tioning a second catch thread in the path of movement of the latch needle hook such that it will be engaged by the hook after the latter has been drawn through the weft loop, carrying the first catch thread, and before the latch is closed thereby to form a second series of chain stitches, the second series of chain stitches being formed simultaneously with selected chain stitches of the first series of chain stitches.

10. The method as claimed in claim 9 including the step of positioning the second catch thread to be engaged by the latch needle hook to form a chain stitch of a second series of chain stitches with every chain stitch of the first series of chain stitches.

11. The method as claimed in claim 9 including the step of positioning the second catch thread to be engaged by the latch needle hook to form a second series of chain stitches, individual stitches of the second series of chain stitches being formed with alternate chain stitches of the first series of chain stitches.

12. The method as claimed in any one of claims 9, la or 11 including the step of controlling the first catch thread by means of a first guide and guiding the second catch thread by means of a second guide, the first guide at least being arranged to be moved to position the first catch thread in the path of movement of the latch needle hook, the second guide being arranged to position the second catch thread in the path of movement of the latch needle hook thus to produce two series of chain stitches in which at least the stitches of the first series are formed at each weft loop insertion.

13. The method as claimed in claim 12 in which the second guide is arranged to position the second catch thread in the path of movement of the latch needle hook each time the latch needle hook engages the first catch thread and in such manner that the first catch thread only is drawn through the successively inserted weft loops.

14. The method as claimed in claim 12 in which the first guide is arranged to be positioned to present the first catch thread to the latch needle hook each time a weft loop is inserted in the shed to produce a chain stitches for each weft loop, the second guide being arranged to present the second catch thread to the latch needle hook for the production of a chain stitch with alternate chain stitches of the first catch thread, the first catch thread only being drawn through the successively formed weft loops.

15. Apparatus for producing a selvedge for a needleloom fabric as claimed in any one of claims 1 to S including means for creating successive warp sheds, means for inserting weft into successively formed warp sheds, and means for producing a chain stitch selvedge at that side of a fabric being woven which is opposite to the side at which the weft inserting means enters a warp shed, characterised in that first and second guide means are provided for first and second selvedge forming catch threads, means for moving said first guide means to position the first catch thread in the path of movement of the means for producing the chain stitch selvedge each time the weft insertion is moved to insert a weft loop thereby to draw the first catch thread through the weft loops, and means for moving the second guide means to position the second catch thread such that it can simultaneously be drawn through selected chain stitches of the first catch thread only by the said means for producing the chain stitch selvedge.

16. Apparatus as claimed in claim 15 in which the first and second guide means are in the form of guide elements each having an eye through which a catch thread may he threaded.

17. Apparatus as claimed in claim 15 or 16 in which the first and second guide means are both movable.

18. Apparatus as claimed in any one of claims 15 or 16 in which the second guide means is fixed in position such that the second catch thread is, in use, presented to the means for producing the chain stitch selvedge each time the weft inserter is moved to insert a weft loop.

19. Apparatus as claimed in claims 15, 16 or 17 in which the first and second guide means are individually movable.

20. Apparatus as claimed in claims 15, 16 or 17 in which the first and second guide means are connected together for simultaneous movement.

21. Apparatus as claimed in claim 15 in which the first guide means is provided with an eye through which a catch thread may be threaded, said second guide means being in the form of operating elements mounted on adjacent heald frames, there being one such operating element on each heald frame whereby, in use, the second catch thread may be "shed" such as selectively to present it to the means for producing the chain stitch selvedge.

22. Apparatus as claimed in any one of claims 15 to 21 in which the means for producing the chain stitch selvedge is a latch needle.

23. A selvedge for a needleloom fabric substantially as hereinbefore described with reference to and as illustrated in Figs.

1 to 4, and Figs. 5 and 12, or Figs. 6 to 9 and Figs. 5 and 12, or Fig. 10 and Figs. 5 and 12 or Fig. 11 and Figs. 5 and 12 of the accompanying drawings.

24. The method of producing a selvedge for a needleloom fabric substantially as hereinbefore described with reference to and as illustrated in Figs. 1 to 4 and Figs.

5 and 12, or Figs. 6 to 9 and Figs. 5 and 12 or Fig. 10 and Figs. 5 and 12 or Fig. 11 and Figs. 5 and 12 of the accompanying drawings.

25. Apparatus for producing a selvedge for a needleloom fabric substantially as hereinbefore described with reference to and as illustrated in Figs. 1 to 4 and Figs.

5 and 12 or Figs. 6 to 9 and Figs. 5 and 12 or Fig. 10 and Figs. 5 and 12 or Fig. 11 and Figs. 5 and 12 of the accompanying drawings.