GB2138455A

GB2138455A - Woven fabric

Info

Publication number: GB2138455A
Application number: GB08409933A
Authority: GB
Inventors: John Dalton Griffith
Original assignee: Bonas Machine Co Ltd
Current assignee: Bonas Machine Co Ltd
Priority date: 1983-04-20
Filing date: 1984-04-17
Publication date: 1984-10-24
Also published as: GB2138455B; GB8409933D0

Abstract

A woven fabric woven on a needle loom has the weft loops secured by a knitted thread construction, the secured weft loops being located inboard of the warp thread defining the opposite edge of the fabric to the edge whereat weft insertion has taken place and the knitted thread construction being woven between warp threads positioned adjacent opposite said edge. The selvedge knitting needle knits more than one loop per weft insertion. <IMAGE>

Description

SPECIFICATION Woven fabric The present invention relates to a woven fabric produced on a needle or rapier weaving loom, a method of weaving the fabric and a loom for weaving the fabric.

When weaving fabric on a needle loom the weft yarn is always inserted from one side of the fabric by a needle or rapier and the weft yarn has to be secured at the opposite side before the needle retracts. After retraction the warp yarns are moved to create a new shed pattern thereby trapping the weft yarn therebetween.

In the accompanying drawings, Figs. 1 to 4 illustrate four different conventional methods for securing the weft yarn.

In Fig. 1 a latch needle (not shown) is used to knit loops 1 2 of weft yarn 11 to one another. Although this method is simple it necessarily creates a bulky edge and in some cases, if this edge is cut or damaged unravelling of the weft yarn can result.

In Fig. 2 a catch thread 1 5 which is separate to the weft yarn 11 is knit so as to form a chain stitch which passes through the loops 1 2. This method creates a neater edge but is even easier to unravel.

In Fig. 3 an additional thread 1 6 is knitted in with the catch thread 1 5 in order to restrain unravelling. Thread 1 6 is usually referred to as a lock thread. Although the lock thread 1 6 makes unravelling more difficult it necessarily makes the edge bulky.

In Fig. 4, a lock thread 1 6 is knitted with loops 1 2 to provide an edge which is resistant to unravelling. Unfortunately, such an edge is necessarily bulky.

Apart from the methods illustrated above there are other methods used which are variations of these methods. For example two catch threads may be knitted in the manner illustrated in Fig. 1 but they pass through different loops 1 2 so that if one caatch thread is broken unravelling of the edge of the fabric is still restrained by the other catch thread.

It is a general aim of the present invention to secure the loops 1 2 of weft yarn in a manner which restrains unravelling without creating a bulky edge.

According to one aspect of the present invention there is provided a woven fabric which has been woven on a needle loom wherein the weft loops are secured by a knitted thread construction, the secured weft loops being located in board of the warp thread defining the opposite edge of the fabric to the edge whereat weft insertion has taken place and the knitted thread construction being woven between warp threads positioned adjacent said opposite edge. The knitted thread construction may comprise a single thread or several threads which are knitted together to define a stitch construction which is resistant to unravelling. More than one knitted thread construction may be provided, each thread construction being arranged to secure selected loops of weft yarn.Preferably, the denier of the or each knitted thread construction is chosen to be approximately the same as the denier of the weft yarn.

According to another aspect of the present invention there is provided a method of weaving fabric on a needle or rapier loom including producing a knitted thread construction at the opposite side of the warp sheet to the side at which the weft yarn is inserted, the thread construction being knitted so as to catch the weft yarn as it protrudes beyond said opposite side and being knited at a sufficiently fast rate so as to be pulled in board of said opposite edge before beat up.

Various aspects of the present invention are hereinafter described with reference to the following accompanying drawings, in which: Figure 5 is a schematic illustration of fabric according to the present invention being shown during weaving; Figures 6 to 8 are schematic illustrations showing a sequence of operations in weaving in accordance with the present invention.

Referring initially to Fig. 5 there is shown a portion of fabric 20 which is located adjacent to the opposite edge 21 to the edge at which insertion of the weft yarn 11 takes place. As seen a knitted thread construction 23 in the form of a string of stitches extends in a sinusoidal manner in the warp direction to interconnect with loops 1 2 of the weft yarn 11. As illustrated the thread construction extends across three warp threads 1 5 to be woven therebetween. In Fig. 6, the thread construction 23 is created by knitting a chain stitch from a single thread 24 by means of a reciprocating latch needle 28 in a manner to be described hereinafter. Preferably the denier of the thread 24 is chosen so that after knitting, the thread construction 23 is of similar denier to the weft yarn 11.

Accordingly, a selvedge is created at said opposite edge which is equivalent to the selvedge at the edge at which weft insertion takes place and thereby a neat edge is produced. Additionally since the thread construction 23 is woven between the warp threads the thread 24 is trapped thereby and so discourages unravelling of itself and the weft yarn.

It is envisaged, however that thread 24 may require some additional locking. Accordingly the thread construction 23 may comprise two or more threads which may be knitted to form a string of stitches resistant to unravelling. This could be achieved for example by either a) using an additional locking thread (analgous to that shown in Fig. 3) which could lock some or all of the catch thead stitches or b) using two catch threads to perform the function of thread 24. These could be used to form stitches alternatively or in any other combination.

By way of illustration, a method of weaving fabric according to the present invention is represented in Figs. 6 to 8.

In Fig. 6 the weft needle 30 has fully inserted the weft yarn 11 and is about to retract. As is conventional the latch needle 28 has advanced through the new loop 1 2 formed by the needle 30 to pick up the yarn 24. The latch needle 28 retracts and the needle 30 begins to retract. In order to enable the loop 1 2 to be drawn in board of the edge of the fabric, the latch needle knits at least one more loop before the needle 30 reaches its fully retracted position. Accordingly, for each pick (i.e. the insertion and retraction of the weft needle) the latch needle 28 knits at least twice. This sequence is illustrated in Figs 7 and 8 wherein in Fig. 7 the latch needle has advanced a second time- to pick up thread 23 and in Fig. 8 the needle 28 has retracted to cast off. Accordingly, if it is desired to position the weft loops 1 2 further inboard from the edge of the fabric the latch needle is arranged to knit more stitches per pick for course adjustment and loops of a tighter or looser nature for fine adjustment.

This mode of knitting provides a further advantage in that in the conventional methods previously illustrated, the knitted loops of the catch thread and, where provided, lock thread have to be small in order to create a neat finish. With the present method this is not necessary since the knitted loops are pulled, and thereby tightened, by the weft yarn 11 during retraction of needle 30. Accordingly problems associated with the setting of the latch needle to produce tight loops are avoided.

Claims

1. A woven fabric which has been woven on a needle loom wherein the weft loops are secured by a knitted thread construction, the secured weft loops being located in board of the warp thread defining the opposite edge of the fabric to the edge whereat weft insertion has taken place and the knitted thread construction being woven between warp threads positioned adjacent opposite said edge.

2. A woven fabric according to Claim 1 wherein the knitted thread construction comprises a single thread knitted to form a string of stitches.

3. A woven fabric according to Claim 1 wherein the knitted thread construction comprises several threads which are knitted together to define a string of stitches which is resistant to unravelling.

4. A woven fabric according to Claim 1 including more than one knitted thread construction, each thread construction being arranged to secure selected loops of weft yarn.

5. A woven fabric according to Claim 1, 2, 3 or 4 wherein the denier of the or each knitted thread construction is approximately the same as the denier of the weft yarn.

6. A method of weaving fabric on a needle or rapier loom including producing a knitted thread construction at the opposite side of the warp sheet to the side at which the weft yarn is inserted, the thread construction being knitted so as to catch the inserted weft yarn loop and being knitted at a sufficiently fast rate so as to be pulled in board of said opposite side of the fabric before beat up.

7. A method of weaving according to Claim 6 wherein the thread construction is knitted using a reciprocating needle and wherein said reciprocating needle undergoes at least two stitch forming reciprocations during each pick of the weft insertion needle or rapier.