GB2145121A - Gripper Axminster looms - Google Patents

Abstract

A gripper Axminster loom comprises a yarn carriage, yarn carriers 10 and associated jacquard lifting mechanism, yarn grippers 14 and a pile yarn cutter 20, wherein tufts of yarn are first drawn by carriage draw off followed by gripper push off and the jacquard cam is profiled so as to allow selected yarn carriers to drop between carriage draw off and gripper push off thereby allowing, in the same row, short tufts to be cut and then to return to the operative position for gripper push off thereby allowing long tufts to be cut. <IMAGE>

Description

SPECIFICATION Sculptured Axminister loom This invention relates to a loom forweaving a pile fabric and in particular relates to a loom ofthe Gripper Axministertype capable of producing sculptured pile effects.

GripperAxminister loomsforthe production of axminister carpets are well known. Briefly, they operate by presenting by means of a yarn carriage mechanism operated by a jacquard system, yarns to yarn grippers, relative movements between grippers and the yarn carriage causes a tuft to be formed which is then cut by a knife mechanism, and the gripper then carries the cut tuft of yard to a station where it is interwoven with the carpet backing thereby producing a tufted pilefabric.Such loomsfall into two basic categories: in the first, after the gripper grips the pile yarn it remains stationary and the yarn carriage moves backwards thereby causing the tuft of yarn to be be pulled; in the second, the yarn carriage remains stationaryandthe gripper moves awayfrom it, in a motion known as gripper push off, again resulting in the tuft of pile yarn being produced.

It has hitherto been possible to produce 'sculptured' effects, that is variation in pile height but, since the yarn tufts across the width of the carpet being woven are pulled simultaneously, it has hitherto only been possible to produce long and shorttufts in successive rows of weft. Thus in any pattern for a sculptured pile, the shorttufts are woven in one weaving cycle, and the long tufts in the next successive cycle. This effectively halves the production rate in comparison to the weaving of conventional single pile length carpet.

The invention seeks to provide a modified form of GripperAxminister loom which is capable of producing sculptured pile effects at production rates comparable with those of single pile height carpets.

According to the present invention there is provided a GripperAxminister loom which comprises a yarn carriage, yarn carriers and associated jacquard mechanism, yarn grippers and a pile yarn cutter characterised in that cams are provided capable of drawing tufts of yarn first by carriage draw off followed by gripper push off, the jacquard cam is profiled so asto allowselected yarn carriers to drop away between carriage draw off and gripper push off thereby allowing short tufts to be cut, and to return to the operative position for gripper push offthereby allowing long tuftsto be cut.

The provision of both carriage draw off and gripper push off, in timed sequence, in conjunction with a modified profileofjacquard cam, enablesfirsty short yarn tufts and secondly long yarn tufts to be drawn on the same weft cycle and woven into the carpet thereby providing a toom capable of producing sculptured effects atthe same production rate as is possible for conventional single pile length carpets.Since, once thejacquard mechanism has selected the yarn carrier heightfora particular colour, it is normal for a selector baror'gagging' barto interengagewith notches at the back ofthe yarn carrierto hold it in position, it is necessaryto modifythe yarn carriage used in the loom ofthe invention so thatthey do not interengage with the gagging bar when selected for long tufts so thatthe dropping away motion programmed into the jacquard cam will result in the carriers dropping away from the cutterwhen programmedfor long tufts.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure lisa perspective view of a modified cutting mechanism for use with a loom in accordance with the invention; Figure 2 is a side view of a modified yarn carrier; Figure 3 is a partial diagrammatic view of the cutter operating mechanism; Figure 4 is an enlarged partial view ofthe cutting mechanism; Figure 5 illustrates on an enlarged scaletwoforms ofyarn carrier; and Figure 6 illustrated the gripper action.

Referring to the drawings, the invention concerns a modification of a standard Gripper Axminister carpet loom the operation of which iswell understood in the art, and thus onlythe modifications introduced in accordance with the invention will be described here in detail. The loom is provided with the normal yarn storage creel for pile yarn together with, the usual methods of introducing warp weft and stufferyarn for the production of an axminister carpet,for example as described in 'Modern Carpet Manufacture' (1958) by A. Crossland. The loom in accordance with the invention has its camming modified so asto be able to produce, in sequence, both a carriage draw off motion and a gripper push off motion as explained more fully hereinafter.

The loom has a yarn carriage in which are located, in side by side relationship as is well known in the art, a pluralityofyarn carriers 10. Pile yarns of eight different colours are sandwiched between adjacent carriers 10 as illustrated in figure 6. The upper portion 12 of the carriers loins connected to a jacquard mechanism which raises or lowers the carriers to one of eight positions allowing the correct yarn to be selected by a yarn gripper 14 (figure 6). The jacquard mechanism is programmed by a punched car, chain or the like as is well known in the art. The yarn carrier 10 illustrated in figures 2 and 5a has four notches or detentes 16 above a relieved portion 18.A conventional yarn carrier ofthe same type would have eight notches 16 and no relieved portion 18. Each ofthe notches 16 is engageable with a gagging bar (not shown) after the jacquard mechanism has selected the yarn carrier height to maintain the carrier atthat heightwhile the gripper selects a tuft oftheyarn of the requisite colour.

In the operation of a normal conventional axminister loom once the gripper had taken hold ofthetuft of yarn as illustrated in figure 6 eitherthe carriage 10 would move backwards,that is to the right as viewed in figure 6, orthe gripperwould move to the left as viewed in figure 6 thereby pulling the tuft of yarn after which it would be cut by the yarn cutter, then the gripperwould pivot away from the carrier 10 and place the cut tuft of yarn in the weaving zone where it would be interwoven with the remainder of the fabric.

In the operation ofthe loom modified in accordance with the invention the jacquard mechanism lifts the yarn carriers 10 to presentthe selected yarn to the grippers 14, afterwhich a carriage draw off motion takes place pulling tufts. The jacquard operating cam is modified in accordance with the invention so that at this stage theyarn carriers 10 drop slightly.

However,the carriers selected for yarns 1 to 4 do not drop sincethegagging barinterengagedwith the notches 16 retains these carriers in place; butthe carriers programmed foryarn 5 to 8 can drop since the gagging bar has no engagement within the relieved portion 18. Thus carriers selected for yarns 5 to 8 will move downwardlywhereas yarn carriers selected for yarns 1 to 4will remain in position. Atthis stage the cutter is operated cutting only those yarns remaining in position, that is yarns 1 to 4. The jacquard cam now brings the carriers that have dropped back into the original position and a gripper push off motion takes place causing the tufts ofthose yarns as yet uncut (5 to 8) to be elongated further, after which a second curt takes place.Thereafter the grippers move to allow the yarnsto bewoven in in a similar manner to conventional looms. The double yarn tuft pulling action togetherwith the double cut and the dropping away ofthe 'long' yarns in between the two cuts, allows both short and long yarns to be pulled and cut on the same cycle of operation and then both woven simultaneously into the same weft rowwhich has not hitherto been possible.

It has beenfoundpreferableto incorporate a modified cutting mechanism 20 in the loom ofthe invention which briefly comprises a main body 22 having a serrated lower edge 24the notches of which will each receive a pile yarn 26. Knife blades 28 are mounted on arms 30 each operated by a rod 32 so as to produce a cutting motion. The rod 32 is connected byasuitable linkageto an operating cam 34driven by the main drive of the loom. Itwill be seen thatthe cam 34hastwo lifting lands36with a relieved portion between thus producing two cuts per cycle as described above.

Figure 5b illustrates a modified form ofyarn carrier 1 Oa in which the notches 16 are replaced by movable pins 38. Inthe yarn carrier illustrated in figure 5a only yarns 1 to 4can be selected for shorttufts and only yarns 5to 8 can be selected for long tufts since the profile ofthe notches 16 and the relieved portion 18 is produced at manufacture. However with the modified version shown infigure5b,the numberof long and shorttuftswhich can be selected can be varied by moving the pins on individual carriers to the right or the left so asto interengagewith the gagging bar and produce shorttufts or asto be clear of the gagging bar and thereby produce long tufts.

The loom of the invention provides a simple way of producing a widevariety of designs of-sculptured axminister carpet atsubstantiallythe same produc tion rate as a standard single pile length carpet.

Claims (8)

1. A gripperAxminister loom which comprises a yarn carriage, yarn carriers and associated jacquard mechanism, yarn grippers, and a pile yarn cutter characterised in that cams are provided capable of drawing tufts of yard first by carriage draw off followed bygripper push off, the jacquard cam being profiled so as to allow selected yarn carriersto drop away between carriage draw off and gripper push off thereby allowing short tufts to be cut, and to return two the operative position for gripper push off thereby allowing long tufts to be cut.

2. A loom as claimed in claim 1 in which the yarn carriage is modified so thatthe gagging bar does not interengage with the yarn carrierwhen selected for long tufts.

3. A loom as claimed in claim 3 in which the yarn carriers have four notches or detentes above a relieved portion.

4. A loom as claimed in any one of claims 1 to 3 having means for providing a double cutting action, the first cutting shorttuftsandthesecondcutting long tufts.

5. A loom as claimed in claim 4 in which the cutting mechanism comprises a main body having serrated lower edgesthe notches of which each receive a pile yarn and having knife blades mounted on arms to produce a cutting motion of the yarns located in the notches.

6. A loom as claimed in claim 5 in which the knife blades are operated by means of a cam having two lifting lands separated by a relieved portion thereby producing two cuts per cycle.

7. A loom as claimed in any one of claims 1 to 6 in which the yarn carriers have, instead of fixed notches, movable pins so that the number of long and short tufts which can be selected can be varied by moving the pins on individual carriers so asto interengage with the gagging bar and produce shottufts whereas to be clear of the gagging bar and thereby produce long tufts.

8. AgripperAxminister loom substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.