US3857419A

US3857419A - Weft gripper for shuttleless looms

Info

Publication number: US3857419A
Application number: US00392906A
Authority: US
Inventors: W Mackie
Original assignee: James Mackie and Sons Ltd
Current assignee: James Mackie and Sons Ltd
Priority date: 1972-08-31
Filing date: 1973-08-30
Publication date: 1974-12-31
Anticipated expiration: 1991-12-31
Also published as: FR2334774B1; ES437055A1; FR2334774A1; BR7306768D0; BE804327A; JPS5285563A; NL7312008A; GB1447861A; DE2344123A1; IT993819B; DD110313A5; ES418352A1; JPS4992365A; CH582261A5; CH579163A5

Abstract

A weft inserter for a shuttleless loom of the transfer type having a pivoted lever carrying or formed with a yarn hook at one end the hook being located adjacent the leading end of the inserter and the lever being pivotally mounted to the inserter adjacent the hook.

Description

United States Patent 1191 Mackie Dec. 31, 1974 WEFT GRIPPER FOR SHUTTLELESS [56] References Cited LOOMS UNITED STATES PATENTS [75] Inventor: W. Denis Grenville Mackie, 2,960,118 11/1960 Ancetet al. 139/122 Templepatrick, Northern Ir la d 3,390,707 7/1968 Scheril1o.. 139/122 3,532,136 10/1970 0010mm. 139/122 Assigneez James Mackie & Sons, Llml 3,578,031 5/1971 Maassen 139/122 Belfast, Northern Ireland 3,613,741 10/1971 Ravella 139/ 122 [22] Filed: 1973 Primary Examiner-Henry S. .laudon [21] App]. No.: 392,906 Attorney, Agent, or Firm-Pollock, Philpitt & Vande Sande [30] A F ;):'e1lg9n7 :prg1ca:1gntP'r1or|ty Data 40498/72 [57] ABSTRACT rea n am A weft inserter for a shuttleless loom of the transfer type having a pivoted lever carrying or formed with a C(i1 y hook at one end the hook being located adjacent [58] Fieid 122 R 123 the leading end of the inserter and the lever being piv- 139/127 otally mounted to the inserter adjacent the hook.

9 Claims, 9 Drawing Figures WEFT GRIPPER FOR SHUTTLELESS LOOMS This invention relates to shuttleless looms of the transfer type, i.e., looms in which the weft thread is carried through the warp shed by means of two weft inserters, e.g., spears or rapiers each being reciprocated into and out from the shed from opposite sides of the loom respectively, one spear gripping the weft thread to carry the weft into the shed, the thread being then transferred at the centre of the shed to the other spear which is then driven outwardly to carry the thread through the remainder of' the shed.

Hitherto it has been proposed to hold the thread transversely across one spear and to provide a barbed hook on the other spear which passes beneath the thread and which on withdrawal catches the thread on the barb, the hook causing the weft to be led to a clamp which tightly holds the weft to pull it across the second half of the shed. The weft then has to be pulled out from the clamp at the right hand side of the loom and this may damage the yarn.

An inserter for a shuttleless loom in accordance with the invention has a pivoted lever carrying or formed with a yarn hook at one end the hook being located adjacent the leading end of the inserter and the lever being pivotally mounted to the inserter adjacent the hook. A yarn clamp surface is preferably provided adjacent the hook so that yarn can be trapped between the hook and the clamp surface and the position of the pivot of the lever enables the yarn to be clamped tightly and positively.

The inserter preferably has two levers one carrying the hook at its outer end and being pivotally mounted on the leading end of the inserter at a point closely adjacent the hook and the other being pivotally mounted between its ends and having its leading end movably connected to the trailing end of the first lever. Pivotal movement ofthe second lever, the pivot point of which is preferably nearer the trailing end than the leading end, caused, for example, by a small downward movement of the trailing end, then provides a positive and relatively large movement of the first lever to enable the hook to be moved to a position to release the yarn. It also enables the hook to be moved to an open position during yarn engagement and immediately thereafter closed, tightly to clamp the yarn. This has significant advantages with certain yarns but is need not be employed with all yarns.

Such a hooked inserter may be modified by the provision of a deflector located to one side of the hook and so designed and arranged as to cause weft yarn held by an inserter designed to lead the weft into the shed to be engaged by the deflector on the two inserters meeting, to be guided over and down behind the hook so that the yarn is caught properly by the hook when the inserters move apart.

A shuttleless loom of the transfer type in accordance with a further feature of this invention has an opener, for the yarn gripper of a weft inserter, which extends over a plurality of warp threads and which is arranged to act through the warp to operate the gripper of an inserter passing through the shed.

The opener may, for example, comprise a block or bridge member possibly attached to the reed and arranged to press on the inserter through the intermediary of the warp threads or preferably for weak yarns it may comprise a row of plates or rods each of which projects down through the warp threads between pairs thereof.

As the opener extends over a plurality of warp threads preferably at the centre of the shed, the wear and tear on the inserter is reduced as the gripper can be opened and closed at any desired speed and for any desired period merely by altering the length of the opener. It will be appreciated that a loom having such an opener for the yarn gripper of a weft inserter may be used either with the particular inserter defined above or with any other weft inserter.

A loom incorporating the inserter of this invention is conveniently provided with an opener as defined above to pivot the hooked lever to open the gripper of the inserter receiving the weft thread during weft release and/or weft transfer. In this case the opener is designed to engage a part of the inserter during the desired period to open the gripper just before weft transfer and to maintain it open long enough for the weft end to be correctly and fully inserted into the gripper. Subsequently the hooked lever is pivoted to clamp the weft yarn. A similar opener may be provided beyond the shed to open the gripper to release the weft thread.

Such an arrangement when applied to either of the inserters defined above would operate to move the hook from the clamp plate so that the weft is pulled fully into the crotch of the hook and clamp plate thus ensuring that the weft thread is firmly clamped during transfer and does not have to overcome spring loading by being forced between the hook and the plate. For this reason it is particularly suitable for weaker threads.

The invention will now be further described by way of example with reference to the accompanying drawings in which:

FIGS. 1 and 2 are diagrams illustrating the inserter which is shown as a right hand" inserter at two stages of operation;

FIG. 3 is a perspective view of the inserter;

FIG. 4 is a diagram illustrating an alternative embodiment of inserter;

FIG. 5 is a plan view of the inserter of FIG. 4;

FIGS. 6 and 7 are diagrams showing the right hand inserter of FIGS. 1-3 in use on a modified loom;

FIG. 8 is a perspective diagram of part of the modified loom showing the means to open the gripper of the right hand inserter; and

FIG. 9 is a diagram corresponding to FIG. 8 showing an alternative opening means.

The shuttleless loom in which the inserter of this invention is to be used if of the transfer type in which weft yarn is carried into the shed by a conventional left hand inserter which reciprocates into and out from the left hand side of the shed and then transferred at the centre of the shed to a right hand inserter in accordance with the invention which reciprocates into and out from the right hand side of the shed and which acts to pull the weft through the right hand side. The usual shed forming devices, reed etc., none of which are shown are, however, present.

Each spear has a gripper to grip a length of weft yarn and pull it through one half of the shed.

The right hand spear 2 shown in FIGS. 1-3 has a hooked arm 4 pivoted at 6 adjacent its leading end and adjacent, but forward of, the hook 8. The rear end 10 of the arm 4 is engaged by the leading end 12 of a second arm 14 which is pivoted to the spear at 16 at a point between its ends. The rear end of the second arm is bowed at 18 and is urged by a spring to a position in which the lower face of the hook 8 is held against a shoulder 22 of the spear to provide a clamp.

As the distance A (see FIG. 3) between the leading end 12 and the pivot 16 of the second arm is greater than the distance B between the top of the bowed rear end of the arm and the pivot, a short downward movement on the rear portion of the arm causes a larger rise of the leading end and a positive movement of the hook. Equally, the thrust supplied by the spring 20 normally holds the hook tightly clamped against the shoulder 22.

When the spears meet at the centre of the shed the hook 8 passes beneath a weft yarn length indicated at 24. As the right inserter reverses the weft is caught by the hook 8 and is clamped between the hook and shoulder 22. The yarn is then pulled from the left hand inserter to be carried to the right hand side of the shed. As the right inserter 2 collects the weft during transfer from the left the hook 8 remains urged towards the shoulder 22 by the spring 20 so that the weft is simply pulled forcibly between the two as the spears reverse their directions. To facilitate this transfer the hook is curved upwardly so as to provide a substantial lead-in for the weft end.

The right spear 2 continues to lay the weft into the remaining half of the shed until the bowed portion 18 of arm 14 engages a bridge member 26 positioned outside the shed which causes the arm 14 to pivot in a clockwise direction about its pivot 16 and the end engaging the recess of lever 4 rises to lift the lever 4 and consequently the hook 8 is disengaged from the shoulder 22 to release the weft end. The inserter continues to move to the right for a small distance to leave the trailing end outside the shed.

In order to grip various weights of yarn between the hook and shoulder the spring 20 may have to be changed. This operation is simply accomplished by taking out the pivot pin 16, lifting off the lever 14 and removing and replacing the spring.

Referring to FIGS. 4 and 5, these show a right hand" inserter similar to that described with reference to FIGS. 1-3 but modified by the provision ofa deflecting member 27 runningparallel with the straight portion of arm 4 and connected thereto at its rear end. This deflector has its free end pointing towards the front of the inserter and extends beyond the free end of the hook 8 which points towards the back of the inserter. The underside of the member 27 is curved downwardly so as to deflect the weft and maintain it under tension as it travels over the upper surface of the hook during transfer from the left to right hand inserter. When the weft reaches the end of the hook it immediately springs down into the slot 28 and on reversal of the inserters is gripped in the hook as previously described. As the bottom of the slot 28 is at least level or slightly lower than the shoulder 22 and the end of the hook 8 curves upwardly to prevent the weft from escaping, there is virtually no possibility of losing a weft end during transfer.

The modified inserter may be used with a conventional left hand" inserter which holds the weft in such a way as to present it between the deflector and the hook of the modified right hand inserter.

Referring to FIGS. 6-9 the modified loom therein illustrated is adapted to open thegripping device of the right hand inserter during transfer of weft from the left hand inserter. Whilst the right hand inserter shown is that hitherto described with reference to FIGS. 1-3 it will be appreciated that the inserter of FIGS. 4 and 5 could be used.

The means to open the gripper, i.e., the hook 8, comprises a plate 30 angled upwardly at each end and fixed to the reed 32 of the loom. During operation this plate actually presses on the warp threads in order to reach the bowed portion 18 of the lever 14 and because the threads will be sandwiched between the plate and the moving lever a resilient pad, e.g., of felt 34 is provided under the plate. The plate is connected to the reed by bars 36 which are bolted to a block 38 positioned on top of the reed the bolts passing through slots 40 in the bars to permit vertical adjustment, determined by the amount of opening required and slots may also be required in the block 38 to allow horizontal adjustment.

In the case of very weak warp yarns which cannot bear the strain of the plate pressing on them a row of thin dividing plates 42 (see FIG. 9) lying between and parallel with the warp threads 44, could be used instead of the plate 30. In other words, the opener actually penetrates the warp to make contact with the inserter without interfering with the warp threads.

When the right hand inserter approaches the left hand inserter it moves from the position of FIG. 6 to that of FIG. 7 the bowed portion 18 of the lever 14 passes under the plate 30 which acts to pivot the lever in a clockwise direction to raise the hook 8 from the clamp surface 22 and to hold the hook in its raised position whilst the weft thread is fully engaged between the hook and the clamp as hereinbefore described. On reversal of the inserter 2, the bowed portion leaves the plate allowing the spring 20 to pivot the hook to its clamp position as shown in FIGS. 8 and 9 to carry the weft thread through the right hand portion of the shed.

Instead of the bridge plate 30 shown in FIGS. 6-8 the gripper opener may comprise a block of the material known as Tufnol at least the ends of which are curved to give gentle opening and closing of the gripper.

The opener of whatever type extends over a plurality of warp threads e.g., 18 to give effective and reasonably gentle opening and closing of the gripper in the centre of the shed.

I claim:

1. A weft inserter for a shuttleless loom of the transfer type having a pivoted lever, a yarn hook formed integrally with one end of said lever, said hook being located adjacent the leading end of the inserter and the lever being pivotally mounted to the inserter adjacent the hook.

2. An inserter as claimed in claim 1 in which a yarn clamp surface is provided adjacent the hook so that yarn can be clamped between the base of the hook and said clamp surface.

3. An inserter as claimed in claim 1 in which said lever is pivotally connected to the body of the inserter at a point between the hook and the leading end of the inserter.

4. A weft yarn inserter as claimed in claim 1 including a second lever pivotally mounted between its ends and having its leading end pivotally connected to the trailing end of said first lever.

8. An inserter as claimed in claim 4 in which the trailing end of the first lever is formed with a recess receiving the leading end of the second lever.

9. An inserter as claimed in claim 1 including a deflector located to one side of said hook and arranged to guide weft thread being received by the inserter over and down behind said hook.

Claims

5. An inserter as claimed in claim 4 in which the position of the pivot of said second lever is nearer the trailing end of that lever than the leading end.

6. An inserter as claimed in claim 4 in which the trailing end of said second lever is bowed upwardly.

7. An inserter as claimed in claim 4 in which the trailing end of the second lever is biased by a spring to a position in which the base of the hook is held downwardly against the body of the inserter.