US3736963A

US3736963A - Weft yarn control device

Info

Publication number: US3736963A
Application number: US00210391A
Authority: US
Inventors: L Allison
Original assignee: North American Rockwell Corp
Current assignee: Draper Corp; Boeing North American Inc
Priority date: 1971-12-21
Filing date: 1971-12-21
Publication date: 1973-06-05
Anticipated expiration: 1990-06-05
Also published as: CH545361A; JPS4947657A; BR7208521D0; JPS5142228B2

Abstract

A weft yarn control device for assuring proper positioning of the weft yarn during the second phase of the weaving cycle in shuttleless looms of the type wherein weft yarn from a stationary source is inserted individually into separate sheds of warp threads in pairs of interconnected picks.

Description

June 5, 1973 [56] References Cited UNITED STATES PATENTS [54] WEFT YARN CONTROL DEVICE Inventor: Leroy K. Allison, Blacksburg, SC.

[ Assigneel North American Rockwell p 3,323,556 6/1967 Higgins et a1................i....139/127 R tion, Pittsburgh, Pa.

Dec. 21, 1971 Appl. No.: 210,391

Primary ExaminerHenry S. .laudon [22] Filed:

Attorney-John R. Bronaugh, Floyd S. Levison, E. Dennis OConnor and Richard A. Speer 1 1 Sh 0t pf mm m h r pp m o U6 mu m i o A m- R e T .wu S vd w an 00 l w 7 WM 5 [Ad R zm 2 2 H 9 BOR m m H u 9 n 3 u l c u r u a c u S L m l s c o cl UmF HUN 555 [[1 139/123, 127 R weaving cycle in shuttleless looms of the type wherein weft yarn from a stationary source is inserted individually into separate sheds of warp threads in pairs of interconnected picks.

1 Claim, 2 Drawing Figures Patented June 5, 1973 I, 3,736,963

1 1 WEFT YARN CONTROL DEVICE BACKGROUND OF THE INVENTION The invention pertains to a weft yarn control device for looms and, more particularly, to such a device for looms of the shuttleless type such as disclosed in U. S. Pat. No. 2,604,123.

In shuttleless looms to which the present invention is applicable, weft yarn is drawn from a stationary source located externally of the inserting means of the loom and is presented to carrier members reciprocated into and from sheds formed by warp threads. The weft yarn as it is drawn from its source is controlled by a mechanism which causes it to be inserted into separate sheds of warp threads in connected pairs of individual picks that are frequently termed hairpins. Generally this mechanism functions as shown and described in U. S. Pat. No. 2,604,124.

From its source of supply the weft passes through a tensioning member, then through an eyelet in a socalled yarn positioner and guide lever and then to a combined device having means for cutting, holding and then releasing the weft during the insertion of the first of a pair of interconnected picks. After this release, the yarn positioner and guide lever is effective in moving the weft laterally to a position where it is received into a so-called second pick positioner, which also forms a part of the above device, and it is then properly located for inserting the second of a pair of interconnected picks. These combined devices are well known to those familiar with shuttleless looms to which the invention is applicable and for a more detailed description of such a device attention is directed to U. S. Pat. Nos. 2,921,611 and 3,037,531.

The weaving of particular types of warp yarns, such for example as polyester blends wherein the individual fibers which are spun together to form such yarn have a large number of their ends protruding from the body of the yarn which gives the latter a bulky and fuzzy-like texture. Such warp yarns are found to be troublesome during the shedding portion of the weaving cycle, for the protruding ends of individual fibers often become entangled with the protruding ends in adjacent yarns causing a condition commonly referred to as the knitting together of warp ends. Such a condition will present an obstructed shed opening, or in other words one in which warp yarns from both the upper and lower sheet of warp yarns have knit together and have not fully crossed to form an unobstructed shed opening. This condition is not particularly troublesome inwardly from the fabric edge for as the carrier members pass through the shed, the inwardly located knitted endsare separated by the carriers. When the warp yarns knit together at the edge and adjacent the edge of the fabric, the inserting carrier as it enters the shed often passes beneath one or more of such yarns of the lower sheet of warp threads which are being held above their normal position. When an inserting carrier enters the shed in this manner the weft yarn extending therefrom which it is introducing is held below its normal path of travel. When the end is released-by the cutting and holding device and the weft then laterally shifted to be in position to be caught and held by the second pick positioner, the lower position of the weft does not permit it to be received into said second pick positioner. This results in failure to introduce the second of a pair of interconnected picks and the obvious cessation of weaving due to lack of weft yarn.

The weft yarn control device according to the present invention forms a part of the combined device for cutting, holding and then releasing the weft during the insertion of the first of a pair of interconnected picks, and is actuated in timed relation to the weaving cycle which provides a means for engaging and moving the weft yarn after its release by thecutting and holding portion to a position which assures its reception by the second pick positioner.

SUMMARY OF THE INVENTION The weft yarn control device comprising the invention is in the form of a lifting arm carried by a pivotal lever which is actuated through linkage from a suitable source of drive. This lifting arm is disposed in close proximity with the looms second pick positioner.

In timed relation with the weaving cycle the lifting arm is raised and lowered and is caused to engage the weft yarn upon its release from the cutting and holding device and to raise said weft to a position for assuring its reception by the second pick positioner.

It is a general object of the invention to improve the weft yarn mechanism so as to effect a more efficient control of the weft in shuttleless looms adapted to insert picks into separate warp sheds in connected paris of individual picks. It is a further object to provide a weft yarn control device functioning in timed relation to the weaving cycle that will engage and position the weft in a positive manner to assure its insertion when forming the second of a pair of interconnected picks.

These and other objects of the present invention will become more fully apparent by reference to the appended claims and as the following detailed description proceeds in reference to the figures of drawing wherein:

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a perspective view of a portion of a shuttleless loom showing a weft yarn control device according to the invention applied thereto; and

FIG. 2 is a view similar to FIG. 1 but showing the weft yarn control device in a position for elevating the weft yarn to a position for presentation to the loom s second pick positioner.

DESCRIPTION OF THE PREFERRED EMBODIMENT As the general construction and operation of a shuttleless loom s weft yarn mechanism is known and familiar to those conversant in weaving art and as the invention is entirely concerned with a weft yarn control device for use with such a mechanism, it is only considered necessary here to illustrate and describe that portion of the mechanism directly concerned with a preferred form of the invention.

Now referring to FIGS. 1 and 2 of the drawings a portion of a shuttleless loom is illustrated including a lay beam 10 having a reed 11 supported thereon and through which warp yarns 13 extend in the usual manner. A conventional harness mechanism (not shown) sheds the warp yarns 13 to form shed openings 14 into which a carrier member 15 is caused to enter for inserting a length of weft yarn 16. The weft yarn is acted upon by the reed in the usual way by the swinging movement of the lay beam to form fabric 17 which is held at its so-called reeded width by temples 18 (one only shown). The carrier member shown in FIGS. 1 and 2 is fixed to the end of a flexible tape 19 which by means not shown is caused to be wrapped about and unwrapped from an oscillating tape wheel so as to cause said carrier to be inserted into and withdrawn from sheds formed by the warp yarns 13.

Numeral 20 generally designates the combined device for cutting, holding, releasing and positioning the weft yarn during its insertion into separate warp sheds in the form of connected pairs of individual picks. The device includes a movable binder and cutter blade element 21 (FIG. 1) and a trap member 22 (FIG. 2) both of which are slidably supported on an elongated arm or bracket 23. When actuated the trap member 22 moves into contact with the forward end of a stem 24 that is fixed on the rearward end of bracket 23 and serves to complete a weft trap or the so-called second pick positioner, the structure and operation of which is described in US. Pat. No. 2,604,123.

The forward portion of bracket 23 is suitably adapted for attachment to the side of a weft control housing (not shown) having a cover 25 and which contains cam and tappet mechanisms of the weft yarn mechanism disclosed and described in the U. S. Pat. No. 2,604,123 above-mentioned.

One cam and tappet mechanism actuates the cutter blade element 21 to first cut, hold and release the weft during the insertion of a first of a pair of interconnected picks and then to move the trap member 22 so as to trap the weftand position it for the second of the pair of interconnected picks.

This same cam and tappet mechanism (not shown) functions to actuate the weft yarn control device according to the invention now to be described.

Bracket 23 is provided with a pair of spaced and laterally extending ear elements 26 (a portion of one only shown) which include aligned openings for supporting the usual spring biased rod (not shown) for reciprocating movement. This spring biased rod carries the cutter blade element 21 as well as the trap member 22 and is actuated by the above-mentioned cam and tappet mechanism. t

A vertically extending lug element 27 is fixed to the end of the spring biased rod and in a known manner is effective in pivoting a weft yarn positioner and guide lever 28 between positions which are effective in locating said weft yarn to effect the first and then the second of a pair of interconnected picks.

On the rearward side of and adjacent the top of the lug element 27 there is provided a fixed and laterally extending finger 29. By means of a screw 30, one end of an adjustable connecting link 31 is attached to the end of finger 29. The opposite end of the connecting link 31 is pivotably assembled by means of a pin 32, within a bifurcated end 33 of a double armed lever 34. The hub portion of this double armed lever 34 is pivotably assembled by means of a bolt 35 to the side of the bracket 23 adjacent the rearward end thereof. The double armed lever 34 is disposed generally vertically and its lower arm includes a foot portion 36 having a forwardly directed lifting arm 37 adjustably assembled therein.

To summarize the operation, the weft yarn as it is drawm from its source of supply extends through a pivotal weft yarn positioner and guide lever which is effective in locating the weft so as to permit its insertion into separate sheds of warp yarns in connected pairs of individual picks. To begin the weaving cycle, the weft yarn is cut and the end held when the carrier enters the shed to insert the first of a pair of interconnected picks. When sufficient weft yarn has been drawn to complete the pick the held end is released and drawn through the shed to complete said pick. When the weft yarn is released the weft yam positioner and guide lever commences to pivot so as to move the weft to a position to be trapped by the second pick positioner and in readiness for insertion of the second of the pair of interconnected picks. As the lug element moves inwardly, or in the direction of the indicating arrow 38 (FIG. 2), to

pivot the weft yarn positioner and guide lever, it moves finger 29 in a like direction which in turn pivots the double armed lever 34 so as to raise the lifting arm 37. The raising of the lifting arm 37 elevates the weft yarn and assures its trapping by the second pick positioner. During the insertion of the second of a pair of interconnected picks, which completes the picking cycle, the weft 16 is released by the second pick positioner as the trap member 22 is caused to move forwardly according to the dictates of the aforementioned cam and tappet mechanism. During this movement the weft yarn positioner and guide lever are pivoted to that position which places the weft yarn in position to repeat the picking cycle after being cut and then held by the binder and cutter blade member 21. When sufficient weft has been withdrawn to complete the second of the pair of interconnected picks the binder and cutter blade member is actuated and the severed end of weft is carried through the shed to complete said second pick.

The weft now extends between its source of supply and the binder and cutter blade member 21 and is in readiness for the next picking cycle.

Intermediate the weft source of supply and the binder and cutter blade member the conventional weft depressor member (not shown) is effective in drawing the weft downwardly to a position for pick up by the inserting carrier during its initial movement toward the shed. When the inserting carrier'has traveled a sufficient distance into the shed to have withdrawn enough weft to complete the pick, the binder and cutter blade member is moved rearwardly to release the held end of weft. This movement as heretofore described is effected by the cam and tappet mechanism within the weft control housing which also causes the lifting arm 37 comprising the invention to be pivoted upwardly.

During insertion of the first of a pair of interconnected picks the pivotal movement of the lifting arm 37 serves no purpose and is intended only to raise the weft, after release by the binder and cutter blade member, a sufficient distance so as to be received and trapped by the second pick positioner just prior to insertion of the second of the pair of interconnected picks.

The dotted line 16' in FIG. 2 identifies weft yarn which is being held below its normal path of travel due to entering the warp shed 14 beneath one or more yarns of the lower warp sheet that have knit together with adjacent yarns of the upper warp sheet. In this position the weft cannot be trapped in the second pick positioner and the lifting arm 37 according to the invention provides a positive means for raising said weft to a position to be trapped by said second pick positioner.

Although the present invention has been described in connection with a preferred embodiment, it is to be unnected picks by means of reciprocating carrier means, a weft yarn control device comprising a clamping member for temporarily holding and then releasing an end of weft while inserting the first of a pair of interconnected picks, a second pick positioner for locating the weft for insertion of the second of a pair of interconnected picks, and a lifting arm for moving the weft after release by said clamping member to a position to be received by said second pick positioner.

Claims

1. In a shuttleless loom of the type wherein weft yarn drawn from a stationary source is inserted individually into separate sheds of warp threads in pairs of interconnected picks by means of reciprocating carrier means, a weft yarn control device comprising a clamping member for temporarily holding and then releasing an end of weft while inserting the first of a pair of interconnected picks, a second pick positioner for locating the weft for insertion of the second of a pair of interconnected picks, and a lifting arm for moving the weft after release by said clamping member to a position to be received by said second pick positioner.