US3777787A

US3777787A - Weft carrier tape guide

Info

Publication number: US3777787A
Application number: US00262797A
Authority: US
Inventors: D Anderson
Original assignee: Rockwell International Corp
Current assignee: Draper Corp
Priority date: 1972-06-14
Filing date: 1972-06-14
Publication date: 1973-12-11
Anticipated expiration: 1990-12-11
Also published as: JPS5212310B2; FR2187969B1; IT985283B; JPS4948962A; CH555909A; FR2187969A1; DE2330052A1; CA978060A; BE800861A; ES415291A1; GB1380512A

Abstract

An improved guide for the flexible tapes of weft carriers in shuttleless looms which includes flexible guide members for decreasing the angle of upward deflection of the tapes as the carriers carried thereon are withdrawn from the warp shed and means operatively associated with the improved guide for indicating deflection of the tapes beyond a predetermined amount.

Description

United States Patent I191 Anderson Dec. 11, 1973 WEFT CARRIER TAPE GUIDE [75] Inventor: Douglas W. Anderson, Westboro, Pnmary ExammerHemy Jaudon Attorney-John R. Bronaugh et al.

[73] Assignee: Rockwell International Corporation,

Pittsburgh, Pa. 22 Filed: June 14, 1972 [571 ABSTRACT [21] Appl' 262797 An improved guide for the flexible tapes of weft carriers in shuttleless looms which includes flexible guide [52] US. Cl 139/127 R members for decreasing the angle of upward deflec- [51] Int. Cl D03d 47/18 tion of the tapes as the carriers carried thereon are [58] Field of Search 139/122 R-l27 R, 320 withdrawn from the warp shed and means operatively associated with the improved guide for indicating de- [56] References Cited flection of the tapes beyond a predetermined amount.

UNITED STATES PATENTS 3,500,873 3/1970 Brown 139/370 5 Claims, 4 Drawing Figures l4 to Y I gm V i Y w l l I a W'li'l l l 0 Aim-"3 1.1. willlll! ll l%sm!;% M Ill 43s lilil\\\\\ \\\\Il p" 10 B 2G I I '\\\\\l l\\|l| l\\\ 2% II:TL Z: -I !!E\ ;IIIII M H- 34 .2525? i 4*? l7 IQ I. l 2.e...P--:!=E- =;:.-$yr e '7 Z L/ l3 LO I WEFT CARRIER TAPE GUIDE BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to shuttleless looms of the type in which weft yarn is supplied from a stationary source and is not carried back and forth through the warp shed by a shuttle or carrier member. In particular the invention pertains to an improved apparatus for guiding and urging the flexible tapes and their respective carrier members toward their intended horizontal path of travel as the carrier members are withdrawn from the warp shed to complete the insertion of a length of weft yarn.

2. Description of the Prior Art In shuttleless looms to which the instant invention is applicable each pick of weft is inserted by two reciprocating carrier members disposed in opposed relation and which are fixed on the free ends of flexible tapes which are caused to be wrapped about and extended from oscillating wheel members at each side of the loom. One of these carriers is commonly referred to as the inserting carrier and the other as the weft receiving or extending carrier.

Certain US. Patents illustrate and describe this type of shuttleless loom and for a more detailed description of such looms attention is hereby directed to US. Pat. Nos. 2,604,123; 2,641,285; and 2,654,399.

Each of the oscillating wheel members has a tape guide element operatively associated therewith which serves to project its flexible tape and the respective carrier member carried thereby in a generally horizontal path as they are caused to enter the warp shed and to be withdrawn therefrom.

As is well known to those conversant in the weaving art, the carrier members are caused to enter the warp shed and to meet at a position near the center thereof where the inserted loop of weft yarn introduced by the inserting carrier is transferred to the extending carrier. After transfer of the weft, the carriers reverse their direction of travel and as they are withdrawn from the shed the extending carrier draws the loop of weft through the remainder of said shed to complete a single pick.

The operational speed at which a shuttleless loom is caused to function necessitates very close and accurate timing of the shed changing apparatus or so-called harnesses. Before the carriers have actually left the shed, the upper and lower sheets of warp threads are moving in a direction to close said shed and are in contact with said carriers.

The tape guides are located in close proximity with the edges of the fabric and shed openings as the latter are formed and are adapted to receive and guide their respective tapes and carriers as they are withdrawn from said shed, to a position in readiness to enter the subsequent shed opening.

Under normal operating conditions the carriers as they are leaving a closing shed are tipped slightly upwardly by the flexing of its respective tape in the area adjacent to said carriers attachment thereto. This flexing of the tape is caused by a slight movement of the lower sheet of warp threads in an upward direction during the closing of the shed which moves the carrier above its path of alignment with the tape guide into which it is drawn by said tape. This slight amount of flexing of the tapes is a normal weaving condition with looms of this type and with said tapes being fabricated from a flexible material they immediately return their respective carriers to their initial horizontal path when drawn clear of the shed.

Excessive flexing of the tapes caused by the lower sheet of warp threads rising above a predetermined and acceptable amount is not an uncommon condition known to develop in shuttleless looms to which the present invention is applicable. Such a condition can be attributed to a number of reasons such, for example, as the timing of the shedding apparatus not being precisely and accurately maintained as well as a slight amount of undetected wear developing in any of the various components of the shedding apparatus, such as the harness cams or treadle rolls.

Excessive flexing of the tapes is considered a very serious problem and a detrimental one, for such a condition not detected in its early stages will reduce substantially the life expectancy of said tapes.

The overflexing of the tapes in the area adjacent to their point of attachment to the carrier members introduces fatique failure of the tape and its subsequent breakage. In the event a tape should break after withdrawing its respective carrier and completing the laying of a pick, a so-called smash would occur, or in other words, the tearing out of many warp threads by the broken tape as it entered the shed for the next weaving cycle.

The improved tape guide according to the present invention has corrected the problem of excessive flexing of the carrier tapes and in addition provides a means for visual indication when such a condition exists so that the necessary adjustments can be made to correct it.

SUMMARY OF THE INVENTION The improved tape guide for shuttleless looms of the present invention is of conventional configuration having a main guide body with three cooperating surfaces which together form an elongated recess into and from which a tape and its respective carrier are slidably guided. A pair of spaced flexible strip members are attached to the upper surfaces of the main guide body in such a manner as to permit the ends thereof adjacent the warp shed to bend upwardly during flexing of the tapes as the latter are withdrawn with their respective carriers from said warp shed. Additionally these flexible strip members form part of an electrical indicating circuit which when caused to bend upwardly beyond a predetermined amount will complete a circuit to a telltale lamp indicating the tapes are flexing a distance greater than the acceptable amount.

It is a general object of the invention to improve the general construction and operational characteristics of the flexible tape guides in shuttleless looms.

A further object of the invention is to provide an improved tape guide which will decrease and relieve the amount of stress to which the flexible tapes are subjected when caused to flex upwardly while being withdrawn from a warp shed.

A further and more specific object of the invention is to provide an improved flexible tape guide having a warning device operatively associated therewith for indicating when a flexible tape is being flexed upwardly beyond a predetermined and acceptable amount.

These and other objects of the 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. 1 is a view in front elevation and partically in section of a portion of a shuttleless loom showing a tape guide of the prior art and the manner in which a flexible tape and its respective carrier are flexed upwardly during withdrawal from a warp shed,

FIG. 2 is a view similar to FIG. 1, but showing a tape guide according to the invention applied thereto,

FIG. 3 is a view similar to FIG. 2 but showing a modification thereof which includes a warning device operatively associated with the tape guide, and FIG. 4 is a sectional view of the tape guide looking in the direction of the indicating arrows of line 4-4 in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT As the general construction and operation of a loom to which the present invention is applicable is well known and familiar to those conversant in the art, and as the invention is entirely concerned with an improved tape guide for such looms, it is only considered necessary here to illustrate and describe those parts which are directly concerned with a preferred form of the present invention In the Figures of drawing the weft extending carrier is shown at It) and is fixed to the end of a flexible tape II which are caused to be guided during their movement by a so-called tape guide. In FIG. l a well known form of tape guide is identified by numeral 12 and in the remaining figures of drawing the improved tape guide according to the invention is identified generally by numeral 13 and will be more fully described hereinafter.

As is well known to those familiar with the art those ends of the tape guides not shown in the figures of drawing are disposed for operative cooperation with an oscillatable tape wheel disposed at the side of the loom about which the flexible tape 11 is wrapped and from which it is extended during the performance of its intended function.

The usual form of reed 114 is carried on a reciprocating lay beam 15 and serves to beat each inserted length of weft into the fell 16 to form fabric indicated at 17. As seen looking from the front of the loom warp yarns 18 extend in a rearwardly direction from the fell 16 through dents 19 of the reed 14 to a conventional 'harness arrangement (not shown) that is effective in shedding sheets of said warp threads to form shed openings into which the carrier 10 is projected and withdrawn during the performance of its intended function.

As shown in FIG. 4 the improved tape guide 13 includes a main guide body 20 having three

surfaces

21, 22 and 23 which together form an elongated recess which serves to guide the tape 11 and its respective carrier 10 in a generally horizontal path as they are projected into and withdrawn from the warp shed.

To prevent the tape and carrier from rising above their intended horizontal path of travel the

uppermost surfaces

24 and 25 of the tape guides main guide body 20 have flexible longitudinally extending

strip members

26 and 27, respectively attached thereto. Any suitable means such as machine screws 28 (FIG. 3) are used to attach the

flexible strip members

26 and 27 along a portion of their length to

surfaces

24 and 25. As shown in FIG. 3, a portion of the length of the

flexible strip members

26 and 27 adjacent the shed or warp yarns 18 are unattached to the main guide body 20 and by means of their attachment screws 28 spaced from this area said strips are biased toward

surfaces

24 and 25.

The flexibility of the strip members in the area where they are unattached to

surfaces

24 and 25 allows the ends thereof to flex upwardly with the tape member 11 as the latter is withdrawn from a warp shed.

Referring to FIG. 3 the warning device for indicating excessive flexing of the tape ll is identified generally by numeral 29 and includes. a generally L shaped support bracket 30 which attaches to and adjacent to the inner end of the main guide body 20. A screw 31 is adjustably assembled in bracket 30 by means of a lock nut 32 and is electrically insulated from said bracket by a grommet member 33 fabricated from any suitable nonconductive material. A flexible metallic strip 34 assembles on the upper surface of the strip member 26 by means of one of the screws 28 and extends to the inner or unattached end of said strip member so as to underlie the lower end of screw 31. Screw 31 forms part of the circuitry to a tell-tale lamp 35'and is fixed in a preselected location so that in the event of excessive flexing of the tape 11 or in other words its moving upwardly beyond an exceptable amount, the metallic strip 34 will make contact with the lower end of the screw 31 to close or complete the circuit to the tell-tale lamp 35 thus indicating that the lower sheet of warp thread is being raised above the acceptable distance for the preferred loom operating conditions.

For purpose of brevity only the weft extending carrier and the flexible tape guide disposed on the lefthand side of the loom have been shown and it should be understood that these elements are applicable to the opposite side of the loom where they would function in cooperation with the inserting carrier and its respective flexible tape.

To summarize the operation, the extending carrier enters a warp shed and is caused to meet the inserting carrier at a point near the center thereof where the loop of weft yarn introduced by said inserting carrier is transferred, in a known manner, to said extending carrier and is drawn through the remainder of the shed to complete a given pick. After transfer of the loop of weft from one carrier to the other and as the carriers are moving in a direction to leave the shed, the upper and lower sheets of warp threads are cuased to move in a direction to close said shed and are in contact with said carriers as they make their exit therefrom. At this point in the shedding cycle, the lower sheet of warp threads has been raised slightly which also slightly raises the tapes and their respective carrier from a true horizontal alignment with the tape guides. As the tapes are drawn into their tape guides they are caused to flex upwardly while their carriers are still in contact with the slightly raised lower sheet of warp threads. During this flexing of the tapes, the flexible strip members forming a part of the improved tape guide are caused to move upwardly with the tapes and they reduce substantially this angle of flexing as is illustrated by a comparison of FIGS. 1 and 2 of the drawing. Should the flexing of the tape become excessive for reasons heretofore described the circuitry of the cooperating warning device is completed to a tell-tale lamp which indicates adjustments are required to return the loom to its desired operating condition.

Although the present invention has been described in connection with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the preview and scope of the invention and the appended claims.

I claim:

1. In combination with a shuttleless loom of the type including a stationary weft supply, a flexible tape attached at one end to a tape wheel capable of moving the tape into and out of the warp shed, and a weft carrier attached to the other end of the flexible tape to engage the weft yarn and carry it through the warp shed, an improved tape guide means for directing the tape in a horizontal path of travel, said improved tape guide means comprising means defining a main guide body having three surfaces which together form an elongated recess into which the tape can slide and flexible means secured to said tape guide means at a location spaced from that end adjacent the warp shed for operative cooperation with said main guide body to urge the tape into said elongated recess.

2. The mechanism as defined in claim 1 wherein said flexible means defines a pair of juxtapositioned strip members yieldable attached to said tape guide means.

3. The mechanism according to claim 1 wherein said flexible means includes means operatively associated therewith for indicating excessive deflection of said tapes from their horizontal path of travel.

4. The mechanism according to claim 3 wherein said indicating means comprises a lamp member, a lamp member circuit with a switch means therein operatively associated with said flexible means for closing said switch and completing the circuit to said lamp through movement of said strip members by deflection of said tapes from their horizontal path of travel.

5. The mechanism according to claim 4 wherein said switch means includes means to prevent the actuation thereof until said tapes exceed a predetermined amount of deflection from their horizontal path of travel.