US3602264A

US3602264A - Terry loom warp control means and method

Info

Publication number: US3602264A
Application number: US861543A
Authority: US
Inventors: Stanley C Tiernan
Original assignee: North American Rockwell Corp
Current assignee: Draper Corp; Boeing North American Inc
Priority date: 1969-09-15
Filing date: 1969-09-15
Publication date: 1971-08-31
Anticipated expiration: 1988-08-31

Abstract

A terry warp yarn control means and method for shuttleless looms which during the weaving of terry fabric is effective in maintaining the warp yarns of the upper terry warp sheet in alignment with a minimum amount of tension when lowered during shedding to cross with the lower terry warp sheet so as to prevent an interference between the end of a cut length of filling being inserted into a shed and the yarns of said upper terry warp sheet.

Description

United States Patent Inventor Appl. No. Filed Patented Assignee Sept. 15, 1969 Aug. 31, 1971 North American Rockwell Corporation Pittsburgh, Pa.

TERRY 100M WARP CONTROL MEANS AND METHOD 7 Claims, 4 Drawing Figs.

US. Cl. 139/25 Int. Cl D03d 39/22 Field olSear-ch l39/55,25, 26, 27

[56] References Cited UNITED STATES PATENTS 2,741,270 4/1956 Mills 139/25 2,988,113 6/1961 Smiley l39/25 Primary Examiner-Henry S. Jaudon Attorneys-John R. Bronaugh, George R. Powers and Floyd S.

Levison ABSTRACT: A terry warp yarn control means and method for shuttleless looms which during the weaving of terry fabric is effective-in maintaining the warp yarns of the upper terry warp sheet in alignment with a minimum amount of tension when lowered during shedding to cross with the lower terry warp sheet so as to prevent an interferene between the end of a cut length of filling being inserted into a shed and the yarns of said upper terry warp sheet.

TERRY LOOM WARP CONTROL MEANS AND METHOD BACKGROUND OF THE INVENTION The invention relates to shuttleless looms for weaving terry fabric and more particularly to an improvement in the means and method of controlling the shedding of the warp yarns during each terry weaving cycle.

Shuttleless looms to which the instant invention is applicable employ reciprocating carriers one of which projects a double length of filling approximately halfway through a shed formed by warp threads and the other of which receives that filling and draws the loose end thereof through the remainder of the shed. The carrier which introduces the filling yarn is known as the inserting carrier and the other which completes the laying of a pick as the receiving or extending carrier.

A number of United States patents describe and clearly illustrate the type of shuttleless loom to which the present invention is applicable 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.

A common terry weave is formed in three-pick cycles; however cycles having four or more picks are often used and either choice is suitable for weaving with the present invention. The three pick terry cycle is woven by placing a so-called loose pick into an open shed of ground warp yarns and then inserting a second loose pick in the same ground shed opening after crossing the warp threads of the upper and lower terry warp sheets. The final step in the three pick cycle is to cross both the upper and lower ground and terry warp sheets and insert a so-called fast pick of filling which is then beat-up along with the two loose picks into the fell of the fabric.

During the crossing of the upper and lower terry warp sheets while inserting the first loose pick, the warp yarns of said upper terry warp sheet are lacking tension and become slack to the extent of creating an interference with the free end of filling yarn being extended through the shed by the extending carrier. As the extending carrier draws the filling through the remainder of the shed, the loose end in many instances, has a tendency to whip around in an uncontrollable manner and very often assumes a position or gets into a condition by which apart of the loose end wraps or entwines itself around one or more of the slack warp yarns of the upper terry warp sheet being drawn down to cross with the lower terry warp sheet. A condition of this nature will result in an incomplete pick by breakage of the filling or the tearing out of one or more warp ends causing loom stoppage and an imperfection in the woven fabric. US. Pat. No. 3,434,504 issued Mar. 25, 1969 to J. D. l-larkey for Shuttleless Terry Loom Warp Shedding Means and Method illustrates an effort to solve this problem.

The terry loom warp control according to the instant invention provides a means for maintaining the warp threads of the upper terry warp sheet in alignment and with a minimum amount of tension while being lowered to cross with the warp threads of the lower terry warp sheet. By holding these warp yarns in alignment during shedding the closeness of these warp yarns forms a shield which prevents the possibility of the crratic moving filling end to become entangled therewith.

SUMMARY OF THE INVENTION The terry loom warp control of the present invention includes in addition to the conventional number of harness members utilized for actuating the shedding function of the upper and lower ground and terry warp sheets, an additional harness member which is arranged and adapted to operate in cooperation with that conventional harness member for controlling the sheet of upper terry warp yarns.

On the initial movement of the regular harness member to lower the upper terry warp sheet to cross with the lower terry warp sheet, the additional harness member is caused to move upwardly for a predetermined distance and then reverse its direction of movement and move downwardly with said regular harness member. This motion applies a minimum amount of tension to the warp yarns of the upper terry warp sheet and as they move downwardly to cross with the lower sheet they are held in alignment and the density thereof is such as to provide a shield which prevents the possibility of the end of filling yarn becoming entangled with these warp yarns.

It is a general object of the invention to provide a method and means for preventing an interference between the warp yarns of the upper terry warp sheet and the filling yarn as it is being extended through a warp shed.

A more specific object of the invention is to provide a method and means for maintaining a minimum amount of tension on the warp yarns of the upper terry warp sheet and to hold them in alignment during their shedding function.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic sectional view through a shuttleless loom for weaving terry fabric showing the warp control device according to the invention applied thereto, and

FIGS. 2, 3 and 4 are schematic sectional views of the harness members in FIG. 1 showing progressively the path of movement the harnesses follow during the shedding function of the upper terry warp sheet.

DESCRIPTION OF THE PREFERRED EMBODIMENT Now referring to the figures of drawing enough of a shuttleless terry loom is shown in FIG. 1 to serve as a basis for a detailed description of the invention applied thereto.

In FIG. 1 there is shown a top or pile warp beam 10 from which pile warp yarns 11 are drawn and which in a known manner forms the pile loops in the terry fabric. This yarn as it leaves the warp beam 10 is guided about the outer periphery of a pair of juxtapositioned pile rolls l2 and 13 and the latter being driven by any suitable means serve to draw the required amount of yarn necessary to form the pile loops when woven with the ground warp yarns identified by numeral 14.

The pile warp yarns after leaving the pile roll 13 make contact with a floating pile guide roll 15 and thence extend forwardly and through a conventional form of a loom warp stop motion generally indicated by numeral 16.

The ground warp yarns 14 are drawn or let off from a warp beam 17 and extending in a generally upward direction are caused to pass about the upper surface of a drag roll 18. From the drag roll 18 the ground warp yarns extend forwardly to be acted upon by a whip roll 19 and thence continue on and pass through the warp stop 16 along with the pile warp yarns l 1.

From the' warp stop motion both the ground and terry warp yarns extend through the heddles of their respective harness members which are identified in the various figures of drawing by

numerals

20, 21, 22 and 23. A portion of the pile warp yarns pass through the heddles of the harness member 20 to form the lower terry warp sheet shown by the dotted line 24 and the upper terry warp sheet shown at 25 as a solid line passes through the heddles of harness member 21. The ground warp yarns are also divided and the upper warp sheet 26 formed thereby is caused to extend through the heddles of harness frame 22. The remaining ground warp yarns extend through the heddles of harness member 23 and form the lower ground warp sheet shown by the dotted line 27.

As is well known to those conversant with the art, the harness members during the shedding function are caused to reciprocate in a generally vertical plane in timed relation to the weaving cycle by underneath parts consisting of cam controlled treadles shown generally at 27 and top motion devices (not shown) such as a clock spring and sheave arrangement.

From the harnesses all of the warp yarns extend forwardly and through the dents of a reed 28 and on to the fell 29 of the fabric shown at 30. The reed 28 is supported by a lay beam 31 that is caused to reciprocate to and fro during the performance of its intended function and the space between the upper and lower warp sheets intermediate the reed and fell defines the shed opening into which a filling carrier 32 (FIG. 1) is inserted and withdrawn.

The fabric 30 as it is formed is advanced by a takeup roll 33 then guided over the upper surface of a pressure roll 34. From this pressure roll the fabric is drawn downwardly by and wrapped on a cloth roll 35.

The additional harness member for performing the function accomplished by the invention is depicted by numeral 36 and is disposed adjacent and rearwardly of harness member 23. The terry warp yarns ll of the upper terry warp sheet 25 in addition to extending through the heddles of harness member 21 also extend through the heddles of the additional harness member 36. In

operation harness members

21 and 36 are actuated simultaneously by

individual pivotablc treadles

37 and 38 which receive their dictates from

harness cams

39 and 40, respectively, carried on a continuously rotatable shaft 41. During the terry cycle of crossing the upper and lower terry warp sheets, harness member 36 will on the initial downward movement of harness member 21 move upwardly a predetermined distancef, which is governed by its respective cam controlled treadle, and then automatically change its direction of travel and move downwardly with said harness member 21 to complete the crossing of the upper and lower terry warp sheets. This motion is effective in preventing the warp yarns from becoming slack and holds them under a desired amount of tension so as to maintain them in alignment thereby avoiding the possibility of an interference between them and the uncontrollable end of filling being extended through the warp shed. On continued operation, the upper terry warp sheet is returned to its upper position and the lower terry warp sheet is returned to its lower position. During this phase of the weaving cycle the upper and lower ground warp sheets are also crossed and they serve to shield the terry warp sheets from interference with the uncontrolled filling end. It is therefore not necessary to additionally tension the terry warp sheets during their return movements.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

I claim:

1. In a shuttleless loom for weaving terry fabric of the type having an external, stationary filling supply source, reciprocable carrier means for inserting picks of filling yarn in cut lengths from said source into sheds formed by the combination of ground warp and terry warp yarns, individual harness members receiving and providing individual shedding movement of upper and lower ground and terry warp sheets formed by said warp yarns, and means for maintaining the warp yarns of said upper terry warp sheet in alignment and under a predetermined minimum amount of tension when lowered by the harness member individual thereto to cross with said lower terry warp sheet which means includes a separately controllable additional harness member with both of said harness members being disposed to act simultaneously upon the warp yarns of said upper terry warp sheet.

2. The shuttleless loom according to claim 1 wherein said alignment and tension maintaining means includes a means for raising the additional harness member a predetermined distance on the initial movement of said first harness member in a downwardly direction, to align and maintain a minimum amount of tension upon the warp yarns during pick insertion and then to lower the first and second harness members to cross the upper terry warp sheet with the lower terry warp sheet.

3. The shuttleless loom according to claim 1 wherein said alignment and tension maintaining means further includes individual cam controlled treadle members for activation of both of said harness members.

4. The shuttleless loom according to claim 3 wherein the cam controlled treadle members are arranged to activate both of said harness members simultaneously.

5. The shuttleless loom according to claim 3 wherein the cam controlled treadle for activating said additional harness member is effective in initially moving the latter in an upwardly direction to align said warp yarns and then reverse its direction of travel to move it downwardly with said first harness member.

6. A method of aligning the sheet of upper terry warp yarns during the weaving cycle of forming terry fabric in shuttleless looms having first and second harness members arranged to act upon said upper terry warp sheet which comprises the steps of:

a. raising the second harness member a predetermined distance on the initial movement of said first harness member in a downwardly direction to maintain tension upon the warp yarns during pick insertion, and

b. lowering both the first and second harness members simultaneously to cross the upper terry warp sheet with the lower terry warp sheet.

7. The method according to claim 6 in which the step of raising the second harness member includes aligning the warp yarns of the upper warp sheet by applying a minimum amount of tension thereto

Claims

6. A method of aligning the sheet of upper terry warp yarns during the weaving cycle of forming terry fabric in shuttleless looms having first and second harness members arranged to act upon said upper terry warp sheet which comprises the steps of: a. raising the second harness member a predetermined distance on the initial movement of said first harness member in a downwardly direction to maintain tension upon the warp yarns during pick insertion, and b. lowering both the first and second harness members simultaneously to cross the upper terry warp sheet with the lower terry warp sheet.

7. The method according to claim 6 in which the step of raising the second harness member includes aligning the warp yarns of the upper warp sheet by applying a minimum amount of tension thereto.