US2795242A - Harness cord - Google Patents

Description

June 11, 1957 D, HOUK ETAL 2,795,242

HARNESS CORD v -Filed July 9, 1953 INVENTOYRS Charles Duane Houk BY Wolter E.Thompson, Jr.

1 fw am@ Ww www@ ATTORN EYS United States Patent() HARNESS CORD Charles Duane Houk, Roslyn, N. Y., and Walter E. Thompson, Jr., Watertown, Conn., assignors to The Heminway & Bartlett Mfg. Co., Watertown, Conn., a corporation of Connecticut f Application July 9, 1953, Serial No. 366,966k

Z Claims. (Cl. 1394-85)V This invention relates to improvements in textile looms provided with a Jacquard attachment for the control of shed formation. More particularly, it relates to provements in the construction of harnesses fory looms equipped with Jacquard attachments.

As' is well known, Jacquard-equipped looms are employed in the weaving of fabrics in which the pattern is too complex to permit shed formation during weaving to be controlled by either a cam or a dobby mechanism. Specifically, a Jacquard-equipped loom must be employed when it is necessary to individually control each warp yarn in one repeat of the pattern being woven.

To provide the required individual control of warp yarns, the heddles in a Jacquard-equipped loom cannot l be carried in groups in frames as they are in looms not so equipped. Rather, each heddle is independent of the others and is raised and lowered' during weaving in planned sequence by a cord or cords connecting it to the Jacquard attachment. The heddle itself differs from the ordinaryA wire heddle in that the eyelet or mail, through which the warp yarn passes, is a separate element carried by a cord structure rather than being an integral part of the heddle shaft. Ordinarily the mail for use with a Jacquard-equipped loom consists of a small, flat, oval-shaped metal button having a yarnreceiving opening in its center and tvv-o smalleropenings, one near each end of the oval, for attachment to supporting cords. The mail and the attached cords together form the heddle. This heddle, together with the mounting and neck cords necessary to connect the heddle to the Jacquard attachment, may collectively be called the harness, and the term will be used in that sense herein.

It is an object of the invention to provide a harness structure for Jacquard-equipped looms which requires less frequent replacement than harnesses heretofore used. An'- other object of the invention is to provide a dimensionally stable harness without the necessity of coating the harness cords with permanent sizing to provide such stability, as has been the practice heretofore. A further object is to permit the preparation of heddles with less expenditure of labor and time than is presently possible.

The details of the invention will be more readily understood from the following description with reference to the drawings attached hereto, in which Fig. 1 is a schematic view of the Jacquard attachment and the harnesses controlled thereby; and

Fig. 2 is an enlarged view' of a portion' of the harness showing the mail and the supporting cords attached thereto.

The harness illustrated in Fig. 1 consists ofa neck cord 1, mounting cords 2, heddle cords 3 and.4-, and mail 5. Thev neck cord as shown controls two mounting cords, which in turn control twoheddles, but, asis well known in the textile art, a neck cord can carry several mounting cords, depending `on the number of repeats in the pattern being woven. Furthermore, although it is not usual, the neck cord may control only one heddle, in. which Mice case the neckcord and' the mounting cord are in effect one structure.

The harness is attached at its neck cord portion to the hook 6 of the Jacquard attachment A, which is of well known construction. Weights or lingoes, indicated generally at W, are attached to the heddle ends and hang freely therefrom to insure proper tension on the harness. The mounting cords 2-pass through holes in the loom comber` board 7 which hold the heddles in' the proper .spaced relationship.

As is well known to those' skilled in the textile art, the heddles 5 are raised and lowered to form the shed by the corresponding hooks 6 ina sequence' determined by the pattern beingy woven. No general description of the operation of the Jacquard attachment in lifting and dropping the hooks is deem-ed necessary, inasmuch as those desiring to practice the invention will understand that such operation yis to be carried out in the ordinary well known manner.

It should be noted, however, that individual control of the warp yarns introduces serious problems not met with in ordinary weaving. This is due to the fact that in any weaving all the warp yarns in both the upper and lower sections of the shed must be substantially parallel; that is, they must be raised or lowered the same distance so that the heddle eyelets always lie in a straight line parallel to the shuttle path. To produce a smooth even fabric, the warp yarns must always be under equal tension, and this will not be the case if the yarn-carrying `eyelets are displaced vertically to varying degrees. In ordinary Weaving, where the heddles are carried in groups in frames, the yarns in either section of the shed-are fixed in the correct parallel` alignment, but in a Jacquardcontrolled loom, this is not vnecessarily thel case. Whether this condition is met depends first on the proper original placement of the harnesses and secondly on the dimensional stability of the harnesses during continued operation. Thus, if certain harnesses should. stretch unduly in use, the required equal warp yarn tension will not be maintained and adjustment, requiring expensive loom shut-down, will be necessary to render the warp yarns again parallel. The importance of minimizing this .difficulty will be understood from a consideration of a typical Jacquard fabric, such as a wide table damask. Such a fabricwill not infrequently be woven 60 inches wide with a warp count of 50 ends per inch and thus its weaving requires the control of 3000 warp ends.

Changes in the length of the harnesses result mainly from two factors. First, in normal weaving operations, it is not unusual to interweave lwith the warp yarns as many as weft yarns per minute. After each weft yarn is laid into the shed, a new shed must be formed by changes in the position of the heddles. Thus, the harnesses are subjected to a large number of rapidly applied cycles of stress and relaxation during the weaving operation. As a result of the continued application of these stresses, the cords tend gradually to elongate. This gradual elongation is not necessarily uniform among the harnesses, however', and thus the undesired variations inA tension in the warp yarns are produced. The second cause of dimensional change in the harnesses derives from the effect of moisture pick-up of the cords. For example, cotton cords tend to retract when exposed to conditions of relatively high humidity and to elongate as they give up moisture to a relatively drier atmosphere. The extent of these changesv in length will vary for different cords of the same construction and harnesses fabricated from them will cause variations in warp yarn tensions.

At present, it is thepractice to meet these difficulties by using two types of cord in harness constructionand by treating the cords with sizing materials. Thus,vcotton cords are used to form the two heddle sections 3 and 4 while neck cord 1 and the mounting cords Z are made of linen, which is stronger and less extensible, although more expensive, than cotton. Furthermore, linen cord has a smoother` surface than does cotton and hence possesses a greater reistance to the abrasion occasioned by the movement of the mounting cords in and out of the holes of the comber board 7.

Both the cotton and linen portions of the harness are treated with a permanent sizing material, `generally Va material containing a high percentage of linseed oil or an equivalent drying oil. This sizing forms a coating on the cords, which is intended to seal them against absorption or loss of moisture and imparts additional smoothness to the linen mounting cords to increase somewhat the desired resistance to abrasion of `these cords. Finally, by `cementing together the individual bers which constitute the cord, the sizing increases the tensile strength and lessensthe extensibility of these cords.

This method is unsatisfactory for several reasons. First is the fact that a considerable amount of both time and labor must be expended in coating the harness cords. If

the coating operation could be omitted, the` fabrication of the `harnesses would involve merely cutting proper lengths of cord and tying the various sections of cord` and the mail together. Finally, because the sizing renders the heddle cords somewhat stiff, the knots attaching these cords to the mail 5 must be tied before the sizing is applied. Extreme caution must be exercised `to keep the warp-receiving eyelet free ,of the sizing material. Even a small droplet of the sizing on the edge of the eyelet will,` when dry, make a heddle `unacceptable for `use for the reason that it will abrade` the `warp yarn passing through it, producing a defect in the finished goods. It may also abrade the yarn to such an extent that it would strip surface fibers therefrom which gradually build up behind thte eyelet and finally resultin breakage of the warp yarn. h

Finally. the well known `deterioration of natural vegetable bers, such as linenand cotton, when exposed to light and air, definitely limits the useful life of harnesses constructed of these materials.

These problems of harness construction for Jacquardcontrolled looms have been .successfully met. by the present invention, which provides a harness of uniform cord structure throughout, which cord need not be coated and which is inherently dimensionally stable, age-resistant, abrasion-resistant and which possesses a .high tensile strength.`

Cords consisting of strands of synthetic resin filaments of the type derived from esters of ethylene glycol and terephthalic acid, especially filaments made by `the condensation of dimethyl terephthalate and ethylene glycol such as the product sold under the trade-name Dacron, have certain properties that render them particularly effective for use in the fabrication of the cord harnesses of the invention. Because of their continuousfilamentary structure, such cords have a smooth surface which insures the maximum resistance to abrasion. The moisture absorption of the cords is low and their aging characteristics such that lightand air cause little or no embrittlement or loss of strength over long periods of use.` Cords are uniformso that there is less variation in properties of the cord along its length than is the case with cords formed of spun yarns, particularly those made of naturally occurring fibers.

Despite these desirable characteristics, however, cords as initially made of such resins are not ideally suited for use as harness elements in Jacquard-controlled looms, for the reason thatthey are characterized by relatively high elongation, and the resinzitself displays the `phenomenon known as plastic memory. By plastic memory is meant the tendency of a plastic body to return to its original shape from a deformed shape upon removal of the deforming stress.

As was earlier described, the cords constituting the harness are subjected many times a minute to rapidly applied elongated stresses. If these cords possess a rela tively high elongation, this leads to gradual stretching of the harnesses and consequent undesirable changes in the position of the yarn-carrying mails. Despite the uniformity of the cords, the degree of stretching is not necessarily the same for all the harnesses for the following reason. In Fig. l the neck cord 1 is shown controlling two mounting cords. However, as was stated, a given pattern may require the use of several, say four, mounting threads which are all attached to the neck cord at the same point. The length of the mounting cords in one pair differs from thelengths of those in the other pair, and the application of the same stress to cords of different lengths will, of course, produce greater elongation in the shorter cords.

If it becomes necessary to stop the loom for a short period, as, for instance, to replace a broken or defective warp yarn, the plastic memory of the cord bodies causes retraction of the stretched cords. The extent of this retraction depends on the length of time the loom is shut down. Thus, substantially complete recovery may result if the `loom is` out of operation for several hours while recovery may be negligible if the loom is started up in a few seconds after being stopped. It is necessary, therefore, if the desirable features of Dacron cord are to be made use of in Jacquard harness construction that the plastic memory of the cord be suppressed and the elongation of the `cord maintained within certain limits. According to the present invention, this is accomplished by stretching the cord at an elevated temperature below the softening point of the resin from which the cord is formed and maintaining the stretched cord under tension during cooling.

A preferred `form of `cord for use in fabricating Jacquard harnesses Iis that obtained by `braiding together the desired number of strands of Dacron, before stabilization treatment, rather than that obtained by simple twisting.` In the braidedV cord, individual strands are interlaced and locked together with the result that stresses applied to the cord as a whole are relatively equally shared by the individual strands.

While the braid may be made in any practical size and maycontain any desired number of strands, for the purpose of illustrating the invention a single cord construction will be described.

Filaments of 250 denier Dacron are braided together to give a cord having 16 ends and a count of 35 picks (repeat crossings) to the inch. This braided cord is then'heated to a temperature in the range of 400 to 410 F. and stretched approximately 10 percent at this temperature. After the cord has been stretched the desired amount, it is cooled down to room temperature while still maintained under tension. has reached room temperature, the process is complete and the nished cord is wound on spools or formed into skeins for later use. As a result of this treatment, the plastic memory is found to be substantially eliminated and the elongation thereof reduced to a value that ren ders practical the use of the stabilized cord in the construction of Jacquard harnesses.

The above discussed stabilization of the cord can either be carried out on single lengths of cord or may be conducted `as a continuous operation by feeding the cord into a heating zone at a controlled constant rate of speed and withdrawing it therefrom into a cooling `zone at a higher `constant controlled speed so that the heated section is subject` to stretching or drafting. After being withdrawn from the `cooling zone, the cord is wound continuously on collecting spools.

When the cord point of the cord and held within narrow limits so that the eect of the drafting operation will be uniform along the length of the cord. It has been found that a temperature within the range of 400 to 410 F. gives a cord of the desired characteristics, provided, of course, that the drafting tension is uniformly applied to the cord being treated. The degree of stretching may be varied between the limits of 8 to 12 percent elongation, and the preferred value of elongation is the average of these figures, or 10 percent. The rate at which the cord is fed into the treating apparatus must be constant, as must be the rate at which the cord is withdrawn, if uniform elongation is to result.

The cord resulting from the treatment of braided Dacron cord to suppress its plastic memory and to reduce its elongation is found to be particularly adapted to the construction of Jacquard harnesses. When used as the harness neck cord, it possesses suicient strength and is sufficiently inextensible to bear the load imposed upon it in lifting any desired number of heddles and the lingoes attached thereto, and the additional load caused by the frictional engagement of the mounting cords with the walls of the holes in the comber board, without undue dimensional change. Furthermore, it is relatively unafected by atmospheric conditions, and undergoes practically no change in length with changes in atmospheric humidity. The smooth surface of the braid in the mounting cords minimizes the effects of abrasion and obviates the necessity of coating these cords with sizing materials. Because of the fact that the cord need not be coated, the heddles are quickly and easily formed merely by tying the mail supporting cords and the mail together without the necessity of protecting the mail from contamination with a sizing material. Finally, because of their resistance to the eiects of light and air the cords remain highly exible, suffering no embrittlement or loss of strength due to aging.

It should be understood that it is not desired to limit this invention to the precise details of construction of the braided cord, herein described, or to exact details of the process of stabilization of the cord, for various modifications are possible and may occur to those skilled in the art.

We claim:

1. A harness cord for a Jacquard-equipped loom formed of filaments of the resinous composition comprising the polyester of ethylene glycol and terephthalic acid, said filaments being braided together, and said cord having length stability as a result of the removal of the plastic memory in an operation involving heating while under tension followed by cooling while under tension.

2. A harness cord according to claim 1 which has been heated at a temperature in the range of 400 to 410 F. under tension so as to produce an elongation of from 8 to 12 percent and cooled to ambient temperature While under tension.

References Cited in the file of this patent UNITED STATES PATENTS 2,512,433 Leben June 20, 1950 2,517,570 Irons Aug. 8, 1950 2,517,581 Lowry et al. Aug. 8, 1950 FOREIGN PATENTS 133,874 Australia Apr. 3, 1947

Claims (1)

1. A HARNESS CORD FOR A JACQUARD-EQUIPPED LOOM FORMED OF FILAMENTS OF THE RESINOUS COMPOSTION COMPRISING THE POLYESTER OF ETHYLENE GLYCOL AND TEREPHTHALIC ACID, SAID FILAMENTS BEING BRAIDED TOGETHER, AND SAID CORD HAVING LENGTH STABILITY AS A RESULT OF THE REMOVAL OF THE PLASTIC MEMORY IN AN OPERATION INVOLVING HEATING WHILE UNDER TENSION FOLLOWED BY COOLING WHILE UNDER TENSION.

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