US2587117A - Elastic yarn and method of making - Google Patents

Description

Feb. 26, 1952 P, E, F, CLAY 2,587,117-

ELASTIC YARN AND METHOD OF MAKING' Filed Oct. 1l. 1949 l 3 Sheets-Sheet 1 /11 ila \v Il Inventor UH/*LIP ERNEST /wws Cuy A ttorney` Feb. 26, 1952 P. E. F. cLAY 2,587,117

ELASTIC YARN AND METHOD OF' MAKING Filed oct. 11. i949 s sheets-'sheet 2 In venlor Pff/UP fR/vefr /ANK CUN A ttorne y Feb. 26, 1952 P. E.' F. CLAY 2,587,117

v ELASTIC YARN AND METHOD oFy MAKING Filed oct. 11. 1949 s sheets-'sheet s Inventor PHILJP EIR/VEST HANK CLA/ By Wm S. ma@

A rtiorney Patented Feb. 26, 1952 Philip Ernest Frank Clay, Radcliffe-on-Trent,

. England f Application October 11, 1949, Serial No. 120,684 "In GreatrBritain November 11,1948

T11 Claims.

This invention is -fcrimprovements .,in. elastic y-fa-bricsand elastic ryarnsfor. use,..ther.ein; the expression elastic fabrics?! as. .used herein.` means and includes fabricsincorporating elastic .(India --rubber threads) thelndia .rubber..may.- be out consistsin providing asuppIy ofelasticthread in.v a state ..of. complete...r.elaxation (i. e. .un-

stretched). .in .conjunction with a supply of carrierthread, .withdrawing rthethreads simultane-f ously from .their respective supplies in such .man- F.nen as tdmaintain. the. elastic .thread substantiallyin itsfull-y relaxed condition .andthen unit- ..,.ing..the twov threadssuchas by .Wrappingthen Y with an inelasticcoveringthreador by .doubling them together. The. carrier...thread inhibits stretching of the..elastic thread .during theprocf -ess ofmaking fabric lconsisting of.v or incorporat- .ing..the. composite .thread and. afterthe fabric has been made the carrier. thread is rendered in- 'operative such. as. by breaking itorl by destroying l.-itby chemical. means. Fabrics produced in this ..manner arenot. liable to pckeringor wrinkling Y fbutmtheyy possessthe inherentdisadvantage associated .with relaxed untensionedrubber threads, namely,A that when stretchedthey. have acomparatively. small. contracting' force.

By way of explanation. it maybe -said. that as- .suming one has .an elastic .thread ten. inches.. in

length .when in a relaXfed, unatensioned .condition '.;.a.nd.one stretches it twcmches so .that it is now )twelve inches. in. len'gth...and then relieves .the .tension it Willcontractto `its .original length of j ..ten..inches butrthe forceof .contraction is' comparativelysmall. If now yone stretcheslthe same piece .of elastic thread 10U-per centso that it is twentyinches andfthen extends it aiurther-two yinches .and releases it, the contracting force cont tracting the .thread from twenty-two .inches .to twenty-inches willbeverymuch greaterthanfwas I the. force..-.of.contraction which...contracted it. in

,- v.,th'eirst instancefrom twelve inchestoten inches. In certain typeof. fabricsit is highly .desirable to.. have... a. A.strong cfm'tractinglf force.- when the ffabric `is. .subjected to Atension', in a direction...to

stretchv the elastic threadsy and the principal `object of. this invention is to provide fabrics` ofthis type.

With this and other obiects in view,...the invention consists-in a method of 4rnakingelastic fabrics which consists in first stretching an .elastic thread to a predetermined extent,..retaining it in a stretched condition, thereafter. applying by Wrapping or otherwise. one or more inextensible thread or threads toinhibit.furtherstretch, introducing the composite thread soiformed into the fabric and thereafter vrendering the said inextensible thread or threads inoperative.,.i-t.will,

.of course, be appreciated that thefabric preferably incorporates a plurality of. such composite threads. The said inextensible thread or 'threads may be removed .by chemical means,.as bythe treatment of the .fabric with a solvent,A and in the latter case said thread or threadsmay. conveniently consist of. soluble alginate yarn.

Further objects. of the inventionV arefto provide elastic yarn suitable for incorporation in. elastic fabrics Aproduced by .the .methodaforesaidr and methods of production of such yarn.

In apreferred method of carrying vtheinvention into eiect, an elastic thread .hasapplied to its .exterior Whilst the thread. islstretched and under tension a..clockwise and a counter-.clockwise helical wrapping. of .threadsswhichrare so applied as to maintain the elasticthread 'under tension, thatisin astretched .conditionwafter the Wrappingrv process has beenA completed.v Machines of the general type disclosed-'in --Patent SpecicationNo. 2,220,213,. may-be utilised for this purpose but it vvillbe appreciated. .that the elastic thread is not drawn from aloose supply in a relaxed condition but is drawn conveniently from a bobbin or the like in a tensionedcondition',v and in this condition-isffedto' twospaced Wrapping stations whereatthe helical clockwise and counter-clockwise Wrappings rare applied.

-' The wrapping fthreads are substantially inextensible threads and may be offcotton orothersuitable textile. The composite.,thread,.hereinafter referredto as. the. basic thread, is .conveniently --Wound/onftoa bobbin and, asstated, .in such i composite thread the elastic threadismaintained L .in a stretchedortensioned conditionV by'itheapplied Wrappings., Duringgthe4 proc.ess`,of.applying .these wrappings lthe thread. may be A.strictched, to .therlimit Of its elastictywoiztb...auxD'thrldsied v. extent,...the.. degree.. of l stretch being.. dependent upon.' the. purposes`..for which .the .-basicr thread f .is..to.be used.

It-Will. be ,appreciated that inthe basic" thread so made the elastic thread is not necessarily extended to the same degree as that to which it was extended during the wrapping process (in other words it may contract to some extent after being wrapped) but the essential point is that the basic thread when made does consist of a central core of elastic thread Which is in a stretched or tensioned condition and the wrapping threads limit the degree to which the elastic thread is allowed to contract. Threads so made l would be quite unsuitable for use in the manufacture of many types of fabrics for the reason that during the process of incorporation of such threads into the fabric they Would be subjected to tension and therefore would stretch and later relax with the result that the finished fabric would be of less width than the fabric as made, Whilst furthermore there would be a great tendency for wrinkles or puckers to be produced in the fabric. In accordance with Ythe present invention, therefore, the basic thread is so treated as to inhibit further stretch during the process of manufacturing the fabric.

A preferred method of inhibiting such further stretch consists in applying to the basic thread whilst in a relaxed or untensioned condition at least one further wrapping, and preferably two or more further wrappings of thread or threads which is/are applied so as to inhibit further stretch and which after the composite thread so formed has been incorporated in the fabric is rendered inoperative such as by being destroyed by chemical means. The thread or threads used for the further Wrapping or wrappings are substantially inextensible and if more than one further Wrapping is applied one moiety of such wrappings may be applied in a clockwise direction and the remainder in a counter-clockwise direction.

The foregoing and other objects of the invention will be more fully understood from the following description, given by way of example and with reference to the accompanying drawings wherein:

Figure 1 illustrates an elastic core thread prior to wrapping,

Figure 2 shows diagrammatically the elastic core thread in course of wrapping,

Figure 3 shows a portion of a completed composite thread,

Figure 4 is an elevation of certain wrapping apparatus employed in one method according to the invention,

Figure 5 is a sectional elevation of another portion of apparatus employable in the exercise of the invention, Y

Figure 6 is an elevation of modified wrapping apparatus,

Figure '7 is a fragmentary View of a portion of elastic fabric incorporating threads as shown in Figure 3,

Figure 8 is a view similar to Figure '7, wherein the stretch-inhibiting wrapping of the elastic threads is removed, and

Figure 9 is a similar view of a piece of fabric as shown in Figure 8 when stretched laterally.

In the manufacture of an elastic yarn according to the invention, primarily for incorporation in elastic fabrics, the elastic or India rubber core thread, whether cut or extruded, is first stretched as shown in Figure 1 of the drawings, wherein the unstretched length of a portion "of core thread is indicated by the bracket A and a length to which the thread may be stretched in exercising the invention is indicated by the 4 bracket B, the latter length being less than a greater length to which the portion of core thread is capable of stretching conveniently and without breakage or loss of resilience, as indicated for example by the extent of the chain dotted portion C of Figure 1.

Figure 2 shows a first stage of forming the composite yarn according to the invention wherein there has been applied to an elastic core thread I0 a first, closely-pitched, clockwise, helical wrapping II of a non-elastic thread, for example a cotton or other suitable textile thread, and thereafter a superimposed, similar but counterclockwise wrapping I2.

The basic yarn thus produced comprises the elastic core and the two superimposed wrappings of thread which are so closely pitched as to prevent the return of the elastic core to its initial unstretched length. It will be appreciated that when released from the tension applied to it by the wrapping apparatus such basic thread may contract to some extent by compression of the two helical wrappings upon themselves under the pull of the elastic but essentially such wrappings will by their grip on the elastic core limit such contraction and ensure that the core is maintained in a stretched condition.

Figure 3 shows a portion of the basic thread after undergoing the final yarn production stage wherein there have been applied over the outer helical wrapping of the basic thread two further, wide-pitched helical wrappings I3 and I4 of an inextensible thread, respectively clockwise and counter-clockwise, which serve while they remain upon the basic thread to inhibit further stretch thereof.

Convenient apparatus for producing the basic thread according to Figure 2 is shown in Figure 4. A reel I4 of India rubber or like core thread I0 is driven by means of a drum I5 the periphery of which engages the core thread upon the bobbin I4 to control the take-off speed. The core thread is withdrawn from the reel I4 by means of a roller I6 in such a manner as to effect a constant rate of stretch of the elastic, the rollers I6 and I5 being conjointly driven at mutually regulated speeds by speed correlating means indicated at I1 so that the peripheral speed of the roller I6 is greater, by say about 50%, than the peripheral speed of the roller I5.

In travelling from the bobbin I 4 to the roller I 6 the core thread passes rst through a tube I8 carrying reel I9 of wrapping thread which is applied about the core by a flier 20, the tube I8 with the reel and flier being driven frictionally by means of a belt 2I from a pulley 22 on a shaft 23 and constituting in known manner a rst wrapping station. After the application of the rst wrapping I I at this station the thread passes through a second wrapping station including a rotating tube 24 carrying a reel of wrapping thread 25 and a nier 26 whereby the second wrapping thread I2 is applied over the first wrapping II. The tube 24 is driven frictionally by means of a belt '26 from a pulley 21 on a shaft 28, and in order to ensure that the successive wrappings II and I2 are applied one in clockwise and the other in counterclockwise direction the shafts 23 and 28 may be connected by any suitable means for ensuring Ytheir rotation in opposite directions, and for effecting any required mutual adjustments of speed, such as a gear box indicated at 29. After the application of the second wrapping thread I2 the basic thread thus constituted passes while still under tension round the reel I6 with f elastic lcor'ef thread frby the-Happliedwrappings .I I vand I2, a'ndlfr this'purp'osethe receivinglbobfbin 3 Imayfbefdriveny-ifort example by means of f ranotherf 'drumA such-eas |555 bearing`l on `the surface landi-rotated -at a' suitable* peripheral speed'- The A`ffibasicthread is"i then in ae'fd'esira'blyrelaiied condition for the follwingfstage. "e-'Alternativelyj the basic threadJ maybe wound upon-a bob'binf -such'n'asrk 3 Ir` or vequivalentmeans, while still in a; istretched condition; subsequently -fbeing relaxedj' priorlto the :applicationof further Wrappings, for. example by meansofj-"apparatus such as "that diagrammaticallyshownin Figure 5.

In such apparatus: theb'obbin lSI' is'mounted on` a; vertical spindle and thread is withdrawn there- -eefrom by vmean'sof a-rollerfsz with the'perip-hery ioffwhich the thread is engaged by a jockey roller 33,3, and is passed' on to a loose pile 34 wherein f any superficial 4tension of thev core,beyo'nd that retained init; bythe wrappings II and` I2, is -released. The nbasicthread is then taken from the pile 34 in its relaxed vcondition for the application of stretch-:inhibiting threads' I3 and l' (Figure 3) by Ameans of kapparatus'such for example as thaty much widerrpitch'or angle of helix relative to ,fthat of the threads II and I2 as indicated in Figure 3, so that the length of each turn of the threads It andlli is as long as .possible consistent with avoidance of slip and said threads I3 and I4 are well disposed to take thestrain of any tension 1'subsequently-applied.to the .elastic yarnas in a vfabric'formingoperation.

In another alternative', stretcheretaining wrap- 2- pings vI I --and i127; and :further stretchvl inhibiting v wrappings` I3 and-I4- may-be'successivelyI applied to the `core thread inone continuousfoperation by means 'of' apparatus suchffor exampleL as= that shown in Figure 6. The apparatus here shown in eiect comprises two sets of apparatus as described with reference to Figure 4, superimposed on one another, and parts corresponding and functioning similarly to those of Figure 4 are indicated by like reference numerals. After the application of the stretch retaining wrappings i I and I2 as shown at the two lower wrapping sta-- tions the basic thread thus formed passes upwards through two further wrapping stations the first ofv which comprises an assembly 35 yof tube, thread reel and flier driven by a belt 36 from a pulley 3'! on a shaft 38 and the second of which comprises an assembly 39 of tube, thread reel and ier driven by a belt 4I) from a pulley 4I on a shaft 62. The required correlation of speeds and directions of rotation of the shafts 28, 38 and 42 is affected by further means such asgear means indicated at 43, lili. While the wrappings I I and i2 are advantageously applied one clockwise and the other counter-clochwise, and similarly the wrappings I3 and I4, as shown in Figures 2 and 3, it is not necessary that i the wr'appng I3 should.' berapplied in: the''oppositeV direction of lrotation to. that o'ffwrappingl 2,

in which case drive'reversingm'eans maybeeliminated from the meansiifldicated` at43," though the latter' may' comprise. speed adjusting means y such yas'to'.v secure alower rate of rotation of the Wrappingass'emblies" 352' and' 35i relative tothe linear speed of th'ebasi'c thread.

From the wrapping station 3S the composite thread, now having the form indicated-in Figure 3,passes around`the tension rollerI to a reel 45. Since the 'elastic' yarn is now both'prevvented fromcontracting'by virtueV of the wrappings II and I2and` prevented from stretching to a greater'extent than thatapplied by means Yof the rollers I5, IB, by virtue of the Wrappings I3, I Ll, thev application' of subsequent tension or lack of tension'in" further loperations is immaterial.

'The composite yarn produced as above de- 1 scribed maybe employed'. in the manufacture of elastic fabrics in any desired manner." For example, composite threads 14S may, beiint'roduced as weft threads ina knitted'warp fabri'caslshown in Figure 7. Since in' the manufactiueoffthe .fabric the composite. threadstdf arer both" prevented from contracting'and inhibited frornfurther stretch by their-various` wrappingsfthey continue in a substantially relaxe'd'stateandthe fabric produced as shown in Figure 7-1willretain its width as it issues-fromthe knitting apparatus. without puckering.

A succeeding stage-in lthe production ofthe fabric consists in they removal zfrom the elastic threads 4S of thest'retch inhibitingV threads i3 and Hi, for exampleby submitting thelfabriclv to chemical treatment' whereafter the finished fabricassurnes-thea-ppearanc-e indicated in Figure 8, -being prevented from npuclrering laterally bythe 'stretch retaininglwrappingsV H and i2 of the elastic thread, but now free to be stretched laterally asl indicatori in'Figure 9. Thefabricfias shown in Figure 8 still retains the width at which it was manufactured intheknittng apparatuaand is devoid of wrinkles or puckers. Further, since the elastic threads `are in a controlled stretched `condition whenlying asl shown iii Figure 8, considerable force' is required to stretch thc-xn,- and the contracting force exercised by the elastic threads"'whenstretched as shownjin Vl-'igure 9 "and tending to restore the fabric to the condition shown in Figure 8, is considerably 'greater than would be the case were the elastic threads initially in an unstretched condition.

The threads i3 and I4 which are Wrapped on the exterior of the basic thread may be of any suitable material. They may, for example, be of alginate or they may be of wool but they are essentially of a material different from that of which the fabric is made and are of such a nature that they can be destroyed by chemical action (calgon is a suitable solvent for alginate) which action has no deleterious effect on the remaining threads incorporated in the fabric including those threads H and I2 which were Wrapped around the elastic core thread in the initial stages of stretch-retaining wrapping to produce the basic thread.

A further advantage of threads produced in accordance with this invention over threads of the type described in Patent Specification No. 2,220,213, is that threads in accordance with this invention are considerably smaller in cross sectional area and consequently more threads per -unit of length may be introduced into the fabric.

The wrapping threads applied to the basic threads can be of comparatively small size so that they increase only very slightly the cross sectional area of the basic thread whereas in the method of the said prior specification the cross sectional area of the composite thread is substantially increased by the inclusion of the carrier thread which is Subsequently rendered inoperative.

I claim:

l. The method of making elastic yarn comprising stretching an elastic thread to a predetermined extent, applying at least one closepitched helical wrapping of thread to said stretched elastic thread to retain it in a stretched condition and thereby produce a basic thread, and associating externally with the basic thread thereby produced an inextensible thread to inhibit further stretch, said inextensible thread being removable or destructible by means harmless to the thread of said close-pitched helical wrapping.

2. The method of making elastic yarn wherein an elastic thread is stretched to a predetermined extent, the initially stretched elastic thread is retained in a stretched condition by applying thereto superimposed clockwise and counter-clockwise close-pitched helical wrappings of thread, applying at least one wide-pitched helical wrapping of an inextensible thread to inhibit further stretch, said inextensible thread being removable or destructible by means harmless to the thread of said close-pitched wrappings.

3. The method of making elastic yarn according to claim 1 wherein the inextensible thread is associated with the basic thread by being wrapped with a wide pitch therearound.

4. The method of making elastic yarn according to claim l, wherein the close-pitched helically wrapped thread is inherently substantially inextensible.

5. The method of making elastic yarn according to claim l, wherein the basic thread has applied to it at least two further wide-pitched wrappings of inextensible thread, one moiety of said wide-pitched wrappings being applied helically clockwise and the remainder of the said wrappings being applied helically counter-clockwise.

6. The method of making an elastic yarn according to claim 1, wherein the inextensible thread is associated with the basic thread by 8 l being wrapped with a wide pitch therearound'and the basic thread is completely relaxed prior to and during the application thereto of said widepitched wrapping of inextensible thread.

7. The method of making elastic yarn according to claim l, wherein the inextensible thread is associated with the basic thread by being wrapped with a Wide pitch therearound and the basic thread is fed to and drawn from at least one wrapping station in a relaxed state by means of bobbins rotated at equal peripheral speeds for the application thereto of said wide-pitched Wrapping of inextensible thread.

8. An elastic yarn comprising an elastic thread held in stretched condition by at least one helical wrapping of close-pitched textile thread, and inhibited from further stretch by at least one further helical wrapping of wide pitched thread of a material removable as by chemical means that is harmless to said close-pitched wrapping.

9. An elastic yarn comprising an elastic thread retained in stretched condition by superimposed clockwise and counter-clockwise close-pitched helical wrappings of thread, and inhibited from further stretch by at least one further widepitched wrapping of an inextensible thread which is removable by chemical means that is harmless to said close-pitched wrapping.

10. An elastic yarn according to claim 9, having at least two of said further wide-pitched wrappings, whereof one moiety is applied helically clockwise and the remainder helically counter-clockwise.

11. An elastic yarn according to claim 8, wherein said wide-pitched helical wrapping is composed of a yarn, such as alginate yarn, which is removable by a solvent.

PHILIP ERNEST FRANK CLAY.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,679,822 Hall Aug. 7, 1928 2,052,875 Gammons' Sept. 1, 1936 2,061,021 Chittenden NOV. 17, 1936 2,210,884 Chittenden Aug. 13, 1940 2,231,808 Isaac Feb. 1l, 1941 2,369,651 Amidon Feb. 20, 1945 2,411,175 Wagler Nov. 19, 1946

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