US2939269A - Apparatus for twisting and/or crimping yarn - Google Patents

Description

A. DOBSON 2,939,269

APPARATUS FOR TWISTING AND/OR CRIMPING YARN June 7, 1960 Filed June 6, 1958 INVENTOR AUS TIN DOBS ON A TORN APPARATUS FOR TWISTING AND/ OR CRIL'IPING- Austin Dobson, Macclesfield, England, assignor to Ernest Scragg & Sons Limited, Macclesfield, England Filed June 6, 1958, Ser. No. 740,262 I Claims priority, application Great Britain June 11, 1957' 3 Claims. c1. 57-774 The present invention concerns a device for imparting false twist to a textile yarn and, more especially, is concerned with the production of crimped yarns from endless synthetic filament yarns.

A false twist device which has been previously proposed includes two sets of rollers rotating in the same sense about parallel axes positioned so that the rollers of one set overlap the rollers of the other set to form cusps between adjacent overlapping rollers where the yarn passed generally parallel to the roller axes in'contact with the roller peripheries. Such a construction failed to provide a satisfactory twisting action due to the difficulty of controlling the engagement of yarn in the cusps.

An object of the present invention is to provide an improved false twist device which overcomes the foregoing disadvantages and which moreover is especially suitable for incorporation in an apparatus for producing crimped yarn by heating and imparting false twist to a synthetic endless filament yarn.

According to the present invention a device for imparting twist to a textile yarn traversing the said device comprises a pair of rotated surfaces so located relative to one another as to form a cusp in which the yarn to be twisted is held by a third rotating surface, the location of the surfaces being such that the same degree and sense of twist is imparted to the yarn by all three surfaces.

Also according to the present invention a twisting device for textile yarns devised to apply a so-called false twist comprises two pairs of rollers the rollers of each pair being located relative to the other so as to form similar cusps, and a third roller located between said pairs, the dimensions and location of the said rollers being such that a yarn run between the cusps is deflected by the third roller from the straight line between the said cusps.

The invention will now be described further, by way of example with reference to the accompanying drawings, in which:

Fig. 1 is an end view of a preferred embodiment of false twisting unit;

Fig. 2 is a corresponding plan; and

Fig. 3 is a diagrammatic elevation of a crimping unit.

A false twisting arrangement for yarn comprises three rollers 11, 12 and 13. All these rollers rotate in the same direction and the yarn passes into the resultant twisting device via the cusp formed between the rollers 11 and 12. All three rollers are contained within a supporting case 14 and are driven from'a pulley 15 by means of a pulley 16. The pulley 15 is carried on a short shaft passing through a bearing 17, the other end of the shaft being provided with a driving pulley 18 which is rotated by a belt 19. The latter belt may run the whole length of the machine and may serve a plurality of twisting heads of the type shown in the figures.

The drive to the roller 11 is via a pulley 20 and the drive to the roller 13 is via a pulley 21. The pulley driving the roller 12 is immediately beneath the pulley 20.

2 A yarn 22 passes through a guide eye 23 and thence, under slight tension, between rollers 11 and 12, both of which act to rotate the yarn about its axis in the same direction,-while the yarn traverses in an upward diree:

tion with reference to Fig. 1. After leaving contact with,

the said rollers,'the yarn passes over the surface of roller 13, this surface being displaced from the straightline of the yarn at its entry so that the yarn is held firmly against the gap'or cusp between the rollers 11 and 12 and against the surface of the roller 13. The surface of the latter is preferably rounded as shown to prevent damage to the yarn. Similarly, the corners of the surfaces of rollers: 11 and 12 are also slightly rounded, and if necessary one or more of the surfaces of the said rollers may be com-- posed of a resilient material such as rubber. Preferably, the surfaces of rollers 11 and 12 are of steel and a coating of resilient material having a high coefficient of friction, is applied to the surface of roller 13.

After leaving the roller 13, the yarn may pass directly through the exit eye 24, but it has been found preferable in practice, to pass the yarn oncemore between two rollers 26 and 27 which rollers are of the same shape and. size as the rollers 11 and 12, the roller 26 being located on,

the same shaft as roller 11 and roller 27 beinglocated on the same shaft as roller 12, so that the peripheral speeds, of the said pairs of rollers, coincide. The rate of drive of all the rollers is such that the yarn receives an adequate degree of twist on one side of the twisting head, thesaid twist being removed at the other side of the head.

In a crimping unit as shown in Fig. 3, the yarn 22 is drawn by a delivery roller Rfrom a yarn supply S through a tensioner T whereupon it is guided through or over a guide means, such as a guide eye G, as shown in the drawing, and is then drawn into contact with a heater H. After leaving the heater H, the yarn 22 passes through the guide eye 23 and thence into the false twisting device F.

It has been found that false twist arrangement enables a yarn such as, for example, one composed of monofilaments of nylon, to receive twist at an extremely high rate, preferably in excess of 50,000 r.p.m. while involving relatively low rotational speeds of all the rollers associated with the said twisting operation. in fact, it is possible to obtain the same degree of twist on the said yarn as is possible with present methods, with a considerably higher rate of transverse of the yarn through the apparatus. In addition, no high speed bearings are required, so that lubrication and driving problems are greatly simplified. A further advantage of the device is that since the rotational speeds of all the moving parts with the exception of the yarn are low, very little vibration and noise is occasioned.

The degree of divergence of the yarn from its original straight line produced by the roller 13 may, if required, be adjusted by altering the position of the centre of retation of the shaft driving roller 13 relative to the positions of the other two driving shafts supporting rollers 11 and 12. The amount of divergence must however be sufficient in conjunction with the yarn tension employed, to cause adequate twisting effect to be imparted to the yarn.

The axial distance between adjacent faces of the rollers 11, 1'2 and 26, 27 is preferably made small so that the yarn has no tendency to become trapped between the said pairs of rollers. The distance between the faces of rollers 12, 26 and 13 can also be made smaller, though this is not thought to be essential.

It will be understood that the rollers may be mounted on shafts, or they may be manufactured so that each shaft and its rollers are formed from a single piece of material. Again, the rollers may be solid, with parallel Patented June 7, 1960 sides; or; they.- may be provided with webs which are thinner than the surface flanges in order toiobtain light-4 ness. 7

I claim:

7 71-. A deviceiforimpartinglalsetwisttoajextile yarncomprising, in combination tworollers rotating-in the same. sense about parallet axes positioned 'so thatthe-two rollers overlap ,to form; a cuspvwhere the: yarn passes generally parajlelzto. theroller. ages in contact both 7 roller peripheries, a thirdsrolleri also. rotating: inthe same.

sense about an axis parallel to the said: axis pressing'the yarn. into the; said cusp, a. fourth roller-g rotating coaxially {with onehof the said first twoirollersandg a fifth-roller combination two; rollers. rotating in thesame sense about parallel axes positioned soathat the two rollers overlap rotating coarialty. with'the other of the said fiist two rollers, said; fourth and fifthrollers being; positioned so that-they overlap .to formra second cusp, said third roller deflecting the yarmfrqma. straight li-neibetween the cusp of: the-first; two.- roll'ers. and the cusp. of the fourthgandfifth; rollers V 2. A, twisting; device. for textile yarns devised to apply-- a sorcalled falseiwist-comprising-rin combination two pairs of rollers, the rollersofi each pair'being located relative to; thejother so; as to form similar-cusps, and a third roller located. between said; pairs of rollers, the dimensions and locationsof the said-rollersbeing suchthat a yarn run between-the cusps is deflected-bythe third roller'from' the straight line hetween the saidcusps.

' 3. false twist device for 'us e with a crimping 9 auna ase wh re y mfnassesee eratly parallel to the 'roller.axe-si i wllteel with both rloller peripheries, a third roller also rotating in the same sense about an axis parallel to the said' aie pressing-theyarn into the ids pi t a r ha tel e ro ating qaxia ly wi h one. at

the said first't'wo rollers and a fifth roller rotating coaxially with the otherofr-i the-sairl'= first two rollers, said fourth and fifth rollers being positioned so that they overlap to form a second cusp, said third roller deflecting the yarn from a straight line between the cusp of 'the' first two rollers and -the cusp of the: fourth and fifth rollers-i References Cited in the fileofthis: patent UNITED STATESTPATENTS 113,831 'A chibal'd' Apr. 1 8, 1 371 V 2,522,332, 7 Abbott Sept- ,2, 1250 2,161 272, afidamme evalsem, 19 6.

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