US2033979A - Manufacture of yarns - Google Patents

Description

Mardi 17, 1936. H, DREYFUS I 2,033,979

MANUFACTURE OF YARNS Filed March 8, 1954 Patented Mar# 17, 1936 PATENT. OFFICE,y

2,033,979 MANUFACTURE .0F YABNS Henry Dreyfus, London, England Application March 8, 1934, Serial No. 714,560 In Great Britain March 28, 1933 3 Claims. (01.1951) This invention relates to the manufacture from continuous laments of yarns which have the appearance and character of spun yarn made from staple libres.A

InU. S. application Serial No. 696,375 led November 2, 1933 methods are described of converting continuous filament threads directly into spun yarns by passing such continuous filament threads successively through at least two pairs of rollers which rotate at successively higher peripheral speeds and so stretch the continuous filaments beyond their breaking point. The brous material so produced is, according to this specication, twisted into a iinal yarn (e. g. by ring or cap spinning devices) as it proceeds from the breaking rollers. In order to produce e'ective results the drawing rollers must grip the'ladifferent laments of the ments quite definitely in order to avoid slippage and consequent non-breakage of the laments. The pressure applied to the yarns for this purpose, if it is of sucient magnitude to prevent slippage is apt to cut all the filaments at the roller instead of gripping them, or to bruise the laments, giving rise to weakness in the yarn produced. If a smaller-force while some of the laments would be broken, others of the laments may be shielded from the nipping eiect of the rollers by their fellows and so pass unbroken through the rollers. It is an object of the present invention to enable pressure of the drawing rollers to be reduced without permitting unbroken filaments to pass through the rollers.

According to the present invention, each pair of rcllers comprises one roller of substantially unyielding material, the surface of which is covered with protuberances which localize the pressure applied between the rollers, such localization taking effect along the length of the rollers as well as along the length of the filaments passing between them. 'Ihe disposition of the protuberances on the surface of the rollers should be such that at any point along the length of the rollers through which the yarn is to pass, localized pressure is applied at some time. In this manner the thread of continuous filaments have a localized pressure applied to them at diii'erent times, and are successively gripped and broken.

The invention is applicable in theproduction f staple iibre yarns from continuous or substantially continuous filaments of any desired kind, particularly artificial filaments. While the invention may be applied to continuous artificial filaments of reconstituted cellulose such as viscose or cuprammonium filaments, it i's especially convenient with continuous iilaments of cellulose acetate or other organic derivatives of cellulose. Examples of other `organic derivatives of cellulose are other cellulose esters such as cellulose formate, propinate or butyrate and cellulose 5 ethers such as ethyl or benzyl cellulose.

By way of example a form of apparatus according to the invention will now be described in greater detail with reference to the accompanying drawing in which:- l0

Figure 1 is a side elevation and Figure 2 a front elevation of an apparatus embodying the rollers according to the invention, while Figure 3 is an enlarged sectional view through .the surface of one of the rollers. l5

,Referring to Figures 1 and 2, a thread 3 consisting of continuous filaments is drawn from a package or is fed substantially without tension as described in U. S.l application Serial No. 714,559 led March 8, 1934 corresponding to British ap- 20 plication No. 9309/33 iiled March 28,1933, and the two pairs of means of a bar 8 and a rod 9 loaded with'a spring 25 or weight (not shown The position' of the rod 9 along the bar 8 is adjustable so as to adjust the proportions of weight carried by the rollers 5 and 1 respectively. f

VThe lower rollers and 6 of each pmr are made 30 of steel or like hard 2, so as to leave upstanding lozenge-shaped domes or protuberances betweenl the grooves. sharpness which may occur at lthe edges of the 35 protuberances is removed by smoothing, e. g. by means of sand blasting, the reduction in height of the protubera'nces resulting from such smooth' ing being taken into account in determining the depth of the helical grooves. 'I'he resultant form 40 is indicated in the enlarged sectional view of In order to avoid excessive local wear, the thread 3 between the pairs of rollers 4, 5 and t, 1 is passed through a tube IU of the kind described .in U. S. application Serial No. 712,148 flied Eebruary 20, 1934, corresponding to British application No. 8765/33 led March 23, 1933 which is mounted on a bar I I adapted to traverse the tube endwise of the rollers 4, 5, 6, 'I. The tube I0 confines the filaments and maintains them in a compact state after they have been broken. It may convenient-ly be made of non-conducting material, so as to reduce the electrication of the fibres and subsequent difficulties in spinning. The length of traverse is substantially equal to the length of that part of the rollers 5, 'I which is covered by the jacket I2 as shown in Figure 2.

The thread 3 proceeds from the rollers 6, 'I in the form of a continuous product of staple bres which passes to the guide I4 of a ring spinning device by means of which it is twisted and wound on a package I6.

Since the breakage by stretching between the drawing rollers 4, 5, and 6, 1 necessitates the stretching of the filaments beyond their maximum extensibility, the extensibility of the yarn ultimately produced may be reduced to an undesirable extent. This reduction in extensibility may be overcome at least partially by the methods described in U. S. application Serial No. 696,- 184 led November 1, 1933.

What I claim and desire to secure by Letters Patent is:-

1. An apparatus for the production of staple bre yarns from continuous filaments, comprising successive pairs of rollers for breaking the filaments, each pair consisting of one roller having'a surface of yielding material and one roller having an unyielding surface covered with proturberances which localize the pressure applied between the rollers, said protuberances being discontinuous both longitudinally and circumferentially of the roller. v

2. An apparatus for the productionk of staple bre yarns from continuous filaments, comprising successive pairs of rollers for breaking the continuous laments, each pair consisting of one roller having a surface of yielding material and one roller having an unyielding surface covered with protuberances which localize pressure applied between the rollers, said protuberances being discontinuous both longitudinally and .circumferentially of the roller and a guide tube disposed between the pairs of rollers and adapted to conne the larnents passing between the pairs of rollers.

3. An apparatus for the production of staple fibre yarns from continuous filaments, comprising successive pairs of breaking rollers, each pair consisting of one roller having a surface of yielding material and one roller having a surface' of unyielding material covered with protuberances which localize pressure applied between the rollers, said protuberances being discontinuous both longitudinally and circumferentially of the roller, and means disposed between the pairs of rollers for traversing the filaments to and fro along the rollers so as to minimize wear on the roller surfaces.

HIENRY DREYFUS.

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