GB489272A - Improvements in the manufacture of staple fibre yarns or like products - Google Patents

Abstract

489,272. Forming staple fibre yarns or like products. POOL, W. Oct. 21, 1936, No. 28593. [Classes 120 (ii) and 120 (iii)] Staple fibre yarns or like products are formed by feeding a substantially twistless bundle of associated continuous filaments towards a rotating drum, separating the filaments of the bundle from each other at the end of the bundle, obtaining from such separated filaments a succession of groups of separated fibres of predetermined length by a cutting operation, holding each group of cut fibres to the peripheral surface of a rotating drum by suction, and withdrawing the succession of groups through a passage to the axis of the drum, the rates of feeding and withdrawal being such that the ends of successive groups overlap and the twist imparted by the rotation of the drum unites them into a continuous twisted product. A number of 'separate successions of groups may be twisted on one drum and collected as a single product, or at least one may be led through one passage and the remainder through another and respectively withdrawn from opposite ends of the drum so as to form separate products. The fibres may be of cellulose acetate or other organic derivative of cellulose. As shown in Fig. 1, a bundle of filaments 24 having little or no twist is withdrawn by feed rollers 28, 29 through a gate tension device 27 and delivered by a compressed-air feed-device 30 in an open state to cutting means from which they pass to the drum 1 and through the tube 16 to winding-up means 57. The drum is surrounded by a casing 22 which is slotted for the passage of the material, and suction through holes surrounding the flared opening of the tube and in the surface of the drum is effected by a conduit 15 and an adjustable valve 13. The feed device 30 is supplied with compressed air from a conduit 34 which serves to eject the filament at intervals and to separate them in the form of a flat band. Severing-means 41, Fig. 8, is arranged between the nozzle of the feed-device and the drum, and is operated by a cam 43 to cut the filaments obliquely to the direction of feed when they are depressed by arms 45 operated by a cam 47. A cam 39, Fig. 6, opens and closes a valve 38 in the feeddevice 30 and is mounted with the cams 43, 47 on a shaft 40 so that filaments are fed forward, severed, and engaged by the drum 1 in succession, the newly cut ends of the main supply being automatically withdrawn into the feed-device from the severing-means. The gate tension-device 27 is made of metal and one or both of the feed rollers 28, 29 may be covered with guttapercha so that an electrostatic charge is generated and maintained in the filaments whereby their separation at the feed-device is facilitated. This effect is maintained by applying french chalk to the rollers and by traversing the tension-device relatively to the rollers, for which purpose it is mounted on a pivoted arm 60. The pressure of the tension device is regulated by a spring-controlled wire 69 connected to the movable gate and, for this purpose, operating as a lever pivoted at a. A feeler 74, Fig. 11, is adapted upon breakage of the yarn to engage a rotary tooth 76 and thereby to release a detent 77, whereby a vertical rod 81 is released and moved by a spring 82 so that an arm 89 is operated to disconnect the drive of the drum, 'the cradle 93 of the roller 28 is raised by the lever 92, and the tail 72 of the wire 69 is operated to lock the tension device to prevent passage of the filaments. A cam 85 is arranged to engage a roller 84 on the feeler 74, when it is moved by the tooth 76, so as to tilt the feeler into a position to facilitate re-threading. Specification 484,192 is referred to.