Patent GB-541812-A (GB)
Title: Improvements in the production of staple fibre yarns and like products
IPC: D01G99/00
Filed: 1940-06-11
Abstract: 541,812. Forming staple fibre yarns from continuous filaments. POOL, W. June 11, 1940, No. 10144, [Classes 120 (ii) and 120 (iii)] Staple fibre yarns and like products are manufactured by feeding a succession of flat wide groups of separated fibres, which may be cut from a bundle of continuous filaments, to the tail of the staple fibre yarn being produced in a direction across the lengh of the tail and applying frictional torques to the tail, e.g. by twist tubes or gaseous vortexes, one close to the end thereof and the other in the opposite direction at a point removed from the end so that the tail is rapidly rotated, an end of each group being brought into engagement with the tail whereby the groups are successively taken up by the tail to form a new tail and the staple fibre yarn so formed being continuously drawn away; the leading or the'trailing ends of the groups of fibres may be arranged to engage with the tail of the yarn being produced and preformed groups of other fibres may be mixed with the flat wide groups of fibres cut from the end of the bundle of continuous filaments. As shown in Figs. 1 and 2 the continuous filament yarn 1 is drawn at a constant rate in terms of weight from a package of the kind described in Specification 504,399 rotated by a friction wheel 3 at a constant angular speed, the yarn passing over a roller 9 surfaced with material removed in the electrostatic series from the material of the filaments and driven at a peripheral speed different from the speed of the yarn so that the filaments thereof become electrified and in passing through a flat wide nozzle 8 supplied with compressed air from a header 7 become separated. The separated filaments pass to a;conduit 10 leading to a second wide flat nozzle 14 also supplied with compressed air from the header 7 and secured to an inner casing 13 with the mouth of the nozzle extending just through the casing into the space between it and an outer casing 12. A disc 15, carrying a pair of diametrically disposed pins 17 lying in the annular space between the casings, is journalled in the casing 12 and rotated so that the pins pass repeatedly across the mouth of the nozzle 14 and deflect the band of separated continuous filaments into the teeth of a cutter 18 of the hair-clipper type driven by a belt 19. The ends of the filaments from the mouth of the nozzle 14 pass around a curved duct 23 leading to a vortex tube 22 disposed just outside the teeth of the cutter 18 and parallel to the axes of the casing 12 and, when they reach an appropriate length, the filaments are severed and the rear ends are brought into engagement with the rapidly rotating tail of the staple yarn 21 being produced, the leading ends, at the same time, being swept sideways through a V-section passage 31 into a conical passage 30 in the tube 22 to form a new tail to the yarn 21. The passage 30 is supplied with compressed air through a pipe 27 leading to small passages inclined towards the wider end of the passage and tangential to the surface thereof, the air forming a rapidly rotating vortex with an axial component in the direction of a pipe 25 in line with the passage 30 and supplied with compressed air through the pipe 28 to induce a suction in the passage. The passage is also in line with a twist control tube 26 in which an air vortex rapidly rotating, in the opposite direction to the vortex in the passage 30, is produced by compressed air supplied by a pipe 29 to oblique passages in the wall of the tube and substantially tangential thereto. The staple fibre yarn engage from an orifice in the end of the tube 26 and passes to a take up device 43 by which it is drawn away and wound up at a constant linear speed. The apparatus may be used for the conversion into a staple fibre yarn continuous filaments continuously with their production, the continuous filament yarns or bundles from.a dry-spinning apparatus passing around continuously-rotating godet rollers to the casing 12. Fig. 9 shows a modification of the apparatus described in Specification 522,017, the continuous filaments 50 from the package 52 passing over the electrifying roller 55, through the nozzle 64 to the nozzle 65 which is supplied intermittently with compressed air from the header 60, the supply being controlled by a valve 61 operated by a crank 62 which also actuates a rocker arm 70 carrying a deflector 69 which presses the filaments emerging from the nozzle 65 at intervals into engagement with the cutter 67. The leading ends of the cut filaments adhere to and are carried forward by a fabric band 73 running over rollers 71, 72 the roller 71 being perforated and suction being applied thereto by a pipe 81 while wool or other fibres, detached from a sliver 78' fed forward by a high draft device 80, are carried up between the band 73 and a cooperating band 74 provided with projecting ribs 75 and are carried forward by the band 73 and mix with the cut filaments; the adjacent runs of the bands are kept in close contact by a cam plate 49. The layer of mixed fibres are carried by the downward run of the band 73 to the vortex tubes 86, the suction applied to the wide end of the conical passage being intermittent and controlled by a valve 93 operated by a crank 94 and opened each time the leading ends of a group of fibres reach the tail of the staple fibre yarn 51 disposed in the vortex tubes; the wall 83 of the suction chamber 82 communicating with the roller 71 is perforated so that suction in the chamber prevents the fibres falling away during the downward run. The supply of either yarn may be discontinued so that a staple fibre yarn consisting wholly of fibres of the other type may be produced or by providing an intermittent feed of either or both types, various effect yarns may be produced. Specification 520,084 also is referred to.