Patent GB-1463244-A (GB)
Title: Arrangements including means for threading a yarn
IPC: B65H51/16
Filed: 1975-02-06
Abstract: 1463244 Threading yarn and tow around rollers; crimping apparatus; drawing frames BARMAG BARMER MASCHINENFABRIK AG 6 Feb 1975 [8 Feb 1974 6 July 1974] 5067/75 Headings D1D, D1F and DIN A threading device for feeding one or more yarns 2 around one or more rollers 1, Figs, 10a and 10b, comprises a tube 4 curved in a plane perpendicular to the axis of the rollers 1 and extending at least through the angle through which the yarn is to be looped around the rollers, the tube 4 having a longitudinal slot 6 along its length through which the yarn or yarns can escape to pass onto the rollers 1; and a fluid flow through the tube for initially feeding the yarn or yarns through the tube. A plug 31, Fig. 9a, is fixed to the leading end of a tow and in the tow drawing apparatus of Figs. 10a and 10b the plug 31 first follows the path of the tube 4 and is then led along another path to a waste collector 53. As the plug 31 passes a detector 41, the detector 41 causes an upstream cutter 40 to sever the tow, the length of the tow between the detector 41 and the cutter 40 is equal to the length of the tow in the tube 4. This ensures that the undrawn part of the tow, which represents waste, can be removed before the leading end of the drawn tow, when released from the slit 6 onto the drawing rollers 1, is fed into an outlet 37 directing the yarn to take-off rollers 12. A curved roller 43 condenses the plurality of tows from a wide sheet into a tight bundle that is delivered to a crimper 44. Cutting of the tow by the cutter 40 switches on an injection nozzle 39 that directs the cut end from the tube 4 into the outlet 37. The crimped tow is deposited in a can 45 which makes traversing movements in two directions, as indicated by the arrows.  In Fig. 10b the slit 6 is in a side face of the tube 4. In Fig. 4 the slit 6.4 faces the roller 1.1 and the slit 6.5 faces the roller 1.2, there being a gap 7 between the tubes 4.1 and 4.2 that is tangential to the rollers. Fig. 3 (not shown) shows an embodiment similar to Fig. 4 except that the gap 7 is replaced by a slit in one side face of a continuous tube 4.1 and 4.2. The curved tube 4 may be displaceable parallel to the axis of the roller around which it extends. Each tube 4 may have injectors which produce an air stream with a high rate of flow in the tube whilst the yarn or tow is being fed therethrough. When the air flow ceases the yarn or tow may be pulled out of the tube 4 via the slit 6 and onto the roller around which the tube 4 is curved. Fig. 13 shows a tube cross-section with blow nozzles 22 for producing a curtain of air in the longitudinal slot 6. The curtain of air prevents the yarn or tow from jumping out of the slot. The nozzles 22 receive air via ducts 23 and tube connections 24. In Figs. 11a and 11b bins of tow 46.1 to 46.2 are carried by a conveyor 47 in the direction of the arrow 48. The tow from each bin passes over drawing rollers 1. When a fresh bin 46.5 is placed on the conveyor the leading end of the tow is fed into a tube 4 of the kind described above to thread the tow by means of an air stream around the rollers 1. When the air stream is switched off the tow is pulled out of the slit in the tube 4 and on to the rollers 1, a traverse mechanism 51 causing all the other tows entering the drawing mechanism to move to one side by one step to make room for the new tow.