GB1269532A - Winding apparatus - Google Patents

Abstract

1,269,532. Yarn traversing mechanism. LEESONA CORP. 24 April, 1969 [29 April, 1968; 3 Feb., 1969], No. 20873/69. Heading D1J. In a strand traversing mechanism of the kind comprising a pair of oppositely moving belts 38, 40, Fig. 4, and in which each belt carries one or more yarn guides 26; there is a further yarn guide 10, Fig. 1, exerting a substantially frictionless biasing force on the strand for maintaining a constant yarn tension during movement of the yarn by the guides 26. In Fig. 1 the guide 10 is a pivoted arm 12 causing the yarn to form a U-shaped loop 20 supported on a pressurized cushion of air. This cushion of air also causes the yarn to move inwardly (dotted lines) and outwardly (phantom lines) with the guide to compensate for fluctuations in tension resulting from variations in yarn length primarily due to yarn traverse. The yarn passes over parallel bars 78 between which the yarn guides 26 extend during the major part of their traverse the bars 78 providing resistance to motion of the strand along the strand traversal path. Each yarn guide has a groove 101 therein in which the yarn Y, Fig. 7, is trapped by the bars 78 during the major part of the yarn traverse. Near the end of a traverse movement the belts 38, 40 and therewith the guides 26, move around sprockets 46, 56; 42, 62; Fig. 4, to withdraw a delivering yarn guide 26D, Fig. 7, from between the bars 78 and permit a receiving yarn guide 26R, accepting the yarn, to enter between the bars 78 and traverse the yarn in the opposite direction. To compensate for the increased velocity of traverse that would take place as a guide 26 commences to move around a sprocket near the end of a traverse, the yarn engaging surface of each groove 101 is curved oppositely to its direction of travel near its tip, as at 96 for guide 26D and 98 for guide 26R. The belts 38, 40 are preferably toothed belts and where a yarn guide 26 is secured to a belt the tooth at that location is removed and the yarn guide 26 is secured in position by means that also acts as a tooth on the belt. Fig. 14 shows one method of securing an L-shaped guide 26R or 26D to a belt, the part 126, 127 of the L-shape acting as a belt tooth as well as a face against which the belt is clamped by means of a clamping plate 126', 127'.