Patent ID: 6237643
Filing Date: 2001-05-29
Classification: D03D,Y10S

Abstract:
A machine for forming a multi-axial yarn structure comprisingwarp yarn supply means for supplying in a warp feed direction warp yarns in the form of a warp sheet, andbias yarn assembly forming means for forming in a succession of bias yarn forming steps in which warp yarns of the warp sheet are displaced in opposite weft directions a non-woven bias yarn assembly comprising two superposed non-woven bias yarn sub-assemblies in which the bias yarns of one sub-assembly are inclined to the bias yarns of the other sub-assembly and in both of which the bias yarns are inclined to the warp feed direction,the bias yarn assembly forming means comprising:a yarn guide member having a support portion extending in the weft direction and a plurality of guide elements which extend laterally from the support portion to form a row of equi-spaced guide elements which terminate in ends lying on a line extending in the weft direction and which define between pairs of adjacent guide elements warp yarn guide openings through which warp yarns of the warp sheet are caused to pass and by which the warp yarns are confined to predetermined relative positions therein along the weft directiona yarn transfer member having a support portion extending in the weft direction and a plurality of guide elements which extend laterally from the support portion to form a row of equi-spaced guide elements which terminate in ends lying on a line extending in the weft direction and which define between pairs of adjacent guide elements yarn transfer openings to which warp yarns of the warp sheet are transferred and by which the warp yarns are confined to predetermined relative positions therein along the weft direction,yarn transfer drive means to cause predetermined relative displacements of the yarn transfer member and the yarn guide member in the weft direction to bring the yarn transfer member to any one of a plurality of transfer positions in which ends of the guide elements of the yarn transfer member oppose and register with ends of the guide elements of the yarn guide member and in which transfer openings in the yarn transfer member register with yarn guide openings in the yarn guide member andshedding means on the supply side of the transfer mechanism for shedding selected warp yarns to cause the selected yarns to move from predetermined first yarn guide openings in the yarn guide member to registering yarn transfer openings in the yarn transfer member and following displacement of the yarn transfer member to another of the plurality of the transfer positions to return the selected warp yarns to the warp sheet and into predetermined second yarn guide openings in the yarn guide member offset from the predetermined first yarn guide openingscharacterised in that:each guide element of one of the members has an end portion which includes or is formed as a salient end portion,each guide element of the other of the members has an end portion which includes or is formed as a re-entrant end portion,the salient and re-entrant end portions of the guide elements are complementary and such as to engage each other at each of the transfer positions and to bring registering guide elements into inter-engaging alignment in the weft direction upon a predetermined engaging movement of the yarn transfer member, andthe yarn transfer drive means is such as to cause the yarn transfer member to carry out the predetermined engaging movement upon advancement of the yarn transfer member to the transfer position and to cause the transfer member to carry out a predetermined disengaging movement upon withdrawal of the yarn transfer member from the transfer position.