Patent GB-1429739-A (GB)
Title: Woven tape for sliding clasp fasteners
IPC: A44B19/54
Filed: 1974-02-25
Abstract: 1429739 Woven zip fastener REMMERT SpA 25 Feb 1974 [27 Feb 1973] 8428/74 Heading D1K [Also in Divisions El and E2] The invention relates to a tape of interwoven weft and warp threads for a sliding clasp fastener having, adjacent one longitudinal edge B, an interengagement member in the form of a flattened helix E formed with an enlarged head portion 7 at each turn thereof for cooperation with the corresponding head portions of a similar helix on a further tape when two such tapes are positioned with their two helices extending parallel to and facing one another, at least the part of each turn of the helix on which the head portions are formed being superposed in part, on the weft of the tape and interwoven with the latter by at least one pair of binding warp threads which encircle the turns and cross each other, as seen in the direction of the weft, between adjacent turns. According to the invention the weft of at least a portion of the tape is formed by at least two distinct threads and the flattened turns of the helix are held between two layers of covering fabric, the weft of each of which is formed of loops of a respective one of the weft threads of the tape fabric and the warp of each of which is formed by at least one pair of first warp threads crossing each other, as seen in the direction of the weft, in spaced relationship and binding together the threads of the loops of the weft, the said two layers of covering fabric being bound together and secured to the helix. A tape suitable for fabrication upon a lappet-type loom, comprises warp threads o in the main tape portion M with loops 1, 2 of weft threads T, T' respectively which are bonded together at the edge opposite that carrying the helix E to form a selvedge. The insertors, not shown, for the weft threads T, T' are introduced between the warp threads o from the right of the helix E, Fig. 1, the threads T and T', which extend respectively above and below the flattened turns of the helix E, being bound together respectively by pairs of first and second warp threads 9, 10 and 11, 12. Each pair of warp threads 9, 10 and 11, 12 is crossed over respectively, as seen in the direction of the weft, between the successive weft threads 1, 2 of the threads T, and T' a further pair of crossed warp threads 15, 16 bonding together the adjacent runs of the threads T, T' to prevent the helix E from moving inwardly of the tape. Additionally the two layers of covering fabric are bound together by a third pair of warp threads 13, 14. The edges of the upper and lower layers T, T', which are shown as being relatively displaced for illustration purposes, are in practice, vertically aligned; and the frequency of the loops 1, 2 may be different. In a modification, Fig. 2 not shown, the tape has only half the number of weft threads (T, T') there being four pairs of warp threads consisting of respective upper and lower pairs (9, 10 and 11, 12) outwardly of the warp threads (13, 14) and respective upper and lower pairs (18, 19 and 20, 21) between the pairs of warp threads (13, 14) and (15, 16). A fourth warp thread (17) is added. In a further modification, Fig. 3, the loops 1 of the weft thread T are not interwoven with the warp threads o and are bound together, adjacent the helix E, by chain stitching 22. In a variant of the tape, Fig. 4, suitable for weaving on a shuttle loom, the chain stitch weave 22, Fig. 3, is obviated. The pairs of first warp threads 9, 10 and 11, 12 and/or the further pairs of first warp threads 18, 19 and 20, 21, could bind the upper and lower layers by periodically encircling the threads T, T' of both of the loops 1, 2.