GB1173086A - Improvements in or relating to Sliding Clasp Fasteners - Google Patents

Abstract

1,173,086. Sliding clasp fasteners. OPTIHOLDING A.G. 17 Feb., 1967 [3 March, 1966, (2)], No. 7715/67. Heading E2S. A sliding clasp fastener comprises two stringer tapes 1 each having a longitudinal row of perforations through which pass teeth 4, formed with enlarged interlocking heads 3, constituted by successive turns of a respective interlocking element 5 made from a filament of plastics material, each stringer tape having been made from a material possessing the ability to shrink in the transverse direction and having been shrunk behind the enlarged heads 3 of the teeth of the interlocking element to restrain the interlocking element from movement in one transverse direction with respect to its tape, the material between the perforations providing support for the teeth, there being means 13 e.g. or 'core to prevent relative movement in the opposite transverse direction between the element and the tape, whereby the element is held to the tape without the use of sewing threads. The shrinkage can be in the transverse direction only or in both the transverse and longitudinal directions and if the tapes are made of cotton it is carried out by a chemical treatment or by a hot wet treatmint; if the tapes are made of synthetic threads they are shrunk by heating. When the teeth of the elements have been passed through the perforations for each tape a marginal portion is bent back so that it lies on the element overlying the main portion of the tape; when the threads of the tapes are of synthetic materials the marginal portions can be heat treated so that they, are made springy so that they tend to remain in place on the teeth. The weft threads can be provided with enlargements at each end where they define the perforations to prevent the warp threads moving.