Patent GB-948794-A (GB)
Title: Improvements in sliding clasp fasteners
Inventor: AUSTIN CHRISTOPHER FREDERIC
IPC: A44B19/60
Filed: 1961-03-16
Abstract: 948,794. Sliding clasp fasteners. LIGHTNING FASTENERS Ltd. March 7, 1962 [March 16, 1961], No. 9687/61. Heading E2S. A method of manufacturing sliding clasp fasteners-of the kind comprising a pair of tapes each provided with a series of teeth to form a stringer, a slider arranged to be movable along the stringers to take the teeth of the respective stringers into and out of engagement with one another and top and bottom stops provided on the stringers to prevent removal of the slider, comprises assembling lengths of toothed tapes together, with the teeth engaged, cutting apertures in the assembled tapes at each of a number of positions along the tapes, each aperture extending over a number of the engaged teeth and being large enough to permit a slider to be inserted therein, inserting at least one slider in each aperture and mounting same on the teeth and securing plastics material to the assembled tape in the vicinity of each aperture either before the aperture cutting or after mounting of the slider and providing end stops on the stringers. In one example of the method (Fig. 3) the lengths of tape 1 are assembled together with their teeth engaged and rectangular apertures 3 are cut from the teeth and tapes and the slider 4 is then inserted into each aperture and mounted on the engaged teeth thus partly disengaging them near the top of a pair of stringers. Strips 5 of the plastics material are then moulded to the assembled tapes on the upper and under surfaces at the top of one pair of stringers and the bottom of the adjacent pair of stringers. In the same moulding operation top end stops 10 and a bottom end stop 11 are formed and completed fasteners are then formed by separating the stringers along the lines 12 and 13. In a second example of the method (Fig. 6), wide strips of the plastics material are moulded on to the upper and under surfaces of assembled lengths of toothed tapes 1 and in the same moulding operation top end stops 21 and bottom end stops 22 are formed. Rectangular apertures 23 are subsequently cut and the top stops of each pair of stringers 24 are slit longitudinally and a slider 25 is inserted into each aperture and mounted on the teeth 2 of the pair of stringers 24 by sliding over the previously formed top stops 21. To permit this to be done the top stops 21 are wedge shaped with the thin ends of the wedge directed towards the aperture the resilience of the material enabling the slider to pass over the top stops and the shape preventing its return. Complete fasteners are then separated by cutting through the plastics material. In a third example of the method, after the two toothed tapes have been assembled together with the teeth engaged, apertures are cut at intervals and two sliders are inserted into each aperture head to head and engaged with the teeth of adjacent pairs of stringers. Strips of the plastics material are then moulded to the assembled tapes on both sides of the apertures and intermediate the apertures and in the same moulding operation top end stops are formed on both sides of the apertures and bottom end stops intermediate the apertures. Individual fasteners are then separated by cutting between the adjacent top stops and adjacent bottom stops. Reference has been directed by the Comptroller to Specification 900,183.