GB1128441A - Improvements in or relating to sliding clasp fasteners - Google Patents

Abstract

1,128,441. Sliding clasp fasteners. T. BRETHERICK. 30 Sept., 1965 [30 June, 1964], No. 26897/64. Heading E2S. A sliding clasp fastener comprises a pair of flexible strips 15 made of synthetic resin material each strip having a series of teeth 16 along one edge, the teeth of one strip being caused to interengage with those of the other strip by means of a slider through which the strips extend, engagement of the teeth being affected by traversing the slider in one direction and disengagement being effected by traversing the slider in the opposite direction the slider having two channels extending from its end 13 which leads when the fastener is being closed, the two channels converging into a single channel which extends to the trailing end 14, the channels being so shaped that the engageable parts of the strips are guided so that they not only converge from the leading end to the trailing end of the slider, but the angular disposition of which in transverse cross section varies progressively from an acute angle to each other at the leading end of the slider facilitating the initial engagement of the teeth of the strips within the slider, to a more acute angle as the teeth become fully engaged beyond the trailing end of the slider, a central projection 23 being provided within the slider extending from its trailing end to engage the teeth of both strips to deflect them one by one as closure takes place to assist in causing full engagement of said teeth. The strips 15 shown are those described in Specification No. 1037263, each strip comprising a mounting flange and a toothed flange, a step 19 being formed between the two flanges; the channels extending from the leading end 13 of the slider have their major portions inclined in transverse cross section through the slider at substantially 60‹ relatively to one another and the two corresponding portions of the single channel are inclined substantially at 120‹ to each other at the trailing end of the slider. The slider is made in two parts 10, 11 which are secured together and the part 11 has two inturned flanges 22 for engagement with the steps 19 of the strips.