GB371007A - Improvements relating to separable fasteners - Google Patents

Abstract

371,007. Sliding-clasp fasteners. LIGHTNING FASTENERS, Ltd., Lion Works, Witton, Birmingham. Dec. 11, 1930, No. 37422. Convention date, Dec. 14, 1929. [Class 44.] In the manufacture of sliding-clasp fasteners in which the elements 14 are formed from lengths of wire bent to U-shape and clamped in spaced relation to the corded edge 13 of the stringer 9, the interlocking surfaces on the elements are formed after they have been secured to the stringer. As shown in Fig. 3, the elements are acted upon in succession by a shaping tool 38 which moves in a direction inclined to the plane of the elements and has a V-shaped recess 39 which squeezes up the metal to form a projection 33. This projection may also be formed by a pair of side tools 42, 43, Fig. 8, which move parallel to the plane of the elements and are formed with rounded noses 44. In both these forms the recess for the reception of the projection 33 on the adjacent element is provided by the space 34, Fig. 7, between the bend of the element and the edge of the stringer, Figs. 11, 12 show a modification in which each element in addition to a projection 18 formed by an inclined wiping tool 27, is formed with a recess 17 produced by a punch 24. During the formation of these projections and recesses each element is supported by side tools 22, 23 which may be arranged to produce indentations 16a, Fig. 18, which render the elements more flexible. The elements are preferably formed from an alloy of nickel, zinc, and copper. Specification 233,344, [Class 44, Fastenings, Lock &c.], is referred to.