Patent GB-391002-A (GB)
Title: Improvements in or relating to the manufacture of sliders for sliding-clasp fasteners
IPC: B21D53/54
Filed: 1932-08-12
Abstract: 391,002. Stamping fastenings. CLARK, D'A. M., 1, Quality Court, Chancery Lane, London.-(Prentice Mfg. Co., G. E.; New Britain, Connecticut, U.S.A.) Aug. 12, 1932, No. 22655. [Classes 83 (ii) and 83 (iv).] Sliders for fastenings of the sliding-clasp type are formed by treating, without sudden or sharp bending, a blank punched out from nickel silver sheet material and having a neck portion uniting parallel front and rear wing portions of the slider. After the wings have been flanged up, pressure is applied to the lateral margins of the slider to narrow the upper part, while at the same time buckling pressure is applied to the neck. The neck is formed by a series of operations into tubular form of substantially elliptical contour at all transverse cross sections with the longer axis vertical, and tapering upwardly as well as downwardly to facilitate movement of the slider along the fastener stringers and to permit the stringers to lie close together in the fastened position of the slider. Fig. 2 shows a form of slider blank B with an integral extension 15 for attaching a pull member to the slider, but such extension need not be integral with the blank. After the sides of the wings 12, 13 have been flanged, they are brought into parallel relationship and the neck 14 is somewhat hollowed to a form shown at 20 in Fig. 5, by apparatus shown in Fig. 27 comprising a lower die bed with a die 54 having an opening 55 to receive the blank and an upper punch 57 with a member 63 to engage and turn the extension 15 through a right-angle. The blank is next transferred to the apparatus shown in Fig. 33 with the hollowed neck 20 resting on a fixed arbor 65 on a die bed 63. A die punch 74, which co-operates with the die bed, has cam bars 76 secured to its opposite sides which engage inclined surfaces 78, 79 on slider jaws 67, 68 and force the jaws towards each other. An arbor 80 with a vertical slot in its lower end and arched at its upper end corresponding to the transverse arch of the slider neck is secured to the punch by a pin 83. A pair of swinging arbors 85, 86 are pivotally secured to the punch in a slot 84 and have pins 87, 88 to extend between the opposed flanges of the slider body, and these arbors are engaged by the inwardly-moving jaws 67, 68 when the punch 74 moves downward to buckle or corrugate the slider body and narrow it transversely while the recess 20 in the neck of the slider is being deepened by the surface 82. The tongue 15 is bent at 22, Fig. 8, by the shorter leg of the arbor 80 at one side of the arched slot. A pull tab 10 is threaded over the tongue 15 which is then bent as at 21a, Fig. 8, to dispose the narrow neck 16, Fig. 2, of the tongue in the recess 20 in the neck. The extreme lateral edges of the neck are then brought into contact by apparatus shown in Fig. 34, comprising a reciprocating punch 93 carrying an arbor to bend the enlarged end 17 of the tongue 15, Fig. 2, against the rear wing, and having in a slot in its under-surface a pair of swinging arbors 96, 97, the lower parts of which enter the slider channels and carry cams to swage the lateral edge portions of the neck material over the part 16 to lock the end 17 in position.