GB1265929A - - Google Patents

Abstract

1,265,929. Punching; making sliding clasp fasteners. M. PERLMAN. 30 June, 1970 [30 June, 1969], No. 31635/70. Headings B3A and B3W. A slide fastener gapping machine comprises a punch 78 which extends through a hold down block 72, the block and punch being vertically reciprocable relative to a die 26 and the hold down including a positioning device 100 for aligning the teeth 52 of a slide fastener chain located on the die relative to the punch so that the punch can clean cut a tooth at each end of a gap to be formed by the punch. The device 100 comprises a bar 104 slidable in a slot 102 in the block 72 and urged downwardly by a spring 110. A finger 112 on the arm is a sliding fit between adjacent teeth of the chain. The die is fixed to a bed 24 and comprises members 62 which are mounted in blocks 54 and can be rotated and turned end to end to present eight different cutting edges. Guide bars 116 and 118 are spring-mounted one at each end of the die to urge feet 120, Fig. 3, to bear on the fastener tapes 48 and thus locate the teeth between the feet. The punch 78 is mounted in a block 80, Fig. 5, guided on posts (84), Fig. 1, not shown, supported on the die bed 24, and normally spaced from the block 72 by pins 92 and springs 98, Fig. 5. In operation, a slide fastener chain is drawn from a reel through a gapping machine and stopped for gap punching to take place. If as the hold down and punch unit descends the finger 112 engages the upper surface of a tooth the finger will move to the left against the action of spring 110 until it drops into a space between teeth. The chain is then moved to the left to so align the teeth with the punch, Fig. 8, that a whole tooth 52a will be severed, leaving adjacent tooth 52b undamaged. Feet 74 of the hold down immobilize the chain in this position. Fragments of teeth are removed from the tapes by scrapers (132), (134), Fig. 6 (not shown), on guide bar 118 and a shield (130) deflects stray chipped-off teeth. There may be more than one positioning finger 112. The punch length is a multiple of the tooth width.