GB893840A - Method of and apparatus for moulding multiple plastic scoops on to stringer tapes of separable fasteners - Google Patents

Abstract

893,840. Injection moulding separable fasteners. PLASCO Ltd. Nov. 26, 1958 [March 12, 1958], No. 38084/58. Class 87(2). In apparatus for moulding fastener elements 64 on to a tape 54 of a separable fastener, wherein plastic material is injected simultaneously into a number of cavities 53 in a pair of relatively movable dies 52, the tape is intermittently fed forwardly a predetermined amount between the opened dies, and means are provided for limiting the tape feed at intervals in accordance with the number of elements in each tape length. As shown in Fig. 1, an adjustable stop plate 59 pivoted at 58 is automatically and periodically moved into and out of the path of tape-feeding grippers 56. Injection is effected by a plunger 34 in a cylinder 29 having a nozzle 47 for each cavity 53. The plunger 34 is operated by a fluid pressure piston 35 and cylinder 21. An extension 37 of plunger 34 moves an apertured slides 25 against the action of a spring 42 to feed material from a hopper 23 to a discharge shoot 28 and inlet aperture 30 in cylinder 29. The cylinders 21, 29 and hopper 23 form part of a frame unit 14 pivoted on a shaft 13. The unit 14 is moved longitudinally on the shaft 13 to bring the nozzles into injecting position by means of a fluid pressure cylinder 16 acting against a spring 20. A cam 31 and roller 33 (see Fig. 4 not shown), control pivoting of the unit 14 about the shaft 13 after injection, to break the sprues.