GB1370005A - Injection moulding apparatus - Google Patents

Abstract

1370005 Die casting SETER SpA 3 Nov 1971 [12 July 1971] 51028/71 Heading B3F [Also in Divisions B5 and E2] A slider for a zip fastener is injection moulded or die cast in a mould 1, 2 having a retractable core 40 defining the stop dog hole 39 in the slider body 37 and a pair of opposed retractable cores 22 having recessed facing ends (23, Figs. 11, 12) in which the pull tab pivot pins 24 are formed, the ends lying within the recesses defining the lugs 36 of the slider during the moulding stage. The core 40 has a head 43 slidable within a channel 44 in a plate 45 urged away from the mould half 2 by elastic sleeves (52, Fig. 7) and is inserted into the mould cavity by forcing the plate 45 against the mould half 2. Rotation of the core 40 is prevented by a key 46 on the head 43 engaging within a plate guide 47. The cores 22 which are sprung loaded away from the mould cavity on the mould half 1 are inserted into the mould cavity by engagement of cam surfaces 32, 33 located on core sleeves 26 and mould half 2 respectively. Rotation of the cores 22 is prevented by keys 27. The moulded slider is ejected by a pair of pins 53 and an air blast. The stop dog may be central, as shown, or offset. The slider may be formed from a plasties material or a metallic alloy.