GB856994A - Piston moulding core - Google Patents

Abstract

856,994. Cores. STERLING ALUMINIUM PRODUCTS Inc. April 12, 1957, No. 12099/57. Class 83 (1). A collapsible core for a piston - casting machine comprises side sections for forming the wrist - pin bosses and a middle core between the side sections, the middle core being insertable into and retractable from the mould and from between the side sections, and comprising a centre - section movable relatively to a lateral-section or sections, which is or are positively locked to the centre-section, and in collapsed position until the entire middle core approaches its final position in the mould in relation to the side-sections, whereupon the lateral section or sections is or are unlocked to permit the centre-section to move relative to the lateralsection or sections to expand the middle core. The apparatus described is substantially as described in Specification 760,263, which is referred to, but the or each lateral-section 33 of the middle core carries a plate 83 pivoted at 84 and counterweighted for anticlockwise rotation by an extension 89, so that at the end of the downward movement of the core a shoulder 85 of the plate snaps over a roller 86 carried by the centre-section 31. The core 31, 33, is then held positively collapsed during its upward movement into the mould, until the plate 83 engages a stop 88, releasing the lateral element 33, whereupon the core may be expanded. Specifications 721,245 and 753,877 are referred to.