Improvements in or relating to casting machines particularly for molding pistons

摘要

656,900. Casting pistons. PERMOLD CO. May 19, 1948, No. 13528. Convention date, June 3, 1947. [Class 83 (i)] Moulds; cores; extracting castings.-A mould more particularly for casting pistons comprises separable sections and a sectional core which has side sections mounted for movement towards and from the central axis of the mould cavity and centre sections adapted to be withdrawn axially from the mould, a common actuating member first withdrawing the centre sections and then moving the side sections towards the central axis. An inverted cup: shaped mould with pouring openings 5 is formed by two mould sections 3 secured to slides 6, Fig. 6, adapted to be moved along guideways by compressed air cylinders 8, the piston-rods 9 of which are coupled to the slides by means of cross-members 14 secured to the slides and pairs of nuts 12 and 13 threaded on the rods. To the end of each pistonrod is secured a wrist pin core 10 projecting through an opening in the mould section. The pairs of nuts 12 and 13 are positioned to give sufficient lost motion for the cores 10 to be withdrawn from the casting before the mould sections are moved apart. Projecting upwardly into the mould cavity is a core comprising two side members 20, Fig. 5, between which is a central member 25 and two end members 27. The central core 25 is secured to the rod 35 of a piston operating in a compressed air cylinder 28 so that it may be withdrawn vertically. End core parts 27 are secured to levers 42, Fig. 7, pivotally mounted at 43 to a cross-head 40 which may be moved vertically up by compressed air cylinders 37. The levers have downwardly depending arms 46 with hooked ends 47 adapted to be engaged by a collar 48 on the piston-rod 35. On the downward movement of the piston, the part 25 is withdrawn, then the collar 48 engages the hooks 47 to rock the parts 27 inwardly as shown in Fig. 7 and then to withdraw them from the mould. The side mould parts 20 are secured to slides 21 and after the withdrawal of the core parts 25 and 27. they are moved inwardly, free from the casting by the engagement of a plate 60 on the piston-rod 35 with the shoulders 59 of two frames 53, pivoted at 51 to the machine and having arms 55 extending upwardly into engagement with the slides 21.