GB1324467A - Method of forming sand mould - Google Patents

Abstract

1324467 Foundry moulding machines and processes S P O Inc 19 July 1971 [20 July 1970] 33797/71 Heading B3F A foundry moulding machine comprises a flask support 8 and a presser head 3 provided with a plurality of presser or peen feet 6 mounted in cylinders at the end of hydraulically operated pistons 5. The presser head is reciprocable by a piston and cylinder 1, 2 towards and away from the flask support 8. In operation, pressure fluid from a reservoir 17 is pumped into a manifold 11 which supplies all the cylinders in a peen feet supporting block 4, thereby to move all the peen feet to their fully extended positions as in Fig. 1a. The presser head 3 is lowered on to a flask 7 to compress sand 10 therein. Firstly, all the peen feet move downwards to the same extent. As the presser head is further lowered (see Fig. 1c) some of the peen feet are forced back into the supporting block 4 in accordance with the degree of compression of the sand under each of the peen feet. As a result the hydraulic fluid pressure in the manifold 11 increases as the fluid is retained by a check valve 14 (Fig. 1a). When a predetermined pressure is reached the check valve 14 opens to return the fluid to the reservoir 17. The presser head is retracted and the finished mould part removed. The manifold 11 is divided into two parts, one supplying the cylinders of the peripheral peen feet and the other the central peen feet cylinders. In this way the compaction of the mould periphery can be increased relative to its centre.