MOULD FOR PRODUCTION OF HOLLOW CASTINGS Russian patent published in 1996 - IPC

FIELD: foundry, in particular, metal-mould casting. SUBSTANCE: mould for production of hollow castings uses metal base with stops and moulding parts of casting cavities in the form of hemisphere, cone, pyramid and their combinations with unambiguous pattern drafts within 20 to 85 deg. to the plane of the larger bases. The mould has additional cavities, whose walls are conjugated with the stops at distance l=(0.4-4.0)r from the smaller base of the mould crushed-in part that is the most dist distant one from the parting line surface, where r-distance from the geometric axis of the mould cavity to the most distant point in the plane of the smaller base of the mould crushed-in part that is the most distant one from the parting line surface. The specific feature of the mould is the use of pattern drafts of the crushed-in moulding parts and natural shrinkage (decrease of dimensions) of the casting and process bosses obtained in the additional cavities, whose walls are conjugated with the stops, for gradual displacement of casting from the mould crushed-in parts towards the smaller base and reduction of forces of their crushing-in. EFFECT: facilitated procedure. 5 dwg