GB807319A - Improvements in and relating to foundry moulds - Google Patents

Abstract

807,319. Moulds. GRIFFIN WHEEL CO. July 26, 1956 [Sept. 14, 1955], No. 23136/56. Class 83 (1). A mould comprises a number of preformed permanent segments, e.g. of graphite, and one of said segments, e.g. the cope 2, has an opening 9, 11 which communicates with the mould cavity 4 and has situated therein a porous head 13 through which slidably extends a stem 8 carrying means 7 for closing a gate 6 provided in one of the segments, e.g. the drag 3, in alignment with said opening. The stopper-stem passes through guiding-means comprising a spider 19 and a fibreboard tube 27, and may be clamped' thereto by a clamp 28 to hold the stopper 7 in its raised position during casting. The cope also comprises a number of circumferentially-spaced risers 37, having resin-bonded sand-liners 33. The riser-liners 33 and the porous, resin-bonded, sand-head 13 are baked in situ by an apparatus comprising a carrier 41 supported on a piston 42. The head baking- unit comprises a metallic-plug 47, stem 49 and electric heater 51. The lower ends of the riserbores 31 are closed by heating-plates 52, each having a sprue-plug 54 and co-operating with a plug 53. Molten metal is pressure-cast upwardly through the gate 6 to fill the cavity, the stopper 7 then being moved to close the gate. After solidification, the cope is removed and the casting lifted by a lifting-device connected to the stem 29. Specification 721,065 is referred to.