GB967154A - Improvements in and relating to vacuum melting-and casting-furnaces - Google Patents

Abstract

967,154. Vacuum melting furnaces. BALZERS PATENT-UND LIZENZ-ANSTALT. May 15, 1963, No. 19260/63. Heading F4B. [Also in Division B3] A vacuum melting furnace and casting machine comprises a main chamber 1 separated from an air-lock chamber 8 by a wall 7 and door 10, chamber 8 being openable to the atmosphere by a lid 8a and a platform 22 rotatable by a hollow shaft 26 to transfer one or more moulds 23 between the two chambers into line with the tilting crucible having an induction heating coil 4. Door 10 is removed from its seating by lever 12 and rotated by lever 13 through linkage 11. Preheated moulds placed on the platform are kept hot by a heating coil 24 having leads 25 passing through the shaft 26. The latter is rotated by hand wheel 27 and moved vertically by lever 28. During casting, the mould may be rotated by a plate 47 on motor-driven shaft 46 which is raised and lowered by a lever 48. The platform 22 may be rotated by a motor through bevel gearing and a drive shaft inside the shaft 26, Fig. 2 (not shown). Instead of the device for rotating the mould during casting, a shaft 51, Fig. 3, extends through the furnace wall 50 supporting a plate 52 having a connection 55 to a vacuum pump 57 and carrying a precision mould 54 on a spacer ring 53, the mould having a porous bottom. In this case, the furnace chamber 1 may be filled with a neutral gas, e.g. argon, so that the combined pressure of the gas and the suction of pump 57 ensures a clean casting.