Hot pressing die

Claim 1

A HOT PRESSING DIE FOR CERAMIC AND LIKE MATERIALS REQUIRING HIGH VALUES OF HEAT AND PRESSURE; A SUBSTANTIALLY CYLINDRICAL UNITARY ASSEMBLY COMPRISING: A GRAPHITE DIE FORMING A PRESSING CHAMBER POSITIONED SUBSTANTIALLY CENTRALLY OF SAID CYLINDRICAL UNIT; MEANS TO EXERT PRESSURE FOR FORMING MATERIAL IN A CENTRAL REGION OF SAID GRAPHITE DIE AND LONGITUDINALLY OF SAID CYLINDRICAL UNITARY ASSEMBLY; AN ANNULAR LINING OF REFRACTORY COMPRESSION-RESISTANT MATERIAL HAVING A CENTRAL OPENING TO RECEIVE SAID GRAPHITE DIE AND SAID LONGITUDINAL PRESSURE EXERTING MEANS; INDUCTION HEATING COILS IMBEDDED IN SAID REFRACTORY MATERIAL IN SUBSTANTIALLY ANNULAR FORMATION AROUND SAID CENTRAL GRAPHITE DIE REGION BUT RADIALLY OUTWARD THEREFROM; A STEEL BAND FORMING THE OUTSIDE PERIPHERAL COVERING OF SAID CYLINDRICAL UNIT AND SURROUNDING AND RETAINING SAID REFRACTORY MATERIAL, SAID INDUCTION COIL, AND SAID GRAPHITE DIE; METALLIC SHUNT ELEMENTS ALSO IMBEDDED IN SAID REFRACTORY MATERIAL BUT SPACED ANNULARLY AROUND IN SAID REFRACTORY MATERIAL RADIALLY OUTWARD FROM SAID INDUCTION COILS BETWEEN SAID INDUCTION COILS AND SAID STEEL BAND; SAID GRAPHITE, REFRACTORY, INDUCTION COILS AND METALLIC SHUNT BEING CONSTRUCTED AND ARRANGED AS AFORESAID SO THAT TENSILE STRENGTH OF SAID STEEL BAND, NECESSARY AT HIGH VALUES OF HEAT AND PRESSURE EXPERIENCED DURING HOT PRESSING OPERATIONS, IS RETAINED BY THE COMBINED EFFECT OF SAID METALLIC SHUNT AND SAID REFRACTORY MATERIAL RADIALLY LOCATED BETWEEN SAID COILS AND SAID STEEL BAND COACTING TO PREVENT REDUCTION IN TENSILE STRENGTH OF SAID STEEL BAND BY EXCESS HEATING OF SAID STEEL BAND.