Indirect metal extrusion and tube press and a sealing plate and a pressure plate therefor

Abstract From the Canadian patent

Indirect metal extrusion and tube press and a sealing plate and a pressure, plate therefor" In order to prevent heat loss by conduction from the billet and billet container in an indirect extrusion press, the sealing plate, which closes off one end of the billet container bore, is made in two parts which are spaced apart when an extrusion stroke is not taking place so that an air gap appears between the two parts to interrupt the path of heat conduction through the sealing plate to the rest of the extrusion press. The air gap may be produced in the pressure plate, between the sealing plate and the moving crosshead, instead of or in addition to the gap in the sealing plate.