GB1481878A - Hydrostatic extrusion press - Google Patents

Abstract

1481878 Hydrostatic extrusion ASEA AB 11 Oct 1974 [12 Oct 1973] 44079/74 Heading B3P In an hydrostatic extrusion press for extruding tubes having a displaceable cylinder 2 closely by a die 4 and a plunger 3; a mandrel 15 and a billet holder 25 for pressing a billet 28 and die 4 against a die support 5 while the cylinder 2 is being closed, the billet holder 25 comprises means 30 for defining a first compartment 27a between the billet 28 and the cylinder wall and a second compartment 27b between the billet 28 and the mandrel 15; first and second flow paths 31-33, 34-36 therethrough and valve means 37, 38 in the flow paths opening at different pressures. The billet holder 25 is provided with an annular projection 30 for defining the compartments 27a, 27b and with a removable bushing 42 for the mandrel 15 which may be movable in a holder 14. Seals 10, 11 at the ends of the cylinder 2 are each formed by two sealing rings (50, 51) (Fig. 2, not shown) the billet loading operation which is similar to that described in Specification 1,295,216, the valve member 37 in the billet holder 25 is opened to fill the compartment 27a with fluid before the mandrel 15, which has previously been moved back within its holder 14 by the smaller diameter forward end of the billet 28, is pressed into the billet 28 by the fluid pressure. The valve member 38 is opened after the mandrel 15 has been pressed into the billet 28 to cause the other compartment 27b to be filled with fluid.