GB1482030A - Hydrostatic extrusion presses - Google Patents

Abstract

1482030 Hydrostatic extrusion ASEA AB 11 Oct 1974 [12 Oct 1973] 44080/74 Heading B3P In an hydrostatic extrusion press for extruding tubes having a displaceable cylinder 2 closed by a die 4 and plunger 3, a mandrel 15 and a billet holder 18 for pressing the billet 27 against a die support 5, the billet holder 18 comprises a first portion 52 surrounding the mandrel 15 and radially movable relative to a second portion 28 engaging the cylinder wall. The billet holder 18 is provided with a bushing 52 which is radially movable within a bore 51 and which is locked in the bore 51 by a ring 53 or by a cover (63) (Fig. 2, not shown). The bushing 52 is centred by resilient elements (70) or springs positioned in the annular gap between the bore 51 and bushing 52. The billet holder 18 is also provided with two annular projections 29, 30 for contacting the tubular billet 27 to define a gap 32 between the billet 27 and the cylinder 2 and a gap 33 between the billet 27 and the mandrel 15 which is fixed in a holder 16 via springs 58. Fluid is supplied through a valve member 39 in the billet holder 18 to the gap 33 and to the gap 32 via inwardly projecting ribs 35 on the billet holder 18. The fluid may be discharged from the gaps 32, 33 through a valve member, 48, a check valve member (67) or through the bushing which acts as a valve member and which is arranged to be axially movable.