Abstract: A high-pressure furnace having a pressure chamber which includes an insulating mantle which encloses the furnace space, the insulating mantle itself including an inner tube which has at least one layer of felt-like, fibrous insulating material mounted on the side which faces the furnace space.

Abstract: In a press for the hydrostatic extrusion of tubes, including a mandrel unit permanently inserted in the pressure chamber of the press and being movable between two axial positions, the unit comprising a mandrel and a tubular sleeve which during the extrusion transmits forces acting on the mandrel to a force-absorbing unit in the press, the sleeve being so constructed as to form an annular gap between the sleeve and the pressure chamber wall, and a stop ring in the gap forming an interference fit with the pressure chamber wall, the sleeve having stop faces thereon designed to cooperate with end faces of the stop ring so as to determine the limit positions of the axially movable mandrel unit.

Abstract: A high pressure apparatus for the manufacture of diamonds includes a pressure chamber formed of holes in annular, disc-like members arranged one after the other and a pair of opposed pressure-exerting members movable into the chamber formed by the holes with compressible gaskets arranged between adjacent disc-like members. The pressure exerting members are frusto-conical and the ends of the holes adjacent these members are similarly shaped.

Abstract: A press for the hydrostatic extrusion of metallic billets to form tubes and other profiles includes a hollow high pressure cylinder having a removable liner which forms the inner wall thereof and which encloses the internal pressure chamber. To protect the removable liner from fatigue breakdown, the inner wall of the liner is coated with a protective coating of an organic polymer and a metallic tube is located adjacent the protective coating and concentric therewith, between the protective coating and the internal pressure chamber.

Abstract: In a hydraulic press which has an expansible pressure cell arranged in a cavity and a pad of elastic material for forming workpieces, with a trough-shaped supporting member for forming tools and workpieces, displaceable into and out of the press, the press includes a second pressure cell arranged below the trough-shaped supporting member, positioned in a cavity formed between two discs which form supporting members for the trough-shaped supporting member.

Abstract: A press for hydrostatic extrusion includes a pressure chamber for enclosing a pressure medium which is formed of a high pressure cylinder, a pressure generating piston, a die and a die support and seals. The die support includes an exchangeable support ring which engages the end surface of the liner and bridges the gap between the liner and the die. A metallic sealing ring is arranged within the liner in engagement therewith, forming a gap between the inner surface of the sealing ring and the outer surface of the die or die support. The die support has a groove in its upper surface which contains a sealing member against which the edge of the metallic sealing ring engages. The lower outer corner of the metallic sealing ring is bevelled to form a space which communicates with the outside of the press.

Abstract: A hydraulic press includes a pressure cell which includes a diaphragm of flexible material with an opening therein surrounded by an annular bead. There are two disc-shaped attachment members for the diaphragm which form between them a first annular groove which fits the bead. The bead and one of the annular members have opposed annular recesses therein, which face a surface of the other annular member. These thus form an annular channel, in which are arranged two sealing rings, one fitting between the bead and one of the attachment members and the other fitting between the two attachment members.