GB763389A - An improved hydraulic extrusion press - Google Patents

Abstract

763,389. Extruding. SCHLOEMANN AKT.-GES. July 13, 1954 [Aug. 7, 1953], No. 20427/54. Class 83 (4). An hydraulic extrusion press has a billet receiver 3 movable towards and away from the extrusion die 27 by hydraulic rams 6b, 6 respectively, the pressure liquid supply circuit to the rams 6 including a stop valve, such as a non-return valve RV which, when the receiver has been raised from the die, causes liquid to be trapped in the ram cylinders 7, thus providing an abutment for the receiver whereby a billet which has become jammed therein may be ejected by the extrusion ram 2. The rams 6, 6b have intermediate crossheads 5b connected by rods 5a, main cross-head 5 and rods 4 to the receiver 3. The receiver is lowered on to the die by the rams 6b whose cylinders 8 are supplied with water under pressure from an hydraulic accumulator through an inlet 9, inlet valve E1 and pipes 20, 20b, 20c. Valve E1 is controlled by a cam 16 on a shaft 12 rotatable by a handle 12a which simultaneously opens an exhaust valve A2 whereby water will be exhausted from the cylinders 7 through pipes 24a, 24b, distributer 24, pipe 23 and outlet pipe 21. For raising the receiver the handle is rotated to position 12c whereby valves E2, Al are opened and valves E1, A2 are closed. Pressure water thus passes into the cylinder 7 and is exhausted from the cylinders 8. To hold the receiver in its raised position, the handle is moved into position 12b whereby all the valves are closed. A safety valve 11 biased by a spring 26 is provided for the ram cylinders 7. The non-return valve RV may alternatively be located between the inlet pipe 9 and inlet valve E2.