GB1425129A - Hydraulic forging press - Google Patents

Abstract

1425129 Forging presses SCHLOEMANN SIEMAG AG 2 May 1973 [2 May 1972] 20775/73 Heading B3H A horizontal hydraulic forging press has a pair of oppositely acting stepped pistons 4, 5 provided with rearwardly extending shanks 8, 9 which provide a movable cylinder 10, 11 for a fixed piston 10<SP>1</SP>, 11<SP>1</SP>, Fig. 1, or a movable piston 10<SP>1</SP>, 11<SP>1</SP> for a fixed cylinder 10, 11, Fig. 2, of a fluid coupling arrangement for the stepped pistons. The coupling arrangement also comprises one or more coupling piston-cylinder units 14a, 14a<SP>1</SP>, 14b, 14b<SP>1</SP>, 15a, 15a<SP>1</SP>, 15b, 15b<SP>1</SP> for each piston. The coupling arrangement is designed to provide at least one cylinder whose volume increases and at least one cylinder whose volume decreases for each stepped piston as the piston moves. The decreasing volume cylinder or cylinders on one side of the press are connected by ducts 19, 20, Fig. 1, to the increasing volume cylinder or cylinders on the other side of the press and vice versa. In one embodiment, Fig. 1, the pistons of the coupling arrangement are all fixed and the cylinders 10, 11 have volumes which increase when the stepped pistons move together and are connected to the decreasing volume cylinders 15a, 15b, 14a, 14b respectively. In a second similar embodiment the cylinders 10, 14a, 14b, 11, 15a, 15b, Fig 2, are fixed and the pistons are all movable In a third embodiment, Fig 3 (not shown), the coupling piston-cylinder units are arranged in alignment and have fixed pistons. In a fourth embodiment, Fig. 4 (not shown), a hybrid arrangement is provided with the coupling piston-cylinder units having fixed pistons and fixed cylinders at each end of the press. In all the embodiments the press frame is composed of a pair of chain-link shaped members la, 1b, which may be fixed to the operating cylinders 2, 3 by straps (1a<SP>1</SP>), (1b<SP>1</SP>), Fig. 4 (not shown).