GB1059127A - Forging press or the like with a pressure fluid drive - Google Patents

Abstract

1,059,127. Forging and stamping presses. H. BECHE. Oct. 15, 1963 [Oct. 15, 1962; July 5, 1963; Aug. 27, 1963], No. 40613/63. Heading B3H. A forging or stamping press has a tup d connected to a piston d<SP>1</SP> actuated through pressure fluid trapped in cylinder chamber A by a smaller piston o which is also actuated by pressure fluid. The tup d is slidable along guide surfaces x and carries a die OG co-operating with a die UG on the press bed. Retraction cylinders e are supplied continuously with compressed air through ports DM. The cylinder space A is supplied with oil from reservoir OB by pump g through pipe g<SP>1</SP> and non-return valve g<SP>11</SP>; excess oil is returned through port i and pipe g<SP>11</SP> and a by-pass valve V<SP>1</SP> permits continuous operation of the pump. Piston c has an enlarged head c<SP>1</SP> supplied with pressure fluid such as compressed air through inlet DM and control S. During descent of the piston c, the port i is closed whereby the trapped oil produces the working stroke of the tup. The control S may provide for part of the stroke of piston c to be produced by expansion. Means may be provided to prevent operation of the control S unless the piston c is fully in its upper position. A deformable copper buffer k absorbs any impact of the piston and a safety valve SV is fitted to the cylinder chamber. In another embodiment, Fig. 2 (not shown), the retraction cylinders are disposed below the tup and the piston c is hollow, Fig. 4 (not shown), and slides over a stationary tube to which hydraulic fluid from an accumulator is admitted for actuating the piston c. In a further embodiment, Fig. 5, for an upstroke press, the tup 52 is driven by a piston 50 whose cylinder 53 is connected by duct 60 to a parallel cylinder 58 for the drive piston 59 actuated by oil from an accumulator 74, Fig. 7 (not shown). A conical portion 61 of the cylinder cushions the stroke of the drive piston.