GB749287A - Hydraulic compensating system for presses - Google Patents

Abstract

749,287. Metal-working presses. HYDROPRESS, Inc. Feb. 11, 1954 [Feb. 17, 1953; April 7, 1953], No. 4019/54. Class 83 (4). [Also in Group XXIX] A press is provided with hydraulic means for counteracting any tendency of the movable platen to tilt. In one embodiment a die forging press has a fixed platen 110 on which cylinders 120 are mounted. Contact members 140 carried by a movable platen 111 engage single-acting pistons 121 when the upper die 114 is about to engage the work. The pressure of the liquid in the cylinders 120 is transmitted through lines 123 and cylinders 125 to pistons 126. Pistons 126 force downwardly a movable crosshead 130 of a pressure resisting unit K, thus moving a piston 132 downwardly into a fixed cylinder 133 supplied with liquid from an accumulator. If the platen 111 tends to tilt, the consequent increase in pressure in one of the cylinders 120 will cause the crosshead to move downwardly and thus reduce the pressure in the other cylinder; the differential force on the pistons 121 opposes the tilting movement of the platen. More than one pair of cylinders may be mounted on the fixed platon, and they may all act on a common pressure resisting unit K, which may have a single cross head. Alternatively the unit K may have two crossheads coupled together by tie-rods, one cylinder of each pair being connected to one crosshead, and the other cylinder to the remaining crosshead. In another embodiment several pairs of cylinders are provided on the fixed platen, and each of the associated cylinders 125 A-F is connected by an extension of the associated line 123 to a similary cylinder 225 A-F. The cylinders 225 are diametrically opposite the corresponding cylinders 125 so that any tendency of the crosshead to tilt is avoided.