GB750282A - Fluid-pressure actuated apparatus - Google Patents

Abstract

750,282. Forging-presses. CHAMBERS-BURG ENGINEERING CO. Feb. 23, 1954 [May 26, 1953], No. 5243/54. Class 83 (4). [Also in Group XXVI] A fluid-pressure operated apparatus particularly an impact forging press, has a pair of coaxial rams 13, 14, movable towards and away from each other by pressure fluid supplied to their respective cylinders 11, 12, and means 56, 57 are provided for detecting lack of synchronism in the movements of the rams and for controlling interconnected correcting valves 35, 38 which vary differentially the flow of pressure fluid to and/or from the cylinders so as to restore synchronism. The press rams carry doubleacting pistons 15, 16 operated by compressed air distributed to either end of the cylinders through passages 23, 24 by distributing valves 27, 28 remotely controlled by a lever 41 through transmitters 39, 40 and receivers 42, 43, which may be hydraulic or electric. A one-way valve 30 communicating with the passage 23 through duct 29 allows the air to enter the outer end of each cylinder to initiate the working stroke and permits air to be trapped in the end of the cylinder to cushion the return stroke. Throttle valves 34, 37 in the supply lines are remotely controlled by a lever 46 through transmitters 44, 45 and receivers 47, 48; these valves regulate the speed of the rams. Forging dies 19, 20 are mounted respectively in heads 17, 18 having cam surfaces 60, 61, co-operating with the detecting levers 56, 57 pivoted on fixed pivots 58, 59. These levers are connected by spring-loaded links 62, 63 to the opposite ends of a rocker arm 54 pivoted at 55 on a swinging arm 50 mounted on a stationary pivot 51 and connected at 52 to a link 49 interconnecting the correcting valves 35, 38. When the rams are in phase the rocker arm 54 moves about its pivot 55 without disturbing the arm 50 but if the rams are out of phase the forces on the rocker arm are unbalanced and cause the arm 50 to swing about its pivot 51 thereby to regulate the correcting valves 35, 38, and restore synchronism. These correcting valves may be in the inlet or exhaust passages 23 or 24 or separate interconnected valves may be provided in both the inlet and exhaust passages, Fig. 8 (not shown).