GB804482A - An improved torque transmission device for use in presses and other workshop machinery - Google Patents

Abstract

804,482. Controlling clutches. EUMUCO AKTIENGESELLSCHAFT FUR MASCHINENBAU. Dec. 5, 1956 [Dec. 5, 1955], No. 37185/56. Class 80 (2). An hydraulically operated friction clutch for driving presses and other machinery is controlled so that the engaging pressure is applied in high and low pressure stages during each cycle of the machine. On actuation of an electromagnetically operated control valve 7 a clutch-driven disc 4 on the machine driving shaft is adapted to be clamped between a flywheel 1 and a pressure plate 3 by low hydraulic pressure supplied from a pump 15 through line 5 to pistons 6. When the pressure from pump 15 reaches its maximum a non-return valve 24 closes and a by-pass valve 16 opens to allow the pump to circulate the fluid pressure. The machine is set in motion by this low pressure engagement until a cam 19 on the crank-shaft 18 of the machine depresses a plunger 20 of a pressure intensifier loaded by compressed air on a differential piston 22, 21. The high pressure developed between plunger 20 and piston 21 is applied to the supply line 5 between the non-return valve 24 and pistons 6 so that the loading of the clutch is increased on depression of the plunger 20 by the cam 19 on each cycle of the machine. Further additional pressure may also be obtained to overcome any high resistance encountered by supplying compressed air to another piston 23 of the intensifier. A brake 8, 9, 10 may be operated in conjunction with the clutch under control of an electromagnetically operated valve 14 from the pump 15 to release as the clutch is engaged and to engage as the clutch is released.