GB581581A - Hydraulically operated controlling means for plants, machines, apparatus and the like - Google Patents

Abstract

581,581. Hydraulic machines; fluidactuated valves. ESCHER WYSS MASCHINENFABRIKEN AKT.-GES. April 20, 1944, No. 7329. Convention date, April 22, 1943. [Classes 69 (ii) and 135] In hydraulic control means in which a number of operations take place in sequence and the duration of each is independently variable by means of a separate timing device A, the latter each comprise a manually adjustable member 26 and a member 27 rotatable from the shaft. 1 controlling all the operations. As shown, operations are effected by hydraulic motors 47-49, controlled respectively by distributing vales 2-4 mounted on a common shaft 1 rotated step-by-step by a differential piston 9 under control of timing devices A. The latter each comprise the member 26 having a port 28, surrounded by the cylinder 27 having a port 31 and rotatable by pawl mechanism 43, 44 from the motor 17 driving the supply pump 16. After a predetermined number of steps, adjustable by rotating member 26 manually, the ports 28, 31 coincide and place the large end of differential piston 9 in connection with a reservoir. Pressure acting on the small end then moves the piston to the right and rotates the shaft 1 one step through ratchet and pawl mechanism 6, 7, 8. This reverses the liquid supply to the first motor 47 and simultaneously causes a cam 46 to lift a member 45 and disengage pawls 43, 44 of the first timing device, while a second member 45 is lowered to engage the pawls of a second timing device. Disengagement of the first set of pawls releases the cylinder 27 which returns under spring influence to close the exhaust connection 28, 31, thereby causing pressure to build up on the large end of piston 9 and effect a return stroke. After a further adjustable number of strokes of the second set of pawls the large end of piston 9 is again exhausted by connecting parts 28, 31 on the second timing device, and piston 9 moves to the right to rotate shaft 1 another step. This cuts out the second timing device to complete the first operation and actuates the first timing device of the distributing valve 3 to actuate cylinder 48 and start the second operation. The cycle proceeds as before. A full stroke of piston 9 is ensured by a lever 75 which is operated by a wheel 76 on shaft 1 and opens a by-pass in the connection between cylinder 9 and timing device A. Any operation may be interrupted by manual operation of valves 53-55 between the distributing valves and their respective motors. Rotation of shaft 1 may also be effected by manual operation of a valve 11 controlling exhaust from the differential cylinder or by manual or automatic control of an exhaust valve 24, or by rotation of a hand lever 77. Speed of operation of motor 47 can be controlled by a throttle valve 72 pressed against an adjustable stop 73 by exhaust pressure. Any operation may also be prevented by a hand-operated locking device 81.