GB602283A - Improvements relating to the control of hydraulic apparatus - Google Patents

Abstract

602,283. Hydraulic machines. STORER, A., and STORER, J. A. Oct. 13, 1945, No. 26808. [Class 69 (ii)] A valve 16 controlling the admission of hydraulic pressure to a series of operational circuits 17 is actuated through a control member 20 susceptible to the variable pressures created by the resistance encountered in the operations, the arrangement of the valve mechanism being such that at the conclusion of each operation the variable pressure builds up and actuates the control member, which in turn effects the actuation of the valve mechanism to close the hydraulic circuit pertaining to the operation which has been completed and to open the circuit pertaining to the next operation in the sequence to be performed. Liquid from the inlet 11 flows through the orifice 12 into the chamber 13, through the stem 15 of the rotary valve 16 controlling the feed ports to the circuits 17. Liquid also flows through passage 18 into cylinder 19 to urge piston 20 downwards. At the end of the working operation pressure builds up in the chamber 13, forces piston 20 upwards until the passages 18 and 23 are connected through the ports 22a, 22 and 22b. Liquid enters cylinder 24, forces operating piston 25 downwards causing the rack 26 to engage teeth 27 which rotate the valve 16 to close the circuit relating to the finished operation and open that relating to the next. Resultant drop in pressure in the chamber 13 permits piston 20 to descend and open the passage 23 to the exhaust 33. Liquid from passage 31 raises piston 25, but due to a ratchet mechanism in 27, does not rotate the valve 16. The process is then repeated for the new operation.