GB688440A - Hydraulic motor cylinder with stroke-limiting valve - Google Patents

Abstract

688,440. Hydraulic machines. BENDIX AVIATION CORPORATION. June 6, 1951 [June 19, 1950], No. 13449/51. Class 69 (ii). A hydraulic motor unit comprises a cylinder 10, cylinder heads 11, 12, a piston 20, a piston rod 21 extending through the head 11, fluid supply and exhaust passages 35, 27 in the heads 11, 12 respectively, a valve seat 38 in the passage 27 facing the cylinder end of the passage, a poppet valve 37 slidably supported in the head 12, a push rod 53 parallel to the cylinder and having an end 53a extending beyond the head 11 and an end 52 adjacent the poppet valve, and a pusher member 60 adjustably secured on the piston rod 21 for engaging the end 53a for shifting the push rod from its normal position (shown in Fig.) into an actuated position in response to inward movement of the piston rod. The unit has means responsive to movement of the push rod for seating the poppet valve and a spring 57 for restoring the push rod to its normal position in response to opening movement of the poppet valve. Fluid connections for supplying and exhausting fluid from either end of the cylinder are provided in the head 12 ; thus one connection leads to the passage 27 and the other via a passage 31 and a tube 32 to the passage 35. Fluid supplied to the passage 27 flows past the open valve 37 to move the piston outward, the fluid on the other side being exhausted through passages 35, 32, and 31. Fluid supplied in the reverse direction moves the piston inwards until the member 60 depresses the push rod 53 to move the cam-shaped end 52 to the left so that the valve 37 seats under the pressure of fluid and the spring 43, thereby preventing further inward movement of the piston.