Cam 3 rotates about fixed axis A. In the position of cam 3 shown, gear pump 1 delivers fluid through open inlet valve 2 and further, through check valve 4, preventing reverse flow of the fluid, and flow-control valve 5 to the right end of power cylinder 6, moving piston 7 to the left. From the left end of cylinder 6 fluid is discharged through flow-control valve 8, check valve 9 and outlet valve 10 to the tank. Relief valves 11 and 12 maintain constant pressure at the flow-control valves which regulate the speed of piston 7. At the position of cam 3 perpendicular to that shown, fluid is delivered by the pump to the left end of cylinder 6, two opposite valves, 13 and 14, being opened by the cam.
$4222$CHP,Dr$