Pump 1 delivers fluid to rotary directional valve 2 from where it is admitted to one or the other end of the cylinder, moving piston 8 in the opposite direction. At the same time, fluid from the pump is delivered to hydropneumatic accumulator 3 and to unloading valve 4. At the end of the piston stroke, the fluid pressure in the working line and in accumulator 3 increases, spool 5 moves to the left (as shown), shifting ball valve member 6 and connecting pump 1 to tank 7 through pipeline 9. When valve 2 is switched over, the pressure in accumulator 3 drops, and spool 5 and ball 6 are returned by springs to the initial position. This disconnects pump 1 from tank 7.
$4161$CHP,Dr$