Patent ID: 7827787

Claim:
A ground engaging vehicle, comprising: a movable member; a hydraulically driven actuator coupled to said movable member, said actuator including a first chamber and a second chamber; a hydraulic pump; a plurality of non-proportional valves including a first valve, a second valve, a third valve and a fourth valve; at least one hydraulic conduit coupling said pump with said first valve and said second valve, said first valve being in direct fluid communication with said first chamber, said second valve being in direct fluid communication with said second chamber, said third valve being in direct fluid communication with said first chamber, said fourth valve being in direct fluid communication with said second chamber, said first valve and said second valve each including an open position and a closed position; an energy storage device, said hydraulic pump being driven by said fluid flow to thereby store energy in said energy storage device, said energy storage device includes a hydraulic accumulator; and a reservoir tank, said third valve being fluidly coupled to said first chamber and to said reservoir tank, said fourth valve being fluidly coupled to said second chamber and to said reservoir tank, said plurality of non-proportional valves further includes a fifth valve and a sixth valve, said fifth valve being directly fluidly coupled to said hydraulic pump and to said reservoir tank, said sixth valve being directly fluidly coupled to said second chamber and said hydraulic pump.