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A circulating flow hydraulic pilot system supplies pressurized fluid from a source to a sump through first and second parallel disposed conduits. Selective pressurization of each conduit is achieved by a pilot valve and a fluid restrictor that are series interposed into each conduit. A fluid actuato

A circulating flow hydraulic pilot system supplies pressurized fluid from a source to a sump through first and second parallel disposed conduits. Selective pressurization of each conduit is achieved by a pilot valve and a fluid restrictor that are series interposed into each conduit. A fluid actuator includes two ports that communicate with respective ones of the conduits intermediate of respective ones of the pilot valves and fluid restrictors. Other pilot valves are provided for manually overriding the pilot system.

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A hydraulic system of the type which includes a directional control valve having a stand-by position and an operating position, source means for supplying pressurized fluid, means for limiting the maximum fluid pressure of said source means, sump means for receiving fluid, and a pilot hydraulic syst

A hydraulic system of the type which includes a directional control valve having a stand-by position and an operating position, source means for supplying pressurized fluid, means for limiting the maximum fluid pressure of said source means, sump means for receiving fluid, and a pilot hydraulic system for actuating said directional control valve to said operating position, in which said pilot system comprises: a first conduit receiving pressurized fluid from said source means and establishing a first fluid flow path to said sump means; a second conduit receiving pressurized fluid from said source means and establishing a second fluid flow path to said sump means; first and second fluid restrictors being interposed into respective ones of said first and second fluid flow paths; first and second pilot valves, each having a free-flow and a flow blocking position, and each being interposed into respective ones of said fluid flow paths in series flow relationship with respective ones of said fluid restrictors; a fluid actuator, operatively connected to said directional control valve, having a first actuator port that communicates with said first fluid flow path intermediate of said first fluid restrictor and said first pilot valve, and having a second actuator port that communicates with said second fluid flow path intermediate of said second fluid restrictor and said second pilot valve, said actuator ports being subject to substantially equal fluid pressures when said pilot valves are in said free-flow position; bias means for resiliently urging said directional control valve to said stand-by position; operating means for moving one of said pilot valves from said free-flow position to said flow blocking position so that unequal fluid pressures are applied to said actuator ports; override means for reestablishing substantially equal fluid pressures applied to said actuator ports when said one pilot valve is in the blocking position; and means for reapplying unequal fluid pressures to said actuator ports when said override means is in operation.