Control valve

Claim 1

A fluid system for controlling a fluid motor in a first operational mode through a plurality of binary control valves actuated by automatic means and in a second operational mode by a manually actuated control valve comprising: a fluid motor; a pilot operated control valve assembly having a control valve portion for conducting pressurized fluid from a pressurized fluid supply to said fluid motor to effect control of said fluid motor and having a pilot valve portion connected to said control valve portion to control said control valve portion, said control valve portion having a passageway for allowing pressurized fluid to be transmitted to successive fluid systems, said pilot valve portion including a piston member and a body having a chamber therein for receiving said piston member, said piston member dividing said chamber into first and second chamber portions, means for directing fluid pressure into the first chamber portion, and means for directing fluid pressure from the first chamber portion into the second chamber portion, said piston member having a greater pressure face against which the fluid pressure in the second chamber portion acts than the pressure face against which the fluid pressure in the first chamber portion acts; a plurality of binary control valves connected to said pilot valve portion to operate said fluid motor in said first operational mode, each of said binary control valves establishing a first signal and a second signal to said pilot operated control valve such that when a first signal is provided by one of said binary control valves or a second signal is provided by another of said binary control valves said pilot operated control valve conducts pressurized fluid to the fluid motor to move the fluid motor in a respective direction during the operation of said system in said first operational mode; a manual control valve for operating said fluid motor in said second operational mode, said manual valve having a neutral position and a second position, said manual valve receiving pressurized fluid transmitted to the second chamber portion from the first chamber portion through said means for directing fluid pressure into the second chamber portion when pressurized fluid is supplied to the first chamber portion, the second position of said manual valve blocking the second chamber portion from fluid communication with the reservoir so that the pressurized fluid received by the second chamber portion from the first chamber portion exerts a force greater than the force exerted by the pressurized fluid in the first chamber portion due to the greater pressure face area, said manual control valve further including means for blocking fluid flow in a conduit means for normally directing fluid from said second chamber to a low pressure reservoir; a selector valve for switching the operation of said fluid motor between said first operational mode and said second operational mode by supplying pressurized fluid to either said manual control valve or said binary control valve to exclusively operate the valve supplied with said pressurized fluid; and said manual control valve including means for overriding the control of said control valve through said binary Control valves during the first operational mode and reversing the direction of said fluid motor movement to an opposite direction upon actuation of said override means.