Gas pressure to hydraulic pressure converter system in an oil pressure actuator

Claim 1

In a gas pressure to hydraulic pressure converter system for use in powering an actuator, wherein a means for supplying pressurized gas is connected with control valve means to control supply and exhaust of pressurized gas to and from first and second gas-to-hydraulic reservoirs partially filled with hydraulic fluid and each being connected with the actuator to operate the actuator in respectively opposite directions when gas pressure is supplied to a respective one of the reservoirs by appropriate operation of the control valve means, the improvement comprising: a conduit connected between the reservoirs at the location of desired maximum hydraulic fluid level therein; a valve body connected at opposite ends thereof in the conduit and having a valve seat at each end thereof; a valve member reciprocable in the body between the seats; and biasing means urging the valve member to a neutral position between and spaced from the seats, the valve member being movable toward one reservoir and into contact with one of the seats when pressure in the other reservoir exceeds the force of the biasing means to thus prevent loss of pressure from one reservoir to the other during actuation, and the valve member assuming its neutral position when gas pressure between the reservoirs is equal to enable flow of hydraulic fluid from one reservoir to the other when the level of hydraulic fluid in said one reservoir reaches the predetermined maximum level.