Abstract: A quick connect/disconnect hydraulic coupler is provided especially for connecting rigid hydraulic members where no axial movement of the coupling halves can be achieved. The quick coupler comprises a male connector attached to one hydraulic line and a female connector attached to another hydraulic line. The male and female connectors each include an annular check valve that is spring-biased against a poppet seat to prevent loss of hydraulic fluid when the coupler halves are disconnected. The male connector has an annular coupling nut surrounding and confining the male check valve. When the male and female connector halves are aligned, the coupling nut can be moved axially toward the female connector and rotated to engage threads on the outside circumference of the female connector. Tightening the coupling nut onto the female connector forces the male check valve to extend and to form a seal with the female check valve.

Abstract: An orifice controlled poppet valve includes a pilot poppet pressure balancing arrangement which prevents fluid leakage between the valve inlet and outlet. The pressure balancing arrangement includes a pin slidable in a passage in the main valve member, which passage extends between the inlet and a pilot outlet passage. One end of the pin engages a stem which projects from from the pilot poppet. The other end of the pin engages a flexible diaphragm which forms a seal between the valve inlet and the passage which receives the pin. An inlet pilot passage includes an annular clearance upstream of an orifice. The radial dimension of the annular clearance is smaller than the diameter of the orifice.

Abstract: A solenoid-operated control valve has a main orifice and a valve member for controlling fluid flow therethrough. A leakage orifice extends through the valve member. A check valve seals the leakage orifice when the main orifice is blocked and moves to open the leakage orifice before the main orifice is opened.