Patent ID: 7568502

Claim:
A coupling for a hydraulic or pneumatic assembly comprising: a housing having a bore; a female coupler movable within the bore between an operating position whereat, when a male coupler is coupled thereto, the male coupler is retained in the female coupler, a release position whereat the male coupler can be released from the female coupler, and a coupling position whereat the male coupler can be coupled to the female coupler; a pressure relief valve that includes a plunger movable from a closed position to an open position respectively blocking and permitting release of pressurized fluid from a flow passage inside the female coupler; a cam member movable to initially move the valve plunger from its closed position to its open position and then to move the female coupler from its operating position to its release position, thereby allowing the pressure relief valve to release pressurized fluid from the flow passage of the female coupler prior to removal of the male coupler; and a stop member for moving the plunger from its closed position to its open position when the female coupler is moved to its coupling position, thereby allowing the pressure relief valve to release pressurized fluid from the flow passage of the female coupler prior to coupling of the male coupler; wherein the cam member can move away from the plunger when the female coupler is in its coupling position and the plunger is held in its open position by the stop member.