Pressure relief valve for a sphygmomanometer

Claim 1

A sphygmomanometer comprising an inflatable cuff, a bulb providing air pressure, an indicating gauge connected to the cuff for measuring air pressure in the cuff, a tube communicating with the cuff, and a pressure-relief valve assembly connecting the bulb to the tube for permitting selective relief of the pressurized air from the cuff, said valve assembly comprising a valve housing having an inlet end connected to the bulb and an outlet end connected to the tube and an internal, axial bore communicating with the inlet and outlet ends, a transverse bore substantially perpendicular to and intersecting the axial bore and communicating with the exterior of the housing, a resilient annular sleeve mounted tightly within the axial bore and sealing off the intersecting end of the transverse bore in normal position while providing communication between the inlet and outlet ends of the housing, and actuating means including a valve plunger axially movable within the transverse bore for acting against said sleeve, said plunger being spring biased in a direction away from the resilient sleeve, and a control lever limiting outward movement of the plunger and for selectively depressing the plunger inwardly against the sleeve to move the sleeve away from sealing relationship with the transverse bore and thereby permit varied relief of the pressurized air from the inflatable cuff.