Patent ID: 8141749

Claim:
An improved control valve for use in a foam soap dispenser, comprising: a lower casing having a hollow cylindrical shape and an internal threaded section disposed on an internal side of an upper portion of the lower casing; an upper casing having a hollow cylindrical shape and an external threaded section disposed on an external side of a lower portion of the upper casing threadedly engaged with the internal threaded section of the lower casing and a hollow joint bushing protruded from the top of the upper casing, the joint bushing having a closed end and a soap feeding inlet formed through a side of a bottom of the joint bushing; and a valve body disposed in the lower casing and having a hollow cylindrical shape, the valve body including: an extending tube disposed at the middle of the valve body; a protruding tube disposed at the top of the extending tube, a spring installed in the protruding tube; a steel ball installed at an upper end of the spring; a hollow bushing sheathed onto an external periphery of the protruding tube to retain the steel ball against a top of the protruding tube and an internal side of an upper edge of the bushing; and a leakproof washer sheathed onto a bottom of the external periphery of the valve body, wherein responsive to a press plate of a soap dispenser being displaced and a vacuum thereby being established within the valve body, the steel ball is moved away from the internal side of the upper edge of the bushing to permit soap to flow from the soap feeding inlet into the valve body, and upon release of the press plate of the soap dispenser, the spring biases the steel ball against the internal side of the upper edge of the bushing to stop the flow of soap and a suction force draws the liquid soap from the valve body.