Patent ID: 7114661

Claim:
A three-way direction control valve that shifts when a fluid passing through said valve reaches a preset temperature, said control valve comprising: a first port, a second port, and a third port, an internal shiftable spool, a thermal actuator, and a spring biasing the internal shiftable spool against the thermal actuator, wherein fluid entering the first port from a first fluid source passes through the thermal actuator and out of the second port until the fluid is warm enough to cause the thermal actuator to expand, shifting said spool so that both the fluid flow from the first source is stopped at the first port, and the second port is now in communication with the third port, so that a second fluid source may flow through the second and third ports, wherein the second and third ports are in fluid communication with a portion of a fluid circuit accepting fluid from the second source, and wherein when the warm fluid cools, the spring keeps the valve spool biased against the thermal actuator so the valve spool moves back toward its original position, permitting fluid to again flow from the first port to the second port.