| 摘要 |
The invention relates to a four-port thermally responsive valve for valving two normally closed fluid ports and one pair of normally open fluid ports in response to predetermined temperatures. A single valve member is movably contained within a housing passageway and spring biased in a first position so that a sealing surface at each end of the valve member is respectively engageable with and spaced from corresponding seating surfaces in the passageway for achieving initially open or closed valved conditions between the individual ports in each pair. A centrally located seal ring mounted in the housing passageway and surrounding the valve member isolates one pair of fluid ports from a second pair of fluid ports when the valve member is moved to a second position thereby permitting three valving functions to be attained with one device. When predetermined temperatures are encountered, a thermally responsive actuator connected to the valve member by a rod overcomes the biasing force generated by the spring and moves the valve member to the second position, valving substantially simultaneously each pair of fluid ports. |
