| 摘要 |
A reversing valve construction having a housing carrying a movable piston-like valve member therein that controls ports of a valve seat of the housing provided with a chamber through the relative position of a cavity of the valve member relative to the ports. The ports comprise first, second and third ports disposed in spaced apart and straight line relation and the cavity bridges the first and second ports while exposing the chamber to the third port when the valve member is in one position thereof and bridges the second and third ports while exposing the chamber to the first port when the valve member is in another position thereof. A flexible sealing annular member is disposed between the valve member and the valve seat and surrounding the cavity to seal the cavity of the valve member to the valve seat while permitting sliding movement therebetween. A biasing member is operatively associated with the valve member and the flexible sealing member to urge and flex the sealing member into sealing engagement with the valve seat so as to tend to sealingly conform the flexible sealing member to the contour of the valve seat. The valve seat has an arcuate cross sectional surface and the valve member also has an arcuate cross sectional surface disposed adjacent the arcuate surface of the valve seat whereby the flexible sealing member is intermediate the arcuate surfaces.
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