| 摘要 |
<p>A rotary valve has a wiper member (26,28) formed from an elastomeric material, the wiper member extending circumferentially of the valve seat, extending radially inwardly of said valve seat (11,13), the wiper member being operatively positioned for it to wipe clean an outer circumferential surface of the valve member (18,20) as the valve member is moved from an open position to a closed position, the wiper member being supported for limited movement relative to the valve seat, whereby, upon stressing of the wiper member by the valve member, the wiper member (26,28) can retract into the valve seat. <IMAGE></p> |
