| 摘要 |
Apparatus for selectively permitting and preventing fluid flow generally radially therethrough, the apparatus includes a generally tubular first member (16,18,20) having a first opening (48) formed through a sidewall portion thereof, a first outer side surface, a first radially enlarged and axially extending inner side surface, and a second radially reduced and axially extending inner side surface, the first opening providing fluid communication between the first outer side surface and the first inner side surface. The apparatus also includes a generally tubular second member (86) having a second opening (96) formed through a sidewall portion thereof, a third inner side surface, a second radially enlarged outer side surface, and a third radially reduced outer side surface, the second opening providing fluid communication between the third inner side surface and the third outer side surface. The second member (86) is axially slidably disposed within the first member (16,18,20), and the second member (86) is axially rotatable within the first member (16,18,20). A ratchet (122) selectively permits axial displacement of the first member (16,18,20) relative to the second member (86). A predetermined pressure differential across the mandrel is utilized to configure the valve in its open and closed configurations. <IMAGE> |
