Bi-directional snub valve

摘要

A bi-directional snub valve provides two parallel fluid paths therethrough and means for restricting the fluid flow through each of the parallel paths to one preferred direction. A movable piston is provided with two land portions which selectively are movable into blocking association with two openings in a fluid chamber. Blockage of either of the two openings in the fluid chamber and the corresponding fluid flow path does not effect the ability of the alternate path to conduct a fluid therethrough. The bi-directional snub valve therefore is able to slow the flow of fluid therethrough as a movable object approaches its end-of-travel position. However, because of the nature of the two parallel flow paths, the movable object can be moved away from its end-of-travel position at full speed. A cam arrangement is used to move the piston of the snub valve in response to movement of the movable object.