| 摘要 |
A manual override control for use with a double-acting hydraulic or electric powered valve actuator provides means for selectively moving the actuator rod between its extended and retracted positions in the event of a failure of the primary actuator control means. The override control includes a generally cylindrical housing having an axial passage throughout its length, means for connecting one end of the passage to an actuator housing, a threaded drive nut rotatably mounted in the other end of the passage, a threaded member having a socket portion at one end thereof for releasably connecting it to an actuator rod, and means for rotating the drive nut to move the threaded member, and thus the actuator rod, in an axial direction. When functional operation of the primary actuator control means is restored, the override control can be quickly disconnected from the actuator rod and/or normal operation of the actuator can be resumed. |
