Rotary motion failsafe gate valve actuator
Patent 3989223 Issued on November 2, 1976. Estimated Expiration Date: 
November 2, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
November 2, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2709062 2883144 3450382 3512421 3628397 3640140 InventorsApplicationNo. 429434 filed on 12/28/1973US Classes:251/58, With mechanical movement between actuator and valve74/89.25, Auxiliary drive (e.g., fluid piston, etc.) for load92/113, Relatively movable elongated part within stem92/116, WITH AXIALLY EXTENDING ELEMENT MOUNTED ON WORKING MEMBER FOR RELATIVE ROTARY MOVEMENT ONLY92/2, ONE WORKING MEMBER RECIPROCATES AND ANOTHER ROTATES COMMON OUTPUT MEMBER92/33Element extends through working member portionExaminersPrimary: Schwadron, Martin P.Assistant: Walton, George L. Attorney, Agent or FirmAbstractAn hydraulically operated failsafe valve actuator for use on non-rising valve stems, particularly in a subsea environment. A rotatable shaft is connected to the non-rising valve stem. In one embodiment the valve is actuated to open by a fluid pressure operated motor acting against the bias of a spring. Means connects means linearly movable along the shaft and converts the linear movement of the linear movable means to rotary movement of the shaft. Spring means moves the linearly movable means in one direction to cause the shaft to rotate in one direction. Fluid pressure means, including a fluid pressure operated motor, rotates the shaft in an opposite direction to cause the linearly movable means to move in an opposite direction along the shaft. In another embodiment the valve is actuated to open by a fluid pressure operated piston acting against the bias of the spring. The piston is mounted on the rotatable shaft and moves linearly along the shaft to cause the shaft to rotate. Spring means moves the piston in one linear direction to rotate the shaft in one direction. Fluid pressure moves the piston in an opposite direction to rotate the shaft in an opposite direction. | |
