| 摘要 |
A fluid pressure actuator includes a lock mechanism for locking the actuator against movement in one end position, and an external lock release lever engageable with an external extension of the lock mechanism for releasing same. The lock release lever is engageable by a lock piston upon application of system pressure thereto to release the lock mechanism. During movement of the lock piston in the unlocking direction, and after disengagement of the lock mechanism, system pressure is ported through the lock piston both to the extend side of the actuator and the opposite end of the lock piston. By using substantially the same size seals on the opposite pressurized side of the lock piston and external extension of the lock mechanism, any effect of fluid pressure acting on such external extension of the lock mechanism is substantially negated. Accordingly, the effective area of the lock piston acted upon by system pressure to release the lock mechanism will remain substantially constant both before and after system pressure is admitted to the extend side of the actuator, whereby the lock is effectively locked open and there is always substantially full flow to the extend side of the actuator despite fluctuations in the extend pressure.
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