| 摘要 |
<p>A threaded leadscrew moves axially within the housing of a linear actuator. The leadscrew's movement rotates a threaded gear nut that surrounds the leadscrew. Stopping the gear nut rotation prevents leadscrew translation. The locking mechanism for selectively blocking rotation of the gear nut includes a cam mounted on the housing, which connects remotely to a user actuated handle. A lever, which mounts on the cam, has a tooth movable between adjacent teeth on the gear nut. The cam also has a blocker that engages the lever. When the cam is in the closed position, the blocker prevents the lever from moving to its released position away from the gear nut's teeth. When the cam is moved to the released position, the blocker releases the lever and allows it to move away from the gear nut. The lever has an opening that is somewhat bigger than a pin on the cam that extends into the opening. When the pin reaches one surface of the opening, it pulls the lever out of its engaged position. However, before the pin reaches that position, the blocker on the cam has already disengaged the lever. Therefore, further movement of the cam pulls the lever out of engagement with the teeth on the gear nut, and the blocker on the cam is moved to a position where it does not prevent that movement.</p> |
