| 摘要 |
A threaded leadscrew (16) moves axially within the housing (12) of a linear actuator (10). The leadscrew's movement rotates a threaded gear nut (18) tha t surrounds the leadscrew. Stopping the gear nut rotation prevents leadscrew translation. The locking mechanism for selectively blocking rotation of the gear nut (18) includes a cam mounted on the housing (12), which connect remotely to a user actuated handle. A lever (90), which mounts on the cam, h as a tooth movable between adjacent teeth on the gear nut (18). The cam (50) al so has a blocker that engages the lever. When the cam (50) is in the closed position, the blocker prevents the lever from moving to its released positio n away from the gear nut's teeth (22). When the cam (20) is moved to the released position, the blocker releases the lever (90) and allows it to move away from the gear nut (18). The lever has an opening (102) that is somewhat bigger than a pin (104) on the cam that extends into the opening. When the p in 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. Therefor further movement of the cam pulls the lever out of engagement with the teeth (22) on the gear nut (18), and the blocker onthe cam (20) is not positioned to prevent that movement.</ SDOAB> |
