| 摘要 |
A rotary actuator having an output drive rod mounted within an output sleeve that is rotated by a drive motor. A driving mechanism for coupling the torque of the drive motor to the output sleeve includes a worm wheel that is mounted on the output sleeve so as to be freely rotatable relative to the output sleeve and a driving portion for transmitting power from the worm wheel to the output sleeve. A clutch also is mounted on the output sleeve for rotation with axial movement along the output sleeve. The clutch is normally biased into its first position for engagement with the drive portion of the drive mechanism for coupling it to the output sleeve for transmitting rotational force. A declutch mechanism causes the clutch to be moved of engagement with the drive portion, if the drive portion ceases to operate and the output sleeve is to be rotated by a hand wheel. When the clutch is moved out of engagement with the drive portion, it is moved into a coupling arrangement with the hand wheel for manually driving the clutch and transmitting a rotational force to the output sleeve. The clutch is retained in its second position until operation of the driving portion is resumed when the clutch is automatically returned to its position in engagement with the driving portion. |
