| 摘要 |
<p>A screw drive mechanism connectable to at least one of a first machine portion and a second machine portion for moving the second machine portion relative to the first machine portion from a first position to a second position. The mechanism has a base for attachment to one of the first and the second machine portions and a motor attached to the base. It includes a drive screw having a rotary motion connection to the motor to be rotated thereby and a drive nut having an internally threaded bore engaged with the drive screw to receive a drive force from the drive screw. A drive nut connection is engaged with the drive nut for conveying the drive force to one of the first and the second machine portions. An anti-rotation member is attached to the drive nut connection, the anti-rotation member engaging the drive nut to prevent rotation thereof. The mechanism also includes an activation member attached to the base, the activation member contacting a disengaging surface portion of the anti-rotation member when such one of the first and the second machine portions is moved to the second position to place the anti-rotation member in a position disengaged from the drive nut so that the drive nut may rotate. A drive nut rotating device is attached to the base, the drive nut rotating device rotating the drive nut to a locking position when such one of the first and the second machine portions is moved to the second position.</p> |
