| 摘要 |
A lifting apparatus has a support structure, a frame pivotally connected to the support structure, an actuating means connected to the frame so as to move the frame between a retracted position and an extended position, a lifting bar pivotally connected to the frame, and a linkage having one end pivotally connected to the support structure and an opposite end connected to the lifting bar. The lifting bar has a first strut with one end pivotally to the frame, a second strut with the one end pivotally affixed to the frame, and a cross member affixed adjacent to opposite ends of the first and second struts and extending thereacross. The linkage includes a first link and a second link each having fixed lengths.
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