摘要 |
A lifter is constructed to include a hollow main upright, a frame pivoted to the main upright to carry a hand winch, a link coupled between the frame and the main upright, a hollow auxiliary upright axially movably mounted in the hollow main upright, a lifting upright axially movably mounted in the hollow auxiliary upright, two first pulley blocks coupled between the hand winch and the hollow auxiliary upright and adapted to lift the hollow auxiliary upright upon operation of the hand winch, and two second pulley blocks coupled between the hollow main upright and the lifting upright and adapted to lift the lifting upright upon operation of the hand winch after the hollow auxiliary upright has been extended out of the hollow main upright.
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