摘要 |
A lift apparatus includes a superstructure frame support, a riser, and an articulated parallelogram boom assembly operatively connected between the superstructure frame support and the riser. The articulated parallelogram boom assembly includes a floating frame, a lower parallelogram boom assembly operationally connected between the superstructure frame support and the floating frame, an upper parallelogram boom assembly operationally connected between the floating frame and the riser, and a lift mechanism for raising and lowering the articulated parallelogram boom assembly. The lower parallelogram boom assembly, the upper parallelogram boom assembly, and the lift mechanism are formed such that the maximum extension height of the articulated parallelogram boom assembly is increased without an increase in the height of the articulated parallelogram boom assembly when lowered.
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