| 摘要 |
A lifting apparatus having a base, a platform disposed above the base, and a vertically extendable mast arrangement coupled between the platform and base to effect vertical lifting of the platform. The mast arrangement normally includes a pair of vertically extendable mast assemblies disposed in parallel relationship, and each having plural vertically elongate masts disposed in vertical sliding relationship with one another. One mast is fixed to and projects upwardly from the base, another is fixed to the platform, and at least one additional mast is vertically slidably coupled therebetween. Each mast has sequencing structure associated therewith for requiring that the individual masts be vertically extended in a controlled sequence, and also has a locking structure for vertically fixedly coupling adjacent masts together when one is vertically extended relative to the adjacent mast. A winding arrangement, including pulleys mounted on the masts and engaged with a cable, couple the base and platform to control vertical raising and lowering.
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