초록 ▼

A lifting device comprises at least two multi-stage masts and a cable mechanism. Each multi-stage mast comprises a first length and a second length that is longer than the first length. Each multi-stage mast further comprises a plurality of stages, such that at least one stage of a mast is verticall

A lifting device comprises at least two multi-stage masts and a cable mechanism. Each multi-stage mast comprises a first length and a second length that is longer than the first length. Each multi-stage mast further comprises a plurality of stages, such that at least one stage of a mast is vertically movable with respect to at least one other stage. The cable mechanism comprises a spool and at least one cable that is coupled to the spool and arranged with respect to the multi-stage masts so that when each cable is wound onto the spool, each mast simultaneously and in unison changes length in a direction from the first length to the second length, and when each cable is unwound off the spool, each mast changes length simultaneously and in unison in a direction from the second length to the first length.

대표청구항 ▼

What is claimed is: 1. A lifting device, comprising:a frame comprising two ends that are opposite from each other along a first axis of the frame,at least two multi-stage masts, each multi-stage mast corresponding to another multi-stage mast to form a pair of multi-stage masts, each multi-stage mast

What is claimed is: 1. A lifting device, comprising:a frame comprising two ends that are opposite from each other along a first axis of the frame,at least two multi-stage masts, each multi-stage mast corresponding to another multi-stage mast to form a pair of multi-stage masts, each multi-stage mast of a pair of multi-stage masts being attached to a respectively opposite end of the frame in an upright configuration with respect to the frame and substantially axially aligned with the other multi-stage mast of the pair of multi-stage masts, the axial alignment of the pair of multi-stage masts being substantially parallel to the first axis of the frame, each multi-stage mast comprising a first length configuration and a second length configuration, the second length configuration being longer than the first length configuration, each multi-stage mast further comprising a plurality of stages, at least one stage of a mast being vertically movable with respect to at least one other stage of the mast; anda cable mechanism coupled to each multi-stage mast, the cable mechanism comprising:a spool; andat least one cable coupled to the spool and arranged with respect to the multi-stage masts so that when each cable is wound onto the spool, each mast simultaneously and in unison changing length in a direction from the first length configuration to the second length configuration, and when each cable is unwound off the spool, each mast changing length simultaneously and in unison in a direction from the second length configuration to the first length configuration.