| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a jib crane which can pull out a mast member at a lowest stage by itself and is therefore suitable as a dismantling machine for a large-sized tower crane, and to provide a method of dismantling the jib crane. <P>SOLUTION: The jib crane comprises: a pedestal 1; a mast 2 which is composed by joining a plurality of mast members 2a; and a crane body 7 which is vertically movable relative to the mast by a climbing apparatus 6 that includes an out mast 3 and a climbing frame 4 which are vertically arranged so as to surround the outside of the mast, and that also includes a hydraulic cylinder 5 for driving vertical movement. The climbing frame is removed in a state in which the crane body is lowered till a position supported by the mast member of a lowest stage, a lower end part of the hydraulic cylinder joined to the climbing frame is joined to a cylinder receiving beam 15 attached to the pedestal, the out mast is lowered by contraction of the hydraulic cylinder and is joined to the pedestal and in this state, the mast member at the lowest stage is pulled out upward by a jib 9 of the crane body. <P>COPYRIGHT: (C)2012,JPO&INPIT |
