| 摘要 |
A self-erecting tower crane for use on a construction site is supported at a top end of a tower that includes tower sections assembled in an end-to-end relationship relative to one another along a tower axis. The tower crane includes a boom assembly for selectively raising tower sections above ground. A boom support structure has an upper portion that rotatably supports the boom assembly relative to the tower axis, and a lower portion that is configured and sized for mounting on and releasably securing to the tower top end. A self-raising sleeve mounts on the tower for axial movement therealong, and selectively and releasably supports the boom support structure on the tower. The sleeve and the boom support structure include a side opening that is configured and sized for allowing a tower section to be assembled to the tower top end for the self-erection of the tower crane.
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