CRANE DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce the overturning moment below the body stabilizing moment of a crane device with boom point mounted with a detachable jib as an extension to the boom, without shortening the boom length and jib operating radius. SOLUTION: A boom 8 is mounted at its point with suspension parts 27 from which a top sheave block 28 is separably suspended to guide hoisting ropes 14. A jib is mounted at its point with top sheaves 10 journalled thereto. Selective installation of the jib and the top sheave block 28 enables the point of at least either of the jib and the boom 8 to sling loads.