| 摘要 |
PROBLEM TO BE SOLVED: To provide a useful crane device in which the lateral bending rigidity of a boom which supports a jib at the front end is increased by a considerably simple structure. SOLUTION: A pair of left and right first tension members 41 are connected, at their one ends, to a third mast 23 at an interval which is provided to the lower base of the triangular or trapezoidal shape of the connected first tension members. The pair of left and right first tension members 41 are connected, at their other ends, to a second mast 22 at the apex of the triangular shape or the upper base of the trapezoidal shape of the connected first tension members. Since the pair of left and right first tension members 41 are disposed so that the lateral width thereof at the third mast 23 is larger than that at the second mast 22, the lateral bending rigidity of the boom 13 which supports the jib 14 can be increased by a considerably simple structure. COPYRIGHT: (C)2011,JPO&INPIT |
