| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a foldable tandem type mobile crane easy to avoid an obstacle during work, having a small working radius and high safety, allowing both the pole and the backbone to be overlappingly folded after working by the length of a basic jib, and easy to move by adjusting an angle between the pole and the backbone having box type structure jibs to connect. <P>SOLUTION: A backbone board (5) having a backbone (6) and a pole (1) are connected through a pull rod (2) and an arm (7). The angle between the pole (1) and the backbone (6) is adjusted by adjusting the amount of pulling of the pull rod (2) and the length of the arm (7) respectively. After finishing work, the arm (7) and the pull rod (2) are stored so that the jibs of the pole (1) and the backbone (6) are as long as the length of the basic jib and overlappingly folded. Thereby, the crane can be easily moved. <P>COPYRIGHT: (C)2004,JPO</p> |
