| 摘要 |
PURPOSE:To lower the center of gravity under travelling and to improve the suspention performance under working, by supporting a counterweight on a boom rotatable up and down on the crane base of a specially equipped car such as a truck crane. CONSTITUTION:When a piston rod 15 of a hydraulic cylinder 14 is retreated, arms 11, 13 are bent around a pin 12 to hold a counterweight 9 suspended by a rotary arm 8 while being jointed to the rear end 1a of a chassis 1, to lower the center of gravity of a crane truck. When projecting the rod 15 of the cylinder 14 from this state, the arm 11 will pivot counterclockwise around the pin 12 while the pivot arm 8 will also pivot in the same direction around a shaft 7 and the arm 13 will pivot clockwise to lift the counterweight 9 to the state shown by the dashed line. When inserting a lock pin 20 through engaging holes 17, 18 and 19 under this state, the arms 11, 13 are coupled linearly to hold the weight 9, resulting in the increase of the suspention capacity. |
