| 摘要 |
PURPOSE:To alter excavation places while keeping the upper turning body of an excavator at the same attitude by a method in which a boom is divided into two sections on the way in such a way as to enable the tip side to be displaced to left and right sides. CONSTITUTION:A boom attached in a vertically movable manner to an upper turnable body is divided into an end side boom 3a and a tip side boom 3b and an insert boom 14 is interposed at the divided portion. Also, an operation cylinder 18 is interposed between the bottom 14 and the booms 3a and 3b and a parallel link 19 is provided between the divided booms, whereby enabling the tip side of the boom 14 to be displaced to both left and right sides. For example, when excavation place is changed to the right side, the cylinder 18 is extended, the boom 14 is turned clockwise, and thereby the tip side boom 3b is altered to the right side. Since the boom 14 and the parallel link 19 make a parallelogammic movement, even when the boom 14 turns to a place as shown by two-dot chain line, the tip side boom 3b can be altered to the right side while keeping it at the same direction attitude. |
