| 摘要 |
PURPOSE:To form horizontally the bottom of a trench as well as vertically the wall of the trench by controlling the second slewing shaft enabling an arm provided to the connection of a boom and the arm to turn horizonatally in such a way as to turn it toward the vertical direction following the tilting and righting actions of the boom all the time. CONSTITUTION:An excavation working device consists of a boom 16 capable of tilting or righting in relation to a slewing body 14, an arm 22 capable of tilting or righting in relation to the boom 16 and also of turning horizoantally around the second slewing shaft 234, a bucket 28 turnable within the tilting and righting movement plane, and a rotary controller to control the second slewing shaft, the arm 22, and the bucket 28 in such a way as to enable their tips to turn toward the vertical direction following the tilting and righting actions of the boom 16 all the time. When the boom 16 is vertically moved, the first slewing axis P and the center axis of the second slewing shaft 34 become horizontal all the time by the controller, the shaft 34 is held in the vertical direction, and the horizontal bottom and vertical wall of the trench can be formed without inclination of the bucket 28. |
