| 摘要 |
PROBLEM TO BE SOLVED: To prevent fall of earth in the natural ground at the crest. SOLUTION: This excavator includes a front shield part 11 and an intermediate and a rear shield parts 12, 13. The shield parts 11 and 12 are rotatably connected to each other through a bearing. The intermediate shield part 12 and the rear shield part 13 are separably connected to each other. A cutter head 14 is freely rotatably disposed at the tip of the front shield part 11. In the front shield part 11, a front gripper 16 is provided to freely project and retreat toward the excavated natural ground excavated surface 15, and a driving motor 17 for driving the cutter head 14 in rotation is provided. A bag 30 where a fluid is injected at need to be expanded is provided between the outer periphery of the rear shield part 13 and the natural ground excavated surface 15. |
