| 摘要 |
PURPOSE: To carry out a straight excavation and accurately bury pipes with a low pressure, by appropriately arranging a cone type rotary disk cutter and an outer peripheral cutter bit. CONSTITUTION: The forefront in the heading side is arranged on almost the same plane against the thrusting direction, in the blade of cone type rotary disk cutters 5, 6. The disk cutters 5, 6 are positioned forwarder than the cutter bit in the axial direction and the cutter bit is positioned outer side than the disk cutter in the radial direction. The rotary disk cutter is rotatably supported in the inner pipe 20 through bearings against thrust. |
