| 摘要 |
PURPOSE:To perform a rapid work, by a method wherein a lateral blade member, which has an excavating blade, extended in a direction extending across an outer pipe for excavation hole, and can be withdrawn into the outer pipe, is coupled to a forward end device. CONSTITUTION:A forward end device 3 is formed such that an inner pipe 2 is engaged with an outer pipe 1 securely provided at its lower end surface with tips 5 for excavation, and a packer 8 is engaged with a body 7. The forward end device is connected to the lower end of the inner pipe 2 through a seal part 6. A lateral blade member 4, which has an excavating blade 11, extended at the forward end in a direction extending across the outer pipe 1 and held to a leg part 12, is coupled to the lower end of the forward end device 3 through a coupling member 10. Further, the lateral blade member 4 is so constituted as to allow withdrawal of the member into the outer pipe 1 in a way that the side parts of the leg part 12 can be engaged with vertical slits 13 of the outer pipe 1. |
