| 摘要 |
PROBLEM TO BE SOLVED: To provide casing excavation and construction equipment which enables an inner cylinder etc. to be recovered to the side of a ground surface in the state of leaving the casing in the ground, after excavation is performed to a predetermined depth while the casing and the inner cylinder are surely engaged with/disengaged from each other. SOLUTION: In this casing excavation and construction equipment, the casing 1 is provided, and the inner cylinder 4, the inner bit 5 of which is provided at an end movable in the direction of excavation, is provided inside a casing sub 2, the end of which has a casing bit 3. A holding member 6, which is provided in the inner cylinder 4, is advanced to/retreated from the side in a direction orthogonal to the direction of excavation, by means of a pushing body 7 moving in the inner cylinder 4, so that the casing sub 2 and the inner cylinder 4 can be engaged with/disengaged from each other. Seal members 10, 11 and 12 are provided among the casing sub 2, the inner cylinder 4, and the pushing body 7, respectively. A down-the-hole hammer can also be attached to the inner cylinder 4 in place of the inner bit 5. COPYRIGHT: (C)2007,JPO&INPIT
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