| 摘要 |
PROBLEM TO BE SOLVED: To provide a friction reducing method of a propulsion pipe and its device capable of not only always smoothly cutting and protrusing by small power with low frictional resistance, but also being easily manufactured at a low cost. SOLUTION: An endless driving chain 4 with bits 5 for cutting a tail void 64 from the top to both sides is eccentrically and annularly placed to a joint of required drive pipes 52 in a forward and reverse rotatable manner when the propulsion pipes 52 with a required length are successively connected to be embedded in the ground while being excavated from a starting shaft. While rotationally operating the endless driving chain 4 in the circumferential direction, the rail void 64 is cut and softened from the top to both sides by the bits 5 to reduce friction between the propulsion pipes 52 and a bedrock. COPYRIGHT: (C)2004,JPO
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