| 摘要 |
PROBLEM TO BE SOLVED: To provide a buffer structure for a pipe body, which protects a joint portion of pipes from being damaged by a driving force even if an outer pipe is formed of vinyl chloride or thin steel, thereby to positively propel the pipe body into the ground. SOLUTION: The buffer structure for the pipe body is formed of a pipe body 20 and the pipe body 40 overlapping each other via a joint portion 3, to thereby transmit an axial force therethrough. The pipe body 40 arranged outside the joint portion 3 has a female screw 41 formed in an inner peripheral surface thereof, and the pipe body 20 arranged inside the joint portion 3 has a male screw 24 formed on an outer peripheral surface thereof. Then, a coil member formed of a resilient material 5 is entangled in a fitting gap which is formed when the female screw 41 is screwed onto the male screw 24. COPYRIGHT: (C)2003,JPO
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