| 摘要 |
PURPOSE:To obtain a propulsion pipe, which is easily transported and stored and has excellent workability, by mutually connecting a plurality of rigid short pipe sections and bendable flexible sections separately interposed among the short pipe sections before underground propulsion. CONSTITUTION:A propulsion pipe 2 is composed of a plurality of rigid short pipe sections 2A (length of approximately 70-300mm) and bendable flexible sections 2B separately interposed among these short pipe sections 2A, and the required length sections of a plurality of these rigid short pipe sections 2A and flexible sections 2B are mutually coupled previously before underground propulsion. The flexible sections 2B are formed so as to have spherical bearing structure consisting of internal cylinders 9, outer circumferential surfaces of which are shaped to a spherical surface, and external cylinders 10, to which the internal cylinders 9 are externally fitted slidably and which receive the internal cylinders 9 at that time, and constituted so that the rigid short pipe sections 2A before and behind the flexible sections 2B are mutually formed in a bendable manner at 3-10 deg. and the propulsion pipe 2 is curved to the small radius of curvature. Accordingly, when spaces among the adjacent flexible sections 2B are set to approximately 100mm, the diameter of a drum 6 on which the propulsion pipe 2 is wound can be shaped to approximately 2m. |
