| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reliably prevent buoyancy material from leaking out even if a joint part of the new pipe swells when a new pipe is given buoyancy and is jacked and inserted in a sheath pipe 1. <P>SOLUTION: A water shut off member 12 on one end of the sheath pipe is formed as one unit of rubber, and consists of a cylindrical part 12a fixed on an inner surface of the sheath pipe 1 by a machine screw, a flap 12b facing an axial center of the sheath pipe on an inner circumference whole surface, and a solid cross section round rubber ring 12c of larger diameter than a tip end thereof on a tip end whole circumference of the flap 12b. The flap has normally flexibility and flexibly correspond to change, fluctuation of size (diameter) of the new pipe sliding in the annular shape part of the flap. Then since a solid cross section circular rubber ring is larger in a diameter than a flap tip edge, the flap is not easily influenced by bent of the flap, sure press contact to the new pipe outer circumference surface is maintained even if the flap is deformed to secure water tightness. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
