| 摘要 |
<p>PURPOSE:To improve working efficiency by securing a new pipe to the rear end of a support frame having a breaking impeller, which is rotatable outward taking the head as a fulcrum, at its head and a breaking and expansion body, which can advance and retract, inserting the front end of the support frame and burying a new pipe while breaking an old pipe with the breaking impeller expanded. CONSTITUTION:A new pipe 12 is secured to the rear end 11 of a support frame 1, and the front end of the support frame 1 is made to advance into an old pipe 3. When the head section of the support frame 1 enters the old pipe 3, an expansion body 10 is made to advance by a driving means 9. By this constitution, a breaking impeller 4 is expanded outward around a rotary shaft 6 by the conic expansion body 10. By this constitution, the old pipe 3 is expanded outward and broken. While taking this breaking action, the new pipe 12 is advanced to be buried.</p> |
