| 摘要 |
<p>PURPOSE:To facilitate the recovery of splinters of a laid pipe by crushing the laid pipe by a crushing head provided on the top end of a new pipe, taking the broken splinters into the new pipe from the splinter intake hole of the crushing head, and drawing a scraper provided on a wire in the new pipe nearer. CONSTITUTION:A new pipe 4 having a crushing head 6 on the top end is installed to a laid pipe 1 and advanced to crush the laid pipe 1 by a crushing edge 9. Splinters 10 are taken in from the splinter inlet 11 of the crushing head 6. The taken splinters 10 are gathered on a starting pit 2 side by a scraper 12 provided in a wire 12 passing through the new pipe 4, carried, and taken out from the new pipe rear end. The new pipe 4 is advanced followed by successive joint of new pipes 4, whereby the new pipe 4 are laid. Consequently, the splinters can be easily removed without being left in the ground.</p> |
