| 摘要 |
<p>A band 13 is helically wound as a lining onto the inner wall of a duct 5. The band 13 passes out from a central duct 23 and is pressed against the wall of the duct 5 by rollers 21 biased into contact with the duct 5 by spring-loaded movable supports 19. The device used for laying the band can be used within ducts 5 of various diameters and different cross-sections, such as the egg-shaped cross-section illustrated and is especially suited for sewer and tunnel construction. <IMAGE></p> |
