| 摘要 |
<p>Corrugated, helically formed lock-seam tubing is formed in a machine wherein clinching rollers (2,3) for closing the lock-seam (8) of the tubing are shaped so that the lock-seam (8) is displaced radially with respect to the circumference of helically wound strip defining the tubing, during the formation of the lock-seam (8), whereby the lock-seam is located at the crest of a helical corrugation (9) formed in the wall of the finished tubing.</p> |
