| 摘要 |
<p>1. A process for forming a collar (11, 11') on the wal of a metal tube (1, 1'), preferably of small thickness, said process being characterized in that the tube (1, 1') being empty of any filling a circular groove (6, 6', 17) delimited by two adjacent sides (7, 8) is formed in per se known manner at the periphery of the tube (1, 1') and on the face opposite to that where the collar is to be produced, by an operation of displacing the metal such as knurling, and that a an axial compression is then applied to the ends of the tube (1, 1') until the two adjacent sides (7, 8) formed in the course of the first phase are brought into contact.</p> |
