The expansion ring comprising at least two rings outer ends and advantages of using the cold expansion in expansion ring

摘要

The present invention relates to a ring of expansion which is characterized in that it comprises a support ring (46) and at least two outer rings (48a - 48d) fitted on the support ring (46), at least one of the outer rings (48a - 48d) having at least one characteristic of the adjustable. Thus, it is possible to obtain a degree of expansion which varies from one piece with the other of a stack. The present invention also relates to a process of expansion in the cold, which uses the expansion ring.