EXPANSION RING COMPRISING AT LEAST TWO EXTERNAL RINGS AND COLD EXPANSION METHOD USING SAID EXPANSION RING

摘要

The invention relates to an expansion ring 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 which one of the outer rings (48a-48d) having at least one adjustable feature. Thus, it is possible to obtain an expansion rate that varies from one room to another of a stack. The invention also relates to a cold expansion method which uses said expansion ring.