Bearing ring for fixing a mounting block on the progressively variable curved finished face of a semi-finished lens or mold blank

摘要

This bearing ring is of the kind comprising, for contact with the semi-finished blank to be processed, a limited number of bearing areas appropriately distributed circumferentially around the axis of the assembly. The planes tangential to the ends of each of the bearing areas form between them a dihedron, the bearing surface that a bearing area of this kind provides being in practice generally convex.