Method of mfg. e.g. bracelets and rings - entails deforming hollow metal cylinder by axial compression

摘要

The compression of the precious or non-rusting metal is effected by placing a split tube, whose ends are folded inwardly, between fixed (5b) and movable (5a) plates and around a cylindrical mandrel (3). The upper end of the mandrel is threaded and secured to a mounting plate (16) by a nut (2). By moving the mandrel downwards through a hole (6) in a lower mounting plate (1a) carrying the fixed plate (5b) the plates are moved together to compress the split tube. The resulting piece of jewellery has non-uniform creases and ribs. The plates may be replaced by telescoping sleeves.