Tangential expander for oil control piston rings

摘要

The joint of the expander is formed by tooth-like portions of the side flanges of a U-shaped spring, bent inward and coiled into a ring. The device comprises a measuring gear which reels off the sinuous profiled spring from a spiral. The gear has a radial slot receiving the reciprocating cutters acting in conjunction with bending punches which bend the cut-off tooth-like ends of the spring, locked into a joint.