Fastener for necklace - has holding pin which passes across tube and through coupling slider which contains coil spring

摘要

The fastener for a necklace consists of an oblong tube (1), open at both ends, and a sliding piece (2) which fits into it. The sliding piece contains a spring (3) and has two rectangular openings (2a) in its longitudinal edges. A fixing pin (5) crosses both elements by passing through the openings in the sliding piece and the spirals of the spring. A hook is fixed to each end of the sliding piece, forming the link to hold the necklace. When the fastener is closed the free end of each hook is pulled into the tube by the spring.