Telephone exchange double coil spring - has two spirals joined by central section with free ends forming actuating members

摘要

The spring comprises two spiral sections (2) joined together by a central section (4), and subjected either to tension or compression load. The free ends of the spring act as actuating members, e.g. operating contacts. It can be made in one piece, e.g. out of spring wire, the central portion being raised, and the free ends can extend centrally away from the spiral sections. The spring can be used in coordinate switches in telephone exchanges, as a coupling device where rails intersect. The free ends can be preloaded against the edge of a cover moved by the rails.