Mechanical timepiece resonator with three parallel arms - has centre arm oscillating in phase opposition to outer arms

摘要

The mechanical resonator, for a timepiece mechanism, has three oscillating arms which are positioned parallel to one another in the same plane and which are of equal length, with the centre arm (10c) oscillating in phase-opposition to the two outer arms (10b, 10b'). A detector magnet (17), a drive magnet (18) and an indexing magnet (19), for cooperating with an indexing wheel, fixed to the ends of the two outer arms (10b, 10b') and the centre arm (10") respectively. The ratio of the width of each outer arm (10b, 10b') to that of the centre arm (10c) is n : 2, where n is a positive whole number greater than 1. the centre of gravity of the combined mass of the detector and drive magnets (17, 18) acts at a point corresponding to that of the centre of gravity of the indexing magnet (19) with the resonator in the neutral position.