Flat spiral for integration in control element of movement in timepiece, has series of turns formed by rolled plate, where outer end portion of spiral includes series of stiffened zones separated by flexible zones

摘要

The spiral (1) has a series of turns formed by a rolled plate and spread over an inner end portion (1.1), an intermediate portion (1.2), and an outer end portion (1.3). The outer end portion includes a series of stiffened zones (1.3.1) and flexible zones (1.3.2), where the stiffened zones are separated by the flexible zones. The succession of the stiffened zones and flexible zones on the outer end portion of the spiral is formed by a thickness variation of the spiral blade or along the turns of the outer end portion, where the spiral is made of silicon.