Spiral balance spring fixation means - employing resilient ring passing round balance axis

摘要

The resilient ring (5) is generally cylindrical with a tangential extension (6) which defines a stop (7) parallel to the balance axis (2). The inner end of the balance spring (1) is bent inwards, with the bent end (3) soldered to the stop (7), at two points situated approximately at the intersections of the two short sides of the rectangular section of the spring (1) with the stop face (7). Pref. a laser is used to solder the bent spring end (3) to the stop (7), which has a rounded face with the resilient ring (5) being thicker than the spiral spring (1).