Attachment for timepiece balance spring - has clamping point diametrically opposite end of spring end section

摘要

The timepiece balance spring fixing system attaches the inner end of the spiral spring to the balance shaft, or to a spring roller. The diameter of the cylindrical balance shaft or roller is selected such that, the clamping point defining the beginning of the active spring length, is diametrically opposite the end of the end section of the spring, where the latter departs from the periphery of the shaft or roller. The diameter of the cylindrical shaft or roller may be defined by a formula in terms of length os the spring end section, or in terms of the length of the spring end section, or in terms of the inner diameter (d) of the spiral spring, the spacing (p) between concentric spring turns and the thickness (e) of the spring band.