Hairspring with modified outer curve

摘要

The balance spring has coils with an inner curve integrated to a balance staff pivoting in a balance-cock that allows a direct or indirect fixation of an outer curve (2) of the spring. An end (6) of the outer curve is rigidified by deformation to define a setting point (7) of the spring, where the deformation is achieved by twisting the end through 90 degrees in a plane perpendicular to a height (h) of the spring.