Method for manufacturing a series of timepiece movements

Abstract

A method for manufacturing a series of timepiece movements (1), comprising steps of:-manufacturing a plurality of balance springs (13);—measuring the stiffness of each of said balance springs (13) and sorting them according to a plurality of classes A1 of stiffness;—manufacturing a plurality of balances (11) according to a moment-of-inertia distribution determined as a function of said classes of stiffness of said balance springs (13);—measuring the moment of inertia of each of said balances (11) and sorting them by moment of inertia into a plurality of classes;—defining a first group of classes of balance spring (13) and a second group classes of balance spring (13), in which the classes of each individual group are sequential, the mean stiffness of the balance springs (13) of the second group of classes of balance spring (13) being greater than the mean stiffness of the balance springs (13) of the first group of 2024/188704 classes of balance spring (13):—pairing each class of balance spring (13) with a corresponding class of balances (11);—assembling a plurality of spring-balance (11, 13) oscillators (9), each comprising a balance spring (13) and a balance (11) which have been paired by class;-assembling a series of timepiece movements (1) each comprising one of said spring-balance (11, 13) oscillators (9) arranged to be maintained by an escapement (7, 15) comprising an escape wheel (7) driven by a going train (5), and in which, for the oscillators (9) comprising balance spring (13) from the second group classes, said corresponding movements (1) are arranged such that the torque available to said escape wheel (7) is less than the torque available to the escape wheel (7) for movements incorporating oscillators (9) comprising a balance spring (13) of the first group of classes.

Dependencies are inferred from the claim text.