Abstract: A method for measuring the torque of a balance spring, made, in particular, of micromachinable material. A gripper places the collet on an insertion guide on the vertex of a mock obelisk-shaped arbor for a first centring of the collet, this balance spring is allowed to slide under its own weight along the guide surmounting a frustoconical shank that completes the self-centring of the collet on the tool axis, and for holding this balance spring without stress on the shank, the mock arbor including a drive device cooperating with the inner contour of the collet for the relative driving in rotation thereof without slipping, a holding tool holds the outer coil of the balance spring, to measure the torque of the balance spring by rotating the main tool and/or the holding tool about the axis, without stressing the balance spring.

Abstract: A method for measuring the torque of a balance spring, made, in particular, of micromachinable material. A gripper places the collet on an insertion guide on the vertex of a mock obelisk-shaped arbor for a first centring of the collet, this balance spring is allowed to slide under its own weight along the guide surmounting a frustoconical shank that completes the self-centring of the collet on the tool axis, and for holding this balance spring without stress on the shank, the mock arbor including a drive device cooperating with the inner contour of the collet for the relative driving in rotation thereof without slipping, a holding tool holds the outer coil of the balance spring, to measure the torque of the balance spring by rotating the main tool and/or the holding tool about the axis, without stressing the balance spring.

Abstract: A method adjusting oscillation frequency of a sprung balance assembly formed at random from balance springs and balance wheels. A production mechanism is set to limit a sample standard deviation of a single batch of balance springs to a predetermined maximum value, and to limit a sample standard deviation of a single batch of balance wheels to a predetermined maximum value within a given unbalance tolerance. The mean of the balance population is classified according to the mean of the balance springs, to obtain a difference corresponding to a maximum inertia decrease value of the balances, between extreme gaussian distribution values of balances and of balance springs. A random balance spring sample is taken from the single batch of balance springs and a random balance from among the single batch of balances. The inertia of the balance is adjusted according to a torque value of the balance spring sample.

Abstract: A method adjusting oscillation frequency of a sprung balance assembly formed at random from balance springs and balance wheels. A production mechanism is set to limit a sample standard deviation of a single batch of balance springs to a predetermined maximum value, and to limit a sample standard deviation of a single batch of balance wheels to a predetermined maximum value within a given unbalance tolerance. The mean of the balance population is classified according to the mean of the balance springs, to obtain a difference corresponding to a maximum inertia decrease value of the balances, between extreme gaussian distribution values of balances and of balance springs. A random balance spring sample is taken from the single batch of balance springs and a random balance from among the single batch of balances. The inertia of the balance is adjusted according to a torque value of the balance spring sample.