In an oscillator for a timepiece including a balance and a hairspring, the balance lacks equilibrium, such that: the curves for running of the oscillator owing to weight of the hairspring as a function of the oscillation amplitude of the balance in at least four vertical positions of the oscillator spaced by 90° each pass through 0 at an oscillation amplitude of the balance between 200° and 240°; and between oscillation amplitudes of 150° and 280°, curves representing the running of the oscillator owing to lack of equilibrium in the balance as a function of the oscillation amplitude in the vertical positions each has an average slope of opposite sign to the average slope of the corresponding curve among the curves representing the running of the oscillator owing to the weight of the hairspring. A reduction in the running discrepancies between the vertical positions can thus be achieved.

A balance spring system of a horology movement, comprising: a balance spring (1); a movement blank; a first element (1c) for indexing the position of an outer end (10) of the balance spring relative to the blank; and a unit (OL) for connection of the outer end (10) of the balance spring to the movement blank,
the first indexing element (1c) being designed such as to be displaceable relative to the connection unit (OL).

A one-piece balance spring including a single strip wound on itself between an inner coil and an outer coil, the strip having a geometry such that when the angle of contraction of the balance spring has a value of 360 degrees, there is a substantially constant distance between each coil from the inner coil to the penultimate coil.

A balance wheel including a rim connected to a hub with at least one arm, wherein the balance wheel includes an adjustable auxiliary temperature compensation system mounted in the space defined by the rim to allow adjustable temperature compensation of the balance wheel.

A bimetallic device, the difference in expansion coefficient of which is between 10 and 30 10.sup.−6 K.sup.−1, for providing a resonator with thermal compensation via the balance wheel.

A device for autonomous adjustment of the active length of a balance spring includes a regulator mounted on a plate with a cock, a balance spring stud holder being pivotally mounted on the cock, the regulator being pivotally mounted on the stud holder and including a pivot arm and device for changing the active length of the balance spring by pivoting the regulator. The device includes an elastic stress device to exert an elastic, return-to-position action on the regulator, and an inertia block, mounted for free rotation on the cock and connected to the pivot arm of the regulator, arranged to move the pivot arm of the regulator between a rest position and a correction position of the device, and simultaneously act on the device for changing the active length of the balance spring.

Disclosed is a tourbillon for a horology movement including a cage rotatably mounted on the horology movement, the cage bearing a regulating organ including a balance including a balance pivot pivotally mounted in balance bearings about a balance axis with an anchor including an anchor pivot pivotally mounted in anchor bearings about an anchor axis and arranged to cooperate both with the regulating organ and also with an escapement wheel including an escapement pivot pivotally mounted in escapement bearings about an escapement axis. The anchor and the escapement wheel are positioned relative to the balance so the distance between the anchor axis and the balance axis and the distance between the escapement axis and the balance axis are greater than the outer radius of the balance. Also disclosed is a movement including such a tourbillon as well as to a timepiece including such a movement.

A spiral spring, in particular for a horological resonator mechanism, the spiral spring (30) extending substantially in a plane, the spiral spring (30) including a flexible strip (2) coiled on itself in a plurality of turns, the strip (2) having a predefined rigidity, the spiral spring (30) including means for adjusting its rigidity, wherein the adjustment means comprise a flexible element (5) in direct contact with the strip (2), the flexible element (5) preferably having a rigidity greater than that of the strip (2), the adjustment means including prestressing means (6) for applying a variable force or torque to the flexible element (5) so as to vary the rigidity of the flexible element (5).

A method for depositing a decorative and/or functional layer on at least a portion of a surface of a finished or semi-finished article made of a non-conductive ceramic material, this deposition method includes the following operations: subjecting the at least a portion of the surface of the article to a carburising or nitriding treatment during which carbon, respectively nitrogen atoms, diffuse in the at least a portion of the surface of the article, then depositing, by galvanic growth of a metallic material, the decorative and/or functional layer on at least a portion of the surface of the article which has undergone the carburising or nitriding treatment.

A balance with hairspring of the present disclosure includes a balance shaft rotatably supported by a support member, a collet fixed to the balance shaft, and a metal hairspring fixed to the collet, and the hairspring includes an inner end portion fixed to the collet, a first winding portion continuously formed from the inner end portion and formed along a Grossmann curve, and a second winding portion continuously formed from the first winding portion and formed along an Archimedes' spiral, and the collet includes a fixing portion to which the inner end portion of the hairspring is fixed, and an outer peripheral shape portion arranged at a position facing an inner surface of the first winding portion and configured to form the first winding portion into a shape of the Grossmann curve.