An assembly (300) includes (i) a hairspring (2) made of a paramagnetic alloy including at least one of the following elements: Nb, V, Ta, Ti, Zr and Hf, notably an alloy including the elements Nb and Zr with between 5% and 25% by mass of Zr and an interstitial doping agent including oxygen, and (ii) at least one fastening part (1; 1′), notably two parts (1; 1′), in particular a stud (1) or a collet (1′), for an end (2a; 2b) of the hairspring (2), the at least one part (1; 1′) having a first portion (10; 10′) that is designed to come into contact with the hairspring (2) and that is made of titanium or titanium alloy or of tantalum or tantalum alloy, notably grade 2 titanium or grade 5 titanium.

A fastening stud (1) for one end of a hairspring, the stud having a first portion (10) designed to come into contact with the hairspring, the first portion being formed such as to have a first surface (10b) and a second bearing surface (10c) with the hairspring.

The piezoelectric balance spring (3) is provided for a circuit (10) for self-regulating an oscillation frequency of an oscillating mechanical system (2, 3), or an energy recovery circuit or a motor circuit for actuating the movement or for the automatic maintenance thereof. The piezoelectric balance spring (3) comprises at least one piezoelectric layer (7, 7′, 17, 17′, 27, 27′) disposed on a top face (20) or bottom face of a certain number of coils of the spring in a plane, and at least two pairs of electrodes (8a, 8b, 8c, 8d), whereby the electrodes of each pair are disposed on two opposing faces of the same piezoelectric layer or respectively two piezoelectric layers so as to apply a reverse bias voltage on each pair of electrodes.

A method for fabrication of a micromechanical part made of a one-piece synthetic carbon allotrope based material, the method including: forming a substrate with a negative cavity of the micromechanical part to be fabricated; coating the negative cavity of the substrate with a layer of the synthetic carbon allotrope based material in a smaller thickness than the depth of the negative cavity; and removing the substrate to release the one-piece micromechanical part formed in the negative cavity.

A balance-spring, particularly for a timepiece resonator mechanism. An adjustment device include a single elongated flexible element (5) arranged in series of strip (2), connecting one end (4, 9) of said strip (2) to a fixed support (11), to add an additional stiffness to the strip (2), and having a stiffness greater than that of the strip (2). A prestressing means (6) applies at least two different stresses on the elongated flexible element (5), the first stress being provided by a tensile/compressive force directed substantially in the longitudinal direction F.sub.L of the elongated flexible element (5), and the second stress being provided, either by a force directed substantially in a direction substantially orthogonal F.sub.T to the longitudinal direction of the elongated flexible element (5), or by a torque M, preferably a bending moment, in such a way as to vary the stiffness of the elongated flexible element (5).

This invention teaches a new class of materials that can be used to manufacture hairsprings and/or other components of mechanical watches, and methods for manufacturing these components. The new class of materials is crystalline compounds, including, but not limited to, gallium arsenide, extrinsically doped gallium arsenide, extrinsically doped silicon, gallium nitride, extrinsically doped gallium nitride, gallium phosphide, extrinsically doped gallium phosphide, and quartz. This invention also teaches laminated/coated crystalline compounds. The lamination/coating may be applied by one of the following methods, including but not limited to: plasma enhanced chemical vapor deposition, atomic layer deposition, sputtering, electron beam evaporation, and thermal evaporation. Using crystalline compounds, in particular extrinsically doping the crystalline compounds, affords the possibility to controllably alter the mechanical, electrical, thermal, magnetic, and/or other properties of the watch components. These properties can be further altered by applying single or multiple laminates/coatings of varying thicknesses and/or geometries.

A method for maintaining and regulating frequency of a timepiece resonator mechanism around its natural frequency, the method including: at least one regulator device acting on the resonator mechanism with a periodic motion, to impose a periodic modulation of resonant frequency or quality factor or a position of a point of rest of the resonator mechanism, with a regulation frequency between 0.9 times and 1.1 times the value of an integer multiple of the natural frequency, the integer being greater than or equal to 2 and less than or equal to 10, and the periodic motion imposes a periodic modulation of the quality factor of the resonator mechanism, by acting on losses and/or damping and/or friction of the resonator mechanism.

A method of manufacturing a clock or watch component (19; 29) includes (i) providing (E11; E21) a wafer (11; 21) having a single slice (12; 22) including a material of the component, notably silicon, diamond, quartz, sapphire or ceramic, optionally first coating the lower surface of the slice (22) with a lower layer (24), (iii) etching (E12 to E14; E22 to E24) the slice (12; 22) starting from its upper surface to form at least one clock or watch component, (iv) revealing (E15; E25) at least one clock or watch component (19; 29), by removing a layer that served as a mask for etching (E15; E25) and (y) optionally releasing (E26) the slice and the at least one etched clock or watch component by removing the lower layer (24).

Process for manufacturing a hybrid timepiece component, wherein the following steps are comprised: comprising structuring at least one wafer (14) of a first micromachinable material so as to form at least one through-opening (15) within the wafer (14), said structured wafer (14) being intended to form a first part (4) of the hybrid timepiece; component and depositing a metal by electroforming, so that the metal extends through the through-opening (15) and over the two upper and lower faces of the wafer (14) as a single piece resulting from one and the same electroforming step, the electroformed metal being intended to form a second part (8) of the hybrid timepiece component.

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.