The hairspring (1; 1) has a spring blade (11; 11) and a connecting member (12; 12) for fastening the hairspring (1; 1) to a frame (5, 6, 8), the connecting member including first (13a; 13a) and second (13b; 13b) fastening element, a first arm (121; 121) connecting the first fastening element (13a; 13a) to the second fastening element (13b; 13b), and a second arm (122; 122) connecting the first arm (121; 121) to the spring blade (11; 11), the second arm (122; 122) being connected to the spring blade (11; 11) in a first joining zone (122a; 122a), the hairspring (1; 1) being configured or arranged so that a first displacement of a first amplitude of the first fastening element (13a; 13a) relative to the second fastening element (13b; 13b) does not cause any displacement of the second arm (122; 122), particularly of the first joining zone (122a; 122a), or causes a second displacement of a second amplitude of the second arm (122; 122), particularly of the first joining zone (122a; 122a), relative to the second fastening element (13b; 13b), the second amplitude being less than 0.15 times or 0.1 times or 0.05 times the first amplitude.

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 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.

The method for manufacturing a timepiece movement component (1) having at least a first portion comprising a surface (11), in particular an upper surface, includes etching (E3) the surface (11) of the timepiece movement component (1) or of a blank (1a) of the timepiece movement component (1) in order to form at least one cavity (7); and depositing a material (E4) in the at least one cavity (7).

A piezoelectric element for an automatic frequency control circuit. The element includes a balance spring formed of a piezoelectric crystal strip, a first electrode connected to the automatic control circuit, and disposed on at least a first side of the strip, and a second electrode connected to the automatic control circuit and disposed on at least a second side of the strip. The first and second electrodes are placed on one portion or over the entire length of the balance spring in a predetermined angular distribution.

The present invention concerns a piezoelectric element (3) for an automatic frequency control circuit. The element includes a balance spring (7) formed of a strip of piezoelectric material, a first electrode connected to the automatic control circuit, and disposed on all or part of one side of the strip, and a second electrode connected to the automatic control circuit and disposed on all or part of another side of the strip of piezoelectric material. The element further comprises at least two discontinuous layers of an insulating material, each discontinuous layer of insulating material being disposed on at least one side of the strip of piezoelectric material and separating a first electrode from a second electrode. The discontinuous layers of insulating material are distributed on predetermined portions of the balance spring substantially forming arcs, with a predetermined angular periodicity.

The invention relates to a method which comprises the steps of providing a plate (2) made of a micromachinable material, forming the timepiece component (1) with at least one attachment (3) for keeping the component attached to the rest of the plate (2), by etching the plate (2); and creating, along a desired breakage line of the attachment, a pre-detachment area (4) comprising at least one gap (5) obtained by etching into the body of the plate (2).

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.

The invention relates to a silicon-based component with at least one chamfer formed from a method combining at least one oblique side wall etching step with a Bosch etching of vertical side walls, thereby enabling aesthetic improvement and improvement in the mechanical strength of components formed by micromachining a silicon-based wafer.

A method to manufacture a hairspring of a timepiece movement, which includes: producing a malleable elongated element in a form of under a fiber or ribbon form, from a first heated material capable of guiding light; conforming the malleable elongated element in order to achieve into a spiral form; and handling processing the spiral form thus created in order to obtain a hairspring for providing both a mechanical oscillating function in a balance wheel and a light guiding guide lighting function arranged for in situ adjusting of a mechanical performance of said hairspring. The conforming includes coiling the malleable elongated element around a rotating mobile conformation tool, and receiving the malleable elongated element in a guiding channel within a guiding mechanism and guiding the received malleable elongated element via mobile equipment turning on an inner periphery of the guiding mechanism.

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.