A spiral spring for a timepiece resonator mechanism, the spiral spring extending substantially in a plane and including a flexible blade wound on itself in several turns and a setting device for modifying the effective length of the wound blade, the setting device including a clamp movable along at least one ending portion of the spiral spring, the clamp extending substantially in the plane of the spiral spring, the clamp including two bearing faces arranged on either side of the wound blade in a multiplicity of positions so as to define a variable effective length of the spiral spring, the clamp and the wound blade being linked to each other by a flexible element allowing the clamp and the bearing faces to be displaced along the wound blade.

In this patent we teach a method for manufacturing hairsprings for mechanical watches using nanofabrication and several resultant geometries. This method produces hairsprings, and other watch components, that are more durable, more precise, more isochronous, possess a different appearance, and are easier to install into a watch. For example, we discuss novel geometries of hairspring coils with non-rectangular cross-sections, hairsprings with attached or integrated collets, detachable collets, notched collets, tabs, and small identifying features. Furthermore, we teach how the cross-section of a hairspring may be modified in order to alter the spring's geometric moment thereby improving isochronism.

A torque-restoring element for an oscillator for a mechanical timepiece and having an oscillator frequency, said torque restoring element comprising a spiral spring body having a number N turnings with an inner terminal end for engagement with a rotational inertial element via a collet, and an outer terminal for engagement with a stationary cock element, and having a width, a height and a total arc length; wherein the spiral spring body includes a core formed from mono-crystalline silicon wafer oriented along the crystallographic axis <110>; and wherein the spiral spring body includes at least one peripheral coating of a material having a thermal elastic constant different from that of the core of the spiral spring body so as to maintain the oscillator frequency an oscillator including the torque-restoring element substantially insensitive to variations of ambient temperature.

A method for manufacturing a resonator in a substrate, including: a) modifying a structure of at least one region of the substrate to make the at least one region more selective; b) etching the at least one region to selectively manufacture the resonator.

A balance spring intended to be fitted to a timepiece balance having fixed inertia, the balance spring being formed of a core having lateral faces connecting an upper face to a lower face, the balance spring including on one of the lateral faces in one portion of the outer coil, a coating formed of one or more layers, the coating including two layers with a first electrically conductive layer coated with a second outer layer made of a ceramic, or a combined layer, made of an electrically conductive ceramic. Also a method of manufacturing this balance spring.

The invention relates to a method for fabrication of a balance spring of a predetermined stiffness comprising the steps of fabricating a balance spring in dimensions of increased thickness, determining the stiffness of the balance spring formed in step a) in order to remove a volume of material to obtain the balance spring having the dimensions necessary for said predetermined stiffness.

The invention relates to a method for fabrication of a balance spring of a predetermined stiffness comprising the steps of fabricating a balance spring in dimensions of increased thickness, determining the stiffness of the balance spring formed in step a) in order to remove, locally, a volume of material, in order to obtain the balance spring having the dimensions necessary for said predetermined stiffness.

The invention relates to a method for fabrication of a balance spring of a predetermined stiffness comprising the steps of fabricating a balance spring in dimensions to obtain a deliberately lower stiffness, determining the stiffness of the balance spring formed in step a) in order to compensate for said missing thickness of material required to obtain the balance spring having the dimensions necessary for said predetermined stiffness.

Method for fabrication of an antiferromagnetic and temperature compensated timepiece balance spring, including the steps of: selecting an amagnetic iron-chromium-nickel-manganese-beryllium compensating alloy, comprising, by mass percent, between and including: from 21.0% to 25.0% of manganese, from 9.0% to 13.0% of nickel, from 6.0% to 15.0% of chromium, from 0.2% to 2.0% of beryllium, the remainder iron, the total of nickel and manganese being higher than or equal to 33.0%, working the alloy to obtain a blank, shaping the blank by casting and/or forging and/or wire drawing and/or rolling and/or drawing, to obtain a blank of spring wire; winding the wire on a winder to obtain a balance spring, subjecting the spiral spring to at least a heat setting treatment, by annealing at a temperature comprised between 540 C. and 650 C., for a duration of 30 to 200 minutes, to obtain a balance spring.

Method for improving an iron-nickel-chromium-manganese alloy for timepiece applications, particularly for producing a balance spring, where a base alloy is chosen and produced, comprising by mass: from 9.0% to 13.0% of nickel, from 4.0% to 12.0% of chromium, from 21.0% to 25.0% of manganese, from 0 to 5.0% of molybdenum and/or from 0 to 5.0% of copper the complement in iron,
and a hardening of this alloy is effected whilst maintaining its anti-ferromagnetic properties, by introduction of carbon and of nitrogen interstitially, with, by proportion of mass of this base alloy: from 0.10% to 1.20% of carbon, and/or from 0.10% to 1.20% of nitrogen.