Patek Philippe Sa Geneve

Csem Centre Suisse D'electronique Et De Microtechnique Sa&#x2014;recherche Et D&#xe9;veloppement

Jean-Luc Bucaille

Olivier Hunziker

Frederic Kohler

Frédéric Maier

Sylvain Jeanneret

Jean-Pierre Musy

Jean-Baptiste Le Bris

Michel Despont

Frédéric Kohler

Séverine Domange

Laurent Guillot

David Ecoffey

Disclosed is a method of making a timepiece spring from monocrystalline material including the following steps: drawing the spring; identifying one or more zones of weakness of the spring in which or in at least one of which the spring will break in the event of excessive deformation; manufacturing the spring from a wafer of monocrystalline material extending in a determined plane, while orienting the spring in the wafer such that the direction of the macroscopic stresses in the or each zone of weakness when the spring is deformed is substantially parallel to a plane of cleavage of the material intersecting the determined plane. Also disclosed is a timepiece spring obtained by such a method.

Method of making a timepiece spring from monocrystalline material and timepiece spring obtained by this method

Disclosed is a method including: a) obtaining a substrate extending in a predetermined plane with a first layer parallel to the plane; b) forming a through-hole in the first layer; c) depositing a second layer on the first, the second layer filling the a through-hole to form a bridge of material; d) etching a hairspring in an etching layer made up of the second layer or the substrate, the one of the second layer and the substrate in which the a hairspring is not etched constituting a support, the bridge of material connecting the hairspring to the support perpendicular to the predetermined plane; e) removing the first layer, the hairspring remaining attached to the support by the bridge of material; f) subjecting the hairspring to a thermal treatment; and g) detaching the hairspring from the support.

Method for manufacturing a spiral spring

A method for producing a timepiece spring includes the following steps: producing a piece based on silicon, having the desired shape of the timepiece spring; thermally oxidising the piece; deoxidising the piece; annealing the piece in a reducing atmosphere; forming a silicon oxide layer on the piece.

Method for producing a silicon-based timepiece spring

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&#xb0; each pass through 0 at an oscillation amplitude of the balance between 200&#xb0; and 240&#xb0;; and between oscillation amplitudes of 150&#xb0; and 280&#xb0;, 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.

Balance-hairspring oscillator for a timepiece

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.

Method for fabrication of a balance spring of a predetermined stiffness by local removal of material

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 a balance spring of predetermined thickness through the addition of material

The timepiece movement includes a balance-and-hairspring oscillator and an escapement cooperating with the oscillator. The outer turn of the hairspring includes a stiffened portion () arranged to at least partially compensate for the variation in the rate of the movement in dependence upon the oscillation amplitude of the balance caused by the escapement. The hairspring further includes at least one of the following features:

Timepiece movement with a balance and hairspring

A timepiece movement includes a balance-and-hairspring regulator and an escapement co-operating with the regulator, the outer turn () of the hairspring including a stiffened portion () arranged to make the development of the hairspring more concentric, is characterized in that the stiffened portion () is also arranged to at least partially compensate for the variation in the rate of the movement in dependence upon the oscillation amplitude of the balance caused by the escapement.

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Beaumont, France

Jean-Luc Bucaille