Method for determining an imbalance characteristic of an oscillator

Patent metadata

Field	Value
Publication number	US-10120341-B2
Application number	US-201314411235-A
Country	US
Kind code	B2
Filing date	Jun 25, 2013
Priority date	Jun 26, 2012
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

A method for determining an imbalance characteristic of a hairspring (5) balance (4) oscillator (3) of a timepiece movement (2), the method comprising at least the following steps: —Setting the hairspring balance oscillator in an oscillating motion at at least two amplitudes, —Determining, for each amplitude and for at least two positions of the oscillator, a piece of data representative of the oscillation period of the oscillator, —Using the data from the previous step to calculate the imbalance characteristic of the hairspring balance oscillator.

First claim

The invention claimed is:

1. A method of calculating an imbalance characteristic of a hairspring-balance oscillator, the method comprising:
putting the hairspring-balance oscillator into an oscillating motion at first and second amplitudes at least;
determining, for the first amplitude, at at least first and second positions of the oscillator, respective first and second data which are representative of a period of oscillation of the oscillator, and for the second amplitude, at at least third and fourth positions of the oscillator, respective third and fourth data which are representative of the period of oscillation of the oscillator, the first and second data determined for the first amplitude and the third and fourth data determined for the second amplitude forming a set of data; and
calculating, from a comparison among the set of data obtained from the determining, the imbalance characteristic of the hairspring-balance oscillator.

2. The method as claimed in claim 1 , wherein the determining of the set of data which is representative of the period of oscillation of the oscillator comprises measurements.

3. The method as claimed in claim 2 , which firstly comprises:
dismantling an escapement unit of a horology movement comprising the hairspring-balance oscillator, or fitting the oscillator on a support which allows the oscillator to oscillate freely.

4. The method as claimed in claim 1 , wherein using of the set of data comprises calculating the imbalance characteristic from a formula which involves the set of data determined during the determining.

5. The method as claimed in claim 1 , wherein the determining comprises performing measurements on a range of amplitudes, wherein the range of amplitudes comprises (i) at least two amplitudes values spaced by at least 30° and (ii) at least two amplitude values situated on both sides of 220° and included in an interval of from 150° to 280°.

6. The method as claimed in claim 1 , wherein the at least first, second, third and fourth positions of the oscillator are positions in which an axis of oscillation of the oscillator is horizontal or substantially horizontal.

7. The method as claimed in claim 6 , wherein the at least first and second positions of the oscillator are positions in which an orientation of the oscillator differs by 90° or more, and the at least third and fourth positions of the oscillator are positions in which an orientation of the oscillator differs by 90° or more.

8. The method as claimed in claim 1 , wherein the at least first and second positions of the oscillator comprise four positions of a horology movement comprising the hairspring-balance oscillator in which an axis of oscillation of the oscillator is horizontal or substantially horizontal, and wherein orientations of the movement are spaced by 90° from one another, and the at least third and fourth positions of the oscillator comprise four positions of a horology movement comprising the hairspring-balance oscillator in which an axis of oscillation of the oscillator is horizontal or substantially horizontal, and wherein orientations of the movement are spaced by 90° from one another.

9. The method as claimed in claim 8 , comprising calculating the imbalance characteristic by one or more of the three following formulae:

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Assignees

• Rolex Sa

Inventors

• Bossart Richard
• Cerutti Marc
• Burger Frédéric
• Hunziker Olivier
• Favez Denis

Classifications

• G04D7/1214

  for complete clockworks · CPC title

• G04D7/085

  by removing material from the balance wheel itself · CPC title

• G04D7/082 Primary

  for balancing · CPC title

• G04D7/1242

  for measuring amplitude · CPC title

• G04B17/20

  Compensation of mechanisms for stabilising frequency · CPC title