Flexible-Guided Oscillator Center of Mass Adjustment for Chronometric Stability

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Solution Overview

Problem

Flexible-guided oscillators in mechanical watches experience frequency changes due to external forces like gravity, affecting their stability and chronometric performance as their rigidity varies with orientation.

Innovation Solution

Adjusting the position of the balance wheel's center of mass relative to the flexible guide to minimize the difference in oscillatory behavior between horizontal and vertical positions, thereby stabilizing the frequency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the oscillator uses a flexible guide to eliminate physical guiding elements, then wear and lubrication requirements are eliminated, but the rigidity becomes influenced by external forces like gravity causing frequency changes

Engineering Contradiction:
Improvewear resistanceVSAvoidfrequency stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the spatial parameter of the center of mass position relative to the flexible guide. By positioning the center of mass at a specific location, the gravitational force creates a compensating moment that counteracts the rigidity changes in the flexible guide, thereby stabilizing the oscillation frequency across different orientations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses the gravitational force acting on the offset center of mass as a counterbalancing mechanism. The weight creates a moment that compensates for the orientation-dependent rigidity changes in the flexible guide, effectively canceling out the frequency variations caused by gravity.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

2Ease of manufacture

If the center of mass is positioned outside the median plane of the flexible guide, then manufacturing is simplified, but the rate difference between horizontal and vertical positions increases

Engineering Contradiction:
Improvemonolithic manufacturingVSAvoidrate consistency
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent optimizes the position parameter of the center of mass relative to the flexible guide's median plane. By carefully selecting this position, the design achieves a balance where gravitational effects in different orientations produce compensating moments, thereby minimizing rate differences while maintaining the benefit of monolithic manufacturing.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This adjustment reduces or eliminates the variation in rate between different orientations, ensuring consistent chronometric performance by simulating the stress conditions in both positions using finite element modal analysis.

Implementation Method 1

suspended from a support by an arrangement of elastic parts, called the 'flexible guide'... In addition to its guiding function, the flexible guide acts as a return spring, necessary for achieving oscillatory behavior

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

their rigidity is influenced by external forces, such as those exerted when the oscillator is subjected to gravity. As a result, their frequency changes depending on the watch's orientation relative to gravity

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP4163735A1Methods for producing and adjusting an oscillator with flexible guide and timepiece movement comprising such an oscillator
Publication Date: 2023.04.12 PATEK PHILIPPE SA
  • EP4163735A1 patent drawingFigure 1(a)~1(b)
  • EP4163735A1 patent drawingFigure 2(a)~2(b)
  • EP4163735A1 patent drawingFigure 3(a)~3(c)

AI summary

The invention relates to a method for making a flexible-guided oscillator comprising the following steps: designing by computer an oscillator comprising a support (4; 13), a balance wheel (2; 11) and a flexible guide (3; 15) suspending the balance wheel from the support and guiding oscillations of the balance wheel relative to the support in a determined plane (P); calculating a step of the oscillator in at least one horizontal position and in at least one vertical position of the oscillator; modifying the position of the center of mass (C) of the balance wheel (2; 11) relative to the flexible guide (3; 15) in the direction perpendicular to the determined plane (P) in order to reduce, and preferably cancel, the difference between the step in at least one horizontal position and the step in at least one vertical position; and manufacturing the oscillator.