Coupled Resonator Frequency Stabilization

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Solution Overview

Problem

Existing frequency stabilization systems for mechanical watch movements are either unreliable or require complex assemblies with numerous components, leading to increased costs.

Innovation Solution

A coupled resonator system comprising a low-frequency hairspring and a higher-frequency tuning fork, which can be manufactured separately or as a single piece from materials with specific elastic constants, mechanically assembled to stabilize frequency against external disturbances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electromagnetic coupling devices with magnets and electronic circuits are used to stabilize frequency, then frequency stabilization is achieved, but device complexity and manufacturing cost increase significantly

Engineering Contradiction:
Improvefrequency stabilizationVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges two resonators (balance spring at low frequency and tuning fork at high frequency) into a single coupled mechanical system. This integration eliminates the need for separate electromagnetic coupling devices, magnets, and electronic circuits, thereby reducing device complexity while maintaining frequency stabilization functionality through direct mechanical coupling.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces the electromagnetic coupling system with a purely mechanical coupling system. Instead of using magnets and electronic circuits to achieve frequency stabilization, the invention uses direct mechanical connection between the balance spring and tuning fork, substituting complex electromagnetic mechanisms with simple mechanical resonance coupling.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If electromagnetic coupling devices with multiple adjusted components are assembled, then frequency stabilization is achieved, but manufacturing cost increases due to assembly complexity

Engineering Contradiction:
Improvefrequency stabilizationVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By combining the balance spring and tuning fork into a single integrated resonating system with direct mechanical coupling, the patent eliminates the need for assembling multiple separate components with precise adjustments. The unified structure simplifies manufacturing processes and reduces assembly complexity while maintaining effective frequency stabilization.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If traditional balance spring alone is used, then system simplicity is maintained, but frequency stability under external shocks is insufficient

Engineering Contradiction:
Improvesystem simplicityVSAvoidfrequency stability under shocks
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces dynamic frequency stabilization by coupling the balance spring with a high-frequency tuning fork. The tuning fork's natural high-frequency vibrations are excited by the balance spring's motion, and this coupling creates a stabilizing effect that reduces frequency variations under external shocks while maintaining the overall simplicity of the mechanical system.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent utilizes mechanical vibration principles by introducing a tuning fork that vibrates at high frequency. The coupling between the low-frequency balance spring and high-frequency tuning fork creates a resonant system where the tuning fork's vibrations help stabilize the balance spring's frequency, particularly under external disturbances such as shocks.

Inventive Principle:
Principle #18Mechanical vibration

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

The coupled resonator design provides a simpler, more reliable frequency stabilization with a stabilization effect of over 20% against shocks, reducing the complexity and cost of the system while maintaining isochronism.

Implementation Method 1

a first resonator consisting of a hairspring and a second resonator consisting of a tuning fork... permanently linked mechanically

Methodology Applied
Scientific EffectMechanical coupling:

Implementation Method 2

a coupled resonator comprising a first low-frequency resonator... and a second resonator at a higher frequency... coupling making it possible to stabilize the frequency

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 3

The materials used must have a certain elastic constant and can for example be chosen from metals or alloys... The two resonators can be manufactured separately from identical or different materials

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2008160B1Coupled resonator for regulating system
Publication Date: 2010.06.30 THE SWATCH GRP RES & DEVELONMENT LTD
  • EP2008160B1 patent drawingFigure 1~3
  • EP2008160B1 patent drawingFigure 4~5

AI summary

The coupled resonator comprises a first or low-frequency resonator such as a balance spring (1), and a second or higher-frequency resonator such as a tuning fork (2), the two resonators (1, 2) comprising permanent mechanical coupling means. Application: to the regulating system of a timepiece.