Nanowire Composite Watch Spring for Temperature-Stable Oscillation

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Solution Overview

Problem

Watch components, particularly those with flexible structures like balance springs, experience frequency variations due to temperature changes, leading to inaccuracies in watch movements due to deformations and changes in elastic properties.

Innovation Solution

A flexible watch component made of a composite material with nanowires arranged parallel to an axis perpendicular to the component's plane, embedded in a matrix with a thermal compensation material having a thermoelastic coefficient opposite in sign to the other materials, compensating for temperature-induced deformations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If flexible components are used in the oscillator mechanism, then the watch movement can achieve compact design and flexibility, but the frequency varies with temperature due to changes in elastic properties

Engineering Contradiction:
ImproveflexibilityVSAvoidfrequency stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies composite materials consisting of a matrix and nanowires with specific thermoelastic coefficients. The matrix has a positive thermoelastic coefficient while the nanowires have a negative thermoelastic coefficient, creating a composite structure where thermal expansion of the matrix compensates for thermal contraction of the nanowires, maintaining stable elastic properties across temperature variations.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the physical parameters of the material by selecting specific thermoelastic coefficients for the matrix and nanowires. By carefully choosing materials with opposite signs of thermoelastic coefficients and appropriate volume ratios, the composite achieves temperature-independent elastic modulus, directly addressing the frequency stability issue.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If conventional materials are used for flexible components, then manufacturing is simpler, but temperature variations cause deformations and changes in elastic properties

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidelastic property stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent employs a composite material system where a matrix is reinforced with nanowires. This composite structure combines the manufacturability of conventional materials with temperature compensation properties, as the nanowires are dispersed within the matrix to provide thermal stability without significantly complicating the manufacturing process.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent utilizes differential thermal expansion between the matrix and nanowires. The matrix expands with temperature increase while the nanowires contract, and vice versa. This opposing thermal behavior compensates for each other, maintaining stable overall dimensions and elastic properties of the flexible component across temperature variations.

Inventive Principle:
Principle #37Thermal expansion

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 component maintains consistent performance across varying temperatures by inversely proportional compensation of elastic modulus changes, ensuring accuracy in watch movements.

Implementation Method 1

the filling material comprises at least in part a thermal compensation material whose thermoelastic coefficient is of opposite sign to that of the other materials of the composite material

Methodology Applied
Scientific EffectThermoelastic coefficient compensation: Thermal Expansion

Data Source

PatentEP3839644B1Flexible timepiece component, in particular for oscillator mechanism, and clockwork comprising such a component
Publication Date: 2026.01.28 NIVAROX FAR SA
  • EP3839644B1 patent drawingFigure 1~2
  • EP3839644B1 patent drawingFigure 3~4
  • EP3839644B1 patent drawing

AI summary

The invention relates to a flexible watch component for the oscillator mechanism of a watch movement, the component comprising at least one part made of a composite material (1), the composite material (1) comprising a matrix (2) and a multitude of nanotubes or nanowires (3) distributed in the matrix (2), the nanotubes or nanowires (3) being juxtaposed and arranged substantially parallel to an axis (A) substantially perpendicular to the plane (P) of the component, the matrix comprising a flexible filling material (4) for filling the interstices between the nanotubes or nanowires (3), the filling material (4) comprising at least in part a thermal compensation material whose coefficient of thermoelasticity (CTE) is of opposite sign to that of the other materials of the composite material (1).