Watch Escapement Blade Pivot Reduces Friction

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Solution Overview

Problem

Conventional lever escapements in watchmaking suffer from mechanical disturbances such as friction, which affect the isochronism of oscillations and reduce mechanical efficiency, limiting the transmission of driving force to 30-40%, and existing solutions using advanced materials like silicon are expensive, fragile, and difficult to produce on an industrial scale.

Innovation Solution

A new geometry for the escapement mechanism featuring a blade pivot with a counter-blade and elastic return member, allowing rotation of the escapement wheel set around an axis of at most 45°, minimizing friction through a blade-edge and groove configuration that reduces contact friction and maintains a constant pulling force, enabling efficient energy transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional lever escapements are used, then the structure is simple and easy to manufacture, but mechanical friction is high and energy transmission efficiency is low (30-40%)

Engineering Contradiction:
Improvemechanical frictionVSAvoidescapement structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The pivot is segmented into two distinct components: a blade portion integrated with the escapement wheel and a counter-blade portion integrated with the anchor. This segmentation allows each component to be optimized for its specific function, reducing overall friction while maintaining structural integrity and manufacturability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a conventional point or cylindrical pivot to a blade-shaped pivot with extended dimensions. The blade geometry introduces a new dimensional aspect to the pivot interface, distributing contact over a larger area and reducing pressure-induced friction while remaining compatible with traditional manufacturing processes

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Loss of energy

If silicon materials are used for escapement components, then friction is reduced, but production cost increases and parts become fragile

Engineering Contradiction:
ImprovefrictionVSAvoidpart fragility
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The invention changes the geometric parameters of the pivot from conventional cylindrical or point shapes to extended blade geometries. This parameter change reduces friction through increased contact area distribution while allowing the use of traditional, reliable materials instead of fragile silicon, achieving low friction without sacrificing reliability

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If silicon deep etching technology is used, then friction is reduced, but manufacturing complexity and precision requirements increase

Engineering Contradiction:
ImprovefrictionVSAvoidproduction technology
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The pivot geometry is changed from conventional forms to blade shapes with specific dimensional parameters. These parameter changes achieve reduced friction through improved contact characteristics while maintaining compatibility with traditional watchmaking manufacturing techniques, avoiding the need for complex silicon deep etching processes

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

The solution significantly reduces mechanical disturbances and energy losses, improving the power reserve and efficiency of the escapement mechanism while being manufacturable with conventional techniques and materials, thus optimizing the lever escapement without increasing complexity or cost.

Implementation Method 1

the pivot of the escapement wheel set comprises a blade and a counter-blade, the blade or the counter-blade being fixed to the body of the wheel set when it is capable of being fixed to a frame element of a watch movement

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3761122B1Timepiece escapement component, associated escapement mechanism and timepiece
Publication Date: 2023.05.24 BESSE FRANCOIS
  • EP3761122B1 patent drawingFigure 1~1A
  • EP3761122B1 patent drawingFigure 2~2A
  • EP3761122B1 patent drawingFigure 3~3A

AI summary

The present invention relates to a watch escapement mechanism (2), in particular an anchor, comprising a pivot (24) defining an axis of rotation (Y) and a body (21) extending in a plane perpendicular to said axis of rotation, characterized in that the pivot (24) defines a virtual axis of rotation (Y) oriented perpendicular to the plane of extension of the body (21). The invention also relates to an escapement mechanism (1) equipped with such a mechanism and an associated watch component.