Watch Component Chevron Elastic Friction Clutch

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing watch components mounted on axes using friction clutches face challenges in achieving precise, reversible, and stable friction forces, leading to difficulties in driving heavy loads and maintaining consistent torque transmission due to variability in manufacturing tolerances and elastic adjustments.

Innovation Solution

A watch component design featuring an opening with three contact zones, where one zone is elastic and the others are rigid, utilizing flexible blades in a chevron configuration to maintain precise positioning and control friction force through adjustable dimensions and angles, ensuring consistent elastic return and distribution of force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If lantern fitting (plastic deformation) is used to create friction clutch, then the watch component can be firmly held on the axis, but the friction force becomes difficult to reproduce and predict precisely

Engineering Contradiction:
Improvefriction forceVSAvoidreproducibility of friction force
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The patent changes the method of creating friction from plastic deformation to elastic deformation. By using elastic material that deforms reversibly during axis insertion and returns to its original shape, the friction force becomes predictable and reproducible based on precise elastic properties rather than unpredictable plastic deformation outcomes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent eliminates the need for disposable components by making the friction clutch reversible. The elastic material allows the watch component to be disassembled and reassembled multiple times without degradation, replacing the single-use nature of lantern-fitted components.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Force

If lantern fitting is used to create friction clutch, then the watch component can be firmly held on the axis, but the assembly becomes difficult to reverse and reassemble

Engineering Contradiction:
Improvefriction forceVSAvoidreversibility of assembly
Core Design Contradiction:
ForceVSEase of repair

Solution Approach 1:

The patent changes the deformation regime from plastic (irreversible) to elastic (reversible). The elastic material deforms during axis insertion to create friction grip but returns to its original shape when the axis is removed, enabling easy disassembly and reassembly without component damage.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic elasticity to the system, allowing the material to adapt its properties during operation. The elastic material dynamically deforms during assembly to create friction and dynamically recovers during disassembly, providing both firm holding and easy reversal.

Inventive Principle:
Principle #15Dynamics

3Ease of repair

If elastic adjustment with flexible elements is used, then the watch component can be disassembled and reassembled, but the friction force is limited by the dimensions of the flexible elements

Engineering Contradiction:
Improvereversibility of assemblyVSAvoidfriction force
Core Design Contradiction:
Ease of repairVSForce

Solution Approach 1:

The patent applies local quality by concentrating the elastic function in a specific localized structure (the elastic material portion) while maintaining overall component integrity. This localized elasticity allows sufficient friction force generation without requiring the entire flexible element to be large, enabling both high friction and reversibility.

Inventive Principle:
Principle #3Local quality

4Ease of repair

If elastic adjustment with flexible elements is used, then the watch component can be disassembled and reassembled, but the friction force is highly subject to manufacturing tolerances

Engineering Contradiction:
Improvereversibility of assemblyVSAvoidconsistency of friction force
Core Design Contradiction:
Ease of repairVSManufacturing precision

Solution Approach 1:

The patent changes from relying on dimensional tolerances of flexible elements to relying on the elastic properties of the material. Elastic modulus and other material properties can be controlled more precisely during manufacturing, leading to more consistent friction forces across production batches compared to dimensional tolerances.

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 design allows for precise and reversible mounting with a stable friction force, capable of driving heavy loads while minimizing manufacturing tolerance impacts, ensuring consistent torque transmission and easy reassembly.

Implementation Method 1

a first contact zone being located on an elastic portion of the timepiece component, the elastic portion being configured to maintain by the elastic restoring force an axis inserted in the opening between the three contact zones

Methodology Applied
Scientific EffectElastic restoring force: Elasticity

Implementation Method 2

the elastic portion comprising at least one pair of flexible blades arranged in a chevron and maintaining the first contact zone suspended in the opening

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

three contact zones each intended to come into point contact with an axis inserted in the opening... maintain by the elastic restoring force an axis inserted in the opening

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4407381A1Timepiece component
Publication Date: 2024.07.31 PATEK PHILIPPE SA
  • EP4407381A1 patent drawingFigure 1~2
  • EP4407381A1 patent drawingFigure 3~4
  • EP4407381A1 patent drawingFigure 5~6

AI summary

A watch component (1) comprising an opening (10) for the insertion of a shaft, the opening (10) comprising three contact zones (11, 12, 13) each intended to make point contact with a shaft inserted in the opening (10), a first contact zone (11) being located on an elastic portion of the watch component, a second and a third contact zones (12, 13) being located on a rigid portion (3) of the watch component, the elastic portion being configured to maintain between the three support zones (11, 12, 13) by the elastic restoring force a shaft (9) inserted in the opening (10), characterized in that the elastic portion comprises at least one pair of flexible blades (2) arranged in a chevron and maintaining the first contact zone (11) in suspension in the opening (10), the first contact zone (11) being located at the top of the chevron.Assembly comprising such a watch component and an axle held by friction in the opening (10) of the watch component (1). Watch part comprising such an assembly.