Timepiece Crown Stem Diagonal Coding Pattern

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Solution Overview

Problem

Existing timepiece setting stems face challenges in manufacturing complexity and wear minimization while detecting high-resolution angular and axial movements due to small size and the need for precise coding patterns for galvanic detection.

Innovation Solution

A diagonal coding pattern on the timepiece setting stem, comprising axial and angular detection encoded rings, allows for easier manufacturing with fewer machining operations and reduced wear through a sensor arrangement that uses conducting and insulating sections for galvanic detection, enabling precise axial and angular position sensing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional coding patterns are used on timepiece setting stems, then galvanic detection of axial and angular positions is achieved, but manufacturing complexity increases and wear is minimized only with difficulty

Engineering Contradiction:
Improvedetection precisionVSAvoidmanufacturing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The coding pattern is segmented into multiple independent circumferential rings, each encoding specific position information. This segmentation allows each ring to be manufactured and positioned independently, simplifying the overall manufacturing process while maintaining high detection precision through the combined information from multiple rings.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A non-conductive coating is applied as an intermediary layer on the setting stem, with conductive traces patterned on top to form the coding pattern. This intermediary approach allows the coding pattern to be created through printing or deposition processes rather than direct machining, reducing manufacturing complexity while enabling precise galvanic detection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If high-resolution detection is achieved through detailed coding patterns, then measurement precision improves, but manufacturing difficulty increases due to small stem size

Engineering Contradiction:
Improveangular and axial detection resolutionVSAvoidmanufacturing ease
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The mechanical machining process is replaced with a deposition or printing process for creating the coding pattern. Instead of mechanically removing material to create conductive traces, the pattern is formed by depositing conductive material onto the stem surface, which is much easier to control for high-resolution features on small diameters.

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

Solution Approach 2:

The manufacturing approach changes from mechanical subtraction to material addition/deposition. This parameter change enables the creation of fine, high-resolution coding patterns on the small-diameter stem without the limitations of mechanical tool access and material removal precision.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If galvanic detection is used for axial and angular position sensing, then reliable detection is achieved, but wear occurs in the sensor arrangement

Engineering Contradiction:
Improvedetection reliabilityVSAvoidsensor arrangement lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The detection method changes from direct continuous galvanic contact to a coded pattern recognition system. The conductive traces on the stem form a unique pattern that sensors can detect and decode to determine position without requiring sustained heavy galvanic contact, thereby reducing wear while maintaining reliable detection through pattern identification.

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 diagonal coding pattern simplifies the manufacturing process, reduces wear, and enables precise detection of axial and angular positions with improved resolution, facilitating efficient operation of timepiece functions.

Implementation Method 1

a sensor arrangement that uses conducting and insulating sections for galvanic detection, enabling precise axial and angular position sensing

Methodology Applied
Scientific EffectGalvanic detection: Conduction (electrical)

Data Source

PatentEP3015926B1Timepiece crown stem with a coding pattern
Publication Date: 2021.04.28 THE SWATCH GRP RES & DEVELONMENT LTD
  • EP3015926B1 patent drawingFigure 1
  • EP3015926B1 patent drawingFigure 2a~2b
  • EP3015926B1 patent drawingFigure 3

AI summary

The present invention concerns a method of making an encoding pattern (3) on a timepiece setting stem (1) for detecting an axial and/or angular movement and/or position of the setting stem (1). The method comprises providing the surface of a shaft (5) of the setting stem (1) with a first section (A) having first material properties and a second section (B) having second material properties to form the encoding pattern (3), where the first and second material properties are at least partially different from each other. The first section (A) comprises a strip (S) extending diagonally on the surface of the shaft (5).