Watch Indexing Device Radial Thrust Mechanism

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Solution Overview

Problem

Horological display mechanisms, such as second time zone displays, face challenges with bulky jumping time/zone wheels and spring elements that are pushed to their limits, leading to non-reproducible force variations due to dimensional variations during production, affecting precise indexing.

Innovation Solution

An indexing device with a coupling member and an indexing member featuring a radial thrust force mechanism, utilizing two elastic arms to provide controlled and reproducible thrust forces, reducing stress on elastic elements and minimizing the effects of production variations, while maintaining a compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If spring elements are pushed to their maximum to ensure winding and operation, then the thrust force is sufficient, but the dimensional variations during production lead to significant force variations that are not reproducible

Engineering Contradiction:
Improvethrust forceVSAvoidforce reproducibility
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The patent changes the physical parameters of the elastic arms by optimizing their geometry (length, cross-section, material properties) to provide sufficient thrust force while maintaining reproducibility. The elastic arms are designed with specific dimensional parameters that can be precisely controlled during manufacturing, unlike overstressed spring elements whose forces vary significantly with minor dimensional changes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent divides the single spring element into multiple separate elastic arms (typically three arms arranged at 120 degrees). This segmentation allows each arm to be independently optimized and manufactured with precise dimensional control, resulting in more reproducible and consistent thrust forces compared to a single overloaded spring element.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If a coupling member with multiple boards/pinions and a star/cam is used to link moving parts, then the indexing function is achieved, but the mechanism has a large bulk

Engineering Contradiction:
Improveindexing functionVSAvoidmechanism volume
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The patent combines multiple functions into integrated components. The coupling member integrates the indexing function, the thrust application, and the linkage between first and second mobiles into a single compact structure. The elastic arms are directly formed as part of the coupling member, eliminating the need for separate spring elements and reducing overall mechanism volume.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs a nested arrangement where the elastic arms are positioned within the coupling member structure, and the indexing relief features are integrated into the indexing member. This nesting allows multiple components to occupy overlapping or adjacent spaces, significantly reducing the overall volume of the indexing mechanism while maintaining full functionality.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 achieves precise and reliable indexing with increased thrust force in a reduced volume, addressing the issues of bulkiness and force variability in existing systems.

Implementation Method 1

The first elastic arm is configured to exert a substantially radial thrust force with respect to the indexing axis, on the indexing part against the indexing relief

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The jumper element comprises a second elastic arm, extending after the indexing part and configured to cooperate with the profile element in order to exert an additional thrust force, substantially radial with respect to the axis indexing, on the indexing part against the indexing relief, the thrust force increasing when the indexing part passes from a hollow to a peak

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4180882A1Indexing device for a timepiece mechanism
Publication Date: 2023.05.17 SOPROD SA
  • EP4180882A1 patent drawingFigure 1~2
  • EP4180882A1 patent drawingFigure 3
  • EP4180882A1 patent drawingFigure 4

AI summary

The present invention relates to a watch indexing device (1) comprising a first moving part (10) for providing a first indication, a second moving part (20) for providing a second indication, an indexing member (30) having an indexing relief (31), and a coupling member (40) cooperating with the indexing member (30) so as to couple the first moving part (10) with the second moving part (20). The coupling member (40) has a jumping element (41) having an indexing portion (43) cooperating with the indexing relief (31), and a first elastic arm (42) exerting a pushing force on the indexing portion (43) against the indexing relief (31). The coupling member (40) is further provided with a profile element (47).The jumping element (41) has a second elastic arm (44) configured to cooperate with the profile element (47) in order to exert an additional pushing force on the indexing part (43) against the indexing relief (31).