Watch Dial with Peripheral and Central Mechanical Fixing

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Solution Overview

Problem

Watch dials made of fragile materials are highly sensitive to mechanical stress, prone to breaking or cracking upon impact, and existing methods of fixation do not adequately address shock resistance, failing to meet quality standards like NIHS_91-10.

Innovation Solution

A dial design featuring a cover plate and support plate fixed peripherally and centrally with removable fastening members, eliminating the need for gluing and allowing for reduced mechanical stress, enabling the use of fragile materials and simplifying manufacturing, while allowing for aesthetic modifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the dial is made of fragile material (mother-of-pearl, stone, ceramic, glass), then aesthetic appearance is improved, but shock resistance deteriorates

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidshock resistance
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The dial is divided into two separate plates: a fragile aesthetic cover plate and a resilient support plate. The cover plate provides the desired aesthetic appearance while the support plate absorbs mechanical shocks, preventing the fragile material from breaking. This segmentation allows each component to fulfill its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dial assembly combines two different materials with complementary properties: a fragile aesthetic material (mother-of-pearl, stone, ceramic, or glass) for the cover plate and a resilient material for the support plate. This composite structure allows the fragile material to provide aesthetic value while the resilient material provides shock resistance, resolving the contradiction between appearance and durability.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If the dial is fixed using gluing method, then manufacturing simplicity is improved, but shock resistance deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidshock resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention replaces the chemical bonding method (gluing) with a mechanical fastening system using peripheral fixing members (screws or clips) and central fixing members. This mechanical system provides superior shock resistance compared to gluing, while still maintaining manufacturing simplicity through standardized fastening components that are easy to install and remove.

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

3Reliability

If the cover plate is mechanically fixed at periphery and center, then shock resistance is improved, but device complexity increases

Engineering Contradiction:
Improveshock resistanceVSAvoidfixing mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fixing mechanism is segmented into two distinct functional zones: peripheral fixing members located at the edges and central fixing members at the center. This segmentation allows each fixing element to be optimized for its specific location and load requirements, while the overall structure remains relatively simple with just two types of fixing components needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The peripheral and central fixing members are designed as universal components that can be applied to various dial sizes and configurations. The peripheral fixing members can accommodate different patterns (radial, circumferential, or combinations), and the central fixing members provide a standardized centering solution, reducing overall device complexity through component standardization.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Adaptability or versatility

If the fixing members are made removable, then adaptability is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveaesthetic modification capabilityVSAvoidfastening precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The fixing members are designed with dynamic characteristics that allow for easy assembly and disassembly. The peripheral fixing members can be screwed in or clipped on, and the central fixing members can be inserted and locked, providing adaptability for aesthetic modifications while maintaining reasonable manufacturing precision through tolerance-designed interfaces that accommodate normal assembly variations.

Inventive Principle:
Principle #15Dynamics

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 significantly reduces deformation of the cover plate during impacts, enhances shock resistance, and simplifies the manufacturing process, enabling the use of fragile materials while allowing for interchangeable aesthetic designs.

Implementation Method 1

an elastic tab bent relative to said bearing surface and separated from said pin by a space forming an interstice in which a radial projection of the covering plate is engaged, said elastic tab being able to be elastically deformed by said radial projection when it is engaged in the interstice

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4109181A1Dial, watch comprising such a dial and method for installing such a dial in a watch
Publication Date: 2022.12.28 ETA SA MFG HORLOGERE SUISSE
  • EP4109181A1 patent drawingFigure 1
  • EP4109181A1 patent drawingFigure 2~3
  • EP4109181A1 patent drawing

AI summary

The invention relates to a dial comprising a cover plate (11) intended to be visible to a user, resting on a bearing surface (120) of a support plate (12) on which it is superimposed, the cover plate (11) and the support plate (12) being fixed to each other at their periphery by the cooperation of peripheral fixing members which they both comprise, and at their center by the cooperation of central fixing members which they both comprise.