Watch Case End-Piece Assembly for Fewer Fasteners and Impact Absorption

Solution Overview

Problem

Existing arm-wearable devices, such as wristwatches, require multiple fixing members to secure the end pieces to the case, which increases complexity and cost, and do not effectively distribute impact forces during drops.

Innovation Solution

A novel assembly method where the case body, frame member, and exterior member are integrated using fewer parts, with the frame member being held between the case body and exterior member, and the end pieces are securely attached to the frame member using a wave-shaped design and protrusions, allowing for impact absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple fixing members are used to secure end pieces to the case, then the attachment reliability is improved, but the device complexity and production cost increase

Engineering Contradiction:

Improveattachment reliabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple fixing members into a single integrated fixing member that extends through the case body and secures both end pieces simultaneously. This merging reduces the total number of parts while maintaining secure attachment of all components to the case.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single fixing member serves multiple functions: it secures the first end piece, secures the second end piece, and provides a mounting structure for the indicator. This multi-functionality eliminates the need for separate fixing members for each component.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If multiple fixing members are used to secure end pieces to the case, then the attachment reliability is improved, but the production cost increases

Engineering Contradiction:

Improveattachment reliabilityVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines multiple fixing members into a single integrated fixing member that extends through the case body and secures both end pieces simultaneously. This merging reduces the total number of parts while maintaining secure attachment of all components to the case.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single fixing member serves multiple functions: it secures the first end piece, secures the second end piece, and provides a mounting structure for the indicator. This multi-functionality eliminates the need for separate fixing members for each component.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If traditional fixing methods are used, then the structure is simple, but the impact resistance is insufficient

Engineering Contradiction:

Improvestructure simplicityVSAvoidimpact resistance

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The wave-shaped portion of the frame member is designed to deform elastically during impact events, absorbing shock energy before it can damage other components. This pre-designed deformation path provides impact protection while maintaining structural integrity.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The frame member's wave-shaped geometry changes its mechanical properties, allowing it to deform elastically under impact loads. This geometric parameter change enables energy absorption through controlled deformation rather than rigid fracture.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20260064081A1Arm-wearable device, timepiece, end piece, and method of making arm-wearable device

Publication Date: 2026.03.05 CASIO COMPUTER CO LTD

AI summary

An arm-wearable device includes: a cylindrical case body extending in a first direction; a frame member disposed at one side in the first direction of the case body; and an exterior member disposed at the one side of the frame member. The case body and the exterior member are fixed by a fixing member. At least part of the frame member is held between the case body and the exterior member, so that the frame member is fixed.