Wristwatch Hold-down Member Anti-rotation Design

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Solution Overview

Problem

Existing wristwatch designs face challenges in preventing the rotation of the timepiece module when attaching the back cover, which can lead to mispositioning of the timepiece module and hinder the integration of additional functions like piezoelectric elements due to the placement of slick members on the back cover.

Innovation Solution

A hold-down member with a two-layer structure comprising a rigid supporting member and highly slick resin sheets, where the resin sheets are adhered to the supporting member and pressed against the back cover, reducing frictional resistance and allowing smooth sliding while preventing the timepiece module from rotating during back cover attachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a slick member is placed on the back cover to prevent rotation of the timepiece module, then the timepiece module positioning is improved, but additional functions like piezoelectric elements cannot be integrated due to space occupation

Engineering Contradiction:

Improvetimepiece module positioning accuracyVSAvoidintegration of additional functions

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The slick member is extracted from the back cover and relocated to the hold-down member. This extraction frees up space on the back cover, allowing piezoelectric elements and other functional components to be integrated, while the hold-down member continues to provide the necessary anti-rotation function through its slick surface that contacts the back cover.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The hold-down member acts as an intermediary carrier that combines both the holding function and the slick surface function. Instead of placing the slick member directly on the back cover, the hold-down member serves as a mediator that transfers the anti-rotation contact to the back cover while freeing up space for additional functionalities.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If the back cover is rotated to attach to the wristwatch case, then the back cover attachment is achieved, but the timepiece module rotates and becomes mispositioned

Engineering Contradiction:

Improveback cover attachmentVSAvoidtimepiece module positioning

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The hold-down member with the slick member pre-applies a counteracting force against the rotational movement. When the back cover is rotated for attachment, the slick surface of the hold-down member creates frictional resistance that counteracts the rotational force, preventing the timepiece module from rotating and becoming mispositioned.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The slick member changes the friction parameter between the hold-down member and the back cover. By providing a slick surface with controlled friction characteristics, it allows the back cover to be attached while preventing unwanted rotation of the timepiece module, thus maintaining positioning accuracy during the attachment process.

Inventive Principle:

Principle #35Parameter changes

3Strength

If a rigid hold-down member is used to support the timepiece module, then structural strength is improved, but frictional resistance increases and prevents smooth sliding

Engineering Contradiction:

Improvehold-down member structural strengthVSAvoidsmooth sliding during attachment

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The hold-down member combines a rigid supporting structure with a slick surface layer. The rigid base provides the necessary structural strength to support the timepiece module, while the slick member (made of low-friction material) provides the smooth sliding surface that contacts the back cover, reducing frictional resistance during attachment.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The hold-down member has different local qualities: the main body is rigid for structural support, while the surface contacting the back cover is made slick with low friction characteristics. This local differentiation allows the hold-down member to simultaneously provide structural strength and smooth sliding capability.

Inventive Principle:

Principle #3Local quality

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 solution ensures accurate positioning of the timepiece module within the wristwatch case, simplifies assembly, and enables the integration of additional functions like piezoelectric elements by reducing frictional loads and preventing the hold-down member from rotating with the back cover.

Implementation Method 1

highly slick resin sheets, where the resin sheets are adhered to the supporting member and pressed against the back cover, reducing frictional resistance and allowing smooth sliding

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS20220413441A1Hold-down member, manufacturing method for same and timepiece

Publication Date: 2022.12.29 CASIO COMPUTER CO LTD

AI summary

A hold-down member including a plate member which is arranged on a first member having an electronic component and supports the first member, and a resin sheet which is adhered to the plate member, pressed by a second member that is arranged to be rotatable with respect to the first member, and slides on the second member.