Watch Clasp Locking Structure to Prevent Push-Button Misoperation

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Solution Overview

Problem

Existing clasp designs, such as the push clasp in JP-A-9-56425, suffer from issues where the lock member can be erroneously moved to a position where the push operation is restricted, leading to the engagement portion and engagement pin being unable to engage, requiring reoperation to secure the clasp.

Innovation Solution

A clasp design featuring a coupling member with an engagement member that can engage or release without operating an operation member, and a lock member that moves to restrict or permit operation, ensuring engagement can be maintained without unintended release, even under external forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lock member is added to restrict push operation, then reliability is improved, but device complexity increases

Engineering Contradiction:

Improveprevention of unintended releaseVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The lock member is integrated with the push button assembly such that the lock member and push button share a common structural framework. The lock member includes a locking protrusion that engages with a locking groove on the push button, creating a unified locking mechanism that prevents unintended release while maintaining operational simplicity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The lock member is positioned within the clasp body structure, with the locking protrusion nested inside the clasp cavity. The lock member can move between a locked position where it engages the push button and an unlocked position where it allows operation, creating a compact nested arrangement that adds functionality without significantly increasing external dimensions.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Reliability

If the lock member restricts push operation, then reliability is improved, but ease of operation deteriorates

Engineering Contradiction:

Improveprevention of unintended releaseVSAvoidoperation convenience

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The lock member is automatically engaged with the push button when the clasp is closed and the push button is in its normal position. This preliminary locking action occurs without requiring user intervention, ensuring that the clasp is secured against unintended release before any external forces are applied. The user only needs to intentionally press the push button to disengage the lock member when opening the clasp.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The lock member is designed to be dynamically movable between a locked position and an unlocked position. When the push button is pressed, the lock member automatically transitions from the locked position to the unlocked position, allowing the push button to move freely. This dynamic behavior ensures that the locking mechanism adapts to the operational state of the push button without requiring separate control mechanisms.

Inventive Principle:

Principle #15Dynamics

3Ease of operation

If the engagement member can engage without operating the operation member, then ease of operation is improved, but reliability deteriorates

Engineering Contradiction:

Improveengagement convenienceVSAvoidprevention of erroneous state

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The clasp mechanism is segmented into distinct functional components: the engagement member for closing the clasp, the push button for releasing the clasp, and the lock member for preventing unintended release. The engagement member can engage with the clasp body without operating the push button, while the lock member remains in its locked position. This segmentation allows independent engagement functionality while maintaining reliable protection against unintended release through the separate lock member mechanism.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS20250375001A1Clasp and timepiece

Publication Date: 2025.12.11 SEIKO EPSON CORP

AI summary

A clasp includes a coupling member having an engaged portion and a clasp main body, in which the clasp main body includes an engagement member, an operation member, and a lock member, the engagement member is configured to be engaged with an engaged portion without operating the operation member in a state where the engagement member is not engaged with the engaged portion, an engagement is released by moving the engagement member to a release position by the operation member in a state where the engagement member is engaged with the engaged portion, and when the lock member is moved to the operation restriction position, the engagement member is restricted from being moved to the release position by the operation member.