Folding Clasp with Simultaneous Pusher Unlocking

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Solution Overview

Problem

Existing folding clasps for watch straps require a two-stage unlocking process, making it difficult for wearers to unlock the clasp, and there is a risk of inadvertent unlocking.

Innovation Solution

A folding clasp design featuring a fixed blade with two articulated folding blades and pushers that, when pressed simultaneously, pivot to unlock both blades in a single operation, ensuring secure locking and easy unlocking by covering the pushers' shoulders to prevent accidental deployment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a two-stage unlocking process is used (pivoting pusher then manually disengaging male component), then the clasp can be securely locked, but the unlocking operation becomes difficult to implement for the wearer

Engineering Contradiction:
Improvesecure lockingVSAvoidunlocking operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent combines the pusher pivoting action with the male component disengagement into a single simultaneous operation. The pusher is designed with an inclined surface that, when pivoted, automatically pushes the male component away from the female component while maintaining engagement until the final release moment, merging two separate actions into one unified motion that is both secure and easy to operate

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pusher is pre-positioned and spring-loaded to automatically perform the disengagement action as soon as it is pivoted. The return spring stores energy that is released to automatically push the male component away, eliminating the need for the wearer to manually disengage it after pivoting the pusher, thus preparing the mechanism in advance to complete the unlocking action

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the pusher can be easily pivoted for unlocking, then the operation is simple, but the risk of inadvertent unlocking increases

Engineering Contradiction:
Improveunlocking simplicityVSAvoidinadvertent unlocking prevention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The pusher features a curved or inclined surface that requires a specific pivoting motion to engage the unlocking mechanism. This curved geometry ensures that accidental linear movements or minor disturbances cannot trigger unlocking, as the pusher must be deliberately pivoted along its curved path to release the spring energy and disengage the male component

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The return spring is pre-loaded in a compressed state that exerts a continuous counter-force on the pusher, creating a preliminary opposing force that must be overcome by intentional user action. This pre-applied elastic force acts as a barrier against inadvertent unlocking while still allowing easy unlocking when the user deliberately applies force to pivot the pusher

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If a complex unlocking mechanism is used to prevent accidental unlocking, then security is improved, but the device complexity increases

Engineering Contradiction:
Improveaccidental unlocking preventionVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pusher serves multiple functions simultaneously: it acts as a locking lever, a spring-loaded actuator, an inclined plane for force transmission, and a user interface element. By making the pusher multi-functional, the patent achieves reliable accidental unlocking prevention without adding separate components, thus maintaining simplicity while improving security

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

Solution Approach 2:

The return spring automatically performs the work of pushing the male component away from the female component after the pusher is pivoted. The spring stores energy during locking and releases it during unlocking, making the system self-actuating and eliminating the need for additional actuators or complex mechanisms to complete the unlocking sequence

Inventive Principle:
Principle #25Self-service

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 clasp facilitates easy and secure single-stage unlocking by requiring simultaneous pressure on both pushers, preventing accidental unlocking and reducing the complexity of the mechanism, while maintaining a compact design with fewer parts.

Implementation Method 1

a force exerted on said folding blade essentially parallel to the axis pivoting of the pusher and directed towards the fixed blade causes the pivoting of the pusher by a first amplitude bringing said pusher into a first position where the second unfolding blade is no longer in abutment against said pusher and can be completely folded down on the fixed blade and so that the pusher returned from said first position to its initial rest position by the elastic return force prevents any movement of the second folding slat relative to the fixed slat

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP2524613B1Clasp with extensible loop
Publication Date: 2014.04.09 BOUCLEDOR
  • EP2524613B1 patent drawingFigure 1
  • EP2524613B1 patent drawingFigure 2~3
  • EP2524613B1 patent drawingFigure 4a~4c

AI summary

The clasp has a first and second mobile blades (2, 3) arranged such that the second blade covers the first blade when the mobile blades are folded on a fixed blade (1). A push-button (7) has unlocking units arranged such that the second blade covers a portion of the first blade and is locked by the push-button when the mobile blades are folded. The units cooperate with the first blade to lift and space the fixed blade that drives the second blade with it, to release the second blade from locking action of the push-button when the push-button is pivoted against action of a return spring (71). The return spring is an edge spring.