Folding Clasp with Conical Roller Locking Mechanism

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Solution Overview

Problem

Conventional folding clasps for bracelets, such as those described in CH 676 415 and DE19620838, face issues with fragility and wear resistance, particularly at the tip of the beak and bars, while requiring specific elasticity and sliding mechanisms for closure, which can be fragile and difficult to produce in a variety of materials.

Innovation Solution

A folding clasp design featuring a fixed blade with articulated folding blades and locking means comprising rigid rollers with conical portions and an elastic element, where the rollers pivot and slide on an axis, using shoulders to engage with the conical portions to lock the blades in place, ensuring secure folding and unfolding without excessive force or wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional spouts and bars are used for locking, then the clasp can be folded and locked, but the tip of the beak and bars exhibit fragility and lower wear resistance

Engineering Contradiction:
Improvewear resistanceVSAvoidfragility of beak tip and bars
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention extracts the locking function from the fragile beak tip and bar components and transfers it to a dedicated roller mechanism with conical portion and shoulder. The roller assembly handles all locking and unlocking forces, allowing the beak tip to serve only its aesthetic and guiding functions without bearing mechanical loads that cause wear and fragility.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of having the beak tip engage directly with the bar for locking, the invention inverts the mechanism by using a roller with conical portion that engages with a shoulder on the blade. The locking action is reversed: rather than the beak pushing against a bar, the roller's conical surface is pushed by the shoulder, which then rotates the roller to engage or disengage the locking position.

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of operation

If elastic elements are used to provide necessary elasticity for movable blades, then the blades can pivot and close the clasp, but the elastic elements and sliding mechanisms become fragile and difficult to produce in various materials

Engineering Contradiction:
Improveelasticity for blade movementVSAvoiddifficulty in production and material selection
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The invention introduces a roller with conical portion as an intermediary between the elastic element and the blade structure. This mediator allows the elastic element to simply push the roller along its axis without requiring complex sliding mechanisms or pivoting joints. The roller converts linear elastic force into rotational motion, simplifying the overall mechanism and making it easier to manufacture in various materials including ceramics and precious metals.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the roller moves on the axis against the elastic element, then the blade can be completely folded and locked securely, but the mechanism requires precise positioning and constraint

Engineering Contradiction:
Improvesecure lockingVSAvoidprecise positioning of roller
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The conical portion of the roller works in conjunction with the shoulder to create a self-positioning mechanism. As the elastic element pushes the roller along the axis, the conical surface naturally guides the roller's movement and rotation. The geometry of the conical portion and shoulder ensures that the roller automatically positions itself correctly without requiring external alignment or complex constraint mechanisms, achieving secure locking through self-alignment.

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 provides a safe, effective, and aesthetically pleasing solution with enhanced wear resistance, ease of use, and adaptability to various materials, ensuring secure locking and unlocking mechanisms while minimizing material constraints.

Implementation Method 1

an elastic element corresponding binding said at least one roller in a first position on the axis

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2813157B1Clasp with extensible loop
Publication Date: 2016.05.18 BOUCLEDOR
  • EP2813157B1 patent drawingFigure 1
  • EP2813157B1 patent drawingFigure 2
  • EP2813157B1 patent drawingFigure 3a~3b

AI summary

The present invention relates to a folding clasp for a bracelet comprising a fixed blade (1), at least one first folding blade (2) hinged to a first end of the fixed blade (1), and means for locking the first folding blade (2) in the folded position on the fixed blade (1). The locking means comprise at least one rigid roller (5) pivotally and slidingly mounted on an axis (7) fixed essentially transversely on one of the fixed blades (1) or the first folding blade (2), and a corresponding elastic element (8) constraining the roller (5) in a first position on the axis (7), and at least one corresponding shoulder (23) carried by the other of the fixed blade (1) or the first folding blade (2) and intended to cooperate with the roller (5). Said roller (5) has a conical portion (51).The shoulder (23) and the conical portion (51) of the corresponding roller (5) are shaped so that when the first folding blade (2) is folded over the fixed blade (1), the shoulder (23) comes into contact with the roller (5) and in particular with the conical portion (51), and so that a force exerted on the first folding blade (2) essentially perpendicular to the axis (7) and directed towards the fixed blade (1) causes the roller (5) to move along the axis (7) against the action of the corresponding elastic element (8), the roller (5) being constrained by the corresponding shoulder (23) cooperating with the conical portion (51) of the roller (5), into a second position in which the corresponding shoulder (23) is no longer in contact with the conical portion (51), the first folding blade (2) being able to be completely folded over the fixed blade (1).The said roller (5) is then returned to its first position by the corresponding elastic element (8) to retain the first folding blade (2) and prevent any movement of the latter relative to the fixed blade.