Bracelet Clasp With Telescopic Rack Adjustment

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Solution Overview

Problem

Existing bracelet clasps require disassembly or addition/removal of links for length adjustment, which is inconvenient and not suitable for subtle changes in wrist size due to temperature variations, and often necessitates tools, affecting aesthetics and precision.

Innovation Solution

A bracelet clasp with a device comprising telescopic bars, fixing rods, and a movable element with a rack and pin system that allows for easy and precise length adjustment without disassembly, using push buttons and springs to unlock and fold branches for adjustment, ensuring the mechanism is concealed and does not compromise aesthetics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional bracelet clasps are used, then the bracelet structure is simple and aesthetic, but the length adjustment requires disassembly or adding/removing links which is complex and requires tools

Engineering Contradiction:
ImproveLength adjustment operationVSAvoidClasp mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The adjustment device is nested within the clasp structure, with the movable element sliding within the cover and the branches folded within the clasp body. The telescopic bars are housed within the cover structure, creating a compact integrated design that maintains aesthetic appearance while enabling adjustment functionality.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The clasp incorporates movable elements that can slide along the rack, branches that can fold relative to each other, and telescopic bars that can extend and retract. These dynamic components enable length adjustment without disassembly, transforming the static clasp into an adjustable mechanism.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If links are added or removed for adjustment, then the bracelet length can be changed, but the operation requires dexterity and tools and affects aesthetics

Engineering Contradiction:
ImproveBracelet length adaptabilityVSAvoidAdjustment operation ease
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The bracelet is divided into adjustable segments through the movable element that can slide to different positions on the rack, and the branches that can fold to different configurations. This segmentation allows continuous length adjustment rather than discrete link additions or removals.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The movable element with rack and pinion acts as an intermediary mechanism between the user's adjustment action and the final bracelet length change. The telescopic bars and folding branches serve as intermediate components that translate simple button pressing into precise length adjustment.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the adjustment device is visible, then the adjustment function is accessible, but the aesthetic appearance of the bracelet is compromised

Engineering Contradiction:
ImproveAdjustment accessibilityVSAvoidBracelet aesthetic appearance
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

All adjustment components including the movable element, rack, telescopic bars, and branches are nested within the cover and clasp structure. The cover conceals the mechanical elements while push buttons remain accessible on the exterior, maintaining aesthetic appearance while enabling operation.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The cover is designed with selective transparency or opening only where necessary for button access, while the majority of the adjustment mechanism remains concealed. This localized exposure maintains overall aesthetic appearance while providing operational accessibility.

Inventive Principle:
Principle #3Local quality

4Reliability

If the clasp is made secure with locking mechanisms, then reliability is improved, but the ease of opening and adjustment is reduced

Engineering Contradiction:
ImproveClasp securityVSAvoidClasp opening ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The retaining means automatically engage with the locking pin to secure the clasp without user intervention. The elastic element provides automatic locking action, and the push buttons provide self-contained release mechanisms that do not require external tools or complex operations.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The elastic element replaces complex mechanical locking systems with a simpler spring-based retention mechanism. The push buttons substitute for manual manipulation of multiple locking components, providing a single-action release system that maintains security while improving ease of operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enables fine and easy adjustment of bracelet length without tools, maintaining aesthetic appeal and preventing accidental dismantling, adapting to subtle changes in wrist size without altering the bracelet's appearance.

Implementation Method 1

Two push buttons 17 are placed in through openings 18 of the side walls 4 of the cover 2 and are accessible by a user regardless of the position of the clasp. On pressing these push buttons 17 against the action of an elastic force, exerted for example by springs 19, the retaining means 16 release the locking pin 12

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP2361523B1Clasp for bracelet
Publication Date: 2014.06.25 WINOX SA
  • EP2361523B1 patent drawingFigure 1
  • EP2361523B1 patent drawingFigure 2a~2b
  • EP2361523B1 patent drawingFigure 3

AI summary

The device has a cover (2) attached to a link point (10a) of a strap (1) and including two sidewalls (4) extending in an axis of the strap. A mobile element (20) i.e. sling, is attached to another link point (10b) of the strap. The cover comprises a closed rack on internal surfaces of the walls. The rack comprises notches in which pins (26) of the element slide, where positions of the element with respect to the cover are determined by the notches. An elastic component i.e. spring stop (30), moves the element along direction of bottom of the notches for blocking the pins in the notches.