Adjustable Link Mechanism for Tool-Free Bracelet Sizing

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Solution Overview

Problem

Existing adjustable bracelet mechanisms require tools for adjustment and are aesthetically unappealing due to their transverse design, which affects the compactness and user experience.

Innovation Solution

An adjustable link mechanism comprising a first and second half-link with transverse locking means and elastic return elements, allowing for discrete position changes without tools, where the connecting and locking member is a tubular element that expands orthogonally and is housed in the first half-link, enabling concealed adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If transverse locking means are used for adjustable link mechanism, then locking reliability is improved, but device complexity and visibility increase

Engineering Contradiction:
Improvelocking reliabilityVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is segmented into discrete locking positions along the bracelet direction, with locking means that can independently engage at specific intervals. This allows reliable locking at predetermined positions while simplifying the overall mechanism structure and reducing visibility of the locking components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking means are arranged to operate primarily in the bracelet direction (longitudinal axis) rather than transversely. The locking surfaces and engagement features are oriented along the length of the bracelet, allowing the link to lock reliably in the adjustment direction while minimizing transverse protrusions and visual complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If transverse locking means are used for adjustable link mechanism, then locking reliability is improved, but aesthetic appearance deteriorates

Engineering Contradiction:
Improvelocking reliabilityVSAvoidaesthetic appearance
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The locking mechanism is reoriented to operate along the longitudinal axis of the bracelet rather than transversely. The locking surfaces, engagement features, and actuating elements are all aligned with the bracelet direction, making the mechanism invisible from the front view and preserving aesthetic appearance while maintaining locking reliability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The locking features are designed with different visual characteristics - the locking surfaces and engagement elements are flush with or recessed into the bracelet link surfaces, while only minimal actuating elements are visible. This local differentiation allows reliable locking functionality while maintaining smooth, continuous aesthetic appearance of the bracelet.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If tool-free adjustment is implemented, then ease of operation is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveadjustment easeVSAvoidlocking position precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The locking positions are pre-defined by precision-machined reference surfaces and guide features during manufacturing. The actuating elements are pre-positioned to engage these reference surfaces at specific intervals, ensuring accurate locking positions are achieved automatically during tool-free adjustment without requiring high precision during the adjustment operation itself.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The adjustment mechanism is designed to be self-aligning and self-locking. The guide surfaces and locking features automatically position the link at the correct discrete positions when actuated, eliminating the need for external tools or complex precision control during operation. The mechanism itself ensures accurate positioning through its inherent geometric constraints.

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

Enables compact, tool-free adjustment of bracelet length while maintaining aesthetics by allowing relative position changes between half-links, ensuring secure locking positions and easy adjustment without visible mechanisms.

Implementation Method 1

said locking means or/and said locking means complementary are movable, under the action of a force exerted in said bracelet direction and greater than a given value, against elastic return means comprising respectively said complementary locking means and/or said locking means

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2759222B1Adjustable link
Publication Date: 2015.12.09 OMEGA SA
  • EP2759222B1 patent drawingFigure 1~6
  • EP2759222B1 patent drawingFigure 7~12
  • EP2759222B1 patent drawingFigure 13~18

AI summary

The link (1) has a half-link (2) comprising a connection and locking element with a locking unit, and another half-link (3) comprising a complementary locking unit. The locking unit and/or the complementary locking unit are movable under action of an effort exerted according to direction (D) of strap and greater than a given value, against an elastic return unit. The return unit includes the complementary locking unit and/or the locking unit to authorize a change of relative position between the half-links according to the direction. Independent claims are also included for the following: (1) a strap (2) a watch.