Wristwatch Clasp Length Adjustment Mechanism

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Solution Overview

Problem

Conventional wristwatch clasps face challenges in fine adjustment, aesthetics, and functionality, including the risk of external objects catching on pushers, increased thickness, weight, and visibility of adjustment mechanisms, which affect comfort and appearance.

Innovation Solution

A folding clasp design with articulated blades, a locking mechanism, and a length adjustment device that allows for precise adjustment without a separate actuating member, integrating the adjustment mechanism into the clasp's structure to reduce thickness and visibility, using a manipulation member to unlock the locking mechanism and enable length adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a separate actuating member is used for length adjustment, then the adjustment function is clear and operable, but the thickness and visibility of the clasp increases

Engineering Contradiction:
Improveadjustment operationVSAvoidclasp thickness
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The patent combines the actuating member with the manipulation member of the locking mechanism into a single integrated component. This merging eliminates the need for a separate actuating member, thereby reducing clasp thickness and improving aesthetics while maintaining the length adjustment function through the same integrated component.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The manipulation member serves dual functions: it operates the locking mechanism to secure the clasp and simultaneously acts as the actuating member to enable length adjustment. This multi-functionality reduces the number of components and minimizes clasp thickness while preserving both locking and adjustment operations.

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

2Ease of operation

If the adjustment mechanism is made visible and accessible, then the adjustment function is easily accessible, but the aesthetic appearance is compromised

Engineering Contradiction:
Improveadjustment accessibilityVSAvoidaesthetic appearance
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

By merging the actuating member with the manipulation member that is already part of the clasp's external structure, the adjustment function becomes accessible through an existing aesthetic element. This integration allows users to operate the adjustment function without compromising the clasp's visual design, as the manipulation member is already positioned for both aesthetic and functional purposes.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If a projection is added for adjustment actuation, then the adjustment function is enhanced, but the risk of catching on external objects increases

Engineering Contradiction:
Improveadjustment actuationVSAvoidcatching on external objects
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent merges the actuating function with the existing manipulation member, avoiding the addition of separate projections that could catch on external objects. The manipulation member's existing structure is utilized for both locking and adjustment actuation, eliminating the need for additional protruding elements that would increase the risk of catching on clothing or other external objects.

Inventive Principle:
Principle #5Merging (Combining)

4Weight of moving object

If the clasp structure is simplified, then the weight is reduced, but the adjustment precision may be compromised

Engineering Contradiction:
Improveclasp weightVSAvoidlength adjustment precision
Core Design Contradiction:
Weight of moving objectVSMeasurement precision

Solution Approach 1:

By integrating the actuating member with the manipulation member, the patent reduces the quantity of materials and components, thereby reducing clasp weight. The precision of length adjustment is maintained through the existing fine adjustment mechanism's design, which uses a carriage system with notching to define discrete length positions, ensuring accurate adjustment despite the simplified structure.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3641584B1Bracelet clasp comprising a device for adjusting the length of the bracelet
Publication Date: 2022.03.16 DEXEL SA
  • EP3641584B1 patent drawingFigure 1~3B
  • EP3641584B1 patent drawingFigure 4~5
  • EP3641584B1 patent drawingFigure 6A~8

AI summary

The invention relates to a band clasp (10, 100, 200, 300), particularly a wristwatch band clasp, including a device (4) for finely adjusting the length of the band. The adjustment device is preferably arranged on a central support structure so as to emerge from a free end of the latter. A latching mechanism (3) is designed such that the activation of a manipulation member (7, 7') causes the movement of a part of the fine adjustment device, so as to unlock a moving part (5) and allow the adjustment of the useful length of the band.