Watch Strap Clasp Notching Adjustment Mechanism

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Solution Overview

Problem

Existing watch strap clasps, particularly those with folding mechanisms, do not allow for easy adjustment of bracelet length to accommodate varying wrist sizes due to temperature changes or activity levels, and existing adjustment systems are complex or prone to inadvertent misadjustment, leading to discomfort and risk of losing the watch.

Innovation Solution

A watch strap clasp with a frame, cover, and slide system featuring notching and stop members that allow for precise adjustment of the slide's position along the longitudinal axis, requiring the clasp to be fully opened for change, thus minimizing inadvertent actuation and ensuring secure locking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an adjustment system with a pusher and tilting stop structure is used, then the bracelet length can be adjusted, but the system becomes complex and prone to inadvertent misadjustment

Engineering Contradiction:
Improvebracelet length adjustmentVSAvoidadjustment system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The adjustment system is segmented into distinct functional elements: the slide component, the notching structure on the stretchers, and the stop member. This segmentation allows each element to perform its specific function independently, simplifying the overall system while maintaining adjustability. The slide moves independently along the longitudinal axis, the notching provides discrete positioning, and the stop member provides the limiting constraint.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses simple, robust components that are easy to manufacture and replace if needed. The notching and stop member are integral parts of the stretcher structure, eliminating the need for complex movable adjustment mechanisms. This approach prioritizes simplicity and reliability over sophisticated adjustability.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Adaptability or versatility

If a complex rack and articulation system is used for adjustment, then the bracelet length can be adjusted, but the manufacturing complexity increases

Engineering Contradiction:
Improvebracelet length adjustmentVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The invention merges the adjustment function with the existing structural elements of the clasp. The notching is formed directly on the stretchers, and the stop member is integrated into the stretcher structure. This merging eliminates the need for separate adjustment mechanisms and reduces manufacturing steps while maintaining the ability to adjust bracelet length.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Instead of using a complex movable mechanism to achieve adjustment, the invention inverts the approach by using a fixed notched structure with a simple sliding component. The adjustment is achieved through the interaction of the slide moving along the notched stretcher, rather than through complex articulation and rack systems.

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

3Ease of operation

If the slide can be adjusted while the clasp is closed, then adjustment is convenient, but inadvertent misadjustment may occur causing discomfort or watch loss

Engineering Contradiction:
Improveadjustment convenienceVSAvoidsecurity against inadvertent misadjustment
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The notching structure on the stretchers provides preliminary positioning that prevents the slide from moving to arbitrary positions. The discrete notched positions ensure that adjustment only occurs at predetermined intervals, reducing the risk of inadvertent misadjustment while maintaining ease of operation through simple slide movement.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The stop member is pre-positioned on the stretcher to limit the range of motion of the slide. This preliminary constraint ensures that the slide cannot move beyond safe adjustment limits, preventing inadvertent misadjustment that could cause discomfort or watch loss while still allowing convenient adjustment within the permitted range.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3292784B1Watch strap clasp
Publication Date: 2019.07.03 BALL WATCH COMPANY
  • EP3292784B1 patent drawingFigure 1~2
  • EP3292784B1 patent drawingFigure 3
  • EP3292784B1 patent drawingFigure 4a~4c

AI summary

The invention relates to a watch strap clasp, comprising: - a frame (10) having a base (100) and at least one first pair of straps (102), and - a first cover (12) connected to the frame (10) by means of a first strand (20) articulated with the frame (10), - a first slide (30), the first end of which is mounted to slide in the first cover (12) along the longitudinal axis of the clasp, and the second end of which is intended to be connected to a strap, said slide comprising a first pair of pads (32), between which the first strand (20) is capable of taking its place when the clasp is in the locked position, said pads being then arranged opposite the straps (102), characterized in that it comprises a structure for adjusting the position of the first slide (30) with reference to the cover (12) along the longitudinal axis, said adjustment structure being formed by a notch (50) arranged on said pads,and by a stop (60), integral with the shafts (102), the notching (50) and the stop (60) being arranged to cooperate with each other and block the translation of the first slide (30) when the clasp is in the locked position.