Watch Strap Attachment Mechanism for Damage-Free Connection

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Solution Overview

Problem

Traditional methods for attaching a bracelet to a watch case are time-consuming, delicate, and can damage the watch case, and do not provide a reliable or aesthetically pleasing connection, especially for watches with small lugs or no lugs.

Innovation Solution

A device featuring a projection on the bracelet end that fits into a U-shaped groove on the watch case, with an elastic element and pin system that ensures secure, play-free attachment and easy detachment, using a pin that aligns through bores in the watch case and bracelet, and an offset elastic element to compensate for misalignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a traditional spring bar method is used to attach a bracelet to a watch case, then the connection can be made and removed, but the operation is time-consuming and delicate

Engineering Contradiction:

Improveease of attachment and detachmentVSAvoidtime for attachment and detachment

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The invention divides the attachment system into distinct components: a groove in the watch case, a projection on the bracelet end, and an elastic element. This segmentation allows for simpler, more intuitive attachment and detachment operations compared to the traditional spring bar method.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The elastic element automatically engages with the projection when the bracelet is inserted into the groove, and automatically releases when a release element is actuated. This self-service mechanism eliminates the need for delicate manual manipulation of spring bar ends, making the operation easier and faster.

Inventive Principle:

Principle #25Self-service

2Ease of operation

If a traditional spring bar method is used, then the bracelet can be attached, but it may leave marks on the watch case lugs

Engineering Contradiction:

Improveease of attachment and detachmentVSAvoidmarks on watch case

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The invention extracts the spring bar component entirely from the system and replaces it with a groove-projection-elastic element mechanism. This eliminates the metal-to-metal contact that causes marking on the lugs, as the elastic element engages with the projection without pressing against the case surface.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If a traditional spring bar method is used, then the bracelet can be secured, but the operation is particularly delicate

Engineering Contradiction:

Improvesecure connectionVSAvoiddelicacy of operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

Inventive Principle:

Principle #25Self-service

4Ease of operation

If a projection and groove system is used instead of spring bar, then attachment is simpler, but reliable fixation without play must be ensured

Engineering Contradiction:

Improveease of attachment and detachmentVSAvoidsecure connection without play

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The elastic element changes its physical state (compression/expansion) to provide a reliable, play-free connection. When compressed during attachment, it engages firmly with the projection; when released, it maintains constant pressure to eliminate play while allowing simple detachment through the release mechanism.

Inventive Principle:

Principle #35Parameter changes

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

Facilitates quick and reliable attachment and detachment of the bracelet, prevents damage to the watch case, and maintains a clean aesthetic appearance by ensuring a secure and play-free connection.

Implementation Method 1

a device (1) for attaching a bracelet (10) to a watch case (2), characterized in that it comprises an elastic element (30) arranged on the bracelet (10), a pin (20) arranged to be received in a bore (7, 17), the pin (20) and the elastic element (30) being arranged to engage one another

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP3560371B1Device for securing a strap to a watch case

Publication Date: 2023.12.27 ROLEX SA

Figure 1~2
Figure 3~5
Figure 6~12

AI summary

Bracelet strand (10) comprising an end intended for removable attachment to a watch case, characterized in that it comprises a projection (16) or a groove disposed at said end, said projection (16) or groove being intended to fit within a groove or projection of a watch case, and in that it comprises at least one vertical opening (17) arranged in the thickness of said projection (16) or of a wall forming said groove and in that it comprises an elastic element (30), so as to be able to receive a pin (20) through the elastic element (30) and through at least a part of the length of said at least one vertical opening.