Watch Bracelet Strand Assembly with Locking Hinge Pin

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Solution Overview

Problem

Existing solutions for attaching a bracelet strand to a watch case are inadequate in terms of reliability, robustness, ease of attachment and removal, and aesthetic appeal, particularly for high-end watchmaking.

Innovation Solution

A timepiece design featuring a case middle with horns and a fastening element, utilizing a hinge pin and locking mechanism to secure the bracelet strand, allowing for reliable attachment, easy removal, and maintaining an attractive aesthetic appearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a common solution with two pairs of horns and a link is used to attach the bracelet strand, then the attachment allows relative articulation between the bracelet strand and the watch case, but the reliability is insufficient and untimely detachment may occur

Engineering Contradiction:
Improveattachment reliabilityVSAvoidattachment structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The attachment system is divided into distinct functional components: the case middle with horns, the separate fastening element, and the bracelet strand with connecting portions. This segmentation allows each component to be optimized for its specific function while improving overall reliability through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A separate fastening element is introduced as an intermediary component between the case middle and the bracelet strand. This fastening element acts as a mediator that securely connects the bracelet to the watch case, preventing direct attachment issues and improving reliability through an additional securing mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a common solution with horns and links is used, then the bracelet strand can be attached to the watch case, but wear occurs over time which deteriorates functionality

Engineering Contradiction:
Improveattachment durabilityVSAvoidfunctional lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The fastening element serves as a sacrificial intermediary that absorbs wear and stress, protecting the permanent components (case middle and bracelet strand) from deterioration. This mediator approach extends the functional lifespan by concentrating wear on the replaceable fastening element.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The fastening element is designed as a consumable component that can be replaced when worn, while the permanent components (case middle and bracelet strand) are preserved. This allows the system to maintain functionality over time by periodically replacing the wear-prone fastening element.

Inventive Principle:
Principle #34Discarding and recovering

3Reliability

If a secure attachment mechanism is used to prevent detachment, then reliability improves, but the ease of removal and reattachment by users deteriorates

Engineering Contradiction:
Improveattachment securityVSAvoiduser-friendly attachment and removal
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The attachment system is segmented into a permanent part (case middle with horns) and a removable part (fastening element with bracelet strand). This segmentation allows the permanent part to provide secure anchoring while the removable part enables easy user operation for attachment and detachment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fastening element incorporates movable components (articulated connecting portions) that allow dynamic engagement and disengagement. The connecting portions can pivot and move to facilitate easy attachment and removal by users while maintaining secure attachment when engaged.

Inventive Principle:
Principle #15Dynamics

4Reliability

If a functional attachment mechanism is implemented, then the bracelet strand can be securely attached, but the aesthetic appearance deteriorates due to visible attachment components

Engineering Contradiction:
Improveattachment functionalityVSAvoidaesthetic appearance
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The fastening element acts as an aesthetic intermediary that conceals the functional attachment mechanism. It provides a visually pleasing transition between the case middle and bracelet strand, hiding the mechanical components (hinge pin, locking means) while maintaining their functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The attachment components are designed with differentiated local qualities: the visible portions (fastening element exterior, connecting portions) are optimized for aesthetic appearance, while the hidden portions (internal locking mechanism, hinge pin) are optimized for functionality. This allows simultaneous achievement of beauty and utility.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4632501A1Assembly of a bracelet strand on a watch case
Publication Date: 2025.10.15 ROLEX SA
  • EP4632501A1 patent drawingFigure 1
  • EP4632501A1 patent drawingFigure 2
  • EP4632501A1 patent drawingFigure 3

AI summary

Timepiece, in particular a wristwatch, comprising at least one bracelet strand (30) extending in a longitudinal direction and removably attached to a caseband (20), which thus occupies a first attachment configuration in which the at least one bracelet strand (30) is attached to the caseband (20) and a second assembly configuration in which the at least one bracelet strand (30) is detached from the caseband (20), characterized in that: - the caseband (20) comprises at least one horn (21), comprising a transverse opening (21a), - the timepiece comprises at least one attachment element (1), separate from the caseband (20) and from the at least one bracelet strand (30), comprising a transverse opening (1a), - the end of the at least one bracelet strand (30) comprises at least two connecting portions (31), in particular at least two connecting links,projecting in the longitudinal direction at the end of the at least one bracelet strand (30) and being transversely separated from each other by a space, the at least two connecting portions (31) each comprising transverse openings (31a) passing through, - in the first fixing configuration, at least one hinge pin (2) is housed in said transverse opening (21a) of the at least one horn (21), in said transverse opening (1a) of the at least one fixing element (1), and in said transverse openings (31a) of respectively the at least two connecting portions (31) of the bracelet, so as to keep the middle (20), the at least one bracelet strand (30) and the at least one fixing element (1) fixed to each other, - in the first fixing configuration,a locking means (3) locks the at least one hinge axis (2) in rotation relative to the at least one horn (21) and relative to the at least one fixing element (1) or relative to the connecting portions (31), so that respectively only the at least two connecting portions (31) of the at least one bracelet strand (30) or the at least one horn (21) and the at least one fixing element (1) are movable in rotation about the at least one hinge axis (2).,