Removable Watch Cap Locking for Secure Shock-Resistant Assembly

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Solution Overview

Problem

Existing watch component protective caps do not adequately meet requirements for simple assembly without damage, robustness against external stresses, reliable fixation, and attractive aesthetic appearance.

Innovation Solution

A watch component design featuring a removable cap with a first part and a movable lock, utilizing engagement members and a play compensation element to ensure secure attachment and easy detachment, allowing for use of various materials for aesthetic appeal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If brazing is used to attach the cap to the component, then the cap is securely fixed and resistant to external stresses, but the assembly process becomes complex and risks damage to the watch component

Engineering Contradiction:
Improvesecure fixation of capVSAvoidassembly process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The attachment mechanism is divided into separate components: a first attachment member on the component, a first assembly member on the cap, and a movable lock. This segmentation allows for simplified assembly where parts are attached through engagement rather than permanent bonding, eliminating the complexity of brazing while maintaining secure fixation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The movable lock transitions between locked and unlocked positions to dynamically control the attachment state. This dynamic mechanism replaces static permanent attachment methods like brazing, enabling both secure fixation during wear and simple removal when needed, without requiring complex heating or bonding equipment.

Inventive Principle:
Principle #15Dynamics

2Strength

If a robust cap material is used to withstand shocks and scratches, then the protective function is improved, but the assembly simplicity is reduced due to material compatibility requirements

Engineering Contradiction:
Improveresistance to shocks and scratchesVSAvoidassembly simplicity
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

By separating the cap into a removable component with its own attachment mechanism, the patent allows use of robust materials like ceramic or hardened metal that would be difficult to bond permanently. The mechanical engagement system works universally across different materials, maintaining assembly simplicity while enabling the use of strong, scratch-resistant materials.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The attachment mechanism uses geometric parameters (engagement geometries, tolerances) rather than material-dependent bonding parameters. This allows the same attachment system to work with various robust materials without requiring material-specific assembly procedures, maintaining ease of operation while achieving high strength and scratch resistance.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the cap is permanently fixed to prevent unintentional disassembly, then reliability is improved, but the ability to remove and replace the cap is lost

Engineering Contradiction:
Improveprevention of unintentional disassemblyVSAvoidremovability and replaceability of cap
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The movable lock provides a dynamic attachment system that can be in a locked state during normal use (preventing unintentional disassembly) and an unlocked state when removal is desired. This dynamic capability allows the cap to be both reliably fixed and easily removable, providing adaptability for replacement or adjustment while maintaining security during wear.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The attachment mechanism is designed to be self-locking through the engagement of the first attachment member, first assembly member, and movable lock. This self-service feature ensures the cap remains securely attached without requiring additional fastening operations, while still allowing intentional removal when the lock is actuated, balancing reliability with adaptability.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3957205B1Timepiece component provided with a cover
Publication Date: 2026.05.20 ROLEX SA
  • EP3957205B1 patent drawingFigure 1~2
  • EP3957205B1 patent drawingFigure 3~4
  • EP3957205B1 patent drawingFigure 5

AI summary

A watch component with a first part (13) and a removable cap (13c) that can be in a fixed and a free configuration. The first part comprises at least one first latching member (50) and a movable latch (9). The cap comprises at least one first assembly member (40) designed to cooperate with the first latching member of the first part and a second assembly member (41) designed to cooperate with the movable latch. In the fixed configuration, the first latching member of the first part and the first assembly member of the cap are engaged. The movable latch is engaged with the second assembly member of the cap. The cap is fixed in a locked manner to the first part. In the free configuration, the movable latch is in an open position in which it releases the second assembly member of the cap and allows the cap to be separated from the first part.