Watch Crown Combination Lock in a Side-Mounted Case Recess

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Solution Overview

Problem

Existing watch combination lock mechanisms are bulky, occupying space within the watch case and requiring modification of the watch movement, making them unsuitable for retrofitting on existing watches.

Innovation Solution

A compact combination locking mechanism for a watch crown that is mounted in a recess on the side of the watch case, utilizing a lock with multi-element discs and an indexing system, allowing the crown to be unlocked by aligning cutouts on the discs with a spring-loaded contact pin, and featuring a lock actuator for secure translation and angular positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a combination lock mechanism is integrated into the watch case to prevent unauthorized use, then security is improved, but the device occupies space within the watch case and requires modification of the watch movement

Engineering Contradiction:
ImprovesecurityVSAvoidspace occupied in watch case
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The locking mechanism is relocated from the internal volume of the watch case to the lateral surface of the case, utilizing the side dimension rather than the internal space. The recess is created on the crown side of the case, allowing the locking mechanism to be mounted externally without encroaching on the movement space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The locking mechanism is separated into distinct functional components: a recess in the case housing, a lock body with combination elements, and a crown assembly. This segmentation allows the locking function to be added without requiring modification of the entire watch case structure or movement.

Inventive Principle:
Principle #1Segmentation

2Reliability

If a combination lock mechanism is integrated into the watch case to prevent unauthorized use, then security is improved, but the watch movement must be developed according to the characteristics of the locking mechanism

Engineering Contradiction:
ImprovesecurityVSAvoidwatch movement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is designed as a separate, self-contained system with its own combination elements and locking components, independent of the watch movement. The lock body is mounted in the case housing around the tube, with no mechanical connection to the movement, allowing the movement to remain unchanged.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tube serves as an intermediary element that passes through the case and connects to the crown, while the locking mechanism is mounted around this tube in the case housing. This arrangement allows the lock to control crown movement without requiring integration with the movement itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a conventional crown is replaced with a lockable crown, then security is improved, but the locking mechanism must be integrated into the watch case structure

Engineering Contradiction:
ImprovesecurityVSAvoidretrofitting capability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The recess is pre-formed in the case housing during manufacturing, creating a prepared mounting location for the locking mechanism. This preliminary action allows the locking mechanism to be easily installed without requiring complex modifications to the case structure, facilitating retrofitting on existing watches.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4484681B1Watch crown with combination locking mechanism
Publication Date: 2025.12.31 DE LA MFG DHORLOGERIE AUDEMARS PIGUET & CIE
  • EP4484681B1 patent drawingFigure 1~3b
  • EP4484681B1 patent drawingFigure 4~7b
  • EP4484681B1 patent drawingFigure 8~10

AI summary

The present invention relates to a lockable crown (10) for a watch component comprising a case (100) incorporating a housing (102) open on a lateral side (101) of the case and communicating, via an opening (106), with a central space (103) for a cage. The lockable crown (10) comprises a crown (12), a shaft (14) integral with the crown (12), a tube (20) mounted on the shaft (14) and intended to be fixed in the opening (106) of the case (102), and a locking mechanism (30) intended to be mounted in the housing (102) of the case (100) around the tube (20). The locking mechanism (30) includes a lock (40), an actuator (48) and a lock (50) with several combination elements (60, 70, 80) mounted pivotally around the tube (20) and actuated in rotation by the crown (12) when the latter is mounted on the case (100) and turned in one direction and the other.The lock (40) is configured to assume a locked position and an unlocked position in which it respectively locks and releases the crown (12) during translation. The lock (40) is intended to be actuated by the actuator (48) from the locked position to the unlocked position when all the combination elements (60, 70, 80) are arranged in a predetermined angular position. The invention also relates to a timepiece comprising the lockable crown (10).