Unidirectional Crown Mechanism for Watch Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing timepiece control mechanisms, particularly in watches, are inconvenient due to fragile components and the need for precise one-directional operation to ensure watertightness and safety, often requiring difficult maneuvers with control rods or internal pushers activated by pointed tools.

Innovation Solution

An external control device featuring a crown with a unidirectional tooth mechanism that allows rotation of internal components in one direction only, utilizing a first barrel with outward-facing unidirectional teeth and a second barrel with inward-facing antagonistic teeth, secured by a spring and elastic return means, ensuring safe and easy operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a traditional control rod or internal pusher is used, then the timepiece can be controlled, but the operation becomes cumbersome and fragile components are exposed

Engineering Contradiction:
Improveease of operationVSAvoidcomponent fragility
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces a crown as an external intermediary control element that transmits rotational force through a control stem to internal components. This mediator allows users to operate the timepiece functions without directly manipulating fragile internal pushers or control rods, thereby improving ease of operation while protecting internal components from damage

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The control mechanism is extracted from the internal fragile components and moved to an external crown structure. The crown and control stem form an external control system that interfaces with internal components only when needed, separating the user interface from the fragile internal mechanisms and eliminating the need for pointed tools or difficult maneuvers

Inventive Principle:
Principle #2Taking out (Extraction)

2Adaptability or versatility

If the control mechanism allows bidirectional rotation, then operation flexibility is improved, but accidental rotation and water resistance compromise occur

Engineering Contradiction:
Improveoperation flexibilityVSAvoidwater resistance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent employs asymmetric engagement between the control stem and the internal component (such as a date wheel or chronograph mechanism). The control stem features a shaped interface that engages with the internal component in only one rotational direction, allowing flexible operation for intended functions while mechanically preventing accidental rotation that could compromise water resistance

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The control mechanism is designed with preliminary anti-action by incorporating a unidirectional engagement system where the control stem can only drive internal components in the intended direction. This pre-prevents accidental bidirectional rotation before it can occur, maintaining water resistance while providing operational flexibility for legitimate functions

Inventive Principle:
Principle #9Preliminary anti-action

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

Enables safe and easy one-directional control of internal timepiece components, enhancing user convenience and safety by preventing accidental rotation, while maintaining watertightness and simplifying complex adjustments like date and chronograph functions.

Implementation Method 1

the tube contains at least one elastic return means bearing lower on a lower frontal surface of the tube or of a support element incorporated in the tube; this at least one elastic return means tends to move the first barrel away from the driver

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP4080294B1External control mechanism for a timepiece
Publication Date: 2023.10.25 MECO SA
  • EP4080294B1 patent drawingFigure 1
  • EP4080294B1 patent drawingFigure 2~4
  • EP4080294B1 patent drawingFigure 5~6

AI summary

External watch control device (100) comprising a crown (1) carrying a first barrel (2) screwed onto a tube (4), coaxially guiding a second barrel (3) includes a driver (7), the first barrel (2) and the second barrel (3) having opposing unidirectional teeth (8; 9), the tube (4) containing a spring (11) tending to move the first barrel (2) away from the driver (7), the unidirectional teeth (8; 9) are at maximum distance when the crown (1) is fully screwed onto the tube (4), and in mesh position when the crown (1) is fully unscrewed, the cooperation between the unidirectional teeth (8; 9) allowing the rotation of the first barrel (3) in a first single direction of rotation of the crown (1), and prohibiting it in the opposite direction against the spring (11) in the manner of a ratchet.