Peripheral Mechano-Electric Watch Generator for Integrated Lighting

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Solution Overview

Problem

Existing mechanical watches with integrated micro-generators for lighting systems occupy significant space, increase volume, and compromise the purely mechanical nature of the movement, particularly in high-end watches.

Innovation Solution

A mechano-electric generator is designed with a rotor and stator arrangement that occupies a peripheral space within the watch movement, using ball bearings for rotation and minimizing axial dimension, with electrical components located outside the movement, and a lighting system powered by the generator without additional batteries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a micro-generator is incorporated into the watch movement to power a lighting device, then the lighting function is achieved, but the generator occupies significant space within the movement and increases the overall volume of the watch

Engineering Contradiction:
Improvelighting functionVSAvoidmovement volume
Core Design Contradiction:
Use of energy by moving objectVSVolume of stationary object

Solution Approach 1:

The patent positions the generator in a peripheral region of the movement rather than integrating it centrally within the mechanical components. This spatial reorganization utilizes the radial dimension of the movement layout, placing the generator outside the central axis where mechanical components are concentrated, thereby achieving lighting functionality without significantly increasing the core movement volume.

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

Solution Approach 2:

The generator is designed with a compact structure that fits within the peripheral space of the movement. The stator and rotor are arranged in a nested configuration where the rotor is positioned within the stator's magnetic field region, maximizing space utilization. The generator's components are tightly integrated into the movement's existing structure, with the rotor meshing with a wheel of the mechanical drive device, effectively nesting the electrical generation function within the mechanical movement's boundary.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Use of energy by moving object

If a micro-generator with axially superimposed magnets and coils is used, then the lighting function is achieved, but the generator has a relatively large height

Engineering Contradiction:
Improvelighting functionVSAvoidgenerator height
Core Design Contradiction:
Use of energy by moving objectVSLength of stationary object

Solution Approach 1:

The patent modifies the geometric parameters of the generator components, specifically optimizing the axial dimensions of the magnets and coils. The magnets are arranged in a configuration that maximizes magnetic field strength while minimizing axial height. The coils are wound with optimized turn density and wire gauge to generate sufficient electrical power within a reduced axial space, directly addressing the height constraint.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If the generator and lighting system are integrated into the movement, then the lighting function is achieved, but the mechanical nature of the movement is compromised with electronic components

Engineering Contradiction:
Improvelighting functionVSAvoidmechanical nature
Core Design Contradiction:
Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The patent segments the watch into distinct functional zones: the central movement area maintains purely mechanical components for timekeeping, while the peripheral region houses the generator and lighting system. This spatial segmentation allows the mechanical movement to retain its traditional character and aesthetic appearance, while the electrical components are isolated in a separate zone, minimizing the compromise to the mechanical nature of the watch.

Inventive Principle:
Principle #1Segmentation

4Use of energy by moving object

If the rotor includes multiple magnets on a disk pivoted on a central shaft, then the lighting function is achieved, but the device complexity increases

Engineering Contradiction:
Improvelighting functionVSAvoidgenerator structure
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The rotor serves multiple functions simultaneously: it acts as the rotating component that generates electrical power through electromagnetic induction, serves as a speed regulator for the striking mechanism, and functions as a structural element that meshes with the mechanical drive device. This multi-functionality reduces the need for separate components, thereby simplifying the overall device structure while achieving the lighting function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The solution provides a discreet, aesthetic lighting system that maintains the mechanical integrity of the watch movement, suitable for high-end watches, without increasing the watch's thickness or revealing electronic components.

Implementation Method 1

a mechano-electric generator (88), in particular a direct current generator, whose rotor (92) is driven in rotation by the barrel (72)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The rotor (92) is supported by a ball bearing (100a, 100b, 100c) and can rotate about a geometric axis (34) of the rotor (92)

Methodology Applied
Scientific EffectBall bearing reduction of friction: Ball Bearing

Data Source

PatentEP4715487A1Watch provided with a mechano-electrical generator
Publication Date: 2026.03.25 THE SWATCH GRP RES & DEVELONMENT LTD
  • EP4715487A1 patent drawingFigure 1~2
  • EP4715487A1 patent drawingFigure 3
  • EP4715487A1 patent drawingFigure 4~5

AI summary

The invention relates to a watch comprising, within a case (6b), a movement (44a) and a mechano-electric generator (88), which includes a stator (106a, 106b, 18a, 18b) and a rotor (92), one carrying permanent magnets (18a, 18b) and the other coils (14). The rotor has an annular structure and is guided in rotation by at least one ball bearing (100a). The rotor has, along its entire height, a free interior space (130) through which the geometric axis of rotation of the rotor passes and in which the movement is at least partially located. In a principal embodiment, the watch includes a mainspring barrel forming a rotor drive device that can be activated on command. In a principal variant, the watch includes a lighting device (64) that is powered by the coils.In an advantageous variant, the rotor (92) carries the coils, which are connected, via an electrical circuit without a battery, to the lighting device which is fixedly arranged on the rotor.