Tourbillon Cage with External Axis Intersection for Gyroscopic Compensation

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Solution Overview

Problem

Existing tourbillon mechanisms do not provide a sufficient gyroscopic or 'spinning top' effect for the balance wheel and escapement, limiting their ability to reduce rate differences between horizontal and vertical positions without increasing the movement's thickness or reducing the balance wheel's diameter.

Innovation Solution

A timepiece movement with a tourbillon mechanism featuring two axes of rotation at an angle α, where the intersection of these axes is outside the escapement holder cage, allowing for a more pronounced gyroscopic effect by using a shaft with a bent portion and an intermediate wheel that rotates around a second axis making a non-zero angle with the first axis, creating a differential gear system to drive the cage and balance wheel in a three-dimensional motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the intersection of the two rotation axes is located inside the cage (prior art), then the structure is simpler and more compact, but the gyroscopic effect is insufficient and the balance wheel cannot traverse enough positions to effectively compensate for gravitational rate differences

Engineering Contradiction:
Improvegravitational rate compensationVSAvoidaxis intersection position
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent moves the intersection of the two rotation axes from inside the cage to outside the cage in three-dimensional space. This dimensional repositioning allows the balance wheel and escapement to traverse a greater range of positions (more than 180 degrees) while maintaining a compact overall structure. The external intersection point enables the cage to rotate around axis A-A while the balance wheel rotates around axis B-B, creating a more effective gyroscopic effect without increasing the movement's thickness.

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

2Reliability

If the angle α between the two axes is increased to enhance the gyroscopic effect, then the rate compensation improves, but the thickness of the movement increases

Engineering Contradiction:
Improverate compensationVSAvoidmovement thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

By relocating the axis intersection outside the cage, the patent enables the use of a moderate angle α (between 10° and 30°) to achieve effective gravitational rate compensation. The three-dimensional arrangement allows the balance wheel and escapement to traverse positions beyond 180 degrees during cage rotation, maximizing the gyroscopic effect at a shallow angle rather than requiring a large angle that would increase thickness.

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

3Length of stationary object

If the balance wheel diameter is reduced to fit within compact tourbillon structures, then the movement remains thin, but the gyroscopic effect and rate compensation capability are diminished

Engineering Contradiction:
Improvemovement thicknessVSAvoidrate compensation
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The external intersection of rotation axes enables the balance wheel to maintain a sufficient diameter while the cage rotates around it. The three-dimensional motion allows the balance wheel to traverse positions that maximize the gyroscopic effect without requiring the wheel to be smaller. The cage's rotation around axis A-A while the balance wheel rotates around axis B-B creates adequate lever arm for gravitational rate compensation.

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

4Reliability

If the cage rotation speed is increased to enhance the gyroscopic effect, then rate compensation improves, but the centrifugal forces and stress on the movement components increase

Engineering Contradiction:
Improverate compensationVSAvoidcentrifugal stress
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

By positioning the axis intersection outside the cage, the patent enables effective gravitational rate compensation at lower rotation speeds. The extended geometry allows the balance wheel and escapement to traverse positions that maximize the gyroscopic effect even when the cage rotates slowly around axis A-A, reducing centrifugal forces and stress on the movement components compared to faster-rotating designs.

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

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

This design enhances the gyroscopic effect, providing an elegant visual display while ensuring the balance wheel and escapement traverse more positions than traditional systems, effectively compensating for gravitational rate differences without increasing thickness or reducing the balance wheel's diameter.

Implementation Method 1

produce a timepiece movement comprising a tourbillon or carousel mechanism with two axes of rotation with an angle α between the two axes making it possible to provide the balance wheel with a gyroscopic or 'spinning top' effect

Methodology Applied
Scientific EffectGyroscopic effect: Gyroscope

Implementation Method 2

moving the intersection of the two axes A-A and B-B so that it is outside the zone of the escapement holder cage

Methodology Applied
Scientific EffectPrecession: Precession

Data Source

PatentEP2407832B1Timepiece movement
Publication Date: 2018.09.05 RICHEMONT INTERNATIONAL SA
  • EP2407832B1 patent drawingFigure 1
  • EP2407832B1 patent drawingFigure 2
  • EP2407832B1 patent drawingFigure 3

AI summary

The movement has an escapement comprising an escapement pinion (2a), an escapement wheel (2b) and an anchor (5), and regulating units comprising a balance (4) and a hairspring (6) mounted in a pivoting cage (30) rotated around an axis (B-B). The cage is mounted on a shaft (22) on which an intermediate wheel (27) is mounted and freely rotated with respect to the cage. The intermediate wheel is engaged with the pinion, and the shaft is rotated around another axis (A-A) making a nonzero angle with the former axis, where intersection of the axes is located at an outer side of the cage.