Flying Fusee System Torque Compensation Space Reduction

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Solution Overview

Problem

Fusée systems in watches face challenges such as occupying excessive space and requiring additional bridges due to variations in torque from modern mainsprings, and most rocket mechanisms need intermediate springs to prevent movement stoppage during winding, which also consume space.

Innovation Solution

A 'flying' fusee system with a compact design that eliminates the conventional bridge and uses a differential gear mechanism, including a crown with internal toothing, a ratchet wheel with external toothing, and double pinions, allowing continuous torque supply to the going train during mainspring winding without an intermediate spring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional fusee system is used to compensate for mainspring torque variations, then torque compensation is achieved, but the space occupied in the movement thickness increases and an additional bridge is required

Engineering Contradiction:
Improvetorque compensationVSAvoidspace occupation
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The fusee support function is merged with the existing moving part (barrel assembly) by integrating the support axis directly into it. This eliminates the need for a separate bridge structure while maintaining the torque compensation function, thereby reducing space occupation in the movement thickness.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The moving part serves multiple functions: it houses the mainspring, provides the support axis for the fusee, and transmits torque. This multi-functionality eliminates the need for dedicated bridge structures, reducing overall space requirements while maintaining fusee operation.

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

2Reliability

If an intermediate mechanism with an intermediate spring is used between the fusee and finishing gear train, then the movement continues during winding, but the space required increases

Engineering Contradiction:
Improvecontinuous operation during windingVSAvoidspace occupation
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The intermediate spring function is merged with the mainspring itself. The mainspring serves dual purposes: providing power to the movement and acting as the intermediate mechanism that maintains torque during winding. This eliminates the need for a separate intermediate spring and reduces space requirements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mainspring performs multiple functions: it stores energy, provides torque compensation through the fusee, and acts as the intermediate mechanism ensuring continuous operation during winding. This multi-functionality eliminates additional components and reduces space occupation.

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

3Stability of the object's composition

If a conventional bridge structure is used to support the fusee, then stable support is provided, but the device complexity and space requirements increase

Engineering Contradiction:
Improvefusee support stabilityVSAvoidbridge structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The fusee support function is combined with the existing moving part structure. The support axis is integrated into the barrel assembly, which already provides stable mounting. This eliminates the need for additional bridge structures, reducing device complexity while maintaining support stability.

Inventive Principle:
Principle #5Merging (Combining)

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 reduces space occupation, allows for uninterrupted clockwork operation during winding, and provides a cleaner upper surface for decoration while offering adjustable torque and power reserve options through varying gear ratios.

Implementation Method 1

The fusee system incorporates a differential gear that allows torque to continue to be supplied to the clockwork movement while the mainspring is being wound

Methodology Applied
Scientific EffectDifferential gear mechanism: Gear

Implementation Method 2

a ratchet wheel with external teeth, the ratchet wheel being intended to be driven during the winding of the timepiece and preferably being positioned by a locking pawl

Methodology Applied
Scientific EffectRatchet mechanism: Ratchet

Implementation Method 3

a crown wheel with internal teeth and a ratchet wheel with external teeth... a spindle wheel, intended to drive the finishing gear train of a timepiece movement

Methodology Applied
Scientific EffectGear meshing: Gear

Data Source

PatentEP3066527B1Fusee system
Publication Date: 2020.06.24 CHRONOMETRIE FERDINAND BERTHOUD
  • EP3066527B1 patent drawingFigure 1
  • EP3066527B1 patent drawingFigure 2
  • EP3066527B1 patent drawingFigure 3~4

AI summary

The invention relates to a fusee system (1) for a timepiece including: a supporting pin (13); a fusee (5) pivoted about said supporting pin (13) and suitable for receiving a chain (3) around the perimeter of said fusee (5). According to the invention, the supporting pin (13) is intended for being secured by a first end to a case element of said timepiece.