Watch Winding Device Unidirectional Coupling Simplified Design

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Solution Overview

Problem

Conventional one-way couplings used in watchmaking for winding barrels are complex and expensive due to their intricate design, particularly the Breguet type coupling, which requires a delicate and costly driven pinion with straight radial teeth.

Innovation Solution

A simplified one-way coupling design that eliminates the need for an intermediary winding pinion by using a pinion with a Breguet toothing mounted on a winding stem, which directly engages with a crown wheel having internal saw teeth, allowing for a two-way coupling mechanism without an intermediate piece.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a Breguet type coupling is used to transmit rotational movement between transmission members with perpendicular axes, then reliable one-way transmission is achieved, but the device becomes complex and expensive due to the intricate driven pinion with straight radial teeth

Engineering Contradiction:
Improvereliable one-way transmissionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges the functions of the driven pinion and crown wheel into a single crown wheel component with integrated straight toothing and saw-toothed toothing. This eliminates the separate driven pinion with complex straight radial teeth, reducing the number of parts while maintaining the one-way transmission function through the elastic member's engagement with the saw-toothed toothing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention extracts and eliminates the complex driven pinion with straight radial teeth from the Breguet coupling mechanism. By integrating the necessary functions into the crown wheel and using the elastic member for one-way engagement, the design removes the delicate and costly component without compromising transmission reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If a Breguet type coupling with straight radial teeth is used, then proper one-way engagement is achieved, but manufacturing cost and difficulty increase due to the delicate nature of the driven pinion

Engineering Contradiction:
Improveproper one-way engagementVSAvoidease of manufacture
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention combines the engagement surfaces and functional elements into the crown wheel structure itself. The straight toothing and saw-toothed toothing are both integrated into the same component, eliminating the need to manufacture a separate driven pinion with delicate straight radial teeth, thereby simplifying the manufacturing process.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention replaces the expensive, delicate driven pinion with a more manufacturable crown wheel design that uses standard toothing techniques. The elastic member provides the necessary one-way engagement without requiring precision-machined straight radial teeth, reducing manufacturing costs and complexity.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If an intermediary winding pinion is used in the Breguet coupling, then proper transmission between perpendicular axes is achieved, but the device size and complexity increase

Engineering Contradiction:
Improveproper transmissionVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The invention merges the intermediary winding pinion function directly into the crown wheel by providing both straight toothing for engagement with the pinion and saw-toothed toothing for one-way engagement with the elastic member. This integration eliminates the need for a separate intermediary component, reducing device size while maintaining proper transmission between perpendicular axes.

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

This design simplifies the winding device by eliminating the need for a costly winding pinion, reducing complexity and size, while maintaining effective rotational movement transmission from a perpendicular axis, preventing improper barrel manipulation.

Implementation Method 1

provided with a first saw-toothed toothing, movable between a first time-setting position and a second winding position and positioned axially in the winding position (B) by an elastic member

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP1978419B1Winding device comprising a unidirectional coupling
Publication Date: 2010.07.21 ETA SA MFG HORLOGERE SUISSE
  • EP1978419B1 patent drawingFigure 1~3
  • EP1978419B1 patent drawingFigure 2

AI summary

A sliding pinion (20) is mounted on a winding stem (22) with a rotational axis (XX) and is fitted with a saw-like contrate toothing (30). The pinion is mobile between time-setting and winding positions, and is positioned in the winding position by a pull-out piece (24) and a lever (26). A crown wheel (32) has a rotational axis (YY) that is perpendicular to the rotational axis of the stem. The wheel is fitted with a saw-like inner toothing (34) that is meshed with the saw-like contrate toothing in the winding position to form a single direction coupling device.