Clockwork Device for Automatic Split-Seconds Hand Indexing

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Solution Overview

Problem

Conventional clockwork devices for automatic adjustment of the relative angular position of moving parts in stopwatches require complex mechanisms with high energy consumption and are prone to errors such as rebound and overshooting, which affect the accuracy of split-seconds hand positioning.

Innovation Solution

A clockwork device utilizing a toothed wheel mechanism with a coaxial toothed wheel and an elastic or manual actuation member to restore the predetermined phase shift between the first and second parts, allowing for efficient energy use and precise indexing without the need for cams and feeler members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional cam and feeler member mechanisms are used for automatic adjustment, then the split-seconds hand can be indexed to the second hand position, but the device complexity increases and energy consumption increases

Engineering Contradiction:
Improveindexing accuracyVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the cam and feeler member components from the automatic adjustment mechanism. Instead of using these complex elements, the patent employs a simplified toothed wheel mechanism where the fourth toothed wheel directly meshes with the third toothed wheel to achieve the indexing function, removing unnecessary complexity while maintaining reliability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a fourth toothed wheel as an intermediary element between the third toothed wheel (linked to the second hand) and the second toothed wheel (linked to the split-seconds hand). This intermediary toothed wheel facilitates the automatic adjustment through simple meshing action, replacing the need for complex cam-based intermediary mechanisms

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If conventional cam and feeler member mechanisms are used for automatic adjustment, then the split-seconds hand can be indexed to the second hand position, but the energy consumption increases

Engineering Contradiction:
Improveindexing accuracyVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention removes the energy-intensive cam and feeler member components from the system. The simplified toothed wheel meshing mechanism requires minimal energy to operate, as it relies on direct mechanical engagement between teeth rather than continuous cam rotation and feeler member actuation

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The automatic adjustment mechanism operates periodically only when needed - specifically when the push piece returns to its initial position after being actuated. The toothed wheel mechanism engages briefly to reset the phase relationship between hands, then disengages, consuming energy only during these periodic adjustment events rather than continuously

Inventive Principle:
Principle #19Periodic action

3Reliability

If conventional cam and feeler member mechanisms are used for automatic adjustment, then the split-seconds hand can be indexed to the second hand position, but errors such as rebound and overshooting occur

Engineering Contradiction:
Improveindexing accuracyVSAvoidpositioning accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The invention employs a simple, robust toothed wheel mechanism that performs the indexing function in a single, clean engagement action. The meshing teeth provide positive stopping without the gradual contact and rebound issues of cam mechanisms, achieving accurate positioning in one decisive mechanical interaction rather than through prolonged or repeated adjustments

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

Solution Approach 2:

The indexing function is segmented into distinct operational phases: the push piece actuates the escape wheel, which rotates the fourth toothed wheel, which then meshes with the third toothed wheel to rotate the second toothed wheel. This segmentation isolates the indexing action to a specific mechanical pathway, preventing the cumulative errors and rebound effects that occur in integrated cam-based systems

Inventive Principle:
Principle #1Segmentation

4Use of energy by moving object

If a simplified mechanism is used for automatic adjustment, then energy consumption is reduced, but the reliability and precision of indexing may deteriorate

Engineering Contradiction:
Improveenergy consumptionVSAvoidindexing accuracy
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The fourth toothed wheel serves as a precise intermediary that ensures accurate power and motion transfer from the third toothed wheel to the second toothed wheel. The meshing teeth provide positive engagement with defined gear ratios, guaranteeing reliable indexing accuracy while maintaining the energy efficiency of the simplified mechanism

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention optimizes the gear parameters of the toothed wheels (number of teeth, tooth profile, meshing geometry) to achieve both high indexing accuracy and low energy consumption. By carefully selecting these parameters, the mechanism ensures precise positioning through clean tooth engagement while minimizing friction and energy loss during operation

Inventive Principle:
Principle #35Parameter changes

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 ensures reliable, energy-efficient automatic adjustment of the split-seconds hand to the second hand position, reducing errors and maintaining precise indexing, thus enhancing the accuracy of split-seconds timing.

Implementation Method 1

said second part being biased, in a first direction S1, by an elastic member arranged to tend to restore said first phase shift value between said first part and said second part

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP1970780B1Horogical device for automatic adjustment of the relative angular position of two parts that are mobile in relation to one another to a phase lag value
Publication Date: 2013.03.06 AUDEMARS PIGUET RENAUD & PAPI
  • EP1970780B1 patent drawingFigure 1
  • EP1970780B1 patent drawingFigure 2
  • EP1970780B1 patent drawingFigure 3

AI summary

The device (1) has a part having a toothed wheel that is connected to a part (3) e.g. sweep second hand wheel. A part meshes with the part , and moves from a location characterizing an annular phase lag value (2) towards another location under the rotational effect of the part . A part (11) moves the part from the latter location towards the former location to mesh with the part . The part induces the rotation of the part (4) to re-establish the phase lag value between the parts (3, 4) when the rotation of parts (3, 4) is authorized by a functional unit.