Chronograph Mechanism Self-Adjusting Stoppers

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Solution Overview

Problem

Existing column-wheel or cam-type chronograph mechanisms require complex and time-consuming adjustments, often necessitating skilled labor, and suffer from precision issues due to the use of either rigid or elastic blockers, which can lead to inaccuracies.

Innovation Solution

The chronograph mechanism features coaxially pivoted seconds and minute stoppers, each individually subjected to a spring, connected by a member allowing angular movement, ensuring automatic synchronization and contact with their respective wheels without manual adjustment, facilitating quick and precise setup by less specialized personnel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rigid blockers are used, then the structure is simple and stable, but the adjustment is complicated and requires skilled labor

Engineering Contradiction:
Improvestructural stabilityVSAvoidadjustment complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The blocker assembly is designed to perform its own adjustment automatically during assembly. The connecting member with specific geometry and the interaction between blocker elements enable self-alignment and self-adjustment without requiring external intervention or skilled manual filing operations

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system transitions from a static rigid blocker requiring manual adjustment to a dynamic assembly where the blocker elements can move relative to each other during assembly, enabling automatic positioning. The connecting member allows controlled movement that facilitates self-adjustment while maintaining operational rigidity

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If elastic blockers are used, then the adjustment is simplified, but precision is lost due to pushing of the counter wheel

Engineering Contradiction:
Improveadjustment simplicityVSAvoidtiming precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The blocker function is divided into separate elements: a main blocker body and a connecting member that links it to the control mechanism. This segmentation allows the blocker to be rigid for precision while the connecting member absorbs adjustment tolerances and enables simplified assembly

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connecting member acts as an intermediary between the control mechanism and the blocker. It transmits the blocking action while accommodating misalignments and preventing the blocker from directly pushing against the counter wheel, thus maintaining precision while allowing simplified adjustment

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If manual adjustment by skilled watchmakers is performed, then precision alignment is achieved, but time and cost increase

Engineering Contradiction:
Improvealignment precisionVSAvoidadjustment speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The blocker assembly automatically aligns itself during the assembly process through the geometric constraints of the connecting member and the interaction between blocker elements. This eliminates the need for time-consuming manual alignment operations by skilled watchmakers while maintaining high precision

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The connecting member is designed with pre-established geometry and features that guide the blocker into correct position during assembly. The self-adjusting mechanism performs the alignment action automatically as parts are assembled, before the chronograph is fully assembled and tested

Inventive Principle:
Principle #10Preliminary action

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 configuration simplifies the adjustment and assembly of the chronograph mechanism, allowing for rapid, precise alignment of stoppers with their wheels, reducing the need for skilled labor and ensuring high precision without machining or retouching, thus enabling quicker and more accurate operation.

Implementation Method 1

each individually subjected to a seconds stopper spring (12) respectively to a minute stopper spring (22) tending to make them pivot in the direction of the chronograph wheel (2) respectively the minute counter wheel (4)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2500785B1Chronograph mechanism and timepiece provided with such a mechanism
Publication Date: 2018.07.18 PATEK PHILIPPE SA
  • EP2500785B1 patent drawingFigure 1
  • EP2500785B1 patent drawingFigure 2
  • EP2500785B1 patent drawingFigure 3~5

AI summary

The mechanism has a seconds lock (15) and a minute lock (6) that engage with a chronograph wheel (2) and a minute counter wheel (4), respectively. The seconds and minute locks are pivoted coaxially and independent from each other. A connection unit e.g. screw or rivet, connects the minute lock to the seconds lock while permitting the angular displacement of the locks with respect to each other with a predetermined value. The locks are arranged such that the locks are in contact with the wheels respectively when the mechanism is in stop position.