Chronograph Mechanism Automatic Synchronization via Clutch Rocker

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Solution Overview

Problem

Conventional chronograph mechanisms face challenges in precise synchronization between the clutch rocker and blocker, requiring manual adjustment and intervention by specialists, which is time-consuming and prone to errors due to manufacturing tolerances and roundness issues, affecting the proper functioning of the chronograph.

Innovation Solution

A chronograph mechanism where the blocker's movements are directly controlled by the clutch rocker via an eccentric or pin, allowing for automatic synchronization and easy adjustment of the penetration depth of the intermediate wheel into the chronograph wheel, eliminating the need for manual retouching and simplifying the assembly process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual adjustment and retouching of parts is performed to achieve synchronization, then synchronization precision is improved, but assembly time and complexity increase

Engineering Contradiction:
Improvesynchronization precisionVSAvoidassembly time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The clutch rocker is designed to automatically control the blocker's movements through direct mechanical coupling. The rocker's oscillating motion directly actuates the blocker to engage and disengage the chronograph wheel teeth without requiring manual intervention for synchronization adjustment, making the system self-regulating

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The clutch rocker serves multiple functions simultaneously: it controls the intermediate wheel engagement with the chronograph wheel, actuates the blocker for synchronization, and manages the start-stop functions. This multi-functionality eliminates the need for separate adjustment mechanisms for each function

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

2Measurement precision

If manual retouching and forging of parts is performed, then synchronization accuracy is improved, but manufacturing complexity and skill requirements increase

Engineering Contradiction:
Improvesynchronization accuracyVSAvoidease of assembly
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The mechanism automatically achieves synchronization through the mechanical coupling between the clutch rocker and blocker. The rocker's motion profile inherently controls the blocker's engagement timing with the chronograph wheel teeth, eliminating the need for specialist intervention or manual retouching

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The design changes the approach from adjusting positional parameters through manual retouching to controlling temporal parameters through the rocker's oscillation frequency and amplitude. The synchronization is achieved by adjusting the rocker's motion characteristics rather than the physical dimensions of contacting surfaces

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the blocker is controlled directly by the column wheel or cam, then control precision is improved, but synchronization difficulty increases

Engineering Contradiction:
Improvecontrol precisionVSAvoidsynchronization complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The clutch rocker serves as an intermediary element between the column wheel/cam and the blocker. Instead of direct control, the rocker translates the column wheel's oscillating motion into precise blocker actuation, mediating the control function and simplifying the synchronization mechanism

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The control functions for both the intermediate wheel engagement and the blocker actuation are merged into a single clutch rocker mechanism. This consolidation reduces the number of independent control systems needed and simplifies the overall synchronization complexity

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

Facilitates precise and rapid synchronization of the chronograph mechanism, reducing the need for manual adjustments and specialist intervention, ensuring accurate operation without reworking parts, thereby enhancing the reliability and efficiency of the chronograph's start and stop functions.

Implementation Method 1

the clutch lever carrying the intermediate wheel is pivoted concentrically to a driving wheel in engagement with the intermediate wheel. When the beak, or free end, of the clutch lever is in contact, under the effect of its return spring, with one of the columns of the column wheel or with an upper part of the cam

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The degree of penetration of these teeth is determined by the position of an eccentric against which the clutch rocker abuts, the eccentric located between the axis of rotation of the clutch rocker and the beak of this rocker

Methodology Applied
Scientific EffectEccentric mechanism: Excentric

Data Source

PatentEP2251747B1Chronograph mechanism and timepiece provided with such a chronograph mechanism
Publication Date: 2018.01.31 PATEK PHILIPPE SA
  • EP2251747B1 patent drawingFigure 1
  • EP2251747B1 patent drawingFigure 2
  • EP2251747B1 patent drawingFigure 3

AI summary

The mechanism has a clutch rocker (3) concentrically pivoted with a driving wheel (2) and carrying an intermediate wheel (4) that is in constant engagement with the driving wheel and engaged in gear teeth of a chronograph wheel (7) along a position of the rocker. A blocker (11) includes a blocking shoe (12) cooperating with the gear teeth, where the blocker and the rocker are subjected to return springs (16, 17). The blocker is supported against a control unit of the rocker under an action of one of the return springs of the blocker.