Chronograph Watch Countdown Display Mechanism

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Solution Overview

Problem

Existing chronograph watches lack a simple and legible way to display both upward and downward time intervals, particularly in regatta applications, with complex mechanisms and poor readability during countdown phases.

Innovation Solution

A chronograph watch design where the chronograph minute hand can be driven clockwise in both chronograph and countdown modes, with a countdown minute disc connected via its own gear train, allowing seamless switching and improved readability through a differential gear mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a separate countdown minute hand is used to display countdown time, then the countdown function is achieved, but the mechanism complexity increases due to series-connected clutches

Engineering Contradiction:
Improvecountdown functionVSAvoidmechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The chronograph minute hand is designed to perform dual functions: displaying both chronograph time (when driven clockwise) and countdown time (when driven counterclockwise). This eliminates the need for a separate countdown minute hand and the complex series-connected clutch mechanism, while maintaining full countdown functionality

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

Solution Approach 2:

The patent merges the chronograph minute hand and countdown minute hand into a single hand that can rotate in both directions. The parallel-connected clutch mechanism allows both the chronograph and countdown functions to drive the same hand simultaneously or independently, simplifying the overall mechanism

Inventive Principle:
Principle #5Merging (Combining)

2Loss of information

If the chronograph minute hand rotates counterclockwise for countdown mode, then the mode distinction is clear, but smooth transition between modes becomes difficult

Engineering Contradiction:
Improvemode clarityVSAvoidmode transition
Core Design Contradiction:
Loss of informationVSEase of operation

Solution Approach 1:

The patent implements a dynamic system where the minute hand can rotate in both clockwise and counterclockwise directions depending on the active mode. The parallel clutch mechanism allows smooth transitions between modes by engaging or disengaging drive paths without requiring the hand to reverse direction abruptly, combining mode clarity with operational smoothness

Inventive Principle:
Principle #15Dynamics

3Loss of information

If the chronograph minute hand rotates in opposite directions for chronograph and countdown modes, then mode identification is improved, but the mechanism complexity increases

Engineering Contradiction:
Improvemode identificationVSAvoidmechanism complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

A single chronograph minute hand serves both chronograph and countdown functions by rotating in different directions. The parallel clutch mechanism enables this multi-functionality by allowing independent engagement of clockwise drive (chronograph) and counterclockwise drive (countdown), achieving mode identification without requiring separate hands or complex switching mechanisms

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

Data Source

PatentEP2239638B1Chronographic watch with adjustable countdown display
Publication Date: 2013.07.31 RICHEMONT INTERNATIONAL SA
  • EP2239638B1 patent drawingFigure 1
  • EP2239638B1 patent drawingFigure 2
  • EP2239638B1 patent drawingFigure 3a

AI summary

The watch has a chronograph display unit (1) with a chronograph second needle (1.1) and a chronograph minute needle (1.2). The display unit is attachably and detachably connected with an energy source and a regulating unit of a chronograph mechanism by wheel works. The chronograph minute needle is operated in clockwise direction in a chronograph mode and countdown mode. An initial position of the minute needle is adjusted in counterclockwise direction in the countdown mode. A drive of the minute needle changes from the countdown mode into the chronograph mode.