Moon Phase Display Mechanism with Hemisphere Switching

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Solution Overview

Problem

Existing moon phase display mechanisms in watchmaking do not accurately account for the correct lunar crescent display in both the northern and southern hemispheres, making it difficult for users to interpret the phases correctly, especially with double moon phases.

Innovation Solution

A moon phase display mechanism featuring a control wheel that drives a moon phase disc behind a dial aperture, utilizing heart-shaped cams and a double lever system to allow direct reading and instantaneous switching between northern and southern hemisphere views without additional components or complex mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a traditional moon phase display mechanism is used, then the mechanism is simple and space-saving, but it cannot properly display the correct lunar phase for both northern and southern hemispheres simultaneously

Engineering Contradiction:
Improvehemisphere adaptabilityVSAvoidmechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a dynamic control system where a control wheel with two positions allows the user to switch between northern and southern hemisphere displays. This dynamic switching mechanism enables the same physical mechanism to adapt to different hemispheric requirements without requiring separate mechanisms for each hemisphere, thus improving adaptability while maintaining relatively simple device complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The moon phase disc is segmented into two distinct patterns: one showing the correct lunar phases for the northern hemisphere and another for the southern hemisphere. By dividing the disc into these two functional segments and using a control wheel to select which segment is visible through the aperture, the mechanism achieves hemisphere adaptability without requiring complex multi-component systems.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If a complex mechanism with multiple stacked discs is used to display detailed moon phases, then the visualization is more detailed, but the device complexity increases and additional components must be managed

Engineering Contradiction:
Improvemoon phase display precisionVSAvoidmechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of using multiple stacked discs with different levels of detail, the patent applies local quality by incorporating both northern and southern hemisphere phase patterns directly onto a single moon phase disc. Each region of the disc is designed with the specific phase orientation needed for its corresponding hemisphere, allowing precise display for either hemisphere without requiring additional stacked components.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If fixed hemisphere-specific discs are fitted during watch assembly, then the moon phase display is accurate for a specific hemisphere, but the user cannot instantly change the visualization between hemispheres

Engineering Contradiction:
Improvemoon phase display accuracyVSAvoidhemisphere switching ease
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces the static, fixed-disc approach with a dynamic switching mechanism. A control wheel with two distinct positions can be operated by the user to instantly switch between northern and southern hemisphere displays. This dynamic design maintains accurate moon phase display for the selected hemisphere while providing ease of operation for changing between hemispheres at any time during use.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3098671B1Clock mechanism for displaying the lunar phase
Publication Date: 2019.10.09 MONTRES BREGUET SA
  • EP3098671B1 patent drawingFigure 1~2
  • EP3098671B1 patent drawingFigure 3~5
  • EP3098671B1 patent drawingFigure 6

AI summary

Moon phase display mechanism (1) comprising a control wheel (30) driven by a movement (900), which drives a moon phase disc (20) behind an aperture (11) of a dial (10). This mechanism (1) comprises, coaxial, superimposed, and permanently driven in opposite directions, a first phase indicator wheel (110) carrying a first heart-cam (80), and a second phase indicator wheel (100) carrying a second heart-cam (90), and said control wheel (30) comprises guiding means (31) for a double lever (40) comprising two arms (43; 53) of which only one at a time is arranged to cooperate in contact with one of said second (90) and first heart-cams (80), each to display the phase of the moon visible in one of the Northern or Southern hemispheres, and to permit the pivoting of said moon phase disc (20) in the appropriate direction for said hemisphere.