Rotating Disc Mechanism for Simultaneous Civil and Solar Time Display

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Solution Overview

Problem

Current display technologies for timepieces either require complex mechanisms for direct solar time reading or only allow indirect calculation of solar time, lacking simplicity in production and usability.

Innovation Solution

A display device with a rotating disc and hand mechanism that simultaneously indicates civil and solar time minutes using a single hand, driven by an equation of time cam, allowing direct reading of solar time with a simple drive mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a hand offset from the civil time hands is used to display equation of time, then the display is simple to produce, but direct reading of solar time is not allowed

Engineering Contradiction:
Improvesimplicity of productionVSAvoiddirect reading of solar time
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The patent introduces a second rotational dimension by adding a rotating disc that can independently rotate relative to the fixed dial. The single hand simultaneously indicates civil time relative to the fixed dial and solar time relative to the rotating disc, enabling direct solar time reading without requiring a separate offset hand or complex mechanism.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If two minute hands are used for working equation of time display, then direct solar time reading is allowed, but the mechanism becomes complicated

Engineering Contradiction:
Improvedirect reading of solar timeVSAvoidcomplexity of mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the functions of two separate minute hands into a single hand that operates on a dual-reference system. The hand indicates civil time minutes relative to the fixed dial and solar time minutes relative to the rotating disc, thereby achieving direct solar time reading while eliminating the need for two hands and their associated complex drive mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

By introducing the rotating disc as an intermediate reference frame, the patent enables a single hand to perform dual functions. The hand's position is interpreted differently depending on the reference frame (fixed dial for civil time, rotating disc for solar time), thus simplifying the mechanism while maintaining direct solar time readability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If two minute hands rotate one revolution per hour in synchronism, then solar time can be displayed, but the drive mechanism becomes complicated

Engineering Contradiction:
Improvesolar time displayVSAvoidcomplexity of drive mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines the synchronous rotation function into a single rotating disc that turns once per hour, driven by a simple mechanism connected to the civil time minute hand. This eliminates the need for complex synchronous drive mechanisms for two separate hands while achieving the same solar time display effect.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2187272B1Device for timepiece display
Publication Date: 2011.10.26 LOUIS VUITTON MALLETIER SA
  • EP2187272B1 patent drawingFigure 1~2
  • EP2187272B1 patent drawingFigure 3~6
  • EP2187272B1 patent drawingFigure 4~5

AI summary

The device has a rotative hour hand (3) moving at a rate of one turn per hour, and a rotative disk (5) rotating concentrically with the rotative hour hand. A driving mechanism i.e. finger, drives the disk such that angular position of the disk with respect to a dial (1) at a given instant corresponds to difference between minutes of solar time and minutes of civil time for permitting a rotative minute hand (4) to indicate the minutes of civil and solar times simultaneously by angular positions of the minute hand with respect to the dial and the disk.