Chronograph Watch Variable Gear Ratio for Selective Scale Resolution
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Solution Overview
Problem
Existing chronograph-watches provide uniform resolution across all time or auxiliary indications, failing to prioritize subsets of interest and often compromise readability when variable detail is needed.
Innovation Solution
A chronograph-watch mechanism with a variable gear ratio between mobiles, allowing the indicator member to rotate at varying speeds to enhance readability and detail in specific subsets of the scale, using logarithmic spiral-shaped cams to manage torque and alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the indicator member rotates at constant speed with uniform scale divisions, then the readability is consistent across all indications, but the resolution for specific subsets of interest cannot be enhanced
Solution Approach 1:
The patent applies the dynamics principle by making the indicator member rotate at variable speed instead of constant speed. The rotation speed is dynamically adjusted based on the angular position, with faster rotation in regions of less interest and slower rotation in regions of interest (such as tachometric, pulsometric, or telemetric zones). This dynamic speed variation allows the scale to provide enhanced resolution for specific subsets while maintaining overall readability across the entire scale.
Solution Approach 2:
The patent implements local quality by creating different measurement resolutions in different regions of the scale. The scale is divided into zones with varying densities of divisions, where regions of interest (such as specific speed ranges for tachometry or heart rate ranges for pulsometry) have finer divisions for higher precision, while other regions have coarser divisions. This local differentiation of quality allows enhanced measurement precision where needed without compromising overall readability.
2Measurement precision
If the scale has variable distance between indications to prioritize subsets, then the resolution for specific subsets improves, but the readability may be compromised when uniform detail is needed
Solution Approach 1:
Rather than using a static scale with variable division distances, the patent employs a dynamic approach where the indicator member's rotation speed varies continuously with angular position. This allows the system to maintain a uniform scale appearance while achieving variable resolution through speed modulation. The dynamic speed adjustment ensures that fine detail is visible in regions of interest without distorting the overall scale geometry, thereby preserving readability across all regions.
3Measurement precision
If the indicator member rotates faster in regions of interest, then the resolution and detail for those regions improve, but the time to traverse other regions increases
Solution Approach 1:
The patent resolves this time-resolution trade-off by implementing dynamic speed variation during the measurement process. The indicator member rotates faster through regions of less interest, allowing quick traversal, and automatically slows down when passing through regions of interest, providing enhanced detail and resolution. This dynamic adjustment occurs continuously during operation, optimizing both time efficiency and measurement precision without requiring manual intervention or sacrificing time in either region type.
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
Improves readability and resolution in subsets of interest by varying the indicator member's speed, enabling more precise information display without compromising overall readability.
Implementation Method 1
the first mobile and the second mobile are arranged to obtain a gear ratio between the first mobile and the second mobile that varies as a function of their relative angular position
Implementation Method 2
using logarithmic spiral-shaped cams to manage torque and alignment
Data Source
AI summary
The present disclosure relates to a chronograph-watch comprising a timepiece mechanism. The timepiece mechanism includes: a current time mobile comprising an axis and being arranged to rotate about this axis, a first mobile comprising an axis and being arranged to be connected to the current time mobile, an indicator member, a second mobile arranged to mesh with the first mobile and to be connected to the said indicator member, an element bearing a scale comprising a set of indications, the indicator member allowing information to be displayed on this scale. The mobiles are arranged so as to obtain a gear ratio between the mobiles which varies as a function of their relative angular position, so that the indicator member rotates with a variable rotational speed in correspondence with at least one subset of said set of indications.