Optical Measurement of Archimedean Spiral Spring Oscillation

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Solution Overview

Problem

Current methods for determining the vibration behavior of spiral springs in mechanical clockworks are time-consuming and not automated, particularly for Archimedean and logarithmic curves, and do not allow for non-invasive, non-contact measurement in assembly lines.

Innovation Solution

An optical measuring method that detects the deflection of adjacent turns of the spiral spring during oscillation by varying the distance between them, using laser measurement or laser scanning, and calculates the oscillation range and frequency based on angular displacement, optimized for use in automated assembly lines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional contact-based measurement methods are used to determine vibration behavior of spiral springs, then measurement can be performed, but the process is time-consuming and not automated

Engineering Contradiction:
Improvemeasurement speedVSAvoidautomation capability
Core Design Contradiction:
ProductivityVSExtent of automation

Solution Approach 1:

The patent replaces mechanical contact-based measurement systems with an optical measurement system. A camera captures images of the spiral spring during oscillation, and image processing algorithms automatically determine vibration behavior parameters. This substitution eliminates manual intervention and enables automated, high-speed measurement suitable for production environments.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates an optical copy (image) of the spiral spring during its oscillation. By capturing the position of marker elements on the spiral spring through camera imaging, the system obtains a visual replica that can be processed computationally to extract vibration parameters, enabling non-contact and automated measurement.

Inventive Principle:
Principle #26Copying

2Extent of automation

If non-contact optical measurement is implemented, then automation and speed improve, but precise detection of small deflections becomes more difficult

Engineering Contradiction:
Improveautomation capabilityVSAvoiddetection precision
Core Design Contradiction:
Extent of automationVSDifficulty of detecting and measuring

Solution Approach 1:

The patent divides the spiral spring structure into discrete marker elements positioned at specific locations. By tracking the position changes of these individual markers during oscillation, the system can precisely measure small deflections. The segmentation of measurement points enables accurate detection of local movements that contribute to overall vibration behavior.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses marker elements with distinct visual characteristics (such as contrasting colors or reflective properties) that stand out against the spiral spring background. These markers enhance the contrast in captured images, making it easier for image processing algorithms to accurately detect and track their positions, thereby improving measurement precision.

Inventive Principle:
Principle #32Color changes

3Ease of manufacture

If constant distance between adjacent coils is maintained, then manufacturing is simplified, but optical detection of deflection becomes less accurate

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidoptical detection accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent incorporates marker elements during the manufacturing process of the spiral spring. These markers are pre-positioned at optimized locations that maximize the sensitivity of optical detection for the expected oscillation modes. By preparing the measurement system in advance during manufacturing, the subsequent optical measurement achieves higher precision without complicating the core spring fabrication.

Inventive Principle:
Principle #10Preliminary action

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

Enables precise, automated measurement of spiral spring vibration behavior, reducing assembly time and improving accuracy by allowing non-invasive, non-contact monitoring of oscillation width and frequency, suitable for high-volume clockwork production.

Implementation Method 1

a deflection of adjacent coils relative to one another and along their respective circular paths is optically detected based on a variance in the distance between the adjacent coils along the coil section

Methodology Applied
Scientific EffectLaser measurement: LIDAR

Implementation Method 2

using laser measurement or laser scanning

Methodology Applied
Scientific EffectLaser scanning: LIDAR

Data Source

PatentEP4398046A1Optical measurement method for archimedean flat spirals and spiral spring with geometry optimized therefor
Publication Date: 2024.07.10 DAMASKO PRÄZISIONSTECHNIK GMBH & CO KG
  • EP4398046A1 patent drawingFigure 1
  • EP4398046A1 patent drawingFigure 2~3
  • EP4398046A1 patent drawingFigure 4

AI summary

The invention relates to a spiral spring (100), suitable for use in an optical measuring method according to one of the preceding claims, with several turns (110) extending along respective circular paths to form a spiral path, which spiral spring (100), particularly for timing a mechanical clockwork, can be excited to an oscillating motion, wherein adjacent turns (110) are deflected along their respective circular paths by an angular displacement (β) relative to each other. It is the object of the present invention to determine the oscillation behavior of spiral springs based on characteristic geometries, and in particular to provide a non-invasive, non-contact measuring method that can be used in automated assembly lines in the line assembly of clockworks.The problem is solved by varying the distance (x) between the adjacent turns (110) at least along a measuring section corresponding to the angular displacement (β).