Rocker Wheel Scanner Carriage for Alignment Precision

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Solution Overview

Problem

Existing on-line sensor systems for measuring sheet material properties during manufacturing face challenges in maintaining accurate alignment and minimizing displacement errors, particularly due to sinusoidal track deflections and random vertical deflections caused by debris or wheel concentricity issues, which affect the precision of cross-directional measurements.

Innovation Solution

A roller carriage system with pivot mechanisms and tandem wheels, where the wheel spacing is optimized to match the interval distances of track supports, allowing for independent wheel movement to maintain a horizontal carriage plane and reduce vertical deflections, ensuring a smooth, linear path and improved alignment accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the sensor system uses a standard roller carriage on tracked rails, then the system can traverse the width of the sheet material, but sinusoidal track deflections cause vertical carriage displacement and alignment errors

Engineering Contradiction:
Improvetraverse capabilityVSAvoidalignment accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent applies the dynamics principle by implementing a rocker mechanism that allows the carriage to dynamically adapt to track deflections. The rocker assembly enables the carriage to pivot and maintain a horizontal orientation despite sinusoidal track variations, transforming a static rigid mounting into a dynamic adaptive system that compensates for track imperfections during traversal.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent addresses alignment errors by introducing a rotational degree of freedom through the rocker mechanism. This adds another dimension (rotation/pivoting) to the otherwise linear traversal motion, allowing the carriage to compensate for vertical displacements caused by track deflections while maintaining proper sensor alignment.

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

2Ease of manufacture

If the wheel spacing is not optimized, then the carriage structure is simpler to design, but alignment errors increase due to sinusoidal track deflections

Engineering Contradiction:
Improvecarriage design simplicityVSAvoidalignment accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by optimizing the wheel spacing to specific values that correspond to the track support intervals. This parameter optimization minimizes the amplitude of sinusoidal track deflections experienced by the carriage, thereby reducing alignment errors while maintaining a relatively simple carriage structure that does not require complex active compensation mechanisms.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If tandem wheels are used with independent movement capability, then vertical deflections are reduced and alignment is improved, but the device complexity increases

Engineering Contradiction:
Improvealignment accuracyVSAvoidcarriage mechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamics by giving the tandem wheels independent movement capability through the rocker mechanism. This allows each wheel to independently respond to vertical track deflections, maintaining contact with the track surface while reducing the transmission of deflections to the sensor carriage, thereby improving alignment accuracy through dynamic adaptation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies segmentation by dividing the wheel assembly into independent tandem wheels that can move relative to each other through the rocker mechanism. This segmentation allows each wheel to independently accommodate track irregularities, reducing the overall impact on carriage alignment while maintaining a relatively simple modular structure.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2431733B1Rocker wheel system for scanner carriages
Publication Date: 2013.07.03 HONEYWELL ASCA INC
  • EP2431733B1 patent drawingFigure 1~3
  • EP2431733B1 patent drawingFigure 4~6
  • EP2431733B1 patent drawingFigure 5A~5B

AI summary

A sensor head-transporting roller carriage has four pairs of wheels acting around pivot points at the four corners of the carriage, which is advanced along tracks that are supported by vertical structures. The lateral wheel spacing is chosen in correlation with the track support interval distances such that the vertical travel of all the wheels together is averaged to be zero. As a result, variations in displacement alignment of the sensor are minimized. In addition, the pivot mechanism results in a fifty percent reduction in the effect of random vertical deflections caused by track debris or wheel concentricity etc. versus standard non-pivoting wheel sets. The roller carriage moves the sensor head along the cross direction to monitoring physical characteristics of a web of material that is moving in the machine direction.