Flat Knitting Gauge Determination Using Needle-Height Correction

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Solution Overview

Problem

Existing methods for determining the number of stitches in knitted articles, such as those described in Patent Document 1, do not always yield optimal gauges, leading to inconsistencies in knitting widths and heights, especially when producing complex items like sweaters with varying parts, as the gauges in the height direction change significantly with knitting width and those in the width direction are less affected.

Innovation Solution

A method and system for converting pattern data into the number of stitches for a flat knitting machine, involving the knitting of multiple samples with varying numbers of needles, measuring stitch sizes, establishing relationships between needle numbers and stitch sizes, and using these relationships to determine the necessary number of knitting courses and needles for target dimensions, thereby correcting for the impact of needle count on stitch size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a constant knitting width is used for texture samples, then the measurement process is simplified, but the gauge determination becomes inaccurate for parts with different knitting widths

Engineering Contradiction:
Improvesimplicity of measurement processVSAvoidaccuracy of gauge determination
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention divides the gauge determination process into multiple segments: first determining a base gauge from a constant-width sample, then applying width correction coefficients to adjust for different actual knitting widths. This segmentation allows the simple measurement process to yield accurate results for varying widths through the correction step.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the parameter approach by introducing a width correction coefficient that adjusts the base gauge according to the actual knitting width. This parameter transformation allows the gauge to be accurately determined for different widths without re-measuring each width separately, thus maintaining measurement simplicity while improving accuracy.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If multiple texture samples with different knitting widths are measured, then accurate gauges for different parts can be obtained, but the measurement and processing complexity increases

Engineering Contradiction:
Improveaccuracy of gauge determinationVSAvoidcomplexity of measurement and processing
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention extracts the width-dependent gauge variation into a separate correction coefficient, isolating it from the base gauge measurement. This allows the majority of gauge determinations to use the simple base measurement, with only a correction step needed for width adjustments, thereby reducing overall complexity while maintaining accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The base gauge measurement serves a universal function for all knitting widths, and the width correction coefficient provides a multi-functional adjustment that can be applied to any width variation. This universal approach eliminates the need for separate measurement procedures for each width, reducing complexity while maintaining accuracy across different parts.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If the number of knitting courses is increased to compensate for inaccurate gauge, then the article can reach target size, but production time increases

Engineering Contradiction:
Improveachievement of target sizeVSAvoidproduction time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention performs preliminary gauge determination with width correction before actual production, establishing accurate needle and course counts in advance. This preliminary accurate determination prevents the need for time-consuming increases or decreases in knitting courses during production, thus achieving target size efficiently without production delays.

Inventive Principle:
Principle #10Preliminary action

4Manufacturing precision

If gauge correction is performed after knitting, then the target size can be achieved, but the number of knitting courses increases and productivity decreases

Engineering Contradiction:
Improveachievement of target sizeVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention performs gauge correction and determination of knitting parameters before the knitting process begins. By calculating the accurate number of needles and courses in advance using the width correction coefficient, the actual knitting can proceed directly without post-knitting adjustments, thus maintaining high productivity while achieving precise target dimensions.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2292820B1Method and design system for determining knitted article gauge
Publication Date: 2016.03.16 SHIMA SEIKI MFG LTD
  • EP2292820B1 patent drawingFigure 1
  • EP2292820B1 patent drawingFigure 2
  • EP2292820B1 patent drawingFigure 3

AI summary

In a method for determining the gauge of a knitted article (40) of the present invention, a plurality of samples (12, 13, 14) that are smaller than a knitted article (40) and different in the number of needles are knitted by using a flat knitting machine (10), and the height of each of the samples (12, 13, 14) is measured. A height function for converting the number of needles used for knitting the samples (12, 13, 14) into the size of stitches in a height direction is obtained on the basis of the measured height. Then the number of knitting courses for each part of the knitted article (40) is determined from the obtained height function, a target height and target width of each part of the knitted article (40). Accordingly, the number of knitting courses for a knitted article (40) can be determined easily and reliably.