Split-Knitting Yarn Load Reduction via Differential Loop Lengths

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Solution Overview

Problem

The existing methods for split-knitting in flatbed knitting machines face challenges in maintaining knitting efficiency and preventing yarn breakage when knit and split knit operations are performed in the same knitting course, as the increased resistance from stitch transfer can lead to yarn breakage due to identical loop lengths.

Innovation Solution

A method that adjusts the drawing amount of knitting needles using a 2nd stitch cam and presser mechanism, allowing for different loop lengths in split knit stitches by altering the needle selection positions and actions of the stitch cam, reducing the load on the yarn and preventing breakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the same loop length is used for both knit and split knit stitches, then the knitting operation is simplified, but yarn breakage occurs due to increased resistance from stitch transfer

Engineering Contradiction:
Improveknitting operation complexityVSAvoidyarn breakage prevention
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies local quality by assigning different loop lengths to different stitch types: knit stitches use a first loop length while split knit stitches use a second loop length. This localized differentiation allows the stitch transfer operation to proceed with reduced yarn resistance and prevents yarn breakage, while maintaining operational simplicity through automated needle selection based on pattern requirements.

Inventive Principle:
Principle #3Local quality

2Reliability

If different loop lengths are used for knit and split knit stitches, then yarn breakage is prevented, but the knitting operation complexity increases

Engineering Contradiction:
Improveyarn breakage preventionVSAvoidknitting operation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements self-service through the needle selection mechanism that automatically identifies and selects needles for split knit stitches based on the knitting pattern. This automation eliminates the need for manual intervention to manage different loop lengths, allowing the system to handle the complexity of differentiated stitch lengths while maintaining operational efficiency and preventing yarn breakage.

Inventive Principle:
Principle #25Self-service

3Productivity

If stitch transfer is performed in the same knitting course as knit operations, then knitting efficiency is improved, but yarn resistance increases leading to potential yarn breakage

Engineering Contradiction:
Improveknitting efficiencyVSAvoidyarn breakage prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies parameter changes by modifying the loop length parameter specifically for split knit stitches performed in the same knitting course as knit operations. By setting the second loop length for split knit stitches differently from the first loop length of knit stitches, the system reduces yarn resistance during stitch transfer operations, preventing yarn breakage while maintaining the efficiency benefit of concurrent operations.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2942428B1Method for split-knitting
Publication Date: 2016.11.30 SHIMA SEIKI MFG LTD
  • EP2942428B1 patent drawingFigure 1
  • EP2942428B1 patent drawingFigure 2
  • EP2942428B1 patent drawingFigure 3(a)~3(b)

AI summary

[Problem to be solved] It is an object to provide a method for split- knitting capable of achieving stable knitting without deteriorating knitting efficiency with no risk of yarn breakage even when knit and split knit are mixed in the same knitting course. [Solution] A cam system 6 is set for a stitch transfer operation and a knitting needle retaining an old stitch is made to advance to a needle bed gap 8 at a stitch sending side. For example, when a carriage runs leftward, an operation of the knit is performed in such a manner that the knitting needle is drawn into a needle bed by a stitch cam 12 with needle selection to an A position. An operation at a sending side of the split knit is performed in such a manner that drawing of the knitting needle by the stitch cam 12 is not made with pressing only by a half presser 21 for the following side with needle selection to a H position. A drawing amount when a sending-side stitch is formed on a knitting needle at the sending side can be reduced to be smaller than a drawing amount when a new stitch is formed in the knit, thereby reducing load on a knitting yarn.