Knit Design Apparatus Yarn Catching Prevention

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Solution Overview

Problem

In intarsia knitting, yarns from adjacent pattern portions can get caught at the boundary, leading to unclear patterns, especially at smaller gauges and higher speeds, and existing solutions either prevent catching by splitting stitch rows or lower knitting efficiency.

Innovation Solution

A knit design apparatus that detects potential yarn catching using detection means and modifies knitting data to replace specific stitches with miss stitches or stitches from adjacent pattern portions, preventing yarn catching without reducing knitting speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If knitting is performed at high speed with small gauge, then productivity is improved, but yarn catching occurs more frequently at pattern boundaries

Engineering Contradiction:
Improveknitting speedVSAvoidyarn catching prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs preliminary detection of potential yarn catching conditions by analyzing the relationship between needle positions, yarn feeder positions, and carriage travel direction before knitting occurs. When a problematic condition is detected, the carriage travel direction is reversed in advance to prevent the yarn catching issue from occurring during high-speed knitting operations

Inventive Principle:
Principle #10Preliminary action

2Reliability

If stitch rows are split into two separate courses, then yarn catching is prevented, but knitting efficiency is reduced

Engineering Contradiction:
Improveyarn catching preventionVSAvoidknitting efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Instead of statically splitting all stitch rows into two separate courses, the system dynamically determines whether to split based on real-time analysis of needle allocation, yarn feeder positions, and carriage travel direction. The carriage travel direction is dynamically reversed only when necessary to prevent yarn catching, allowing continuous knitting in most cases and maintaining high efficiency while preventing yarn catching when needed

Inventive Principle:
Principle #15Dynamics

3Productivity

If needle allocation at pattern boundaries is not carefully controlled, then knitting speed is maintained, but pattern clarity is reduced due to yarn catching

Engineering Contradiction:
Improveknitting speedVSAvoidpattern clarity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The system incorporates feedback mechanisms that continuously monitor needle allocation, yarn feeder positions, and carriage travel direction. When the analysis indicates a potential yarn catching condition at a pattern boundary, the system provides feedback to reverse the carriage travel direction, thereby maintaining both high knitting speed and clear pattern definition by preventing yarn catching

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2492382B1Knit design apparatus
Publication Date: 2015.03.25 SHIMA SEIKI MFG LTD
  • EP2492382B1 patent drawingFigure 1
  • EP2492382B1 patent drawingFigure 2~3
  • EP2492382B1 patent drawingFigure 4~5

AI summary

In a course in which a cam system (C1) on the front side in the travelling direction of a carriage (34) of a flat knitting machine (32) knits a first knitted fabric (A) on the rear side in the travelling direction with respect to the boundary between intarsia pattern portions and a cam system (C2) on the rear side in the travelling direction knits a second knitted fabric (B) on the front side in the travelling direction with respect to the boundary, a knit design apparatus (2) detects from knitting data a stitch that is at an end of the first knitted fabric (A) and that projects further to the front side in the travelling direction than a course knitted immediately before, as a first stitch (K3-2, 45). In a case where the first stitch (K3-2, 45) is detected, a second stitch (46) in the second knitted fabric (B) positioned one course below the first stitch (K3-2, 45) is replaced by a miss stitch.