Coaxial Toe-Closing Mechanism for Circular Knitting Machines

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Solution Overview

Problem

Current circular knitting machines for producing stockings and socks face inefficiencies in toe closing processes, leading to reduced production quantities and quality due to the need for manual intervention or external mechanical devices that halt production and require frequent adjustments.

Innovation Solution

A system integrating a coaxial pick-up device within the knitting machine that allows for continuous tubular production by picking up semi-finished articles and transferring them to an overturning mechanism for internal toe sewing, enabling simultaneous production without interruptions and minimizing material waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If autonomous mechanical accessories are applied to close the toe directly on the knitting machine, then automation of toe closing is improved, but tubular production must be halted and productivity decreases

Engineering Contradiction:
Improveautomation of toe closingVSAvoidquantitative production
Core Design Contradiction:
Extent of automationVSProductivity

Solution Approach 1:

The patent implements a dual-cylinder system where while one cylinder is performing toe closing operations on a completed tubular article, the other cylinder continues knitting new tubular articles. This allows the toe closing operation to proceed without interrupting the continuous production of tubular knitted goods, thereby maintaining productivity while achieving automation of the finishing process

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The knitting machine is divided into two independent working cylinders, each capable of autonomous operation. One cylinder is dedicated to tubular production while the other handles toe closing, allowing both operations to occur simultaneously and independently, thus resolving the conflict between automation and continuous production

Inventive Principle:
Principle #1Segmentation

2Extent of automation

If external mechanical devices are used for toe closing, then automation is achieved, but continuous adjustments and checks are required during production

Engineering Contradiction:
Improveautomation of toe closingVSAvoidproduction stability
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The toe closing function is merged with the knitting machine itself by integrating a second cylinder directly onto the machine structure. This unified system eliminates the need for external devices that require frequent adjustments, as the integrated cylinder operates synchronously with the knitting process under the same control system, thereby improving reliability and reducing maintenance interruptions

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If the knitting machine is stopped for toe closing operations, then quality control is improved, but production time increases and efficiency decreases

Engineering Contradiction:
Improvequality of toe closingVSAvoidproduction interruption time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The tubular article is completely knitted and prepared for toe closing before the actual closing operation begins. The second cylinder is pre-positioned and ready to receive the completed tubular article, allowing the toe closing to start immediately without any interruption to the overall production flow, thus eliminating time loss while maintaining quality

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2024544B1Method and integrated system for knitting a stocking on a circular knitting machine and for closing the toe of the stocking
Publication Date: 2011.04.20 NTA INC
  • EP2024544B1 patent drawingFigure 1
  • EP2024544B1 patent drawingFigure 1A~1B
  • EP2024544B1 patent drawingFigure 2

AI summary

It concerns a system that allows to close the point of a stitch circular product, and particularly of a stocking, without breaking off the sewing operations, with a circular device that is inserted inside the cylinder that works the stocking and that, opportunely programmed, goes to catch hold of the stitch under the needles in order than to drag it to the sewing machine.