Flat Knitting Machine Weft Thread Insertion via Needle Selection

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Solution Overview

Problem

Existing flat knitting machines lack an efficient method to insert and secure a weft thread within the same knitting row, requiring a separate thread guide and struggling to integrate the weft thread effectively for design and technical textile applications.

Innovation Solution

A flat knitting machine equipped with at least two knitting systems, a first thread guide, and a hold-down device that allows the weft thread to be inserted and secured by controlling needle selection, enabling simultaneous weft insertion and stitch formation, and allowing for repeated weft insertion and stitch formation in a knitting row without a separate weft thread guide.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a separate thread guide is used for inserting weft thread, then the weft thread can be inserted into the knitted fabric, but the device complexity increases and a dedicated weft thread guide is required

Engineering Contradiction:
Improveweft thread insertion capabilityVSAvoidthread guide system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The existing thread guide system is made multi-functional by enabling it to perform both its original function (guiding threads for stitch formation) and a new function (inserting weft threads). This is achieved through programmable needle selection that allows the thread guide to operate in different modes without requiring a separate dedicated weft thread guide, thus reducing device complexity while maintaining versatility

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

Solution Approach 2:

The function of inserting weft threads is merged with the existing thread guide system and knitting process. By combining these functions into a single integrated system controlled by programmable needle selection, the patent eliminates the need for separate dedicated components, thereby reducing overall device complexity while achieving weft thread insertion capability

Inventive Principle:
Principle #5Merging (Combining)

2Productivity

If the weft thread is inserted in the same knitting row as stitch formation, then productivity increases, but the manufacturing precision decreases due to potential thread displacement

Engineering Contradiction:
Improveknitting row efficiencyVSAvoidweft thread positioning
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The hold-down device is activated in advance to secure the weft thread in its inserted position before the knitting system continues its operation. This preliminary securing action prevents thread displacement during subsequent knitting operations in the same row, thereby maintaining manufacturing precision while allowing simultaneous weft insertion and stitch formation to improve productivity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The hold-down device acts as an intermediary element between the inserted weft thread and the knitting process. It provides temporary mechanical support and positioning for the weft thread, ensuring it remains in the correct position during stitch formation without requiring separate positioning steps, thus maintaining precision while enabling simultaneous operations for higher productivity

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If needle selection is used to control stitch formation, then the ease of operation increases through programmable control, but the device complexity increases due to additional control mechanisms

Engineering Contradiction:
Improvethread function controlVSAvoidneedle selection system
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The needle selection system is designed to automatically determine whether to form stitches or insert weft threads based on programmed instructions. The system serves itself by using the same control mechanism for both functions, eliminating the need for separate control systems for weft insertion and stitch formation, thereby improving ease of operation without proportionally increasing device complexity

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3309282B1Flat knitting machine for loading weft threads
Publication Date: 2022.02.09 KARL MAYER STOLL R&D GMBH
  • EP3309282B1 patent drawingFigure 1
  • EP3309282B1 patent drawingFigure 2a~2b
  • EP3309282B1 patent drawingFigure 3a~3d

AI summary

A flat knitting machine configured to insert a first yarn as a weft yarn in the same knitting row and to knit with it, comprising at least one first and one second knitting system (S1, S2) and a first yarn guide (FF1) associated with the first knitting system (S1) which guides a first yarn, and at least one holding device (NH) arranged between the knitting systems (S1, S2) for holding down the first yarn, and a needle selector configured to select needles in the area of ​​the first knitting system (S1) when appropriately controlled to form stitches, wherein the first yarn is inserted as a weft yarn when the needle selector is not controlled.