Circular Knitting Machine Transferring Needle Loop Seaming

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Solution Overview

Problem

Existing methods for seaming knitted fabrics in circular knitting machines face issues with inconsistent loop size, reduced durability, and wasteful processes due to insufficient pin arrangements and unnecessary yarn consumption, leading to suboptimal quality and efficiency in closing the toe portion of socks.

Innovation Solution

A method and system where the number of knitting needles matches the transferring needles, allowing for precise alignment and joining of inner loops to match the size of outer loops, using a transferring needle unit and sewing machine to ensure consistent loop density and strength, and employing a transferring sinker mechanism to guide the loops for efficient seaming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the number of pins is smaller than the number of knitting needles and pins are arranged inside the knitting needle cylinder, then the apparatus structure is simplified, but the reliability of holding the same position constantly is insufficient

Engineering Contradiction:
Improveapparatus structureVSAvoidposition holding reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The transferring needle unit is divided into two halves that can be opened and closed. This segmentation allows the transferring needles to be positioned precisely relative to the knitting needles when closed, ensuring reliable position holding while keeping the overall structure manageable through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Transferring needles act as an intermediary between the knitting needles and the seaming process. The transferring needle unit provides a stable intermediate platform that ensures consistent positioning of knitted loops during transfer, resolving the reliability issue without requiring every pin to directly correspond to every knitting needle.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If inner loops are not divided into groups for joining, then the seaming process is simpler, but the loop size consistency and durability are reduced

Engineering Contradiction:
Improveseaming process complexityVSAvoidloop size consistency
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

Inner loops are divided into first and second loop groups that are joined sequentially. This segmentation allows for controlled joining of loops in stages, ensuring that each loop is properly formed and sized before the next is joined, thereby maintaining loop size consistency and durability while keeping the process manageable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first loop group is joined before the second loop group in a predetermined sequence. This preliminary action ensures that the foundation loops are properly established and sized before additional loops are incorporated, maintaining manufacturing precision throughout the seaming process.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If waste yarn portion and selvage are cut away during sewing, then the seaming can be completed, but yarn is wasted and time is consumed

Engineering Contradiction:
Improveseaming completionVSAvoidyarn waste
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The knitted fabric structure itself provides the necessary selvage and edge stability through the knitting process, eliminating the need for separate waste yarn portions and additional selvage creation. The transferring needle unit works directly with the existing fabric structure, allowing seaming completion without consuming extra yarn or time on unnecessary cutting operations.

Inventive Principle:
Principle #25Self-service

4Manufacturing precision

If the number of knitting needles matches the transferring needles for precise alignment, then loop size consistency is improved, but the device complexity increases

Engineering Contradiction:
Improveloop size consistencyVSAvoidneedle arrangement complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The matching of knitting needles and transferring needles is achieved through segmented arrangement where corresponding needles are positioned to match. This segmentation allows precise alignment for loop size consistency while maintaining manageable device complexity through organized, modular needle groups rather than a monolithic complex structure.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3187633B1Circular knitting machine knitted fabric seaming method and circular knitting machine system
Publication Date: 2019.03.06 NAGATA SEIKI
  • EP3187633B1 patent drawingFigure 1
  • EP3187633B1 patent drawingFigure 2
  • EP3187633B1 patent drawingFigure 3

AI summary

Provided are a knitted-fabric seaming method for a circular knitting machine for making a linking portion dense as with other loops, and a circular knitting machine system. Transferring needles (34) are advanced in an axial direction of knitting needles (21), such that the transferring needles (34) and the knitting needle (21) are continuous with each other in the axial direction. A tip-end protrusions (34e) of each of the transferring needles (34) is shifted inward. Transferring sinkers (49) are moved from the knitting needles (21) to the transferring needles (34) in the axial direction of the knitting needles (21). Tip-end protrusions (34e) of the transferring needles (34) are inserted into inner loops (26a) of a knitted fabric (27), which are located inside final loops (26) caught on the knitting needles (21), such that the knitted fabric (27) is transferred from the knitting needles (21) to the transferring needles (34). The inner loops (26a) transferred to the transferring needles (34) are linked. The size of each of the loops to be linked becomes smaller in comparison with the case where the final loops are transferred to the transferring needles to perform the linking. Thus, it is possible to make a linking portion dense as with other loops, so as to increase durability and the quality of the outer appearance.