Circular Knitting Machine Motion Control for Garment Fit and Speed

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Solution Overview

Problem

Existing methods for producing seamless garments with two leg pieces and a body, such as tights, on a circular knitting machine are inefficient, resulting in poor fit and slow production due to the use of either continuous or reciprocating motion, which limits the garment's snugness and production speed.

Innovation Solution

A method that combines continuous and reciprocating motion on a circular knitting machine, using multiple feeds to knit leg pieces and body sections, with specific sequences of partial rows of varying lengths to form side pockets and a central portion, optimizing motion direction and needle selection to enhance fit and production speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If reciprocating motion is used to knit the body portion, then the garment fit is improved, but the production speed decreases

Engineering Contradiction:
Improvegarment fitVSAvoidproduction speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The body portion is divided into two separate pockets of fabric, each knitted with reciprocating motion to achieve proper fit. This segmentation allows the critical fit areas to be produced with high precision while other portions can use faster continuous motion

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different knitting motions are applied to different regions: reciprocating motion is used specifically for the body pockets where fit is critical, while continuous motion is used for leg pieces where speed is more important. This local differentiation optimizes both fit and production speed

Inventive Principle:
Principle #3Local quality

2Productivity

If continuous motion is used to knit the entire garment, then the production speed increases, but the garment fit deteriorates

Engineering Contradiction:
Improveproduction speedVSAvoidgarment fit
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The garment is segmented into different knitting zones: leg pieces knitted with continuous motion for speed, and body pockets knitted with reciprocating motion for fit. This allows the majority of the garment to be produced quickly while only the critical areas use the slower reciprocating motion

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Continuous motion is applied to the leg pieces where high production speed is prioritized, while reciprocating motion is applied locally to the body pockets where proper fit is essential. This localized application of different knitting modes resolves the contradiction between speed and fit

Inventive Principle:
Principle #3Local quality

3Device complexity

If the body is knitted with the same number of stitches per row as the leg pieces, then the production process is simplified, but the body height is insufficient and the elastic edge is too close to the crotch line

Engineering Contradiction:
Improveknitting process complexityVSAvoidbody height
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The body is segmented into two separate pockets of fabric with different stitch counts. Each pocket is knitted with reciprocating motion and can have a different number of stitches per row, allowing independent optimization of body height without complicating the overall process

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The number of stitches per row is changed for the body pockets compared to the leg pieces. By using reciprocating motion, the machine can accommodate variable stitch counts in different sections, allowing the body pockets to have more stitches for increased height while maintaining a relatively simple knitting process

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3058125B1Method and machine for producing a knitted article with body and leg pieces, and article thus obtained
Publication Date: 2020.10.14 GOLDEN LEDI CO SPA
  • EP3058125B1 patent drawingFigure 1~2
  • EP3058125B1 patent drawingFigure 3
  • EP3058125B1 patent drawingFigure 4

AI summary

According to the invention, a garment (1) is produced, comprising two leg pieces (3, 5) and a body, wherein the body (7)comprises two side pockets (17, 19) of fabric and preferably a central portion (15) between the two side pockets. The body is produced with a plurality of feeds of yarns. Moreover, the pockets are formed with reciprocating motion and the central portion with continuous motion of the needle cylinder.