Circular Knitting Machine Turner Mechanism for Internal Seam Closure

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Solution Overview

Problem

Existing hosiery and knitwear circular machines face challenges in efficiently closing the ends of tubular articles, such as socks, with solutions either requiring complex modifications, producing unsightly external seams, or being difficult to implement and prone to wear and tear.

Innovation Solution

A circular machine with a turner mechanism that aligns axially with the cylinder, allowing the tubular article to be extracted and turned inside out, then repositioned to align stitches on opposite needles for internal seam formation, using a transferring apparatus and synchronized movement of the head and yarn stations to facilitate this process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the tubular article is kept sucked upwards within a recess during production, then the article can be closed from the inside, but the machine requires substantial modifications and the operation becomes extremely complex

Engineering Contradiction:
Improveinternal seam closureVSAvoidmachine structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies inversion by turning the tubular article inside out after production but before closing. This allows the closing operation to be performed on the inverted article, creating an internal seam that will be hidden inside the final product. The article is extracted from the cylinder, turned inside out by a turner mechanism, and then the ends are joined using the cylinder needles, achieving internal seam closure without requiring the article to be kept inverted during production.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent applies preliminary action by performing the turning inside out operation after production but before the closing operation. This preliminary inversion prepares the article for internal seam closure, allowing the seam to be formed on the inside of the final product. The turner mechanism inverts the article, and then the closing operation is performed on the inverted state, achieving the desired internal seam configuration.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the article is turned inside out during production, then internal seam closure is achieved, but the space above the cylinder is occupied by machine head and yarn feeding stations making the operation difficult

Engineering Contradiction:
Improveinternal seam closureVSAvoidturning operation
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The turning inside out operation is performed as a preliminary step after production but before closing. The article is extracted from the cylinder and inverted by the turner mechanism while the machine head and yarn feeding stations are positioned to allow this operation. Once the article is inverted and closed, the machine components return to their normal positions, avoiding interference during the turning operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs dynamic positioning of the machine head and yarn feeding stations. These components can be moved or repositioned to create sufficient space above the cylinder for the turner mechanism to operate on the extracted article. This dynamic adjustment allows the turning operation to be performed without permanent obstruction from machine components.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If the ends of the tubular article are joined without turning inside out, then the production process is simple, but the seam is external and unpleasant to consumers

Engineering Contradiction:
Improveclosing processVSAvoidexternal seam appearance
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies inversion by turning the tubular article inside out after production but before closing. This allows the closing operation to be performed on the inverted article, creating an internal seam that will be hidden inside the final product. The simple cylinder needles are used for closing, maintaining ease of manufacture, while the inversion ensures the seam is internal rather than external.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP4476390B1Improved circular machine for hosiery and knitwear and process for closing an end of a tubular manufactured article directly on a circular machine
Publication Date: 2026.01.28 SGM AUTOMAZIONI SRL
  • EP4476390B1 patent drawingFigure 1~2
  • EP4476390B1 patent drawingFigure 3
  • EP4476390B1 patent drawingFigure 4~5

AI summary

The invention refers to a circular machine (1) for producing tubular manufactured articles (8) and to a respective process. The circular machine comprises a turner (9) arranged above and axially aligned with a cylinder (4) of the machine and configured to extract the tubular manufactured article from said cylinder (4) and, at the same time, turn it inside out, and a transferring apparatus (12) for collecting, from at least one first half of the cylinder needles, the respective stitches and coupling them with the stitches initially arranged on a second half of the cylinder needles, so that there are two stitches that have to be joined by processing at least one yarn (7) through at least said half of the cylinder needles on each of the needles of one half of the cylinder needles.