Seamless 3D Knitting Method for Closed Bottom Face

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Solution Overview

Problem

Existing methods for knitting three-dimensional articles with a bottom face are limited in seamlessly knitting the bottom face, restricting the creation of articles like gloves, socks, and bags that require a closed bottom face.

Innovation Solution

A method using a flat-knitting machine with two needle beds to knit a first and second stitch row as ribs, followed by continuous stitch rows to form a bottom face, and then knitting the four side faces into a cylinder, employing hook stitches to create a seamless knitted fabric with a closed bottom face.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a bottom face of a three-dimensional article is knitted using conventional methods, then the article can be produced, but the bottom face cannot be knitted seamlessly, requiring joins or seams

Engineering Contradiction:
Improveseamless knitting of bottom faceVSAvoidcomplexity of knitting process
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The bottom face knitting process is segmented into multiple stitch rows (first through sixth stitch rows) with specific knitting directions and needle bed assignments. This segmentation allows each portion to be knitted separately and then joined seamlessly, resolving the contradiction between achieving seamless knitting and managing process complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention utilizes the third dimension by moving stitch rows between needle beds in the longitudinal direction and employing bidirectional knitting (front and back needle beds). This dimensional approach enables the formation of a closed bottom face without seams, transforming a two-dimensional knitting problem into a three-dimensional solution.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If hook stitches are used to create empty needles for seamless knitting, then a closed bottom face is achieved, but the device complexity increases

Engineering Contradiction:
Improveclosed bottom face formationVSAvoidneedle bed operations
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The knitting machine performs self-service by automatically creating empty needles through hook stitches and managing the complex needle bed movements. The system handles its own complexity through automated operations, allowing the bottom face to be knitted seamlessly without requiring additional manual intervention or complex external equipment.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If multiple stitch rows are knitted continuously to form a bottom face, then a snug fit is achieved, but the knitting time increases

Engineering Contradiction:
Improvesnug fit of bottom faceVSAvoidknitting duration
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention maintains continuous useful action by knitting multiple stitch rows continuously without interruption to form the bottom face. The process transitions smoothly from the first stitch row through the sixth stitch row, ensuring continuous knitting that achieves a snug fit while minimizing non-productive time through efficient needle bed transitions.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The knitting process employs periodic action by alternating between front and back needle beds in a regular pattern. This periodic switching allows the machine to maintain high-speed operation while forming the complex bottom face structure, reducing overall knitting time compared to sequential single-needle-bed operation.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2149629B1Three-dimensional knitting method, and three-dimensional article knitted by the method
Publication Date: 2015.01.21 SHIMA SEIKI MFG LTD
  • EP2149629B1 patent drawingFigure 1
  • EP2149629B1 patent drawingFigure 2
  • EP2149629B1 patent drawingFigure 3

AI summary

A bottom face 8 is knitted, starting from a rib course 6, and meanwhile sides 10, 12 are moved relatively horizontally to form sides 14, 16 which are constituted by hook stitches. Four side faces of a three-dimensional article 40 are knitted by the sides 10, 12 and wales connected to the sides 14, 16 which are constituted by the hook stitches. Then, an upper face 30 is knitted and joined to stitches of sides 34, 35, and stitches of a side 32 is subjected to bind-off, whereby the three-dimensional article 40 is obtained. A three-dimensional knitted fabric having a bottom face can be seamlessly knitted.