Circular Knitting Shoe Upper Process
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Solution Overview
Problem
Current processes for producing knitted shoe uppers are inefficient, requiring numerous manual steps, long production times, and increased costs due to the need for cutting excess yarn and adding additional seams.
Innovation Solution
A circular knitting machine process using multiple groups of needles that alternate between tuck stitch, jersey stitch, and missed stitch positions to knit multiple yarns continuously, allowing for the simultaneous creation of three-dimensional pouches, lace slots, and other features without the need for manual cutting or additional seams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a rectilinear knitting machine is used to produce knitted uppers, then the upper is light in weight and has minimal seams, but the production time is long (25-45 minutes) and requires manual cutting of excess yarn
Solution Approach 1:
The patent inverts the conventional rectilinear knitting approach by using a circular knitting machine with radially distributed needles. This inversion allows continuous knitting without the need to stop and cut yarn, transforming the production process from batch-oriented to continuous, thereby reducing production time while maintaining the lightweight characteristic
Solution Approach 2:
The circular knitting machine enables continuous knitting action by distributing needles around a circumference and rotating the cylinder. The yarn is fed continuously through the knitting process without interruption, eliminating the manual cutting step required in rectilinear machines and significantly improving productivity
2Device complexity
If a rectilinear knitting machine is used, then the upper structure is simple with single yarn construction, but additional seams are required to close the upper and connect to the sole
Solution Approach 1:
The circular knitting machine divides the upper production into multiple independent zones, each handled by specific groups of needles. Different needle groups simultaneously knit different portions of the upper (front, back, sides, heel, toe), allowing the entire upper to be closed and shaped in one continuous operation without additional seams
Solution Approach 2:
The circular knitting machine performs multiple functions simultaneously: it knits the main body, forms three-dimensional pouches, creates lace slots, and closes the upper all in one process. This multi-functionality eliminates the need for separate operations to add seams and connect the upper to the sole
3Manufacturing precision
If manual processes are used after knitting, then the upper can be shaped and closed, but production costs increase and production waste is generated
Solution Approach 1:
The circular knitting machine is designed to automatically perform shaping and closing operations through its needle configuration and knitting pattern. The machine self-regulates the formation of three-dimensional pouches, lace slots, and upper closure without requiring manual intervention, thereby reducing production costs and eliminating waste from manual processing
Data Source
AI summary
The process for realizing an upper for shoes consists of using at least a first and second group of needles of a needle-bearing cylinder of a circular knitting machine, each needle of said first group and of said second group of needles being used in a tuck stitch or loop position and/or in a plain drop stitch position and/or in a missed stitch position at least during the forward rotation of said needle-bearing cylinder, said at least first and second group of needles being used alternatively in said at least forward rotation of said needle-bearing cylinder so as to knit several yarns together without having to continuously cut them.