Knitting Machine Independent Spinning Units for Variable Yarn Thickness
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Solution Overview
Problem
Existing knitting machines are limited in producing knitted fabrics with complex patterns involving varying yarn thicknesses within a row of stitches, as they can only produce striped patterns by using different roving strengths, requiring time-consuming bobbin exchanges for pattern changes.
Innovation Solution
A machine with multiple spinning devices, each with independent drive control, allows for varying yarn thicknesses to be supplied to stitch-forming elements, enabling patterns with yarn thickness changes within a row of stitches using the same roving, and incorporating drafting systems with adjustable roller speeds and twisting elements for stable yarn production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple spinning units with independent drive control are assigned to each stitch-forming element, then yarn thickness can be varied stitch-by-stitch to create complex patterns, but device complexity increases
Solution Approach 1:
The machine divides the knitting system into multiple independent stitch-forming elements (needles), with each needle assigned its own spinning unit. This segmentation allows each needle to operate independently with its own drive control, enabling stitch-by-stitch variation in yarn thickness while maintaining overall system functionality through modular architecture.
Solution Approach 2:
The spinning units are equipped with independently controllable drive mechanisms that can dynamically adjust yarn feed rates and thickness in real-time during the knitting process. This dynamic control capability allows the machine to create complex patterns with varying yarn thicknesses without requiring physical reconfiguration, resolving the contradiction between versatility and complexity.
2Adaptability or versatility
If different roving strengths are used to produce varying yarn thicknesses for pattern creation, then pattern diversity is achieved, but production time increases due to bobbin exchanges
Solution Approach 1:
The machine uses a single roving source that is fed to multiple spinning units, each capable of producing different yarn thicknesses through independent speed control. This universal feeding system eliminates the need for multiple rovings and bobbin exchanges, allowing pattern diversity to be achieved through control variations rather than material changes, thus eliminating pattern change time.
Solution Approach 2:
Instead of changing physical materials (different roving strengths) to achieve pattern variation, the system changes operational parameters (spinning unit speeds, yarn feed rates) to produce different yarn thicknesses from the same roving. This parameter-based approach allows instant pattern changes without time-consuming material exchanges.
3Device complexity
If drafting units with mechanically coupled rollers are used, then device simplicity is maintained, but the ability to produce varying yarn thicknesses within a row is limited
Solution Approach 1:
The drafting system is segmented into multiple independently controllable roller pairs, each associated with a specific spinning unit. This segmentation breaks the mechanical coupling constraint, allowing each roller pair to be controlled independently to achieve precise yarn thickness variation while maintaining a relatively simple overall structure through modular design.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the production of knitted fabrics with diverse patterns, including hard and soft transitions, and unique geometric designs, previously only achievable with slub yarns, by varying yarn thicknesses stitch-by-stitch, offering greater design flexibility and efficiency.
Implementation Method 1
The circumferential speeds of the rollers (20a, 20b; 21a, 21b; 22a, 22b) differ from one another, with the result that the roving (VG) is drawn, that is to say, is thinned, between the rollers (20a, 20b; 21a, 21b; 22a, 22b)
Implementation Method 2
Subsequently, the fiber composite (FB) is given a twist by a twisting element (18) in order to stabilize the fiber composite (FB) for transport
Data Source
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AI summary
A machine for producing knitted fabrics with a plurality of knitting elements and with at least one knitting station (15, 15.1, 15.2, 15.3), to which a spinning unit (12, 12.1, 12.2, 12.3) is assigned, which produces a fiber composite (FB) or a yarn from a roving (VG) and feeds this to the knitting elements (14), wherein each spinning unit (12, 12.1, 12.2, 12.3) has separate drive units (30, 31, 30.1, 31.1, 30.2, 31.2, 30.3, 31.3) which can be controlled such that each spinning unit (12, 12.1, 12.2, 12.3) produces a fiber composite (FB) or a yarn of variable properties from the roving (VG). Thickness can be produced and supplied to the mesh-forming elements (14).