Knitting Machine Drafting System Suction for Fiber Fly Control

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Solution Overview

Problem

Existing drafting systems for spinning and knitting machines face issues with fiber fly and abrasion, leading to contamination and malfunctions due to accumulated fibers and dust, particularly in the gaps between rollers, and existing solutions are either ineffective or too large for practical use.

Innovation Solution

A drafting system that employs targeted suction close to the outlet of the rollers, eliminating the need for a housing encapsulation, allowing for direct cleaning of the rollers and maintaining accessibility, with compressed air directed through the base plate to prevent fiber accumulation, and includes a nozzle for imparting twist and preventing clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If compressed air is introduced to blow out fibers from the gap between rollers and base plate, then fiber accumulation is prevented, but fibers are blown off and become attached to other machine parts

Engineering Contradiction:
Improvedrafting system operationVSAvoidfiber fly
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful effect of compressed air blowing fibers away into a beneficial system by introducing a suction device that actively removes fiber fly at its source. The suction device creates a controlled airflow that prevents fibers from accumulating on rollers and base plates, while the housing contains the airflow to prevent dispersion to other machine parts.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces a housing as an intermediary structure that contains the airflow generated by the suction device. This housing acts as a mediator between the suction force and the surrounding environment, directing the airflow to remove fibers from critical areas while preventing the dispersion of fiber fly to other machine components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If a housing is used to cover the drafting system rollers, then fiber fly is contained, but accessibility for maintenance and checking is reduced

Engineering Contradiction:
Improvefiber fly containmentVSAvoidroller accessibility
Core Design Contradiction:
Object-generated harmful factorsVSEase of repair

Solution Approach 1:

The patent segments the housing into an openable cover structure that can be removed to provide access to the rollers. This segmented design allows the housing to provide fiber fly containment when closed, while enabling easy access to the rollers for maintenance and checking when the cover is opened. The housing is divided into a fixed portion and a removable cover portion.

Inventive Principle:
Principle #1Segmentation

3Object-generated harmful factors

If a suction device is placed far from the rollers in an open housing, then fiber fly is removed, but the construction becomes very large

Engineering Contradiction:
Improvefiber fly removalVSAvoiddrafting system size
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the suction device with the housing structure, placing the suction inlet directly in the housing that covers the rollers. This integration eliminates the need for separate, distant suction components and reduces the overall system size. The suction device is combined with the housing assembly, creating a compact unit that effectively removes fiber fly without requiring excessive space.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If the suction extends over both top rollers including the apron roller, then fiber fly and dust are effectively removed, but the suction system becomes more complex

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidsuction system coverage
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent designs the suction system to serve multiple functions: it removes fiber fly from the roller surfaces, cleans dust from the base plate, and maintains the aprons clean during operation. By extending the suction coverage to include both top rollers and the apron rollers, the system achieves comprehensive cleaning effectiveness while using a unified suction design that avoids excessive complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The solution effectively minimizes fiber fly and abrasion-related issues, maintains system accessibility for maintenance, and reduces installation space, enabling its use in both spinning and knitting machines without compromising performance.

Implementation Method 1

uses suction in a targeted manner close to where the fiber fly originates, in the area of the two top rollers closest to the drafting system outlet

Methodology Applied
Scientific EffectSuction: Suction

Implementation Method 2

the back of the base plate can be at least partially covered in an airtight manner by a housing cover which is provided with at least one supply opening for compressed air, and the base plate can have passage openings for the compressed air

Methodology Applied
Scientific EffectCompressed air flow: Pressure Gradient

Data Source

PatentEP2986765B1Drawing system for a knitting machine
Publication Date: 2018.02.14 SIPRA PATENTENTWICKLUNGS UND BETEILIGUNGSGESELLSCHAFT MBH
  • EP2986765B1 patent drawingFigure 1
  • EP2986765B1 patent drawingFigure 2~3
  • EP2986765B1 patent drawingFigure 4

AI summary

A drawing system (10) for a knitting machine for producing a fibre composite from a roving having double aprons, which are guided over an apron roller pair (14, 15), and an outlet pressure roller pair (16, 17), wherein the apron roller pair (14, 15) and the outlet pressure roller pair (16, 17) in each case have an upper pressure roller (15, 17) and a lower roller (14, 16) which is driven by electric motor, and the rollers (12-17) are arranged on the front side (11.1) of a base plate (11), whereas the axles (26, 27, 28) thereof are guided through the base plate (11), and the drive means for the lower rollers (12, 14, 16) are arranged at least partially on the rear side of the base plate (11), wherein an extraction means (20) which extends over both upper rollers (15, 17) is arranged on the upper roller (17) of the outlet pressure roller pair (16, 17) and the upper roller (15) of the apron roller pair (14, 15).