Yarn Guide Apparatus Position Stability in Circular Knitting

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Solution Overview

Problem

Conventional yarn guide apparatuses in circular knitting machines experience issues with yarn carriers being tilted out of position due to excessive tensile force from knitting yarns, leading to frictional forces that can damage the fabric or needles, especially when handling thick polyester yarns with low tensile force.

Innovation Solution

A yarn guide apparatus configuration where the inward tilting force at the yarn feed port is greater than the outward tilting force, featuring a yarn carrier ring, holder, and guide with a torsion spring mechanism, ensuring the guide hole is aligned with the yarn feed port to maintain the yarn carrier at the proper position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tensile force in feeding the knitting yarn is increased to prevent filament spreading, then the yarn carrier can be held at the proper position, but the frictional force at the yarn feed port increases causing damage to knit fabric or needles

Engineering Contradiction:
Improveyarn carrier position stabilityVSAvoidfrictional force damage to fabric or needles
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The guide hole is positioned at a specific distance from the shaft portion to act as an intermediary that redirects the tensile force. By placing the guide hole at the optimal distance, the force vector is changed so that the yarn passes through the guide hole and creates an inward tilting force on the yarn carrier, rather than creating friction at the yarn feed port. This mediator position transforms the harmful frictional force into a useful positioning force.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the geometric parameter of the guide hole position relative to the shaft portion. By optimizing this distance parameter, the force transmission characteristics are changed - the guide hole position determines how the tensile force is transmitted to the yarn carrier, converting it into an inward tilting force that stabilizes the yarn carrier without creating damaging friction at the yarn feed port.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If the yarn carrier is allowed to tilt outward for easy yarn insertion, then yarn feeding is simplified, but the yarn carrier shifts out of position causing friction and potential damage

Engineering Contradiction:
Improveyarn insertion easeVSAvoidyarn carrier position accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The spring mechanism provides a preliminary inward tilting force that counteracts the outward tilting tendency before yarn feeding occurs. This pre-applied counter-force ensures that even when the yarn carrier tilts outward during yarn insertion, it is quickly returned to the correct position, preventing the harmful friction and damage that would occur if the carrier remained tilted.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The yarn carrier is designed to be dynamically tiltable rather than fixed, allowing temporary outward tilt for yarn insertion while the spring continuously provides a restoring force. This dynamic design enables easy yarn insertion while automatically maintaining position accuracy through the spring's inward tilting force that acts whenever the carrier deviates from its proper position.

Inventive Principle:
Principle #15Dynamics

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

Prevents yarn carriers from shifting out of position, thereby preventing damage to the knit fabric or needles, ensuring consistent yarn feeding and reducing the risk of yarn breakage.

Implementation Method 1

a spring (18) for pressing against the shaft portion (17)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the guide hole (21) of the yarn guide (20) is disposed facing the yarn feed port (71) of the second yarn carrier (7) such that a distance from the guide hole (21) to the shaft portion (17) is substantially the same as a distance from the yarn feed port (71) to the shaft portion (17)

Methodology Applied
Scientific EffectMechanical Force: Force

Data Source

PatentEP2540890B1Yarn guide apparatus in circular knitting machine
Publication Date: 2016.03.23 PRECISION FUKUHARA WORKS LTD
  • EP2540890B1 patent drawingFigure 1~2(b)
  • EP2540890B1 patent drawingFigure 3(a)~4(c)
  • EP2540890B1 patent drawingFigure 5(a)~6

AI summary

The present invention prevents a yarn carrier from coming off a proper yarn feed position due to a large tensile force of a knitting yarn while a knitting machine operates. In a yarn guide apparatus in a circular knitting machine, a guide hole of a yarn guide is disposed facing a yarn feed port of a yarn carrier such that a distance from the guide hole to a shaft portion is substantially the same as a distance from the yarn feed port to the shaft portion, thereby providing at the yarn feed port an acting force equal to or greater than a force that acts so as to tilt the yarn carrier upward due to a knitting yarn. It is preferable that the yarn guide that surrounds a yarn carrier ring is attached together with a yarn carrier to a center portion of the shaft portion.