Flatbed Knitting Yarn Gripping Device Standby Position Control

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Solution Overview

Problem

The existing knitting yarn gripping devices in flatbed knitting machines often cause yarn breaks or cast-offs due to excessive tension when the outer gripping device is lifted, and there is a challenge in controlling the inner and outer gripping devices independently to prevent these issues.

Innovation Solution

A knitting yarn gripping device with a plurality of gripping mechanisms, each comprising a mounting plate, an operation plate, a tension spring, an open/close lock mechanism, and an operation lock mechanism, which allows for controlled opening and closing of the gripping portion to prevent excessive tension and ensure reliable yarn gripping, even when the inner gripping device is in a standby condition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the outer gripping device is lifted to catch the knitting yarn, then the knitting yarn can be caught and gripped, but excessive tension is applied to the knitting yarn causing yarn breaks or cast-offs

Engineering Contradiction:
Improveyarn gripping reliabilityVSAvoidexcessive tension on yarn
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The inner gripping device is moved to a standby position in advance, ready to immediately grip the knitting yarn when the outer gripping device is lifted, preventing excessive tension and yarn breaks

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The inner gripping device acts as an intermediary between the knitting yarn and the needle bed, providing support and preventing excessive tension when the outer gripping device operates

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the inner gripping device is moved to standby position, then the knitting yarn can be supported, but the device complexity increases due to additional control mechanisms

Engineering Contradiction:
Improveyarn support reliabilityVSAvoidgripping device control complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control mechanisms for the inner and outer gripping devices are integrated into a unified control system that coordinates their movements, reducing overall system complexity while maintaining independent operation capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gripping devices are designed with multi-functionality, serving both as catching mechanisms and as tension control mechanisms, reducing the need for separate dedicated components

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 prevents yarn breaks and cast-offs by controlling the gripping mechanisms to maintain optimal tension, allowing for reliable yarn gripping and feeding, even when the outer gripping device is lifted, and enables selective operation modes to manage yarn tension effectively.

Implementation Method 1

a tension spring (23) which is provided between the mounting plate (18) and the operation plate (22) and urges the operation plate (22) in a direction in which the distance for the operation plate (22) to be lowered relatively from the mounting plate (18) decreases

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2341171B1Knitting yarn gripping device of flatbed knitting machine, and control method of the same
Publication Date: 2014.12.17 SHIMA SEIKI MFG LTD
  • EP2341171B1 patent drawingFigure 1
  • EP2341171B1 patent drawingFigure 2
  • EP2341171B1 patent drawingFigure 3

AI summary

[Object] To provide a knitting yarn gripping device of a flatbed knitting machine which is capable of preventing a yarn break or a yarn cast-off, even when the outer gripping device is lifted, with the inner gripping device in the standby condition while gripping the knitting yarn, and a control method of the same. [Technical Solution] A controller 31 is set so that a standby position of at least the inner gripping mechanism 11a, at which a gripping portion 12a is closed to grip an end of a knitting yarn 6a and is put in standby, is upper in level than a lower limit of a stroke for the gripping portion 11a to move up and down. When the gripping mechanism 11a is first moved down to a position lower in level than the standby position, then is turned around, and then is moved up, the gripping portion 12a is opened. On the other hand, when the gripping mechanism 11a is moved up directly from the standby position, the gripping portion12a is kept in the closed state. Thus, when the outer gripping mechanism 11b is moved up so that the knitting yarn 6b can be caught by the gripping portion 11b, the inner gripping mechanism 11a can also be moved up together, while keeping the condition of the gripping portion 12a that grips the knitting yarn 6a without pulling it, to prevent a yarn break or yarn cast-off.