Conductive Drop Wire Yarn Break Detection Circuit

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Solution Overview

Problem

Conventional circular weaving machines require manual monitoring for warp yarn end detection, which is prone to operator error and inefficient, especially in dusty environments, leading to fabric wastage and machine downtime.

Innovation Solution

An automated system using an improved drop wire with electrically conducting elements that maintain contact upon yarn breakage, completing an electric circuit to notify the operator, designed to function effectively in dusty conditions and distinguish between temporary slack and permanent breakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If manual monitoring by operator is used for yarn end detection, then the system is simple, but operator error increases and monitoring efficiency decreases

Engineering Contradiction:
Improvedetection system complexityVSAvoidyarn end detection reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system enables self-service detection through the drop wire mechanism that automatically monitors yarn tension and triggers alerts without requiring continuous operator attention. The weighted drop wire self-activates the electrical circuit when yarn ends, making the system monitor itself autonomously

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the purely manual mechanical monitoring system with an electromechanical system. The drop wire mechanism combines mechanical tension sensing with electrical circuit completion to create an automated detection system that substitutes operator labor with mechanical-electrical automation

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Extent of automation

If automated electrical sensor systems are used for yarn end detection, then operator monitoring burden is reduced, but the system malfunctions frequently in dusty environments

Engineering Contradiction:
Improveyarn end detection automationVSAvoidsensor functioning reliability
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The drop wire acts as an intermediary mechanical element between the yarn and the electrical circuit. Instead of using electrical sensors to directly detect yarn conditions, the system uses the physical drop wire as a mediator that converts yarn tension changes into mechanical motion, which then completes the electrical circuit. This intermediary approach protects the electrical components from direct exposure to dusty environments

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent partially replaces electrical sensing with mechanical sensing. The core detection mechanism uses mechanical tension sensing through the weighted drop wire rather than electrical fields or optical sensors, making the primary detection function immune to dust interference while still achieving automation through electrical circuit completion

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If continuous operator monitoring of multiple bobbins is required, then yarn end detection can be achieved, but fabric wastage increases due to delayed detection

Engineering Contradiction:
Improveyarn end detection accuracyVSAvoidfabric wastage
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system enables each yarn path to self-monitor through its own drop wire mechanism. Multiple independent detection systems operate simultaneously without requiring a single operator to monitor all bobbins, ensuring timely detection of yarn ends across the entire weaving machine and preventing fabric wastage through immediate alert notification

Inventive Principle:
Principle #25Self-service

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 system reduces fabric wastage and machine downtime by accurately detecting yarn ends and sending notifications, even in dusty environments, while minimizing false alarms and ensuring timely intervention.

Implementation Method 1

a gravity-controlled 'drop wire' made of metals such as stainless steel through which the tape used for fabric making passes. When warp yarn/tape ends, yarn/tape loses it tension which causes it to slag causing drop wire to fall down.

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3356586B1A device and a method for sensing end of warp yarn or tape on a fabric weaving loom
Publication Date: 2020.04.08 LOHIA SIDDHARTH
  • EP3356586B1 patent drawingFigure 1
  • EP3356586B1 patent drawingFigure 2
  • EP3356586B1 patent drawingFigure 3

AI summary

The invention discloses a device for sensing end of warp yarn on a circular weaving machine (CWM). It has an improved drop wire and a device to detect the end of a running yarn on a CWM. The device also incorporates an electric circuit which is kept open during normal working of the loom. When a yarn break is detected by a yarn detection means which is also a part of the device, the electric circuit is completed and a notification is sent to the loom operator and the CWM is stopped. The invention is particularly suitable in dusty environment in which CWMs typically operate. The drop wire is provided with an electrically conducting first element having a spatially curved external surface. The device also incorporates a set of electrically conducting second elements having curved internal surfaces. Upon the loss of elevation of the first elements, the first and second elements come in electrical contact with each other, thereby completing the electric circuit and causing a signal to be sent indicating yarn breakage.