Rotary Drum Yarn Feeder with Optical Loop Sensor

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Solution Overview

Problem

Existing storage yarn feeders with rotary drums lack the capability to provide accurate, reliable absolute information about the amount of yarn unwound, relying on relative measurements which can lead to inconsistent yarn tension and defects in textile products.

Innovation Solution

A yarn feeder with a rotary drum and a yarn-unwinding sensor system that uses infrared light-emitting and receiving diodes, combined with an annular light guide and optical fiber, to detect and count the unwinding yarn loops, providing absolute information about the yarn unwound, regardless of the drum's rotation speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a storage yarn feeder uses relative measurement methods (photoelectric cells detecting unwinding yarn sequence) to control drum rotation, then the system can maintain yarn stock at a predetermined level, but the sensor cannot provide absolute information about the amount of yarn unwound, leading to potential tension instability

Engineering Contradiction:
Improveyarn unwound measurementVSAvoidyarn tension stability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the mechanical/relative measurement system (photoelectric cells detecting yarn sequence) with an optical absolute measurement system (infrared LED and photodetector measuring yarn loop diameter). This substitution enables direct measurement of the actual yarn stock level on the drum, providing absolute information about yarn unwound rather than relative changes, thereby resolving the measurement precision and reliability contradiction.

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

2Productivity

If the drum rotates faster to increase productivity, then more yarn can be processed per unit time, but the existing sensor system cannot accurately measure unwound yarn at varying speeds, compromising measurement reliability

Engineering Contradiction:
Improveyarn processing speedVSAvoidmeasurement accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent replaces speed-dependent mechanical measurement methods with an optical measurement system that measures the physical dimension (diameter) of yarn loops directly. This optical system is inherently independent of drum rotation speed, allowing accurate measurement of yarn stock level whether the drum rotates slowly or quickly, thus maintaining measurement reliability while enabling high productivity.

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

3Stability of the object's composition

If the yarn stock on the drum is maintained at a constant optimal level, then yarn tension remains stable, but the existing relative measurement system requires complex control mechanisms to achieve and maintain this balance

Engineering Contradiction:
Improveyarn tension stabilityVSAvoidcontrol system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent implements a feedback control system where the optical sensor continuously measures the actual yarn stock level (loop diameter) on the drum and provides this information to a control unit. The control unit compares the measured value with the optimal level and automatically adjusts the drum rotation speed to maintain the optimal yarn stock, thereby stabilizing yarn tension. This direct feedback mechanism simplifies control compared to relative measurement systems that require complex indirect control strategies.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces complex mechanical control mechanisms with an optical measurement and electronic control system. By using infrared LED and photodetector to directly measure yarn loop diameter, the system obtains accurate real-time data on yarn stock level, enabling simple and effective electronic feedback control to maintain optimal tension without complex mechanical adjustments.

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

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

Ensures stable yarn tension by accurately monitoring and maintaining the optimal yarn stock level on the drum, preventing excessive tension or accumulation, thus reducing defects in the textile production process.

Implementation Method 1

a first light-emitting means, in particular an infrared light-emitting diode (46), and a first light-receiving means, in particular an infrared light-receiving diode (72)

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

a first light-emitting means, in particular an infrared light-emitting diode (46), and a first light-receiving means, in particular an infrared light-receiving diode (72)

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 3

an annular light guide (50) arranged between drum (12) and emitting diode (46) and adapted to direct a light beam generated by emitting diode (46) towards cylindrical surface (30a) of cover (30)

Methodology Applied
Scientific EffectOptical waveguide: Waveguide (optics)

Implementation Method 4

The light-guiding means further comprise an optical device (62), which is incorporated in cover (30) and is adapted to focus the light from annular light-guide (50) towards an inlet end (64) of an optical fiber cable (66)

Methodology Applied
Scientific EffectOptical fiber transmission: Optical Fibre

Data Source

PatentEP2907907B1Storage yarn feeder with rotary drum and yarn-unwinding sensor
Publication Date: 2017.05.03 L G L ELECTRONICS SPA
  • EP2907907B1 patent drawingFigure 1
  • EP2907907B1 patent drawingFigure 2
  • EP2907907B1 patent drawingFigure 3~5

AI summary

A motorized, yarn-winding rotary drum (12) rotatably supported with respect to a motor-housing (16) is adapted to have a plurality of yarn loops (Y) wound on itself, which are adapted to be unwound upon request from a downstream machine. A yarn-unwinding sensor counts the yarn loops unwinding from the rotary drum (12) and comprises light-emitting means (42) and light-receiving means (44), both integral with the motor-housing (16), one of which has an annular configuration operatively facing an annular surface (30a) of the rotary drum (12) from which the yarn is unwound. Light-guiding means (66) integral with the rotary drum (12) guide the light from the light-emitting means (42) to the light-receiving means (44) through a light passage (30c) defined on the annular surface (30a). The unwinding of yarn from the rotary drum (12) is determined on the basis of the light dimming resulting from the yarn transiting on the light passage (30c).