Textile Machine Bobbin Reverse Drive for Thread Tension Control

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Solution Overview

Problem

In textile machines, maintaining constant thread tension during automatic reattachment of threads after interruptions is challenging, leading to potential further tears and twists in the thread.

Innovation Solution

The method involves driving the bobbin in reverse rotation while forming the thread loop, matching the reverse rotation speed to the infeed movement of the feeder element, ensuring the exact thread length is returned from the bobbin, and using a controller to coordinate the drive operations, which helps maintain constant thread tension and prevent twists.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the bobbin is driven in reverse direction to unwind thread and form a thread loop, then the thread can be reattached after interruption, but the thread tension becomes difficult to maintain constant, causing further thread breaks and twists

Engineering Contradiction:
Improveautomatic thread reattachmentVSAvoidthread tension stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies dynamics by making the bobbin rotation speed variable during the thread loop formation process. The bobbin drive speed is dynamically adjusted to match the feeder's infeed movement speed, ensuring constant thread tension. This resolves the contradiction by enabling automatic reattachment while maintaining thread tension stability through speed synchronization between the bobbin drive and feeder mechanism.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the bobbin is driven in reverse direction to unwind sufficient thread length for loop formation, then the thread can be picked up by the feeder, but excessive thread unwinding occurs, consuming unnecessary time

Engineering Contradiction:
Improvethread reattachment efficiencyVSAvoidthread unwinding time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent applies feedback by using the feeder's infeed movement as a reference signal to control the bobbin drive speed. The system continuously monitors the feeder's movement and adjusts the bobbin rotation speed accordingly, ensuring that the exact required thread length is unwound without excess. This feedback mechanism eliminates unnecessary thread unwinding and reduces time loss while maintaining productivity.

Inventive Principle:
Principle #23Feedback

3Ease of manufacture

If the suction nozzle is moved away from the bobbin surface after drawing in the thread, then the thread is stretched for loop formation, but thread tension cannot be kept constant, leading to twists in the drawn-in thread

Engineering Contradiction:
Improvethread loop formationVSAvoidthread structure integrity
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent uses the bobbin drive as an intermediary mechanism to maintain thread tension during loop formation. Instead of directly controlling thread tension through the suction nozzle movement alone, the system introduces the bobbin drive as a mediating element that actively compensates for tension changes. The synchronized bobbin rotation provides continuous thread supply at controlled speed, preventing twists and maintaining thread structure integrity during the loop formation process.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This approach allows for precise control of thread tension, reducing the risk of further breaks and twists, and optimizing the thread length required for piecing, while minimizing unnecessary thread unwinding and time expenditure.

Implementation Method 1

The suction nozzle is subjected to a vacuum for this purpose

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP3511275B1Textile machine and method for automatically piecing a thread at a working unit of a textile machine
Publication Date: 2020.08.12 MASCHINENFABRIK RIETER AG
  • EP3511275B1 patent drawingFigure 1
  • EP3511275B1 patent drawingFigure 2
  • EP3511275B1 patent drawingFigure 3

AI summary

In a method for automatically attaching a thread (4) at a work station (2) of a textile machine (1), one end (4a) of the thread (4) is located on the surface of a bobbin (7) by means of a suction nozzle (10), and the thread (4) is unwound from the bobbin (7) in the opposite direction to its regular take-up direction (AR). The thread (4) is drawn into the suction nozzle (10), while the bobbin (7) is driven in reverse (RR) by a reverse drive (8). By means of a feeder movement (9), a thread loop (4b) is formed from the thread (4) and fed to an attachment device (12). The bobbin (7) continues to be driven in reverse (RR) even while the thread loop (4b) is being formed, and the thread (4) continues to unwind from the bobbin (7). The reverse rotation speed of the bobbin (7) is synchronized with the feeder movement of the feeder (9).The textile machine (1) has a control (15) which is designed to operate the reverse rotation drive (8) of the bobbin (7) accordingly.