Automatic Piecing Unit Yarn Threading Mechanism

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Solution Overview

Problem

Ring spinning machines experience frequent yarn breakage, requiring manual intervention and posing health risks to workers due to the need for continuous monitoring and manual piecing, while existing automatic piecing units fail to effectively insert yarn into the rotatable traveler, especially with the vertical movement of the balloon control ring hindering the process.

Innovation Solution

An automatic piecing unit with a top suction tube, gripper arm, rocker arm, and tensioning arm, which moves the yarn tangentially to the ring without contacting the balloon control ring, using a blow jet to rotate the traveler and retract the arms for successful yarn insertion, utilizing pneumatic, electric, or hydraulic actuators for precise movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual piecing is used to join broken yarn ends, then yarn continuity is maintained, but worker health deteriorates due to continuous monitoring and manual intervention along long machine frames

Engineering Contradiction:
Improveyarn continuityVSAvoidworker health
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The piecing unit is equipped with automatic sensing units that detect broken yarn ends and trigger the piecing mechanism without human intervention. The system serves itself by automatically navigating to broken yarn locations, threading the yarn through the traveler, and completing the piecing operation, thereby eliminating the need for workers to continuously monitor and manually piece broken yarns

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the manual mechanical piecing operation with an automated robotic system that uses sensing units, drive units, and mechanical arms to perform the piecing operation. The automatic piecing unit substitutes human workers' manual dexterity and continuous monitoring with automated detection and execution mechanisms

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

2Object-affected harmful factors

If automatic piecing units are introduced to replace manual piecing, then worker health is protected, but yarn insertion into traveler fails due to balloon control ring movement

Engineering Contradiction:
Improveworker healthVSAvoidyarn insertion
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent employs a dynamic yarn path that adapts to the balloon control ring's vertical movement. The piecing unit's yarn feeding mechanism is designed to flexibly adjust the yarn route, allowing the yarn to be threaded into the traveler regardless of the balloon control ring's position during its up-and-down motion cycle

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces an intermediary yarn path or guide mechanism that mediates between the stationary piecing unit and the moving traveler. This intermediary structure allows yarn transfer without direct contact between the piecing unit and the balloon control ring, enabling successful yarn insertion despite the ring's vertical movement

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If complex mechanisms with multiple links and levers are used for yarn threading, then yarn insertion capability is achieved, but device complexity increases making the system impractical

Engineering Contradiction:
Improveyarn insertion capabilityVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates unnecessary intermediate components from the yarn threading mechanism. Instead of using multiple links, levers, and mounting plates as in prior art, the invention employs a simplified direct yarn path with essential guiding elements, removing redundant mechanical complexity while maintaining the core yarn insertion function

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Rather than using a complex mechanism to actively push or guide the yarn through multiple stages, the patent inverts the approach by allowing the yarn to follow a simplified natural path with minimal intervention. The system uses passive guidance and tension control instead of active mechanical manipulation through multiple components

Inventive Principle:
Principle #13The other way round (Inversion)

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

Enables automatic and efficient yarn threading into the rotating traveler, reducing manual labor and health risks, allowing continuous operation without looping the yarn with the balloon control ring, thus enhancing the automation of yarn piecing in ring spinning machines.

Implementation Method 1

a top suction tube for holding an end of a broken yarn lifted from a cop

Methodology Applied
Scientific EffectSuction: Suction

Implementation Method 2

a blow jet configured to rotate a traveler of the ring spinning machine

Methodology Applied
Scientific EffectCompressed air jet: Jet

Data Source

PatentEP3967798B1Piecing unit of ring spinning machine with a yarn threading arrangement
Publication Date: 2023.11.01 LAKSHMI MACHINE WORKS LTD
  • EP3967798B1 patent drawingFigure 1
  • EP3967798B1 patent drawingFigure 1a
  • EP3967798B1 patent drawingFigure 2~2a

AI summary

The present invention relates to an automatic piecing unit (2) of a ring spinning machine (10) for piecing broken yarns. The automatic piecing unit (2) comprises a top suction tube (15) for holding an end of a broken yarn (12) inside, a gripper arm (3), a rocker arm (4), a tensioning arm (7) and a blow jet (6). The gripper arm (3) moves to hook the end of the yarn (12) held between the top suction tube (15) and the cop (17). A rocker arm (4) moves to hook the end of the yarn (12) held between the gripper arm (3) and the cop (17). A tensioning arm (7) is configured such that the yarn (12) held does not make contact with the balloon control ring (19) and guides upon the tensioning arm (7) and reaches the traveler (13) position without any hindrance. The gripper arm (3) and the rocker arm (4) holds the yarn (12) tangential to the ring (14) such that the yarn (12) is threaded inside the rotating traveler (13) by the blow jet (6).