Sewing Machine Thread Feed Inter-winding Mechanism

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Solution Overview

Problem

Existing sewing technologies face challenges in creating sewing threads with varying characteristics to effectively attach elastic fabrics, particularly in achieving seams with similar elasticity to the attached fabrics, and in efficiently winding bobbins for sewing machines.

Innovation Solution

A method and apparatus for inter-winding low-melting point nylon filament with conventional textile filament to create a composite sewing thread, using the locomotive power of a sewing machine to draw and guide the filaments, which melts to provide adhesive properties when heated, and a thread feed mechanism with spool retention and guide mechanisms to ensure consistent thread supply.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If pre-wound spools of composite thread are used, then the thread is ready for immediate use, but the operator cannot customize filament combinations and the thread cannot be produced in-situ

Engineering Contradiction:
Improvecustomization of filament combinationsVSAvoidthread feed mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The thread feed mechanism is divided into separate functional modules: first spool for first filament, second spool for second filament, guide mechanism, and inter-winding mechanism. This segmentation allows independent selection and control of different filaments while maintaining a manageable overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses the sewing machine's own locomotive power to drive the inter-winding mechanism, eliminating the need for external power sources or complex motor assemblies. The guide mechanism and spool retention mechanisms are designed to automatically guide and secure filaments during the inter-winding process.

Inventive Principle:
Principle #25Self-service

2Productivity

If manual bobbin winding operations are used, then the operator has control over the process, but significant time is consumed and operator effort is high

Engineering Contradiction:
Improvebobbin winding speedVSAvoidtime for bobbin winding
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The composite thread is inter-wound and prepared in advance using the sewing machine's locomotive power before being fed to the stitching tool. This preliminary action of inter-winding multiple filaments eliminates the need for manual bobbin winding operations during the sewing process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The manual mechanical process of bobbin winding is replaced by an automated inter-winding mechanism that uses the sewing machine's existing motive power. This substitution dramatically reduces the time and effort required while maintaining control over the thread formation process.

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

3Reliability

If conventional sewing thread is used, then the thread provides basic sewing function, but it cannot provide adhesive properties for elastic fabrics

Engineering Contradiction:
Improveseam adhesionVSAvoidthread production complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sewing thread is constructed as a composite of multiple filaments with different properties: elastic filaments for stretchability, low-melting-point filaments for adhesive properties, and conventional filaments for structural integrity. This composite structure enables the thread to provide both sewing and adhesive functions simultaneously.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The low-melting-point filaments undergo a phase change from solid to liquid when exposed to heat from the sewing machine's presser foot or iron, transforming from a structural element to an adhesive substance. This parameter change (temperature-induced phase transition) enables the thread to provide adhesive properties without requiring separate manufacturing processes.

Inventive Principle:
Principle #35Parameter changes

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 enables the creation of composite sewing threads with desired elasticity and color/thickness, efficiently feeding threads to sewing machines, reducing operator effort and improving seam adhesion and handling robustness, while allowing for in-situ production of composite threads with various filament combinations.

Implementation Method 1

A composite sewing thread, which has a low-melting point nylon filament (though other materials, such as polyester, polypropylene, for example) twisted with a conventional polyester filament yarn is commercially available in spools which are pre-wound, ready for use. Once the seam is ironed the nylon melts and the two pieces of fabric are adhered

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

the thread feed further comprises an inter-winding mechanism which, using motive power of the sewing machine causes inter-winding of the first and second filaments to create composite sewing thread

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP2529046B1Method of feeding thread to a sewing machine and sewing machine thread feed
Publication Date: 2015.01.07 J & P COATS LTD
  • EP2529046B1 patent drawingFigure 1
  • EP2529046B1 patent drawingFigure 2~3
  • EP2529046B1 patent drawingFigure 4

AI summary

A sewing machine thread feed for a supplying sewing thread to a sewing machine, the sewing thread including a low melting point filament and a textile filament, the feed comprising: a guide mechanism for guiding sewing thread to a needle of the sewing machine; first and second spools carrying first and second filaments respectively, one of the spools carrying a low- melt filament and the other carrying a textile filament; first and second retention mechanisms for retaining the first and second spools respectively in position against force applied to them when filament is drawn off; the first and second filaments run from the first and second spools respectively to the guide mechanism; wherein the first filament runs from the first spool, through the centre of the second spool, so that the action of the second filament, when being drawn off the second spool, causes inter-winding of the first and second filaments to create composite sewing thread.