Weft Saving Device for Shuttle-Less Weaving Machines

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Solution Overview

Problem

Shuttle-less weaving machines face challenges in optimizing the weaving process due to the presence of split selvages, which result in yarn waste and complicate fabric management, limiting the number of weft colors and fabric breadth variations.

Innovation Solution

A weft saving device that controls weft thread tension and arranges protruding weft portions using mechanical and pneumatic elements, with specific side bindings and a shear system to cut and recover weft tails, allowing for intuitive management and recycling of excess yarn, while maintaining uniform interlacing and versatility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If split selvages are used to ensure uniform weft/warp interlacing and simplify fabric management, then fabric quality and versatility are improved, but yarn waste increases and operational complexity increases

Engineering Contradiction:
Improvefabric versatilityVSAvoidyarn waste
Core Design Contradiction:
Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The invention extracts and eliminates the split selvage portions from the fabric structure. A cutting device removes the protruding weft threads at the fabric edges, allowing the use of continuous weft threads without the traditional split selvage structure, thereby eliminating yarn waste while maintaining fabric quality

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention recovers the previously discarded weft threads by implementing a collection device that gathers the cut weft portions at the fabric edges. This transforms the waste material into recoverable resources, reducing yarn loss while maintaining the simplified continuous weft structure

Inventive Principle:
Principle #34Discarding and recovering

2Ease of operation

If split selvages are used to simplify fabric management and allow pick-at-will color selection, then ease of operation is improved, but device complexity increases due to multiple rapiers

Engineering Contradiction:
Improvefabric managementVSAvoidloom complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention removes the complex multi-rapier color selection mechanism by extracting only the essential function of weft insertion. A single rapier inserts continuous weft threads, and the previously necessary complex control systems for managing multiple weft entries are eliminated, simplifying the loom structure

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using multiple rapiers to manage different weft colors at the entry side, the invention inverts the approach by using a single rapier and managing color changes through the continuous weft system and pick-at-will selector, with the cutting device handling the edge portions, thereby simplifying the rapier system

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

3Loss of substance

If continuous weft threads are used without split selvages, then yarn waste is reduced, but weft tension control and edge stabilization become more difficult

Engineering Contradiction:
Improveyarn wasteVSAvoidweft tension stability
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The invention applies preliminary tensioning to the continuous weft threads before they reach the fabric edges. Tensioning devices pre-adjust the weft tension along the fabric width, ensuring stable interlacing and preventing edge distortion before the fabric reaches the cutting point

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention introduces intermediary devices such as guide rollers and tensioning mechanisms that mediate between the continuous weft supply and the fabric formation process. These intermediaries stabilize the weft tension and ensure uniform interlacing at the edges without requiring split selvages

Inventive Principle:
Principle #24Intermediary (Mediator)

4Loss of substance

If cut weft threads are eliminated and continuous weft is used, then yarn waste is reduced, but weft tail arrangement and cutting precision become critical

Engineering Contradiction:
Improveyarn wasteVSAvoidcutting precision
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The invention replaces manual or simple mechanical cutting with an automated cutting device that uses precise mechanical positioning and cutting mechanisms. This ensures consistent cut quality and accurate positioning of the cut weft portions, maintaining manufacturing precision while enabling continuous weft usage

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

Solution Approach 2:

The invention implements a standardized cutting and collection system that replicates the optimal cutting parameters across all fabric edges. By copying the precise cutting geometry and tension settings, the system maintains consistent precision without requiring complex adjustments for each fabric type

Inventive Principle:
Principle #26Copying

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 device eliminates split selvages, enabling efficient use of all weft threads, recycling excess yarn, and allowing for broader fabric breadth variations, improving production performance and reducing operational complexity.

Implementation Method 1

a suction system (7), positioned under the blades (4, 5), and connected to the fixed guiding table (6) and the fixed blade (4) of the shear (17)

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP4018027B1Device for collecting cut weft threads for weaving machines
Publication Date: 2024.09.11 SANTEX RIMAR GRP SRL
  • EP4018027B1 patent drawingFigure 1
  • EP4018027B1 patent drawingFigure 2a~2b
  • EP4018027B1 patent drawingFigure 3

AI summary

A weft threads saving device for shuttle-less weaving machines comprises a comb (2), a temple (3), a guiding plane (6), a fixed blade (4), a movable blade (5) of a shear (17), a fabric winding cylinder (8) and a suction system (7) connected both to the guiding plane (6) and to the fixed blade (4) of the shear (17).