Weaving Loom Grippers with Ceramic Coating for Yarn Interference

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Solution Overview

Problem

Modern high-speed weaving looms experience frequent interference between grippers and warp yarns, leading to entanglement, wear, and reduced gripper lifespan due to increased stress and advanced shed closing times.

Innovation Solution

The grippers are designed with a single-piece extruded metal body of high rigidity, featuring a smooth D-shaped section and ceramic coating, and utilize a permanent magnet for controlled wedge-like tip movement, minimizing bulk and interference with warp yarns, and an electrolytic ceramic coating for enhanced durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If the opening degree of the shed is reduced to decrease stresses on warp yarns, then the stress on warp yarns is reduced, but the grippers interfere more frequently with warp yarns

Engineering Contradiction:
Improvestress on warp yarnsVSAvoidgripper-warp yarn interference
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The gripper surface is coated with a ceramic material layer that provides localized wear resistance and smoothness only where contact with warp yarns occurs. This selective surface treatment reduces friction and prevents yarn entanglement without requiring changes to the overall gripper structure or shed opening degree.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The gripper combines a metallic base structure with a ceramic coating layer, creating a composite material system. The metal provides structural strength while the ceramic surface provides low friction and wear resistance, enabling the gripper to operate reliably in reduced shed openings where interference with warp yarns is inevitable.

Inventive Principle:
Principle #40Composite materials

2Productivity

If the loom speed is increased to improve productivity, then the productivity is improved, but the grippers interfere more frequently with warp yarns due to advanced shed closing time

Engineering Contradiction:
Improveloom speedVSAvoidgripper-warp yarn interference
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The ceramic coating is applied specifically to the gripper surfaces that contact warp yarns during high-speed operation. This localized surface enhancement reduces friction and prevents yarn catching even when the grippers must operate at advanced positions in the shed closing cycle required for high-speed loom operation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The ceramic coating is applied in advance to the gripper surfaces before operation, creating a protective layer that prevents damage from inevitable interference with warp yarns during high-speed operation. This pre-applied protection cushioning allows the loom to run at high speeds without the grippers causing yarn damage or premature wear.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Productivity

If the gripper operates with frequent interference with warp yarns, then the gripper can function in reduced shed openings and at high speeds, but micro-defects and notches form on the gripper surface reducing its useful life

Engineering Contradiction:
Improveoperational capability in reduced shedVSAvoidgripper useful life
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The ceramic coating provides localized protection to the gripper surfaces that are subject to wear from warp yarn contact. This selective surface hardening prevents the formation of micro-defects and notches in the contact zones, extending the gripper's service life while maintaining the ability to operate in reduced shed openings at high speeds.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The combination of metal substrate and ceramic coating creates a composite structure where the ceramic layer protects the metal from wear and fatigue damage. This composite construction allows the gripper to withstand frequent interference with warp yarns without developing the micro-defects that would normally limit its useful life duration.

Inventive Principle:
Principle #40Composite materials

4Ease of operation

If the gripper surface has micro-defects from wear, then the gripper can operate initially, but the frequency of warp yarn catching increases and fatigue failure occurs

Engineering Contradiction:
Improveinitial operational capabilityVSAvoidwarp yarn catching frequency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The ceramic coating provides a consistently smooth surface quality in the exact locations where warp yarn contact occurs. This localized surface perfection prevents yarn catching by eliminating micro-defects and notches that would otherwise form through wear, maintaining reliable operation throughout the gripper's service life.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The ceramic coating is applied beforehand to create a wear-resistant surface that prevents the formation of micro-defects during operation. This pre-established protective layer cushions against the inevitable friction and contact with warp yarns, preventing the initiation of fatigue cracks and maintaining low yarn catching frequency throughout the operational period.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 design significantly reduces warp yarn catching, extends gripper lifespan by eliminating micro-defects and fatigue failure points, and simplifies manufacturing while maintaining high technical performance.

Implementation Method 1

a permanent magnet (6) is provided, embedded in the body (1) of the drawing gripper (T) and capable of attracting control rod (7)

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

an electrolytic ceramic coating has been subjected to a PEO (Plasma Electrolytic Oxidation) treatment

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Data Source

PatentEP2573241B9Pair of carrying and drawing grippers for weaving loom
Publication Date: 2015.04.22 ITEMA
  • EP2573241B9 patent drawingFigure 1A
  • EP2573241B9 patent drawingFigure 1B
  • EP2573241B9 patent drawingFigure 2A

AI summary

Pair of carrying and drawing grippers for a weaving loom, wherein the body of the carrying gripper is formed starting from a segment of extruded metal profile (1), through mechanical machining operations of shaving removal. On at least part of the outer surface of the gripper, at the end of all mechanic operations, a coating of a dense, hard and thin surface layer of ceramic material with a thickness of 20-30 micrometres is applied.