Welting Machine Corner Knife Mechanism for Angle Selection

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Solution Overview

Problem

Conventional corner knife mechanisms in welting machines require manual adjustment and replacement of corner knives to balance between preventing damage to the welting patch and achieving optimal cutting performance, which is cumbersome and time-consuming, especially when dealing with different types of cloth.

Innovation Solution

A corner knife mechanism with multiple corner knives of varying cutting edge angles and mounting angles, controlled by a knife selecting actuator and operation control means, allowing for easy selection and switching of knife combinations to suit the cloth type, eliminating the need for manual adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the mounting angle of the corner knife is increased to make the triangular portion smaller and improve external appearance, then the quality of sewn product is improved, but the raised portion of the welting patch is more likely to be damaged by the cutting edge

Engineering Contradiction:
Improvequality of sewn productVSAvoiddamage to welting patch
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by providing multiple corner knives with different mounting angles (e.g., 45°, 60°, 75°) and different cutting edge angles. This allows selection of appropriate parameters based on cloth type and quality requirements, resolving the contradiction between producing small triangular portions and preventing damage to the welting patch.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamics by enabling dynamic selection of corner knives through the knife selecting actuator and operation control means. The system can switch between different corner knives during operation based on the specific requirements, making the mounting angle adjustable rather than fixed, thus resolving the contradiction adaptively.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the cutting edge angle of the corner knife is increased to prevent damage to the raised portion, then the reliability of preventing patch damage is improved, but the cutting performance decreases

Engineering Contradiction:
Improveprevention of patch damageVSAvoidcutting performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent provides corner knives with various cutting edge angles (e.g., 30°, 45°, 60°) to change the cutting parameters. This allows selection of appropriate cutting edge angles based on cloth type, resolving the contradiction between preventing patch damage and maintaining cutting performance for different materials.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system enables dynamic selection of corner knives with different cutting edge angles through the knife selecting actuator. This makes the cutting parameters adaptable to different cloth types, allowing optimization of both reliability and productivity based on specific processing requirements.

Inventive Principle:
Principle #15Dynamics

3Reliability

If manual adjustment and replacement of corner knives is performed to balance between preventing patch damage and achieving optimal cutting performance, then the quality and reliability are improved, but the time consumption and operation complexity increase

Engineering Contradiction:
Improvebalance between patch protection and cutting performanceVSAvoidtime for adjustment and replacement
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements self-service by providing an automated knife selecting actuator and operation control means that automatically select and position the appropriate corner knife based on programmed parameters. This eliminates the need for manual adjustment and replacement, resolving the contradiction between maintaining high reliability and reducing time loss.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the manual mechanical adjustment system with an automated control system comprising the knife selecting actuator and operation control means. This substitution automates the knife selection process, eliminating manual intervention and significantly reducing the time required for knife replacement while maintaining optimal cutting parameters.

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

Data Source

PatentEP2154282B1Corner knife mechanism of welting machine
Publication Date: 2017.06.07 JUKI CORP
  • EP2154282B1 patent drawingFigure 1
  • EP2154282B1 patent drawingFigure 2
  • EP2154282B1 patent drawingFigure 3

AI summary

The invention relates to a corner knife mechanism (100A, 100B) of a welting machine (10). The corner knife mechanism (100A, 100B) includes a plurality of first corner knives (101, 102, 101A, 102A) having different cutting edge angles (¸e1, ¸e2) or different mounting angles (¸1, ¸2), a plurality of second corner knives (103, 104, 103A, 104A) having different cutting edge angles (¸e3, ¸e4) or different mounting angles (¸3, ¸4), a corner knife holder (105) on which the first and second corner knives are arranged, a knife selecting actuator (121) which moves the corner knife holder (105) in a direction (Y) along which of the first and second corner knives are arranged, a cutting actuator (131, 132) which selectively moves up and down the first and second corner knives; and an operation control means (80) which controls the knife selecting actuator (121) and the cutting actuator (131, 132) to select a combination of one of the first corner knives and one of the second corner knives and to form a corner cut. The first corner knife and the second corner knife of the combination are symmetrically oriented with respect to the cloth feeding direction (F) and have the same mounting angle (¸1, ¸3; ¸2, ¸4) or the same cutting edge angle (¸e1, ¸e3; ¸e2, ¸e4).