Plasma Torch Front End Assembly for Quick Consumable Replacement

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Solution Overview

Problem

Current plasma arc torches are inefficient and cumbersome due to the need to remove and reinstall multiple parts to replace consumable components like electrodes and nozzles, which are subject to deterioration during operation.

Innovation Solution

A front end assembly for the plasma arc torch featuring a shield, shield retainer, nozzle retaining cup insert, and nozzle retaining cup body allows for the quick and easy replacement of consumable components as a single unit, eliminating the need for specialized fixtures or tools, with a gas diffuser or insulator ensuring proper alignment and sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If multiple parts are removed one at a time to access consumables, then access to consumables is achieved, but the replacement process becomes inefficient and cumbersome

Engineering Contradiction:
Improveease of consumable replacementVSAvoidtime for part removal and reinstallation
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The torch is divided into a main body and a removable front end assembly. The front end assembly includes the nozzle, electrode holder, and associated components that can be removed as a single unit from the main torch body, eliminating the need to remove multiple individual parts sequentially.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The front end assembly containing the consumables (nozzle and electrode) is extracted as a complete unit from the torch body. This allows the entire consumable assembly to be removed in one operation and replaced with a new pre-assembled unit, significantly reducing replacement time.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If consumables are replaced as a complete front end assembly, then replacement efficiency is improved, but the device structure becomes more complex

Engineering Contradiction:
Improveconsumable replacement speedVSAvoidtorch assembly structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The torch is segmented into a permanent main body and a replaceable front end assembly. The front end assembly is further segmented into the nozzle, electrode holder, and retaining components, allowing for modular replacement while keeping the main torch body simple and unchanged.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrode holder is nested within the front end assembly, and the nozzle is nested within the electrode holder. The entire nested assembly is retained by the retaining cup and secured with a retaining ring, creating a compact modular unit that replaces as one piece.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If the nozzle and electrode holder are retained by multiple separate components, then secure retention is achieved, but the disassembly process becomes cumbersome

Engineering Contradiction:
Improveretention securityVSAvoiddisassembly ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The retaining ring is extracted as the single fastening element that secures the entire front end assembly. By removing this one component, the entire assembly (nozzle, electrode holder, and retaining cup) is released and can be removed as a unit, simplifying the disassembly process while maintaining secure retention during operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3068572B1Plasma arc torch and method for assembling and disassembling a plasma arc torch
Publication Date: 2018.03.21 ESAB GROUP INC
  • EP3068572B1 patent drawingFigure 1
  • EP3068572B1 patent drawingFigure 2
  • EP3068572B1 patent drawingFigure 3

AI summary

A front end assembly for a plasma torch and methods for assembling and disassembling a torch wherein a plurality of front end parts form a unit that is removable from, and installable in, the torch in a single operation without a special fixture. The front end assembly includes a nozzle retaining cup body connectable to a body of the torch, and a forward end connectable to a shield retainer. A nozzle retaining cup insert fits into the nozzle retaining cup body. The shield retainer has an inner surface for retaining the shield. A nozzle is received within the nozzle retaining cup insert. A stop on the nozzle engages the nozzle retaining cup insert when the front end assembly is removed from the torch so the nozzle does not remain in the torch. The shield engages an insulator, which engages the nozzle, to limit forward axial movement of the nozzle.