Threaded Welding Contact Tip Assembly for Cooling and Alignment

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Solution Overview

Problem

Conventional MIG welding systems face issues with the wear and replacement of consumable components, leading to reduced productivity and increased costs due to reliance on axial friction for retaining gas nozzles and contact tips, which can result in premature failure and misalignment of welding torch liners.

Innovation Solution

The design incorporates a contact tip with a non-threaded proximal end portion that protrudes into the welding gas stream for cooling and a gas diffuser with internal threads that mate with external threads on the contact tip, providing improved axial alignment and retention, along with a liner stop to maintain concentricity between the welding torch liner and contact tip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If axial friction is used to retain gas nozzles and contact tips, then the components can be retained in the welding torch, but the components experience premature failure and misalignment

Engineering Contradiction:
Improvecomponent retentionVSAvoidcomponent service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces the conventional axial friction retention mechanism with a threaded mechanical engagement system. The contact tip and gas nozzle now feature external threads that mate with internal threads in the welding torch, providing positive mechanical retention instead of relying on friction. This substitution eliminates premature failure and misalignment while extending component service life.

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

2Ease of operation

If contact tips are retained using conventional methods, then they can be installed in the welding torch, but replacement takes time and reduces productivity

Engineering Contradiction:
Improvecontact tip installationVSAvoidwelding productivity
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent segments the contact tip assembly into modular components with standardized threaded interfaces. The contact tip, gas nozzle, and liner are designed as separate, independently replaceable units that screw onto the welding torch body. This segmentation allows for rapid tool-free replacement of consumables, significantly reducing downtime and maintaining high welding productivity.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If the non-threaded proximal end portion contacts the gas diffuser, then axial alignment may be achieved, but the contact tip retains less heat for longer duration

Engineering Contradiction:
Improveaxial alignmentVSAvoidcontact tip temperature
Core Design Contradiction:
Manufacturing precisionVSTemperature

Solution Approach 1:

The patent introduces a threaded middle portion as an intermediary element between the proximal end and the gas diffuser. This threaded section provides the necessary mechanical engagement and axial positioning, while the non-threaded proximal end portion remains thermally isolated from the gas diffuser. The intermediary threaded portion ensures precise alignment without creating unwanted thermal contact, allowing the contact tip to retain heat for improved weld penetration.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enhances the performance and longevity of contact tips by cooling them through convection, reduces radiant heat absorption, and improves wire electrode feedability, while also simplifying the replacement process and maintaining proper alignment, thus increasing productivity and reducing costs.

Implementation Method 1

The non-threaded distal end portion comprises a tapered outer surface adjacent the threaded middle portion and configured to abut a mating tapered inner surface of the gas diffuser of the welding torch. The non-threaded proximal end portion is configured not to physically contact the gas diffuser when the welding contact tip is fully installed into the gas diffuser.

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3386673B1Contact tip and gas diffuser for welding torch
Publication Date: 2023.02.01 ILLINOIS TOOL WORKS INC
  • EP3386673B1 patent drawingFigure 1
  • EP3386673B1 patent drawingFigure 2
  • EP3386673B1 patent drawingFigure 3

AI summary

In certain embodiments, a welding contact tip includes a first axial end portion having a welding wire outlet of an internal bore of the welding contact tip. The welding contact tip also includes a threaded middle portion adjacent the first axial end portion. The threaded middle portion includes external threads configured to mate with internal threads of a gas diffuser of a welding torch. The first axial end portion includes a tapered outer surface adjacent the threaded middle portion. The welding contact tip further includes a second axial end portion adjacent the threaded middle portion. In other embodiments, a welding torch liner assembly includes a liner stop configured to be attached to a first axial end of a welding torch liner. The welding torch liner assembly also includes a liner receiver configured to secure a second axial end of the welding torch liner. The second axial end of the welding torch liner is opposite the first axial end of the welding torch liner.