Rotating Power Connector for Welding Torch Cables

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Solution Overview

Problem

Conventional fixed connections in electric welding power cables lead to mechanical wear and failure due to torsional stress when the welding torch is rotated, especially in robotic applications where coaxial mounting applies rotational torque to the cables.

Innovation Solution

A rotating power connection system that allows the welding torch's power cable to rotate with the robot axis, featuring a cylindrical housing with a fixed connector pin and a rotatable stud, along with a secondary electrical contact ring and biasing members to ensure reliable electrical and gas communication, reducing mechanical stress on the cables.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed connection is used for the power cable, then the electrical connection is simple and reliable, but the cable is subjected to torsional stress and mechanical wear when the torch is rotated

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidcable mechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies the dynamics principle by introducing a rotating connection mechanism that allows the power cable to rotate with the torch during manipulation. The rotating connector includes a rotating element that can freely rotate relative to the cable, converting the static fixed connection into a dynamic rotating connection. This resolves the contradiction by allowing the cable to accommodate rotational movements without experiencing torsional stress, while maintaining reliable electrical connection through continuous contact between the rotating element and cable conductors.

Inventive Principle:
Principle #15Dynamics

2Ease of manufacture

If the cable is installed in a fixed position, then the installation is simple, but the cable twists and suffers mechanical wear during torch manipulation

Engineering Contradiction:
Improveinstallation simplicityVSAvoidcable connection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The rotating connector incorporates a dynamic rotating element that simplifies installation by requiring only attachment to the torch, while automatically accommodating all rotational movements during operation. The rotating element is designed to rotate freely within the connector housing, eliminating the need for complex cable routing or positioning. This resolves the contradiction by maintaining installation simplicity while dramatically improving connection reliability through the rotating mechanism that prevents cable twisting and wear.

Inventive Principle:
Principle #15Dynamics

3Strength

If a rotating connection is implemented, then the cable can rotate with the torch reducing mechanical wear, but the connector structure becomes more complex

Engineering Contradiction:
Improvecable mechanical strengthVSAvoidconnector structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The rotating connector uses a relatively simple rotating element design that includes a rotational bearing or bushing mechanism allowing the cable to rotate freely. The rotating element consists of basic components such as a rotational joint with contactless electrical connection or sliding contacts, avoiding complex multi-component mechanisms. This resolves the contradiction by implementing the necessary rotational freedom to protect cable strength while keeping the connector structure sufficiently simple for practical manufacturing and maintenance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotating connector introduces an intermediary rotating element between the fixed cable and the moving torch. This intermediary component absorbs all rotational movements, allowing the cable to remain stationary while the torch rotates. The rotating element serves as a mediator that transfers power and signal while accommodating mechanical rotation, thus protecting the cable from torsional stress without requiring complex modifications to either the cable or torch structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If the torch is coaxially mounted on the robot, then the mounting is compact and efficient, but rotation of the robot axis applies severe torque to the cable

Engineering Contradiction:
Improverobotic welding efficiencyVSAvoidcable mechanical strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The rotating connector is specifically designed to handle the severe torque conditions in robotic welding applications. The rotating element incorporates a high-capacity rotational joint that can accommodate the torque generated during robotic arm rotation while maintaining electrical connection. The design allows the cable to remain stationary while the torch and robot arm rotate around it, converting the severe torsional stress scenario into a configuration where the cable experiences minimal to no torque, thus preserving cable strength while maintaining robotic welding efficiency.

Inventive Principle:
Principle #15Dynamics

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 rotating power connection system significantly reduces mechanical wear on the power cables, extending their lifespan by allowing them to rotate with the torch, thus preventing torsional stress and maintaining efficient electrical and gas transmission.

Implementation Method 1

At least one biasing member is disposed between the rotating stud and the contact ring. The biasing member urges the rotating stud into engagement with the connector pin and urges the contact ring into engagement with the rotating stud.

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP2109513B1Rotating power connector for electric welding torch unicables
Publication Date: 2014.06.25 ILLINOIS TOOL WORKS INC
  • EP2109513B1 patent drawingFigure 1
  • EP2109513B1 patent drawingFigure 2
  • EP2109513B1 patent drawingFigure 3

AI summary

A rotating power connector for an electric welding torch unicable includes a generally cylindrical outer housing having a longitudinal axis. A connector pin is fixedly, axially disposed within the outer housing and extends from one end thereof. A rotating stud is rotatably, axially disposed within the outer housing and extends from another end thereof. The connector pin and the rotating stud have ends in contact within the outer housing. A secondary electrical contact ring also is disposed within the outer housing. The secondary- electrical contact ring includes at least one contact portion contacting the rotating stud. At least one biasing member is disposed between the rotating stud and the contact ring. The biasing member urges the rotating stud into engagement with the connector pin and urges the contact ring into engagement with the rotating stud.