Cable Feedthrough Contacting Device for Continuous EMI Shielding

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Solution Overview

Problem

Existing cable bushings fail to provide continuous shielding against electromagnetic radiation due to the lack of electrical connection between cables and the partition wall, leading to incomplete protection against both electrical and magnetic fields.

Innovation Solution

A contacting device with metal discharge elements and a fastening device, such as a metal comb back, is integrated into cable bushings to establish an electrically conductive connection between the cable shielding and the wall, ensuring continuous shielding against electromagnetic radiation. The fastening device is designed to provide a low contact resistance connection, typically less than 1 Ω, and is easily assembled without additional work.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cable bushings use non-conductive materials for sealing, then sealing performance is improved, but continuous shielding against electromagnetic radiation is compromised

Engineering Contradiction:
Improvesealing performanceVSAvoidelectromagnetic radiation shielding
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system separates sealing functionality from electromagnetic shielding functionality. The non-conductive sealing module handles mechanical sealing while the contacting device with conductive elements provides continuous electromagnetic shielding through electrical connection to the cable shielding.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cable bushing system uses composite construction combining non-conductive sealing materials with conductive contacting elements. This composite approach allows simultaneous achievement of mechanical sealing and electromagnetic shielding properties.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If conductor elements are made flexible to adapt to cable diameter, then adaptability is improved, but contact resistance increases

Engineering Contradiction:
Improvecable diameter adaptabilityVSAvoidcontact resistance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The conductor elements are designed with dynamic characteristics - flexible enough to adapt to different cable diameters but with sufficient stiffness to maintain reliable electrical contact. The elements can deform to accommodate cable variations while maintaining adequate contact pressure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The conductor elements are designed with specific dimensional parameters (diameter, length, flexibility) that allow them to adapt to varying cable diameters while maintaining optimal contact properties. The parameters are optimized to balance adaptability with contact resistance requirements.

Inventive Principle:
Principle #35Parameter changes

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 solution ensures reliable electrical contact and continuous shielding against electromagnetic radiation, effectively protecting cables from electromagnetic interference while maintaining mechanical and sealing functions.

Implementation Method 1

metal discharge elements, which are electrically conductive on the one hand with the cable shielding at least one through the Wall opening passed through cable and on the other hand connected or connectable via at least one fastening device with the wall and preferably ground potential of an electrical device

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3139719B1Contacting device for cable feedthrough and cable feedthrough
Publication Date: 2020.02.26 LAPP ENG
  • EP3139719B1 patent drawingFigure 1
  • EP3139719B1 patent drawingFigure 2a~2c
  • EP3139719B1 patent drawingFigure 3a

AI summary

The contacting device (1), which is provided for a cable entry point used in electrical devices such as control cabinets for routing cables (9), in particular shielded cables, comprises a wall (8) provided with a wall opening (81) and metallic conductive elements (3) which are electrically conductive on the one hand to the cable shielding (91) of at least one cable (9) passing through the wall opening (81) and on the other hand, via at least one fastening device (4), to the wall (8) and preferably to the ground potential of an electrical device. According to the invention, the at least one fastening device (4) is designed as a metallic comb-like back to which the conductive elements (3), which project into the wall opening (81) in a wire-like manner, are attached as comb fingers.The cable entry (10) according to the invention preferably comprises a first cable entry (6) serving to mechanically hold and/or seal cables (9) passed through, which is connected by means of connecting means (7) preferably parallel to the discharge elements (3) to the contacting device (1), which serves as the second cable entry.