Cable Feedthrough Bristle Contact for Shield Reliability

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Solution Overview

Problem

Existing cable bushings face issues with maintaining a reliable electrical contact between the shield contact element and the cable shield, especially when the cable moves, due to poor quality of electrical contact.

Innovation Solution

The use of an elastic and electrically conductive bristle element that contacts the cable shield, allowing for multiple points of contact and flexibility to maintain the connection even with cable movement, with the bristle element being inserted and fixed within the housing via a non-positive frictional connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional shield contact element is used, then the structure is simple, but the electrical contact quality with the cable shield is poor and unreliable especially when the cable moves

Engineering Contradiction:

Improveelectrical contact qualityVSAvoidshield contact element structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The shield contact element is segmented into multiple individual bristles instead of a single solid contact surface. Each bristle acts as an independent contact point, allowing the element to conform to the cable shield surface and maintain reliable electrical contact even when the cable moves or is bent.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The contact element changes its physical parameters by using elastic bristles that can deform and flex. This allows the bristles to adapt their shape and position in response to cable movement, maintaining continuous electrical contact without requiring a complex mechanical adjustment mechanism.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a rigid shield contact element is used, then the manufacturing is simple, but the element cannot follow cable movement and maintains poor contact

Engineering Contradiction:

Improvecontact stability during movementVSAvoidbristle element fabrication

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The shield contact element uses flexible bristles instead of rigid structures. These bristles can bend and flex to follow cable movement while maintaining contact, providing contact stability during movement without requiring complex mechanical components that would difficult to manufacture.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The bristle element combines materials with different properties - elastic materials for flexibility and electrical conductivity for electrical contact. This composite approach allows the element to simultaneously achieve flexibility for movement accommodation and electrical conductivity for reliable contact, while remaining manufacturable.

Inventive Principle:

Principle #40Composite materials

3Reliability

If the bristle element is firmly fixed in the housing, then the electrical contact with housing is secure, but the assembly and disassembly becomes difficult

Engineering Contradiction:

Improveelectrical contact reliabilityVSAvoidassembly and disassembly

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The fixation mechanism uses elastic prestressing to create a dynamic, reversible connection between the bristle element and the housing. The elastic element allows the bristle element to be firmly held during operation for reliable contact, but can be easily released by applying force to overcome the elastic retention, enabling simple assembly and disassembly.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The fixation system changes the force parameters through elastic prestressing - maintaining a constant retaining force during operation for reliable contact, but allowing the force to be temporarily overcome during assembly/disassembly. This parameter change enables both reliable operation and easy maintenance.

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

This solution ensures a stable and reliable electrical connection between the cable shield and the shield contact element, allowing for easy assembly and disassembly while maintaining contact integrity during cable movement.

Implementation Method 1

the bristle element comprises elastic and electrically conductive bristles

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

elastic and electrically conductive bristles

Methodology Applied

Scientific EffectElectrical Conduction: Conduction (electrical)

Implementation Method 3

an element which expands outwards as a result of elastic prestressing. Such an outwardly expanding element is made, for example, from a resilient material.

Methodology Applied

Scientific EffectElastic Prestressing: Elasticity

Implementation Method 4

the bristle element is fixed in the housing in a non-positive manner. Such a fixation can be realized, for example, in that the bristle element rests in a non-positive manner on an inner surface of the housing

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentEP1710885B1Cable feedthrough

Publication Date: 2008.10.29 LAPP ENG

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AI summary

A cable entrance comprises a housing (10) which can be fixed on an appliance and a fixture (26,40,50) for a cable and a screen contact element (60) held on the housing. The screen contact element has a bristle element (60) contacting a cable screen with elastic and electrically conducting bristles.