Cable Feedthrough Sealing With Axial Compression and No Shear

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Solution Overview

Problem

Existing cable bushing technologies face challenges in providing a simple, cost-effective, and reliable seal for pre-assembled electrical cables, particularly due to complex handling requirements and limited adaptability to various housing dimensions, often resulting in undesirable shear forces and restricted cable sizes.

Innovation Solution

A cable feedthrough system featuring a cover with two housing shells, an elastic sealing element, and a counter-pressure plate that applies axial pressure, ensuring a secure seal without shear forces, and allowing for flexible adaptation to different cable and housing sizes through a conically widened opening and continuous cable passages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a screw connection piece is used to apply pressure to a seal, then the seal is secured, but shear forces are generated that adversely affect the sealing element

Engineering Contradiction:
Improvesealing reliabilityVSAvoidshear forces on sealing element
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

Instead of applying pressure from the front (which generates shear forces), the patent applies pressure from the rear using a counterpressure plate. This inverted approach pushes the sealing element against the conically widened opening, creating compression without shear forces and eliminating the harmful side effect while maintaining sealing reliability

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces the screw connection mechanism (which generates shear forces through threading) with a direct axial pressure application system using a counterpressure plate. This substitution eliminates the mechanical complexity and harmful shear forces while achieving the same sealing function through pure compressive force

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

2Reliability

If a block-shaped insert with zigzag-shaped slot is used, then sealing is achieved, but cable insertion becomes cumbersome and costly

Engineering Contradiction:
Improvesealing qualityVSAvoidcable insertion ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

Instead of using a zigzag-shaped slot that requires complex opening and closing operations, the patent inverts the approach by using a simple axial slot that opens automatically when the sealing element is compressed. This allows cable insertion from the rear without cumbersome handling, maintaining sealing quality while dramatically improving ease of operation

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The sealing element is pre-compressed between the cover and counterpressure plate, which automatically opens the slot before cable insertion. This preliminary compression action prepares the system for easy cable access without requiring manual manipulation of complex slot mechanisms

Inventive Principle:
Principle #10Preliminary action

3Reliability

If axial pressure is applied to a sealing element, then sealing is improved, but the sealing element is subjected to compression that may deform it

Engineering Contradiction:
Improvesealing effectivenessVSAvoidsealing element shape stability
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The patent changes the geometric parameters of the opening (conical widening) to match the compression direction of the sealing element. By aligning the cone angle with the compression force, the sealing element deforms uniformly along its axis without lateral buckling or distortion, maintaining shape stability while achieving effective sealing through compression

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 provides a stable, easy-to-handle, and cost-effective cable bushing with a reliable seal suitable for a wide range of cables and housings, eliminating shear forces and accommodating cables of various dimensions.

Implementation Method 1

at least one elastic and/or flexible sealing element is provided to seal the housing

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3714520B1Cable feedthrough
Publication Date: 2024.02.21 HARTING ELECTRIC STIFTUNG & CO KG
  • EP3714520B1 patent drawingFigure 1
  • EP3714520B1 patent drawingFigure 2a~2c
  • EP3714520B1 patent drawingFigure 3a~3e

AI summary

The invention relates to a cable feedthrough for feeding at least one cable (4) into a housing (1) with an opening (10) that is provided with a covering (112) comprising at least two housing shells (11, 12), said covering (112) having at least one opening (14), wherein a separating plane of the housing shells (11, 12) extends centrally through said opening (14); and wherein to seal the housing (1), at least one elastic and/or flexible sealing element (3) is provided that comprises a cable passage (34) with a slit (340) extending to the lateral edge of said cable passage; and wherein a counter pressure plate (2) is provided that comprises at least one cable passage (234) and covers the opening (10), said counter pressure plate (2) cooperating with the sealing element (3) and the covering (112) to seal the housing (1). The sealing element (3) is arranged with a predetermined oversize between the covering (112) and the counter pressure plate (2) and is under pressing force, as a result of which the sealing element (3) is compressed.