Plug-in Connector Seal for Cross-Linked Cable Weather Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing connector elements face challenges in sealing weather-resistant cables with cross-linked jackets, as the cross-linking prevents a tight connection with the surrounding material, leading to issues with strain relief and water penetration during axial pull, bending, and torsion.

Innovation Solution

A connector element design that uses a combination of materials including a crimpable metal sleeve, heat-shrinkable tubing, and a housing element made from reinforced polyamide or polypropylene, with a plastic material that forms a tight seal (IP 45 or better) between the sleeve, housing, and cable sheathing, ensuring strain relief and protection against torsion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cross-linked cable jacket is used to improve weather resistance, then weather resistance is improved, but a tight connection with the surrounding plastic material cannot be achieved

Engineering Contradiction:
Improveweather resistanceVSAvoidsealing tightness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent introduces a special sealing element as an intermediary component between the cross-linked cable jacket and the plastic material. This sealing element has dual functionality: it adheres to the cross-linked cable jacket through its outer surface and forms a tight seal with the plastic material through its inner surface, thereby mediating the connection between two incompatible materials and resolving the sealing issue.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs composite material structure by combining the cross-linked cable jacket with a specially designed sealing element that has heterogeneous surface properties. The sealing element itself is a composite structure with different surface characteristics on its inner and outer surfaces, allowing it to bond effectively with both the cable jacket and the plastic material, thus achieving a tight sealed connection.

Inventive Principle:
Principle #40Composite materials

2Strength

If the cable jacket is cross-linked to improve durability, then durability is improved, but strain relief and tight connection are compromised

Engineering Contradiction:
ImprovedurabilityVSAvoidstrain relief
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The sealing element acts as a mediator that absorbs and distributes mechanical stresses between the rigid cross-linked cable jacket and the surrounding plastic material. This intermediary component provides a compliant interface that maintains strain relief capabilities while preserving the durability benefits of the cross-linked structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the material parameters of the sealing element to create a gradient structure or selective property distribution, where the outer surface has properties matching the cross-linked cable jacket for strong bonding, while the inner surface has properties that allow tight sealing with the plastic material and provide strain relief through appropriate elasticity or compliance.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a two-part sealing element is used to seal the cable connection area, then sealing is improved, but the structure becomes complex and production costs increase

Engineering Contradiction:
Improvesealing capabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing element is segmented into functionally distinct surface zones: an outer surface specifically designed to bond with the cross-linked cable jacket and an inner surface designed to seal with the plastic material. This segmentation of functional surfaces within a single component achieves complex sealing requirements without the need for multiple separate parts, thereby reducing structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The single sealing element performs multiple functions simultaneously: it provides mechanical bonding to the cable jacket, creates a tight seal with the plastic material, and offers strain relief. This multi-functionality consolidates what would traditionally require multiple separate components into one universal element, simplifying the overall structure and reducing production complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Manufacturing precision

If additional casting compound is applied to increase tightness, then tightness is improved, but production complexity and cost increase

Engineering Contradiction:
ImprovetightnessVSAvoidproduction simplicity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The sealing element is pre-formed with specific surface properties and geometries that enable tight sealing and strong bonding before the final assembly. This preliminary preparation of the sealing component with built-in sealing features eliminates the need for additional casting compounds or post-assembly sealing operations, thereby simplifying the manufacturing process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces expensive and complex additional casting compound processes with a cost-effective, pre-formed sealing element that provides equivalent or superior sealing performance. The sealing element is a simple, disposable component that can be easily installed without requiring complex manufacturing steps or additional materials.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 reliable, weather-tight connection that withstands axial pull, bending, and torsion, while simplifying production and assembly, reducing costs, and ensuring efficient strain relief and pressure protection.

Implementation Method 1

a shrink tube (6) to be arranged between the cable sheathing (9) and the sleeve (5), the shrink tube (6) sealing with the cable sheathing (9) and the sleeve (5)

Methodology Applied
Scientific EffectThermal contraction: Thermal Contraction

Data Source

PatentEP2245705B1Plug-in connector element having a seal in the cable connection region
Publication Date: 2016.04.13 LAPP ENG
  • EP2245705B1 patent drawingFigure 1~2

AI summary

The invention relates to a plug-in connector element, comprising a sleeve which is to be disposed about a cable having at least one sheathing and which can be connected to the exterior sheathing of the cable, a plug-in contact to be electrically connected to at least one cable conductor within the sleeve, and a housing element, which encompasses the plug-in contact and abuts the sleeve. At least part of the housing element abutting the sleeve, the sleeve itself, and at least part of the cable leading away from the housing element, or from the sleeve, are surrounded by a plastic material. The plug-in connector element further comprises a heat shrink tube creating a seal between the plastic material and the cable sheathing.