Pre-expanded Cable Cover Friction Reduction

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Solution Overview

Problem

Existing cold shrinkable cover assemblies for electrical cables and connections are difficult to unroll due to high friction, often caused by mesh tubes digging into the rubber and grease settling in openings, leading to a hard-to-unroll jacket.

Innovation Solution

A pre-expanded cover assembly with friction reducing layers made of thin, flexible tubes wrapped around the outer sleeve and retention layers, providing a low friction surface for easier sliding and installation, and lubrication layers to facilitate unrolling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If mesh tubes and grease are used in the cover assembly, then the outer sleeve can be retained in folded state, but the friction increases making it difficult to unroll

Engineering Contradiction:
Improveretention of folded stateVSAvoidease of unrolling
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

A friction reducing layer made of PTFE (polytetrafluoroethylene) is introduced as an intermediary between the mesh retention layer and the outer sleeve. This mediator layer has low friction properties that prevent the outer sleeve from bonding to the mesh tube, allowing easy unrolling while the mesh tube continues to provide retention functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If the outer sleeve is made elastic and foldable, then it can be stored in compact form, but high friction prevents easy deployment

Engineering Contradiction:
Improvecompact storage volumeVSAvoidease of deployment
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The PTFE friction reducing layer serves as a mediator between the elastic outer sleeve and the mesh retention layer, enabling the sleeve to be easily deployed from its compact folded state by reducing friction during the unrolling motion.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The outer sleeve is designed with elastic properties that allow it to change from a compact folded state to an expanded deployed state. The friction reducing layer ensures that this parameter change (expansion) occurs easily without excessive friction resistance.

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 significantly reduces the effort required to unroll the cover assembly, preventing bonding and maintaining a low friction interface, thus making the installation process easier and more reliable.

Implementation Method 1

an elastomeric outer sleeve defining a cable passage to receive the electrical connection

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

Cold shrinkable covers are commonly employed to protect or shield electrical power cables and connections

Methodology Applied
Scientific EffectCold shrinkage: Elastic Recovery

Implementation Method 3

a first friction reducing layer between the first retention layer and the first outer section of the outer sleeve; a second friction reducing layer between the second retention layer and the second outer section of the outer sleeve

Methodology Applied
Scientific EffectFriction reduction: Friction

Data Source

PatentEP3545596B1Cover assemblies for cables and electrical connections and pre-expanded units and methods including same
Publication Date: 2021.05.26 TE CONNECTIVITY CORP
  • EP3545596B1 patent drawingFigure 1
  • EP3545596B1 patent drawingFigure 2A
  • EP3545596B1 patent drawingFigure 2B

AI summary

A pre-expanded cover assembly unit for covering an electrical connection between first and second cables includes a cover assembly in a folded state including an elastomeric outer sleeve defining a cable passage to receive the electrical connection. The outer sleeve includes an intermediate section and first and second outer sections. The first outer section is folded at a first annular fold and is on the intermediate section and/or the second outer section. The cover assembly includes a first retention layer between the intermediate section and the first outer section. The cover assembly includes a first friction reducing layer between the first retention layer and the first outer section. The cover assembly unit includes a removable holdout mounted within the outer sleeve. The cover assembly is movable from a folded state to an unfolded state by sliding the first outer section in a first axial direction away from the intermediate section.