Flat Spiral Electrical Cable for Vehicle Energy Supply

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Solution Overview

Problem

Existing electrical lines for vehicles, particularly those with electric drives, face challenges such as high restoring forces requiring complex and costly annealing processes, limited storage space due to large volumes in rest positions, and vulnerability to damage and theft, while also needing to efficiently bridge varying distances with minimal effort.

Innovation Solution

A spirally wound electrical line with a shaping element, such as a metal or shape-memory polymer spring, that automatically retracts into a compact rest position, minimizing storage space and using magnetic elements for additional fixation, allowing for easy handling and protection against environmental and vandalism-related risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a helically wound electrical line is used to enable automatic retraction, then the line can be brought into a compact rest position, but the restoring force becomes excessively high requiring complex annealing processes and special connector designs

Engineering Contradiction:
Improvecompact rest positionVSAvoidannealing process complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The patent changes the geometric parameters of the spiral configuration, specifically using a flat spiral layout with optimized pitch and radius ratios. This parameter optimization reduces the restoring force while maintaining compact storage, eliminating the need for complex annealing processes required by traditional helical wound cables.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent transitions from a three-dimensional helical winding to a two-dimensional flat spiral configuration. This curvature transformation fundamentally changes the mechanical properties, reducing the restoring force from high (helical) to manageable levels (flat spiral) while maintaining automatic retraction capability.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Force

If a small screw diameter is used to generate greater restoring force, then the line retracts effectively, but the storage device must protrude deep into the vehicle compartment

Engineering Contradiction:
Improverestoring forceVSAvoidstorage device protrusion depth
Core Design Contradiction:
ForceVSLength of stationary object

Solution Approach 1:

The patent redistributes the restoring force generation from the radial dimension (small screw diameter) to the planar dimension (spiral arm length and pitch). The flat spiral configuration generates sufficient restoring force through its extended planar geometry rather than compact radial winding, allowing shallow storage device mounting.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The transition from helical to flat spiral geometry changes how restoring force is generated. Instead of relying on tight radial coiling (small screw diameter), the flat spiral uses its extended planar form with optimized pitch to generate the necessary restoring force, reducing storage device protrusion depth.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Length of stationary object

If a large screw diameter is used to reduce storage depth, then the storage device protrudes less, but a large area is required for accommodation

Engineering Contradiction:
Improvestorage device protrusion depthVSAvoidstorage area
Core Design Contradiction:
Length of stationary objectVSArea of stationary object

Solution Approach 1:

The patent optimizes the spiral parameters (pitch, outer radius, inner radius ratios) to achieve compact area utilization. The flat spiral configuration with optimized parameters packs the cable efficiently in a shallow device with minimal footprint, balancing both depth and area requirements for vehicle integration.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If the cable is freely suspended to cover different distances, then flexibility over distance is achieved, but the cable is vulnerable to weathering, damage, and theft

Engineering Contradiction:
Improvedistance flexibilityVSAvoidweathering and damage risk
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements automatic retraction through the flat spiral's inherent restoring force, which actively pulls the cable back into the storage device after use. This self-service mechanism minimizes the time the cable is exposed to external environmental factors, reducing vulnerability to weathering, damage, and theft while maintaining distance flexibility during operation.

Inventive Principle:
Principle #25Self-service

5Force

If high restoring force is used to ensure automatic retraction, then the line returns to rest position reliably, but the connector is subjected to large shearing forces requiring special securing measures

Engineering Contradiction:
Improverestoring force reliabilityVSAvoidconnector strength requirements
Core Design Contradiction:
ForceVSStrength

Solution Approach 1:

The patent optimizes the spiral geometry parameters to reduce the restoring force to a manageable level. The flat spiral configuration with optimized pitch and radius ratios generates sufficient force for reliable retraction while keeping the connector shear forces within standard design limits, eliminating the need for special securing measures.

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 enables efficient energy transfer with reduced material and production costs, optimized space utilization, and enhanced safety by minimizing contact with soiled parts and preventing unintentional disconnection, while allowing for easy deployment and retraction with minimal user effort.

Implementation Method 1

A spirally wound electrical line with a shaping element, such as a metal or shape-memory polymer spring, that automatically retracts into a compact rest position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

A spirally wound electrical line with a shaping element, such as a metal or shape-memory polymer spring

Methodology Applied
Scientific EffectShape Memory Polymer: Shape Memory Polymer

Implementation Method 3

using magnetic elements for additional fixation

Methodology Applied
Scientific EffectMagnetism: Magnetism

Data Source

PatentEP2695262B1Electrical cable for the energy supply of vehicles
Publication Date: 2016.05.18 LAPP ENG
  • EP2695262B1 patent drawingFigure 1
  • EP2695262B1 patent drawingFigure 2
  • EP2695262B1 patent drawingFigure 3~4

AI summary

The invention relates to an electrical cable (10), in particular for the energy supply of a vehicle (50), comprising a sheath (16), within which at least two insulated electrical conductors (12) are provided, which are connected to at least one plug connector (18) at at least one first end of the cable (10). According to the invention, the sheath (16) and/or the conductors (12) and/or at least one shaping element (20) preferably provided in the cable (10) is designed in such a way that the cable (10) is held in a resting position by means of a restoring force, in which resting position the cable (10) has the shape of a spiral and is oriented along a flat or curved resting surface.