Two-Layer Multi-Strand Cable for Flexible Tire Apex Plies

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing cables for tire apex plies are too rigid, leading to increased sensitivity to aggression and reduced endurance performance, particularly in applications with installation angles less than 10°, necessitating a balance between flexibility and tensile strength.

Innovation Solution

A two-layer multi-strand cable design with specific layer configurations and structural elongation, comprising inner and outer layers of helically wound strands with varying diameters and pitches, ensuring flexibility and sufficient breaking strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a cable has a large cross-section to carry high currents, then the current carrying capacity is improved, but the cable becomes increasingly inflexible and difficult to handle

Engineering Contradiction:
Improvecurrent carrying capacityVSAvoidflexibility
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The cable is divided into multiple individual strands (at least 5 strands) instead of a single solid conductor. Each strand can flex independently, allowing the cable to bend and flex while maintaining sufficient cross-sectional area for high current carrying capacity. The strands are twisted together to form the composite cable structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cable structure transitions from a single-dimensional solid conductor to a multi-dimensional composite structure with strands arranged in multiple layers. At least two strands are positioned in an inner layer and at least two strands in an outer layer, creating a spatial arrangement that enhances flexibility while maintaining current carrying capacity.

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

2Quantity of substance

If a cable has a large cross-section to carry high currents, then the current carrying capacity is improved, but the cable becomes increasingly prone to corrosion

Engineering Contradiction:
Improvecurrent carrying capacityVSAvoidcorrosion resistance
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The cable employs a composite structure with at least two different metal materials used for the strands. This allows combining materials with different properties - such as copper for electrical conductivity and corrosion resistance, or aluminum for lightweight and corrosion resistance - to achieve both high current carrying capacity and improved corrosion resistance.

Inventive Principle:
Principle #40Composite materials

3Quantity of substance

If a cable has a large cross-section to carry high currents, then the current carrying capacity is improved, but the cable becomes increasingly difficult to bend

Engineering Contradiction:
Improvecurrent carrying capacityVSAvoidbendability
Core Design Contradiction:
Quantity of substanceVSShape

Solution Approach 1:

The cable is divided into multiple individual strands (at least 5 strands) instead of a single solid conductor. Each strand can flex independently, allowing the cable to bend and flex while maintaining sufficient cross-sectional area for high current carrying capacity. The strands are twisted together to form the composite cable structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cable structure transitions from a single-dimensional solid conductor to a multi-dimensional composite structure with strands arranged in multiple layers. At least two strands are positioned in an inner layer and at least two strands in an outer layer, creating a spatial arrangement that enhances flexibility while maintaining current carrying capacity.

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

Data Source

PatentEP4540454B1Multi-strand cable with two multi-strand layers
Publication Date: 2026.04.15 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP4540454B1 patent drawingFigure 1
  • EP4540454B1 patent drawingFigure 2
  • EP4540454B1 patent drawingFigure 3

AI summary

The invention relates to a multi-strand cable (50) with two multi-strand layers, the cable (50) comprising: - an inner layer (CI) of the cable, made up of X = 3 or 4 multi-strands (M1) comprising K = 2, 3 or 4 strands (T1) helically wound around an axis (B), each strand (T1) being a strand with at least two layers (C1, C3); and - an outer layer (CE) of the cable, made up of Y > 1 multi-strands (M2) wound around the inner layer (CI) of the cable, each multi-strand (M2) comprising L = 2, 3 or 4 strands (T2) helically wound around an axis (A'), each strand (T2) being a strand with at least two layers (C1'; C3'), with the multi-strands of the inner layer (M1) and of the outer layer (M2) being helically wound around a main axis (A). The cable (50) has a structural elongation As such that As ≥ 1.0%.