Multi-Strand Tire Cable Structure for Elastomer Penetration

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Solution Overview

Problem

Existing multi-strand cables used in heavy industrial vehicle tires are susceptible to corrosion due to the entry and propagation of corrosive agents, and increasing cord diameter or number to enhance breaking force compromises flexibility and penetrability.

Innovation Solution

A two-layer multi-strand cable design with a desaturated outer layer and specific pitch ratios (0.36 ≤ (p3-p2)/p3 ≤ 0.57) to allow elastomer composition penetration, enhancing penetrability while maintaining breaking force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the cord diameter is increased to enhance breaking force, then the breaking force is improved, but the flexibility and penetrability of the cord deteriorate

Engineering Contradiction:
Improvebreaking forceVSAvoidflexibility and penetrability
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The cable is divided into multiple strands (at least three strands) wound around a central element, with each strand containing multiple cords. This segmentation allows the cable to maintain high breaking force through multiple load-bearing elements while improving flexibility and penetrability through the distributed, finer structure of individual strands and cords.

Inventive Principle:
Principle #1Segmentation

2Strength

If the number of cords is increased to enhance breaking force, then the breaking force is improved, but the penetrability of the strands by elastomer composition deteriorates

Engineering Contradiction:
Improvebreaking forceVSAvoidpenetrability by elastomer composition
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The cable structure implements local quality by having strands with different characteristics: some strands have tighter cord packing for strength, while the overall strand arrangement and helical winding create localized spaces that allow elastomer penetration. The core element and helical geometry create channels for elastomer flow without compromising the breaking force of individual cord assemblies.

Inventive Principle:
Principle #3Local quality

3Strength

If the unit strength of each cord is increased to enhance breaking force, then the breaking force is improved, but the investment in cord manufacturing facilities increases significantly

Engineering Contradiction:
Improvebreaking forceVSAvoidmanufacturing facility investment
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

Instead of using fewer high-strength cords requiring specialized manufacturing, the invention segments the load-bearing function across multiple cords within strands, and multiple strands within the cable. This allows use of standard cord manufacturing processes while achieving high breaking force through the cumulative strength of many cords working together in parallel.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3810850B1Double-layer multi-strand cable with improved penetrability
Publication Date: 2025.10.15 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP3810850B1 patent drawingFigure 1~2
  • EP3810850B1 patent drawingFigure 3
  • EP3810850B1 patent drawingFigure 4

AI summary

The cable (50) comprises: -K>1 inner strands (TI) comprising: an inner layer (C1) of Q=1 inner wire (F1), an intermediate layer (C2) of M intermediate wires (F2) wound around the inner layer (C1) with a pitch p2, an outer layer (C3) of N outer wires (F3) wound around the intermediate layer (C2) with a pitch p3, -L>1 outer strands (TE) comprising: an inner layer (C1'), an outer layer (C3'), the average inter-strand distance E separating two adjacent outer strands being greater than or equal to 30 µm; the intermediate layer (C2) of each inner strand (TI) is incomplete; the outer layer (C3) of each inner strand (TI) is incomplete; and 0.36≤(p3-p2)/p3≤0.57.