Heavy-Vehicle Tyre Crown Structure With Chainmail Puncture Shield

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Solution Overview

Problem

Radial tires for heavy vehicles and agricultural vehicles with load indices greater than 110 face significant puncture risks due to damage from sharp objects on rough terrains, despite existing protective layers, which are costly and inefficient in absorbing transverse forces.

Innovation Solution

Incorporating a crown reinforcement with a radially outermost anti-perforation layer made of a chainmail of metal rings coated with a polymeric material, replacing traditional protective layers, to enhance puncture resistance while maintaining flexibility and reducing mass.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional protective layers are used in the crown reinforcement, then puncture resistance is provided, but the mass of the crown reinforcement increases and transverse force absorption is inefficient

Engineering Contradiction:
Improvepuncture resistanceVSAvoidmass of crown reinforcement
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent changes the material parameter from traditional textile/cord protective layers to a metal chainmail structure. This parameter change enables the anti-perforation layer to achieve superior puncture resistance through the rigid interlinked metal rings, while the open mesh structure of the chainmail reduces the overall mass compared to solid textile layers.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure by coating the metal chainmail with polymeric material. This composite combines the high strength and puncture resistance of metal with the flexibility and adhesion properties of polymers, achieving effective puncture protection while managing the mass through the coating rather than solid filler materials.

Inventive Principle:
Principle #40Composite materials

2Reliability

If traditional protective layers are used in the crown reinforcement, then some protection is provided, but the structure becomes complex and costly

Engineering Contradiction:
Improvepuncture resistanceVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the protective function from the traditional multi-layer textile/cord construction and consolidates it into a single metal chainmail layer. This extraction simplifies the overall structure by replacing complex layered textile arrangements with a single, functionally superior metal mesh layer that provides equivalent or superior protection.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using flexible textile fibers woven into protective layers, the patent inverts the approach by using rigid metal rings linked together. This inversion of material rigidity creates a structure that is simpler in conception (interlinked rings) yet provides superior protection through the rigid geometry that resists puncture forces.

Inventive Principle:
Principle #13The other way round (Inversion)

3Weight of moving object

If the anti-perforation layer has lower breaking strength, then mass is reduced, but puncture resistance may be compromised

Engineering Contradiction:
Improvemass of anti-perforation layerVSAvoidbreaking strength
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent utilizes the curved, circular geometry of the metal rings in the chainmail structure. This curvature allows the rings to deform elastically under impact loads, distributing stress around the circumference rather than concentrating it at single points. The rounded geometry enables the structure to absorb impact energy through controlled deformation while maintaining overall integrity, achieving protection with lower breaking strength materials.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent creates a dynamic structure where the metal rings can move and deform relative to each other under impact loads. This dynamic response allows the anti-perforation layer to absorb impact energy through controlled deformation and ring movement, rather than relying solely on high breaking strength. The structure adapts to the applied force, distributing loads dynamically across multiple rings.

Inventive Principle:
Principle #15Dynamics

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 chainmail layer significantly improves puncture resistance by deforming and distributing impact forces, offering improved performance with reduced mass and minimal impact on rolling resistance, even with lower breaking strength compared to traditional protective layers.

Implementation Method 1

The chainmail layer significantly improves puncture resistance by deforming and distributing impact forces

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

a chainmail of metal rings coated with a polymeric material

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP4486577B1Optimised tyre architecture
Publication Date: 2025.10.01 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP4486577B1 patent drawingFigure 1~2
  • EP4486577B1 patent drawingFigure 3~4

AI summary

The invention relates to a radial tyre for heavy vehicles having a load index greater than 1050 kg, comprising a crown reinforcement (3) comprising at least two layers of transverse metal reinforcements (321, 322), forming, with the circumferential direction, angles oriented with opposite signs at least equal to 10° and at most equal to 70°, having a breaking strength at least equal to 80 daN. The crown reinforcement comprises at least one radially outermost anti-perforation layer, consisting of a mesh of metal rings of a ferrous alloy, said mesh being embedded in at least one polymeric material, and the mass of an anti-perforation layer is at most 70% of the mass of the other crown layers.