Zigzag-Wound Crown Reinforcement for Civil Engineering Tyres

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Solution Overview

Problem

Civil engineering tires face challenges in carrying heavy loads on aggressive soils while maintaining manufacturing simplicity and cost-effectiveness, as existing designs are complex and difficult to manufacture efficiently.

Innovation Solution

A tire design featuring a crown reinforcement with at least one bilayer of circumferentially zigzag-wound metal reinforcements, where the zigzag trajectory satisfies specific geometric relationships to reduce the number of layers and simplify manufacturing, while maintaining structural integrity and load-carrying capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional crown reinforcement designs are used, then load-carrying capacity is sufficient, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidtire architecture complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges multiple crown layers into a single integrated crown reinforcement structure with metal reinforcements arranged in specific patterns (radial, circumferential, and diagonal orientations). This consolidation reduces the number of discrete layers and simplifies manufacturing while maintaining the necessary structural complexity for load-bearing performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The crown reinforcement is segmented into distinct zones with different reinforcement orientations and densities. The metal reinforcements are arranged in specific patterns including radial cords at 0°, circumferential cords at 90°, and diagonal cords at ±45°, creating functionally segmented regions that optimize both manufacturing efficiency and mechanical performance.

Inventive Principle:
Principle #1Segmentation

2Strength

If multiple crown layers are used, then structural integrity is improved, but manufacturing difficulty increases

Engineering Contradiction:
Improvestructural integrityVSAvoidmanufacturing efficiency
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

Multiple crown layers are merged into a single integrated structure where metal reinforcements are embedded within the elastomeric matrix in a unified manufacturing process. This eliminates the need for separate layer-by-layer assembly while maintaining the structural integrity that would result from multiple layers.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs composite materials consisting of metal reinforcements (steel or aluminum wires) embedded within an elastomeric matrix. This composite structure provides the strength and rigidity of multiple metal layers while the elastomeric binder integrates them into a single manufacturable component, improving both structural integrity and manufacturing efficiency.

Inventive Principle:
Principle #40Composite materials

3Reliability

If complex crown reinforcement patterns are used, then load distribution is improved, but manufacturing cost increases

Engineering Contradiction:
Improveload distribution homogeneityVSAvoidreinforcement pattern complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The crown reinforcement employs local quality variations with different reinforcement orientations and densities in different radial and circumferential zones. Radial cords (0°) provide strength in the radial direction, circumferential cords (90°) resist hoop stresses, and diagonal cords (±45°) handle shear loads. This localized optimization achieves homogeneous load distribution without requiring uniformly complex patterns throughout the entire structure.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3890993B1Tyre for a civil engineering vehicle, comprising a level-wound crown reinforcement with metal reinforcements
Publication Date: 2023.02.15 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP3890993B1 patent drawingFigure 1
  • EP3890993B1 patent drawingFigure 2
  • EP3890993B1 patent drawingFigure 3~5

AI summary

The present invention relates to a tyre for a civil engineering vehicle, which comprises an at least partially level-wound crown reinforcement with metal reinforcements and is compatible with a use under high load and on aggressive soils. According to the invention, the reinforcements of the crown layers (211, 212) are metallic and are wound, in the form of a strip (5) of width W, in a zigzag circumferential trajectory according to a periodic curve (7) and extend over a number N of periods P distributed over a number T of circumferences 2ΠR and satisfying the two equations N*(W/sinA) = 2ΠR*t, wherein 0.6 ≦ t ≦ 1 and N*P=2ΠR*T, so as to constitute a bilayer (21). Furthermore, for at least 40% of the axially positioned strip crossovers (53) and with respect to the circumferential direction (XX') at an axial distance L1 being at most equal to 0.25 times the amplitude L of the periodic curve (7), the circular portion of the bilayer (213), which is centered on the strip crossover (53) and has a radius R1 equal to twice the width W of the strip (5), comprises Ne outer strip crossovers and Ni inner strip crossovers, such that |Ne-Ni|/(Ne+Ni)<= 0.3.