Tyre Stiffening Structure With Circumferential Cut-Outs for Contact Stability

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Solution Overview

Problem

Existing tires with stiffening structures suffer from early separation of wire stiffening elements at bead and vertex interfaces due to peeling stress, leading to reduced endurance and irregular contact areas, which affects the tire's radial, axial, and drift rigidity.

Innovation Solution

The tire features a stiffening structure with radially interior and exterior reinforcement structures that anchor stiffening elements securely, preventing peeling and sliding, and a tread design with main circumferential cutouts that distribute forces effectively, enhancing the tire's radial, axial, and drift rigidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wire stiffening elements are secured to bead and crown surfaces using elastomeric cushions, then the stiffening structure can be assembled, but the interfaces are stressed in peeling leading to early separation and reduced endurance

Engineering Contradiction:

Improveendurance of stiffening structureVSAvoidservice life of bead and crown interfaces

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent extracts the stiffening element from the surface-secured configuration and repositions it to be embedded within the tire structure. The stiffening element passes through the crown and is anchored to the bead, removing it from the vulnerable surface interface environment where peeling stresses occur.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The stiffening element is nested within the tire structure, passing through the crown reinforcement and being anchored within the bead structure. This nesting protects the stiffening element from external peeling stresses and integrates it into the load-bearing path of the tire.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Strength

If a stiffening structure is added to improve radial, axial and drift rigidity, then the tire's structural performance is enhanced, but the contact patch becomes irregular compared to conventional tires

Engineering Contradiction:

Improveradial, axial and drift rigidityVSAvoidregularity of contact patch

Core Design Contradiction:

StrengthVSShape

Solution Approach 1:

The stiffening effect is localized to specific regions where it is most needed - the crown and bead areas - while the tread contact patch maintains its natural flexibility. The stiffening element is positioned to provide structural support without interfering with the contact patch geometry, allowing different parts of the tire to have different mechanical properties.

Inventive Principle:

Principle #3Local quality

3Strength

If stiffening elements are positioned to maximize structural support, then rigidity is improved, but the interfaces become sensitive to repeated stresses causing early destruction

Engineering Contradiction:

Improvestructural support capabilityVSAvoidresistance to repeated peeling stresses

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The elastomeric cushions at the bead and crown interfaces are designed as sacrificial elements that can absorb and dissipate peeling stresses. While these cushions may degrade over time, they protect the more critical stiffening element and tire structure from damage.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP4313628B1Tyre comprising a circumferential cut-out and a durable stiffening structure and enabling optimised flattening of the tread

Publication Date: 2025.01.15 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)

Figure 1A~1C
Figure 2~3
Figure 4~5

AI summary

The invention relates to a tyre (10) that includes a stiffening structure (50) comprising stiffening elements (52) anchored in the crown (12) and extending into the toroidal cavity (35) between a radially inner anchoring point (54A, 54B) and a radially outer anchoring point (56A, 56B). The tread (14) has a profile height and comprises a plurality of ribs (102, 104, 106, 108, 110), two adjacent ribs being axially separated from each other by a main circumferential cut-out (112, 114, 116, 118) having a depth greater than or equal to 50% of the profile height. The radially outer anchor point (56A, 56B) is aligned with one of the ribs (102, 104, 106, 108, 110).