Self-Sealing Tyre Sleeve Application via Radial Expansion and Rolling

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Solution Overview

Problem

Current self-sealing tyre production methods lack flexibility, as the application of the self-sealing layer is often limited to after vulcanisation, restricting adaptability to different tyre types and layouts, and struggles with achieving consistent adhesion on varying tyre surfaces, especially those with large cross-sections and complex profiles.

Innovation Solution

A two-step process involving radial expansion and rolling of a self-sealing sleeve to ensure complete and air bubble-free adhesion to the radially inner surface of the tyre, allowing for application to both green and vulcanised tyres, regardless of size or surface irregularities, using a radially expandable support and rolling device to position and secure the sleeve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the self-sealing layer is applied after vulcanisation, then the process is simple, but the adaptability to different tyre types and layouts is limited

Engineering Contradiction:
Improveprocess simplicityVSAvoidadaptability to different tyre types
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent applies a radially expandable support device that transitions from a compact state for insertion to an expanded state for applying the self-sealing layer. This dynamic mechanism enables the same device to adapt to different tyre sizes and configurations while maintaining a simple post-vulcanisation application process, thus resolving the contradiction between process simplicity and adaptability.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If a standard application method is used, then the device is simple, but achieving consistent adhesion on varying tyre surfaces is difficult

Engineering Contradiction:
Improvedevice simplicityVSAvoidadhesion consistency
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The radially expandable support allows the application surface to dynamically adapt to the specific curvature and profile of different tyre inner surfaces. This dynamic adjustment ensures uniform contact and consistent adhesion of the self-sealing layer across varying tyre geometries without requiring complex customised devices for each tyre type.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The expandable support device serves multiple functions: it provides a stable base for applying the self-sealing layer, adapts to different tyre sizes and profiles, and ensures uniform pressure distribution for consistent adhesion. This multi-functionality achieves manufacturing precision across varying surfaces while maintaining relative device simplicity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If the tyre has large cross-section and complex profile, then the tyre design is flexible, but achieving complete adhesion without air bubbles is difficult

Engineering Contradiction:
Improvetyre design flexibilityVSAvoidadhesion completeness
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The radially expandable support dynamically conforms to complex tyre profiles and large cross-sections by expanding to match the specific geometry. This dynamic adaptation ensures the self-sealing layer is applied uniformly across the entire inner surface, eliminating air bubbles and achieving complete adhesion while preserving design flexibility for various tyre configurations.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3727821B1Process for producing self-sealing tyres
Publication Date: 2022.02.02 PIRELLI TYRE SPA
  • EP3727821B1 patent drawingFigure 1
  • EP3727821B1 patent drawingFigure 2
  • EP3727821B1 patent drawingFigure 3

AI summary

In a process for producing self-sealing tyres, a tyre (2), a support and a self-sealing sleeve (19) are arranged according to a sequence of actions a)-c). The support carrying the self-sealing sleeve (19) is introduced within the tyre (2) according to an action d) until it is arranged in a position coaxial with the crown portion (12) and radially internal with respect thereto. The support is radially expanded according to an action e) until the self-sealing sleeve (19) partially adheres to the radially inner crown surface (12a). The contracted support is extracted from the tyre (2) according to an action f). A rolling device (30) is introduced within the tyre (2) according to an action g) and a rolling action is executed according to an action h) up to reaching a final configuration in which the self-sealing sleeve (19) completely adheres to the radially inner crown surface (12a).