Run-Flat Tyre Drum Radial Shrink Mechanism

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for manufacturing run-flat tires, such as variable diameter drums, cause unpredictable deformation and irregularities in the inner liner due to stretching, leading to uniformity issues and potential inaccuracies in subsequent tire layers.

Innovation Solution

A drum with shrink sections that move radially inward to a smaller diameter under partial vacuum, allowing the tire layer to shrink locally and reduce wrinkles and irregularities, improving the uniformity and predictability of the tire layer conformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the drum is expanded from a first diameter to a greater second diameter to receive the inner liner, then the inner liner can be stretched and pulled into the grooves, but this causes unpredictable deformation and irregularities in the inner liner

Engineering Contradiction:

Improveuniformity of inner linerVSAvoidcomplexity of drum expansion mechanism

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Instead of expanding the drum to pull the inner liner into grooves, the invention inverts the approach by keeping the drum at a constant diameter and using movable support profiles that can be radially adjusted to guide and support the inner liner into the grooves without drum expansion, thereby avoiding unpredictable deformation

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The support profiles are divided into multiple segments that can be independently adjusted radially. This segmentation allows precise control over how the inner liner is guided into grooves, maintaining uniformity while avoiding the need for complex drum expansion mechanisms

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If the drum expands considerably to pull the inner liner into grooves, then the inner liner can be forced into position, but this causes irregularities in the transition from stretching to pulling

Engineering Contradiction:

Improveuniformity of tire layersVSAvoidease of inner liner placement

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The support profiles are preliminarily positioned and radially adjusted before the inner liner is placed. This preliminary action creates a smooth transition path for the inner liner into the grooves, eliminating irregularities that would otherwise occur during the stretching and pulling process

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The movable support profiles act as intermediaries between the drum surface and the inner liner. These profiles provide a controlled transition mechanism that guides the inner liner into grooves without the need for considerable drum expansion, maintaining uniformity while simplifying the placement process

Inventive Principle:

Principle #24Intermediary (Mediator)

3Manufacturing precision

If the groove is not symmetrical or has sharp angles, then the inner liner may not be completely pulled into the groove, but this affects the accuracy of splicing subsequent layers

Engineering Contradiction:

Improveaccuracy of layer splicingVSAvoidease of groove formation

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The support profiles are designed with local quality variations to match the specific geometry of each groove. By radially adjusting these profiles, the invention creates locally optimized support conditions that ensure complete inner liner integration into grooves of any shape, guaranteeing accurate splicing of subsequent layers

Inventive Principle:

Principle #3Local quality

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

This approach reduces the risk of wrinkles and irregularities, enhances the accuracy of tire layer splicing, and ensures complete integration of the inner liner into the drum grooves, improving the overall quality and uniformity of the tire manufacturing process.

Implementation Method 1

creating a partial vacuum between the shrink surfaces and the first tyre layer at the first shrink section and the second shrink section; and shrinking the first tyre layer onto the shrink surfaces in the shrink position under the influence of the partial vacuum

Methodology Applied

Scientific EffectPartial vacuum: Vacuum

Data Source

PatentUS11040508B2Method and drum for manufacturing a tyre, in particular a run-flat tyre

Publication Date: 2021.06.22 VMI HOLLAND BV

AI summary

A method for manufacturing a tyre is provided, in particular a run-flat tyre. The method includes providing a drum with a first shrink section and a second shrink section. Each shrink section is provided with a shrink surface that is radially movable. The method includes moving the shrink surfaces radially inwards with respect to the central axis from a level position to a shrink position in which the drum, at the shrink surfaces, has a circumference with a second diameter that is smaller than the first diameter, while creating a partial vacuum between the shrink surfaces and a first tyre layer at the first shrink section and the second shrink section. The method further includes shrinking the first tyre layer onto the shrink surfaces in the shrink position under the influence of the partial vacuum. A drum for use in the aforementioned method is also disclosed.