Retreaded Tire Tread Voids That Close During Curing

Solution Overview

Problem

In retreaded tire treads, submerged voids such as grooves or sipes become partially filled with uncured bonding material during the curing process, reducing their effectiveness in providing traction and skid depth due to the influx of material from the underside, which diminishes their performance in wet conditions and local tread stiffness.

Innovation Solution

The retreaded tire design features a pre-formed tread with submerged voids that have openings along the bottom side, which are configured to close or substantially reduce their opening when the tread is reconfigured from an uninstalled to an installed state, using alternating non-linear paths and tapers to prevent the influx of uncured bonding material, thereby maintaining the void's effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a pre-formed tread with submerged voids is used in cold retreading operations, then the submerged voids are open to the bottom side for bonding, but uncured bonding material flows into the voids during curing, reducing void depth and effectiveness

Engineering Contradiction:

Improvesubmerged void effectivenessVSAvoidvoid volume

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The tread is pre-formed with submerged voids that are open to the bottom side before bonding. The voids are intentionally designed to be open during the bonding operation to allow bonding material to contact the carcass, but then close during curing to prevent material influx that would reduce void effectiveness.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The submerged void opening transitions from an open state during bonding to a closed state during curing. This dynamic behavior allows the void to serve dual functions: enabling bonding material flow to the carcass initially, then preventing material influx that would fill the void and reduce its depth and effectiveness.

Inventive Principle:

Principle #15Dynamics

2Loss of substance

If the submerged void opening is kept closed during bonding, then material influx is prevented, but bonding material cannot reach the carcass surface effectively

Engineering Contradiction:

Improvevoid volumeVSAvoidbonding effectiveness

Core Design Contradiction:

Loss of substanceVSEase of manufacture

Solution Approach 1:

The tread is pre-formed with submerged voids that are open to the bottom side before bonding. The voids are intentionally designed to be open during the bonding operation to allow bonding material to contact the carcass, but then close during curing to prevent material influx that would reduce void effectiveness.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The submerged void opening transitions from an open state during bonding to a closed state during curing. This dynamic behavior allows the void to serve dual functions: enabling bonding material flow to the carcass initially, then preventing material influx that would fill the void and reduce its depth and effectiveness.

Inventive Principle:

Principle #15Dynamics

3Area of stationary object

If the tread is designed with open submerged voids for bonding, then bonding surface area is increased, but uncured material displacement into voids reduces skid depth and traction performance

Engineering Contradiction:

Improvebonding surface areaVSAvoidskid depth

Core Design Contradiction:

Area of stationary objectVSManufacturing precision

Solution Approach 1:

The tread is pre-formed with submerged voids that are open to the bottom side before bonding. The voids are intentionally designed to be open during the bonding operation to allow bonding material to contact the carcass, but then close during curing to prevent material influx that would reduce void effectiveness.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The submerged void opening transitions from an open state during bonding to a closed state during curing. This dynamic behavior allows the void to serve dual functions: enabling bonding material flow to the carcass initially, then preventing material influx that would fill the void and reduce its depth and effectiveness.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11993045B2Retreaded tire treads having improved submerged voids and methods for forming the same

Publication Date: 2024.05.28 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)

AI summary

The invention includes methods for forming a retreaded tire and treads there for. Particular embodiments of such methods include providing a tire carcass configured to receive a tire tread along an annular tread-receiving area and a pre-formed tread comprising a tread body and a submerged void arranged along a bottom side of the tread and extending into the tread thickness to a top end located below the top side of the tread, the submerged void having a length and an opening arranged along the bottom side when the tread is in an uninstalled configuration, where the opening of the submerged void extends in a direction of the submerged groove length along an alternating, non-linear path. Further steps include assembling a retreaded tire by arranging the tire tread atop a bonding layer arranged between the tire tread and the tire carcass and comprising uncured bonding material.