Run-flat tire and method for mounting the same on four-wheeled vehicle

Patent metadata

Field	Value
Publication number	US-9895939-B2
Application number	US-201214238072-A
Country	US
Kind code	B2
Filing date	Oct 5, 2012
Priority date	Oct 12, 2011
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A run-flat tire 1 comprises a carcass 6 , a pair of side reinforcing rubber layers 9 , and a pair of sidewall rubber components 10 . At a tire maximum-width position, a first side reinforcing rubber layer 9 A disposed in the side of a first bead portion has a thickness B 1 greater than a thickness B 2 of a second side reinforcing rubber layer disposed in the side of a second bead portion, and a first sidewall rubber component disposed in the side of the first bead portion has a thickness A 1 smaller than a thickness A 2 of a second sidewall rubber component disposed in the side of the second bead portion.

First claim

The invention claimed is:

1. A run-flat tire comprising:
a carcass extending between bead cores each disposed in a first bead portion and a second bead portion, through a tread portion and sidewall portions,
a pair of side reinforcing rubber layers made of rubber having a high hardness, and each having a crescent cross-sectional shape and disposed axially inside the carcass in each sidewall portion, and
a pair of sidewall rubber components each disposed axially outside the carcass in each sidewall portion in such a manner that the sidewall rubber components are directly adjacent to the carcass and form part of the outer surface of the tire,
wherein the side reinforcing rubber layers comprise a first side reinforcing rubber layer disposed in the side of the first bead portion, and a second side reinforcing rubber layer disposed in the side of the second bead portion,
wherein the sidewall rubber components comprise a first sidewall rubber component disposed in the side of the first bead portion, and a second sidewall rubber component disposed in the side of the second bead portion,
wherein at a tire maximum-width position in a tire cross section including a tire axis under a standard condition in which the tire is mounted on a standard rim and is inflated to a standard pressure, but no tire load is loaded, the first side reinforcing rubber layer has a thickness B 1 greater than a thickness B 2 of the second side reinforcing rubber layer, and the first sidewall rubber component has a thickness A 1 smaller than a thickness A 2 of the second sidewall rubber component, and
wherein the respective thicknesses A 1 , A 2 , B 1 and B 2 satisfy the following relationships:
1.4≦ A 2/ A 1≦2.0; and

1.15≦ B 1/ B 2≦1.4.

2. A method for mounting the run-flat tire according to claim 1 on a four-wheeled vehicle, comprising a step of
mounting the run-flat tire on a rear wheel of the four-wheeled vehicle so that the first bead portion is arranged at an inboard side of the rear wheel.

3. A method for mounting the run-flat tire according to claim 1 on a four-wheeled vehicle, comprising a step of
mounting the run-flat tire on a front wheel of the four-wheeled vehicle so that the first bead portion is arranged at an outboard side of the front wheel.

4. The run-flat tire according to claim 1 ,
wherein a loss tangent (tan δ 1 ) of the sidewall rubber component is greater than a loss tangent (tan δ 2 ) of the side reinforcing rubber layer in each sidewall portion, and
wherein a complex elastic modulus E* 1 of the sidewall rubber component is smaller than a complex elastic modulus E* 2 of the side reinforcing rubber layer in each sidewall portion.

5. The run-flat tire according to claim 4 , wherein the respective thicknesses A 1 , A 2 , B 1 and B 2 satisfy the following relationship:
0.9≦( A 1+ B 1)/( A 2+ B 2)≦1.1.

6. A method for mounting the run-flat tire according to claim 4 on a four-wheeled vehicle, comprising a step of
mounting the run-flat tire on a rear wheel of the four-wheeled vehicle so that the first bead portion is arranged at an inboard side of the rear wheel.

7. A method for mounting the run-flat tire according to claim 4 on a four-wheeled vehicle, comprising a step of
mounting the run-flat tire on a front wheel of the four-wheeled vehicle so that the first bead portion is arranged at an outboard side of the front wheel.

8. The run-flat tire according to claim 1 , wherein the respective thicknesses A 1 , A 2 , B 1 and B 2 satisfy the following relationship:
0.9≦( A 1+ B 1)/( A 2+ B 2)≦1.1.

9. A method for mounting the run-flat tire according to claim 8 on a four-wheeled vehicle, comprising a step of
mounting the run-flat tire on a rear wheel of the four-wheeled vehicle so that the first bead portion is arranged at an inboard side of the rear wheel.

10. A method for mounting the run-flat tire according to claim 8 on a four-wheeled vehicle, comprising a step of
mounting the run-flat tire on a front wheel of the four-wheeled vehicle so that the first bead portion is arranged at an outboard side of the front wheel.

Assignees

• Sumitomo Rubber Ind

Inventors

• Tanaka Susumu

Classifications

• Y10T29/49494

  Assembling tire to wheel body · CPC title

• B60C17/0009 Primary

  comprising sidewall rubber inserts, e.g. crescent shaped inserts · CPC title

• B60C19/001

  Tyres requiring an asymmetric or a special mounting · CPC title

• B60C3/06

  asymmetric · CPC title

• B60C2013/007

  Thickness · CPC title