Pneumatic radial tire

Patent metadata

Field	Value
Publication number	US-9505270-B2
Application number	US-201214123993-A
Country	US
Kind code	B2
Filing date	Jul 13, 2012
Priority date	Jul 14, 2011
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A pneumatic radial tire according to the present invention has a tread pattern specifying a tire rotation direction and an optimized shape of a groove wall on a kicking-out side of a lateral groove.

First claim

The invention claimed is:

1. A pneumatic radial tire comprising:
a directional pattern specifying a rotation direction of the tire;
at least one lateral groove provided in a tread surface of the tire extending from a tread end to the inside, in the width direction, of a widthwise midpoint P of a tread half having the tread end;
a circumferential groove extending on a tire equatorial plane in a tread circumferential direction; and
at least one transverse groove that extends outwardly from the circumferential groove in the tread width direction and remains within the tread surface without crossing any other groove, wherein
a groove wall on only a kicking-out side of the at least one lateral groove has a single protruding portion,
the protruding portion protrudes toward a groove wall on a stepping side,
with reference to a point Q representing a midpoint in a tread width direction between the tread end and the widthwise midpoint P, the protruding portion extends in the tread width direction from a position between the point P and the point Q to the inside of the point P in the width direction, and
the lateral groove at least partially overlaps the transverse groove when projected in a tire circumferential direction.

2. The pneumatic radial tire according to claim 1 , wherein an overlapping area of the transverse groove and the lateral groove measures 0 mm to 20 mm in the tread width direction.

3. The pneumatic radial tire according to claim 1 , wherein the protruding portion has a wall surface that is parallel in cross section to the wall surface on the stepping side of the lateral groove.

4. The pneumatic radial tire according to claim 3 , wherein a minimum distance between the wall surface of the protruding portion and the wall surface on the stepping side of the lateral groove is 15% to 30% of a width of the lateral groove.

5. The pneumatic radial tire according to claim 1 , wherein the protruding portion is provided in the width direction across an area of at least 40% to 60% of a tread half width L from a tire equatorial plane CL.

6. The pneumatic radial tire according to claim 1 , wherein the protruding portion is provided across an area of at least 80% to 100% of a depth H of the lateral groove.

7. The pneumatic radial tire according to claim 1 , wherein the lateral groove has an inclination angle of 5° to 45° relative to the tread width direction.

Assignees

• Koyanagi Jun
• Bridgestone Corp

Inventors

• Koyanagi Jun

Classifications

• B60C11/1323

  asymmetric · CPC title

• B60C11/0302 Primary

  directional pattern, i.e. with main rolling direction · CPC title

• B60C2011/0344

  provided at the equatorial plane · CPC title

• B60C2011/1338

  comprising protrusions · CPC title

• B60C11/0316 Primary

  further characterised by the groove cross-section · CPC title