TIRE

• US 20190315160A1
• Filed: 03/20/2019
• Published: 10/17/2019
• Est. Priority Date: 04/16/2018
• Status: Active Grant

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Sumitomo Rubber Industries Limited
• Inventors: YAMAMOTO, Tetsuya, OKADA, Takashi
• Granted Patent: US 11,014,406 B2
• Time in Patent Office: Days
• CPC Class Codes: B60C 11/0083 characterised by the curvature of the tyre tread
• CPC Class Codes: B60C 11/01 Shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered
• CPC Class Codes: B60C 3/04 characterised by the relative dimensions of the section, e.g. low profile B60C3/06 takes precedence
• CPC Class Codes: Y02T 10/86 Optimisation of rolling resistance, e.g. weight reduction

Abstract

A tire comprises a tread portion provided with a tread profile. The axial distance L₃ from the tire equator to a contact point P₃ between the tread profile and a tangential line thereto at which the angle θ of the tangential line becomes 3 degrees with respect to the tire-axial-direction line, is smaller than 65% of a half tread width Tw. The difference (θ₉₀−θ₆₀) of an angle θ₉₀ of the tangential line at an axial position P₉₀ apart from the tire equator by 90% of the half tread width Tw, from an angle θ₆₀ of the tangential line at an axial position P₆₀ apart from the tire equator by 60% of the half tread width Tw, is in a range from 7 to 12 degrees.

Claims

1. A tire comprising:

a tread portion provided with a tread profile such that,

in a meridian section of the tire under its standard state in which the tire is mounted on a standard wheel rim and inflated to a pressure of 30 kPa and no tire load is applied thereto,

an axial distance L₃ from the tire equator to a contact point P₃ between the tread profile and a tangential line thereto at which the angle θ

of the tangential line becomes 3 degrees with respect to the tire-axial-direction line, is smaller than 65% of a half tread width Tw, and

the difference (θ

₉₀−

θ

₆₀) between

an angle θ

₆₀ with respect to the tire-axial-direction line, of the tangential line at an axial position P₆₀ apart from the tire equator by 60% of the half tread width Tw, and

an angle θ

₉₀ with respect to the tire-axial-direction line, of the tangential line at an axial position P₉₀ apart from the tire equator by 90% of the half tread width Tw is in a range from 7 to 12 degrees.

2. The tire according to claim 1, wherein

a central part of the tread profile including the tire equator is formed by a circular arc having a radius of curvature Rc of not less than 700 mm.

3. The tire according to claim 1, wherein

the tread portion is provided with at least two main grooves including two crown main grooves disposed on both respective sides of the tire equator,

the ratio (Wc/Σ

Wg) between the width we of a center land portion defined between the two crown main grooves, and the sum Σ

Wg of the widths Wg of the two crown main grooves is in a range from 0.50 to 1.60, and

the sum (Wc+Σ

Wg) of the center land portion width we and the total crown main groove width Σ

Wg is not more than 50% of the half tread width Tw.

4. The tire according to claim 2, wherein

the tread portion is provided with at least two main grooves including two crown main grooves disposed on both respective sides of the tire equator,

the ratio (Wc/Σ

Wg) between the width we of a center land portion defined between the two crown main grooves, and the sum Σ

Wg of the widths Wg of the two crown main grooves is in a range from 0.50 to 1.60, and

the sum (Wc+Σ

Wg) of the center land portion width we and the total crown main groove width Σ

Wg is not more than 50% of the half tread width Tw.

5. The tire according to claim 1, wherein

a pair of shoulder parts of the tread profile on both respective sides of the central part is formed by a circular arc having a radius of curvature Rs of from 10% to 30% of the radius of curvature Rc of the central part,

the axially inner edge of each of the of shoulder parts is located at a distance Lsi of not less than 50% of the half tread width Tw from the tire equator, and

the axially outer edge of each of the of shoulder parts is located at a distance Lso of not more than 95% of the half tread width Tw from the tire equator.

6. The tire according to claim 2, wherein

a pair of shoulder parts of the tread profile on both respective sides of the central part is formed by a circular arc having a radius of curvature Rs of from 10% to 30% of the radius of curvature Rc of the central part,

the axially inner edge of each of the of shoulder parts is located at a distance Lsi of not less than 50% of the half tread width Tw from the tire equator, and

the axially outer edge of each of the of shoulder parts is located at a distance Lso of not more than 95% of the half tread width Tw from the tire equator.

7. The tire according to claim 3, wherein

a pair of shoulder parts of the tread profile on both respective sides of the central part is formed by a circular arc having a radius of curvature Rs of from 10% to 30% of the radius of curvature Rc of the central part,

the axially inner edge of each of the of shoulder parts is located at a distance Lsi of not less than 50% of the half tread width Tw from the tire equator, and

the axially outer edge of each of the of shoulder parts is located at a distance Lso of not more than 95% of the half tread width Tw from the tire equator.

8. The tire according to claim 4, wherein

a pair of shoulder parts of the tread profile on both respective sides of the central part is formed by a circular arc having a radius of curvature Rs of from 10% to 30% of the radius of curvature Rc of the central part,

the axially inner edge of each of the of shoulder parts is located at a distance Lsi of not less than 50% of the half tread width Tw from the tire equator, and

the axially outer edge of each of the of shoulder parts is located at a distance Lso of not more than 95% of the half tread width Tw from the tire equator.