PNEUMATIC TIRE

• US 20170100966A1
• Filed: 04/22/2015
• Published: 04/13/2017
• Est. Priority Date: 05/20/2014
• Status: Active Grant

• Current Assignee: Bridgestone Corporation
• Original Assignee: Bridgestone Corporation
• Inventors: WAKIYAMA, Tadashi, MATSUNAGA, Ietomo
• Granted Patent: US 10,639,939 B2
• Time in Patent Office: Days
• CPC Class Codes: B60C 11/03 Tread patterns
• CPC Class Codes: B60C 11/0302 directional pattern, i.e. with main rolling direction
• CPC Class Codes: B60C 11/0304 Asymmetric patterns
• CPC Class Codes: B60C 11/13 characterised by the groove cross-section, e.g. for buttressing or preventing stone-trapping
• CPC Class Codes: B60C 11/1323 asymmetric
• CPC Class Codes: B60C 5/00 Inflatable pneumatic tyres or inner tubes B60C1/00, B60C9/00 - B60C17/00 take precedence

Abstract

A pneumatic tire includes a tread having a tread surface, circumferential main grooves on the tread, and land portions formed between the circumferential main grooves. Each of the circumferential main grooves has, in a lateral cross-sectional view, a groove bottom surface, an outside groove wall surface, an inside groove wall surface, an outside curved portion connecting the groove bottom surface with the outside groove wall surface, and an inside curved portion connecting the groove bottom surface with the inside groove wall surface. In the lateral cross-sectional view, (a minimum curvature radius of the outside curved portion)>(a minimum curvature radius of the inside curved portion) is satisfied. (the groove wall angle α [between a tread normal line and the outside groove wall surface])<(the groove wall angle β [between a tread normal line and the inside groove wall surface]) is satisfied.

Claims

1. A pneumatic tire comprising:

a tread that has a tread surface;

a plurality of circumferential main grooves that are formed on the tread; and

a plurality of land portions that are formed, on the tread, between the plurality of circumferential main grooves, wherein

each of the plurality of circumferential main grooves has, in a lateral cross-sectional view, a groove bottom surface, an outside groove wall surface located on an installation outer side, an inside groove wall surface located on an installation inner side, an outside curved portion connecting the groove bottom surface with the outside groove wall surface, and an inside curved portion connecting the groove bottom surface with the inside groove wall surface,

(a minimum curvature radius of the outside curved portion)>

(a minimum curvature radius of the inside curved portion) is satisfied in the lateral cross-sectional view, and,

when, in the lateral cross-sectional view, an angle of the outside groove wall surface to a tread normal line at a border edge between the outside groove wall surface and the tread surface is denoted as a groove wall angle α and

an angle of the inside groove wall surface to a tread normal line at a border edge between the inside groove wall surface and the tread surface is denoted as a groove wall angle β

, (the groove wall angle α

)<

(the groove wall angle β

) is satisfied.

2. The pneumatic tire according to claim 1, wherein

the minimum curvature radius of the outside curved portion is not more than twice the minimum curvature radius of the inside curved portion.

3. The pneumatic tire according to claim 1 or 2 claim 1, wherein

the groove wall angle β

is in a range from (the groove wall angle α

+2°

) to (the groove wall angle α

+30°

).

4. The pneumatic tire according to claim 1, wherein

the tread surface has beveled portions adjacent to the outside groove wall surface and the inside groove wall surface.

5. The pneumatic tire according to claim 4, wherein

the beveled portions includes an outside beveled portion adjacent to the outside groove wall surface and an inside beveled portion adjacent to the inside groove wall surface, and,

when a distance along a tire radial direction from an uppermost portion of the land portion on which the outside beveled portion is formed to the border edge between the outside beveled portion and the outside groove wall surface is denoted as H1 and a distance along a tire radial direction from an uppermost portion of the land portion on which the inside beveled portion is formed to the border edge between the inside beveled portion and the inside groove wall surface is denoted as H2, H1>

H2 is satisfied.