PNEUMATIC TIRE

• US 20150273952A1
• Filed: 09/25/2013
• Published: 10/01/2015
• Est. Priority Date: 10/24/2012
• Status: Active Grant

• Current Assignee: Bridgestone Corporation
• Original Assignee: Bridgestone Corporation
• Inventors: Kiwaki, Yukihiro
• Granted Patent: US 9,868,325 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60C 11/0309 further characterised by the groove cross-section
• CPC Class Codes: B60C 11/1236 with special arrangements in the tread pattern
• CPC Class Codes: B60C 11/1307 with special features of the groove walls
• CPC Class Codes: B60C 2011/0341 Circumferential grooves
• CPC Class Codes: B60C 2011/0344 provided at the equatorial plane
• CPC Class Codes: B60C 2011/0381 Blind or isolated grooves
• CPC Class Codes: B60C 2011/1338 comprising protrusions

Abstract

A pneumatic tire, while achieving excellent drainage performance by projections and depressions formed in a circumferential groove, can reduce road noise by making the circumferential stiffness of a land portion uniform even in the presence of such projections and depressions. A plurality of protuberances are arranged in at least one circumferential groove at intervals in the tread circumferential direction, the protuberances being raised from the inner surface of the circumferential groove and extending from the groove bottom of the circumferential groove to at least one groove wall surface in the tread width direction. A plurality of sipes are arranged in a land portion adjacent to the groove wall surface of the circumferential groove to which the protuberances extend, the sipes being open to the circumferential groove in areas where the respective protuberances are arranged.

Claims

1. A pneumatic tire in which at least one circumferential groove continuously extending in a tread circumferential direction is formed in a tread surface to define land portions by the circumferential groove,

wherein a plurality of protuberances are arranged in the circumferential groove at intervals in the tread circumferential direction to define an intra-groove groove between protuberances adjacent in the tread circumferential direction, the plurality of protuberances being raised from an inner surface of the circumferential groove and extending from a groove bottom of the circumferential groove to at least one groove wall surface in a tread width direction, and

a plurality of sipes are arranged in a land portion adjacent to the groove wall surface of the circumferential groove to which the plurality of protuberances extend, the plurality of sipes being open to the circumferential groove in areas where the respective plurality of protuberances are arranged.

2. The pneumatic tire according to claim 1, wherein both side surfaces of each of the plurality of protuberances extending in the tread width direction are each shaped like a circular arc in a tread pattern developed view, the side surfaces being on both sides of the protuberance in the tread circumferential direction.

3. The pneumatic tire according to claim 1, wherein an outer surface of each of the plurality of protuberances in a tire radial direction is shaped like a circular arc concave to the groove wall surface to which the protuberance extends, in a sectional view along a direction orthogonal to the direction in which the circumferential groove provided with the protuberance extends.

4. The pneumatic tire according to claim 1, wherein the plurality of protuberances are arranged with a pitch equal to a pitch with which the plurality of sipes are arranged in the tread circumferential direction, and

a tread circumferential distance between protuberances adjacent in the tread circumferential direction is less than or equal to half a tread circumferential length of each of the plurality of protuberances, at a tread widthwise center position of the protuberance extending in the tread width direction.

5. The pneumatic tire according to claim 1, wherein each of the plurality of sipes has one end open to the circumferential groove, and the other end terminating in the land portion in which the sipe is provided.

6. The pneumatic tire according to claim 2, wherein an outer surface of each of the plurality of protuberances in a tire radial direction is shaped like a circular arc concave to the groove wall surface to which the protuberance extends, in a sectional view along a direction orthogonal to the direction in which the circumferential groove provided with the protuberance extends.

7. The pneumatic tire according to claim 2, wherein the plurality of protuberances are arranged with a pitch equal to a pitch with which the plurality of sipes are arranged in the tread circumferential direction, and

a tread circumferential distance between protuberances adjacent in the tread circumferential direction is less than or equal to half a tread circumferential length of each of the plurality of protuberances, at a tread widthwise center position of the protuberance extending in the tread width direction.

8. The pneumatic tire according to claim 3, wherein the plurality of protuberances are arranged with a pitch equal to a pitch with which the plurality of sipes are arranged in the tread circumferential direction, and

a tread circumferential distance between protuberances adjacent in the tread circumferential direction is less than or equal to half a tread circumferential length of each of the plurality of protuberances, at a tread widthwise center position of the protuberance extending in the tread width direction.

9. The pneumatic tire according to claim 6, wherein the plurality of protuberances are arranged with a pitch equal to a pitch with which the plurality of sipes are arranged in the tread circumferential direction, and

a tread circumferential distance between protuberances adjacent in the tread circumferential direction is less than or equal to half a tread circumferential length of each of the plurality of protuberances, at a tread widthwise center position of the protuberance extending in the tread width direction.

10. The pneumatic tire according to claim 2, wherein each of the plurality of sipes has one end open to the circumferential groove, and the other end terminating in the land portion in which the sipe is provided.

11. The pneumatic tire according to claim 3, wherein each of the plurality of sipes has one end open to the circumferential groove, and the other end terminating in the land portion in which the sipe is provided.

12. The pneumatic tire according to claim 4, wherein each of the plurality of sipes has one end open to the circumferential groove, and the other end terminating in the land portion in which the sipe is provided.

13. The pneumatic tire according to claim 6, wherein each of the plurality of sipes has one end open to the circumferential groove, and the other end terminating in the land portion in which the sipe is provided.

14. The pneumatic tire according to claim 7, wherein each of the plurality of sipes has one end open to the circumferential groove, and the other end terminating in the land portion in which the sipe is provided.

15. The pneumatic tire according to claim 8, wherein each of the plurality of sipes has one end open to the circumferential groove, and the other end terminating in the land portion in which the sipe is provided.

16. The pneumatic tire according to claim 9, wherein each of the plurality of sipes has one end open to the circumferential groove, and the other end terminating in the land portion in which the sipe is provided.