Pneumatic tire

Patent metadata

Field	Value
Publication number	US-9764596-B2
Application number	US-201514605595-A
Country	US
Kind code	B2
Filing date	Jan 26, 2015
Priority date	Jan 27, 2014
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A pneumatic tire is provided in a tread portion 2 with shoulder main grooves 3 and 4 and a center main groove 5 and divided into shoulder land portions 6 and 7 and crown land portions 8 and 9 . The total width of the shoulder main grooves 3 and 4 and the center main groove 5 is 24% to 28% of the tread width TW. The crown land portions 8 and 9 are not provided with a groove having a width of not less than 2 mm and extending across the entire width of the crown land portion, but provided with a plurality of crown sipes 10 having a width of less than 2 mm. The crown sipes 10 include first sipes 11 comprising a lateral direction part 11 a extending parallel with the tire axial direction and an oblique part 11 b inclined with respect to the lateral direction part 11 a . The ratio ΣLy/ΣLs of the sum ΣLy of the lengths Ly of the lateral direction parts 11 a and the sum ΣLs of the lengths Ls of the crown sipes 10 is not more than 0.15.

First claim

The invention claimed is:

1. A pneumatic tire comprising:
a tread portion provided with an asymmetrical tread pattern such that the tire has a side to be faced outward when the tire is installed on a vehicle and thereby the tread portion has an outside tread edge to be positioned outward and an inside tread edge to be positioned inward,
the tread portion being provided with a pair of shoulder main grooves extending continuously in the tire circumferential direction and disposed one on each side of the tire equator, the pair of the shoulder main grooves being an outside shoulder main groove on the outside tread edge side and an inside shoulder main groove on the inside tread edge side, and
a center main groove extending continuously in the tire circumferential direction and disposed between a pair of the shoulder main grooves so that the tread portion is divided into a pair of crown land portions between the center main groove and the shoulder main grooves and a pair of shoulder land portions axially outside the shoulder main grooves, the a pair of the crown land portions being an outside crown land portion between the center main groove and the outside shoulder main groove, and an inside crown land portion between the center main groove and the inside shoulder main groove,
wherein
the sum of the widths of the shoulder main grooves and the width of the center main groove is 24% to 28% of a tread width,
in the crown land portions, a groove having a width of not less than 2 mm and extending across the entire width of the crown land portion is not provided, whereas a plurality of crown sipes having a width of less than 2 mm are provided,
the crown sipes include first sipes having a lateral direction part extending parallel with the tire axial direction and an oblique part inclined with respect to the lateral direction part, said first sipes being provided in the inside crown land portion, and
the ratio ΣLy/ΣLs of the sum ΣLy of lengths Ly of the lateral direction parts and the sum ΣLs of lengths Ls of the crown sipes is not more than 0.15.

2. The pneumatic tire according to claim 1 , wherein the outside and inside shoulder main grooves and the center main groove are straight.

3. The pneumatic tire according to claim 1 , wherein the width of the outside shoulder main groove is less than the width of the inside shoulder main groove, and less than the width of the center main groove.

4. The pneumatic tire according to claim 3 , wherein a pair of the shoulder land portions are an outside shoulder land portion between the outside shoulder main groove and the outside tread edge, and an inside shoulder land portion between the inside shoulder main groove and the inside tread edge, and
the inside shoulder land portion is provided with inside shoulder axial grooves extending to connect between the inside shoulder main groove and the inside tread edge.

5. The pneumatic tire according to claim 3 , wherein the crown sipes include second and third sipes disposed in the outside crown land portion,
the second sipe extends to connect between the center main groove and the inside shoulder main groove, and
the third sipe extends axially inwardly from the outside shoulder main groove and terminates within the outside crown land portion.

6. The pneumatic tire according to claim 1 , wherein a pair of the shoulder land portions are an outside shoulder land portion between the outside shoulder main groove and the outside tread edge, and an inside shoulder land portion between the inside shoulder main groove and the inside tread edge, and
the inside shoulder land portion is provided with inside shoulder axial grooves extending to connect between the inside shoulder main groove and the inside tread edge.

7. The pneumatic tire according to claim 6 , wherein the outside shoulder land portion is provided with outside shoulder lug grooves extending axially inwardly from the outside tread edge and terminating within the outside shoulder land portion.

8. The pneumatic tire according to claim 7 , wherein the crown sipes include second and third sipes disposed in the outside crown land portion,
the second sipe extends to connect between the center main groove and the inside shoulder main groove, and
the third sipe extends axially inwardly from the outside shoulder main groove and terminates within the outside crown land portion.

9. The pneumatic tire according to claim 6 , wherein the crown sipes include second and third sipes disposed in the outside crown land portion,
the second sipe extends to connect between the center main groove and the inside shoulder main groove, and
the third sipe extends axially inwardly from the outside shoulder main groove and terminates within the outside crown land portion.

10. The pneumatic tire according to claim 1 , wherein the crown sipes include second and third sipes disposed in the outside crown land portion,
the second sipe extends to connect between the center main groove and the inside shoulder main groove, and
the third sipe extends axially inwardly from the outside shoulder main groove and terminates within the outside crown land portion.

Assignees

• Sumitomo Rubber Ind

Inventors

• Sanae Ryuhei

Classifications

• B60C2011/0344

  provided at the equatorial plane · CPC title

• B60C11/1281

  different within the same sipe, i.e. enlarged width portion at sipe bottom or along its length · CPC title

• B60C11/0304 Primary

  Asymmetric patterns · CPC title

• B60C2011/0365

  characterised by width · CPC title

• B60C2011/0341

  Circumferential grooves · CPC title