Pneumatic tire

Patent metadata

Field	Value
Publication number	US-10173474-B2
Application number	US-201514801520-A
Country	US
Kind code	B2
Filing date	Jul 16, 2015
Priority date	Aug 7, 2014
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

A pneumatic tire has a tread pattern capable of improving wet performance and steering stability in a well balanced manner. An inboard middle land portion is provided with inboard middle axial grooves connecting between an inboard shoulder main groove and an inboard crown main groove and inclined at 20 to 30 degrees. An outboard middle land portion is provided with outboard middle semi-blind grooves extending axially inwardly from a outboard shoulder main groove, and outboard middle sipes extending from the axially inner ends of the outboard middle semi-blind grooves to the outboard crown main groove. The outboard middle semi-blind grooves and the outboard middle sipes are inclined at 20 to 30 degrees. A center land portion is provided with inboard crown semi-blind grooves extending from the inboard crown main groove, and outboard crown semi-blind grooves extending from the outboard crown main groove.

First claim

The invention claimed is:

1. A pneumatic tire comprising:
a tread portion provided with a tread pattern asymmetric about the tire equator, and having an outboard tread edge and inboard tread edge to be positioned toward the outside and inside of a vehicle, respectively, wherein
the tread portion from the outboard tread edge to the inboard tread edge is divided into five land portions, which are an outboard shoulder land portion, an outboard middle land portion, a center land portion, an inboard middle land portion, and an inboard shoulder land portion, by four circumferentially continuously extending main grooves, which are an outboard shoulder main groove, an outboard crown main groove, an inboard crown main groove, and an inboard shoulder main groove,
the inboard middle land portion is provided with open axial grooves each extending across the entire width of the land portion to have both ends opened to the main grooves on both sides of the land portion, and not provided with semi-blind axial grooves each having one end opened to one of the adjacent main grooves and the other end closed in the land portion, wherein said open axial grooves are inboard middle axial grooves extending from the inboard shoulder main groove to the inboard crown main groove and inclined at an angle of from 20 to 30 degrees with respect to the tire axial direction,
the outboard middle land portion is provided with semi-blind axial grooves each having one end opened to one of the adjacent main grooves and the other end closed in the land portion, and not provided with open axial grooves each extending across the entire width of the land portion to have both ends opened to the main grooves on both sides of the land portion, wherein said semi-blind axial grooves are outboard middle semi-blind grooves extending axially inwardly from the outboard shoulder main groove and terminating within the outboard middle land portion, and
further the outboard middle land portion is provided with outboard middle sipes respectively extending from the axially inner ends of the outboard middle semi-blind grooves to the outboard crown main groove,
the outboard middle semi-blind grooves and the outboard middle sipes are inclined at an angle of 20 to 30 degrees with respect to the tire axial direction, and
the center land portion is provided with inboard crown semi-blind grooves extending from the inboard crown main groove toward the outboard crown main groove and terminating within the center land portion, and
outboard crown semi-blind grooves extending from the outboard crown main groove toward the inboard crown main groove and terminating within the center land portion.

2. The pneumatic tire according to claim 1 , wherein the inboard middle axial grooves and the outboard middle sipes are inclined in the same direction.

3. The pneumatic tire according to claim 1 , wherein the number of the inboard middle axial grooves is less than the number of the outboard middle sipes.

4. The pneumatic tire according to claim 1 , wherein depths of the inboard crown semi-blind grooves and the outboard crown semi-blind grooves are not more than 5 mm.

5. The pneumatic tire according to claim 1 , wherein the inboard crown semi-blind grooves and the outboard crown semi-blind grooves are inclined in the same direction.

6. The pneumatic tire according to claim 1 , wherein
the inboard middle land portion is circumferentially divided by the inboard middle axial grooves into a row of inboard middle blocks, and
each of the inboard middle blocks is provided with an inboard middle sipe extending from the inboard crown main groove toward the inboard shoulder main groove and terminating within the inboard middle block.

7. The pneumatic tire according to claim 1 , wherein
the inboard middle land portion is provided with sipes, wherein the sipes are inboard middle sipes each extending axially outwardly from the inboard crown main groove to have an open end and terminating within the inboard middle land portion to have a closed end, and the inboard middle sipes are arranged alternately with the inboard middle axial grooves, and
the outboard middle land portion is provided with sipes, wherein the sipes are said outboard middle sipes respectively extending from the axially inner ends of the outboard middle semi-blind grooves to the outboard crown main groove.

8. The pneumatic tire according to claim 7 , wherein the axial length of the outboard middle semi-blind grooves is 5% to 18% of the axial width of the outboard middle land portion.

9. The pneumatic tire according to claim 8 , wherein the inboard middle axial grooves and the outboard middle sipes are inclined in the same direction.

10. The pneumatic tire according to claim 9 , wherein
the inboard crown semi-blind grooves and the outboard crown semi-blind grooves are arranged alternately in the tire circumferential direction, and inclined in the same direction, and
depths of the inboard crown semi-blind grooves and the outboard crown semi-blind grooves are not more than 5 mm.

Assignees

• Sumitomo Rubber Ind

Inventors

• Sueno Junya

Classifications

• B60C2011/0381

  Blind or isolated grooves · CPC title

• B60C11/12

  characterised by the use of narrow slits or incisions, e.g. sipes · CPC title

• B60C2011/0353

  characterised by width · CPC title

• B60C11/0306

  Patterns comprising block rows or discontinuous ribs · CPC title

• B60C2011/0383

  at the centre of the tread · CPC title