Pneumatic tire

Patent metadata

Field	Value
Publication number	US-2016288580-A1
Application number	US-201615058884-A
Country	US
Kind code	A1
Filing date	Mar 2, 2016
Priority date	Apr 3, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

A pneumatic tire includes a tread portion including a first tread pattern and a second tread pattern. The first tread pattern and the second pattern are formed as substantially symmetrical design to the tire equator and arranged such that pattern phases thereof are shifted one another in a circumferential direction of the tire. Each of the first tread pattern and the second tread pattern is provided with lateral inclined grooves each extending axially inwardly with an inclination from a tread edge to an axially inner end located near the tire equator, an inner connecting groove connecting between a pair of circumferentially adjacent lateral inclined grooves, and an outer connecting groove connecting between a pair of circumferentially adjacent lateral inclined grooves. A central connecting grooves is arranged to connect between a pair of axially adjacent lateral inclined grooves.

First claim

What is claimed is:

1 . A pneumatic tire comprising:
a tread portion comprising a first tread pattern formed between a tire equator and one of tread edges, and a second tread pattern formed between the tire equator and the other one of the tread edges; the first tread pattern and the second pattern being formed as substantially symmetrical design with respect to the tire equator, the first tread pattern and the second pattern being arranged such that pattern phases thereof are shifted one another in a circumferential direction of the tire, each of the first tread pattern and the second tread pattern being provided with a plurality of lateral inclined grooves each extending axially inwardly with an inclination from the tread edge to an axially inner end located near the tire equator without reaching the tire equator, an axially inner connecting groove having an opposite inclination to the inclination of the lateral inclined grooves and connecting between a pair of circumferentially adjacent lateral inclined grooves, and an axially outer connecting groove having an opposite inclination to the inclination of the lateral inclined grooves and connecting between a pair of circumferentially adjacent lateral inclined grooves; and a plurality of central connecting grooves arranged axially inward of the inner connecting grooves of the first and second tread patterns, each central connecting groove extending across the tire equator and connecting one of the lateral inclined grooves arranged on the first tread pattern with one of the lateral inclined grooves arranged on the second tread pattern.

2 . The pneumatic tire according to claim 1 ,
wherein the tread portion is not provided with any circumferentially and continuously extending straight main grooves.

3 . The pneumatic tire according to claim 1 ,
wherein the outer connecting groove has an end that forms a T-shaped groove junction with one of the lateral inclined grooves, the inner connecting groove has an end that forms a T-shaped groove junction or a cross-shaped groove junction with one of the lateral inclined grooves, and the central connecting groove has an end that forms a T-shaped groove junction with one of the lateral inclined grooves.

4 . The pneumatic tire according to claim 1 ,
wherein each of the lateral inclined grooves comprises a groove center line, the groove center line comprises an intersection point A with the tread edge, an intersection point B with an axially inner end of the outer connecting groove, an intersection point C with an axially inner end of the inner connecting groove and an intersection point D with the central connecting groove, and angles θab, θbc and θcd satisfy the following relations:
θ ab<θbc<θcd,

25(deg.)<θ ab< 35(deg.),

45(deg.)<θ bc< 55(deg.), and

55(deg.)<θ cd< 65(deg.),

where “θab” is an angle of a segment AB extending from the point A to the point B with respect to an axial direction of the tire, “θbc” is an angle of a segment BC extending from the point B to the point C with respect to the axial direction of the tire, and “θcd” is an angle of a segment CD extending from the point C to the point D with respect to the axial direction of the tire.

5 . The pneumatic tire according to claim 4 ,
wherein an axial length Lab of the segment AB, an axial length Lbc of the segment BC and an axial length Lcd of the segment CD satisfy the following relations:
Lab<Lbc<Lcd,
0.39×TW≦ Lab ≦0.47×TW,

0.33×TW≦ Lbc ≦0.41×TW, and

0.27×TW≦ Lcd ≦0.36×TW,

where “TW” is a tread half width which is an axial distance measured from the tire equator to one of the tread edges.

6 . The pneumatic tire according to claim 1 ,
wherein the tread portion comprises a central block surrounded by a pair of circumferentially adjacent lateral inclined grooves, the inner connecting groove and a pair of central connecting groove, a middle block surrounded by a pair of circumferentially adjacent lateral inclined grooves, the inner connecting groove and the outer connecting groove, and a shoulder block surrounded by a pair of circumferentially adjacent lateral inclined grooves, the outer connecting groove and one of the tread edges.

7 . The pneumatic tire according to claim 6 ,
wherein the inner connecting groove comprises an extended portion that extends across one of the lateral inclined grooves and terminates within the middle block.

8 . The pneumatic tire according to claim 6 ,
wherein the central block is provided with a sipe extending substantially in an axial direction of the tire.

9 . The pneumatic tire according to claim 6 ,
wherein the middle block is provided with a sipe extending substantially in parallel with the inner connecting groove.

10 . The pneumatic tire according to claim 6 ,
wherein the shoulder block is provided with a sipe extending substantially in parallel with the lateral inclined grooves.

Assignees

• Sumitomo Rubber Ind

Inventors

• HIGASHIURA Kazuki

Classifications

• B60C11/0302 Primary

  directional pattern, i.e. with main rolling direction · CPC title

• B60C11/03

  Tread patterns · CPC title

• B60C11/1236 Primary

  with special arrangements in the tread pattern · CPC title

• B60C2011/0372

  with particular inclination angles · CPC title

• B60C11/1204

  with special shape of the sipe · CPC title