Pneumatic tire

Patent metadata

Field	Value
Publication number	US-10974549-B2
Application number	US-201715808564-A
Country	US
Kind code	B2
Filing date	Nov 9, 2017
Priority date	Nov 22, 2016
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A pneumatic tire 1 comprises a tread portion 2 provided with main grooves 3 extending zigzag continuously in the tire circumferential direction, and lateral grooves 4 extending in the tire axial direction. The main grooves 3 include a pair of shoulder main grooves 6 . The lateral grooves 4 include shoulder lateral grooves 17 extending from the shoulder main grooves 6 to tread edges Te. The maximum groove width W 8 of the shoulder lateral grooves 17 is 0.2 to 0.6 times the maximum groove width W 1 of the shoulder main grooves 6.

First claim

The invention claimed is:

1. A pneumatic tire comprising:
a tread portion having tread edges and provided with a plurality of main grooves extending zigzag continuously in the tire circumferential direction, and a plurality of lateral grooves extending in the tire axial direction,
the main grooves including a pair of shoulder main grooves disposed one on each side of the tire equator and having a maximum groove width,
the lateral grooves including a plurality of shoulder lateral grooves extending axially outwardly from the shoulder main grooves to the tread edges and having a maximum groove width, wherein
the maximum groove width of the shoulder lateral grooves is 0.2 to 0.6 times the maximum groove width of the shoulder main grooves, and
each of the shoulder lateral grooves is composed of an axially inner straight shoulder lateral groove segment, an axially outer straight shoulder lateral groove segment, and an in-between shoulder lateral groove segment connecting therebetween and the in-between shoulder lateral groove segment is bent in a V-shape having an acute angled portion.

2. The pneumatic tire according to claim 1 , wherein
the main grooves include a single crown main groove disposed between the shoulder main grooves, and
a zigzag amplitude in the tire axial direction of the crown main groove is greater than a zigzag amplitude in the tire axial direction of each of the shoulder main grooves.

3. The pneumatic tire according to claim 2 , wherein
zigzag pitches in the tire circumferential direction of the crown main groove are equal to zigzag pitches in the tire circumferential direction of each of the shoulder main grooves.

4. The pneumatic tire according to claim 2 , wherein
axially outermost points of the crown main groove on both sides in the tire axial direction are respectively connected with axially innermost points of the shoulder main grooves.

5. The pneumatic tire according to claim 2 , wherein
the crown main groove is composed of alternate first crown main groove oblique segments and second crown main groove oblique segments, wherein, toward one tire circumferential direction, the first crown main groove oblique segments are inclined with respect to the tire circumferential direction to one tire axial direction, whereas the second crown main groove oblique segments are inclined with respect to the tire circumferential direction to the other tire axial direction, and
a groove width of the first crown main groove oblique segments and a groove width of the second crown main groove oblique segments are less than the minimum groove width of the shoulder main grooves, wherein
the crown main groove has first outermost parts located at axially outermost positions on one side of the tire equator, and second outermost parts located at axially outermost positions on the other side of the tire equator,
the first oblique crown main groove segments and the second oblique crown main groove segments connect between the first outermost parts and the second outermost parts, and
the first outermost parts are connected with the one of the shoulder main grooves, and the second outermost parts are connected with the other of the shoulder main grooves.

6. The pneumatic tire according to claim 1 , wherein
the axially inner straight shoulder lateral groove segment is inclined to the same direction as the second oblique crown main groove segments at an angle θ 6 with respect to the tire circumferential direction, and
the axially outer straight shoulder lateral groove segment is inclined to the same direction as the axially inner straight shoulder lateral groove segment at an angle θ 7 with respect to the tire circumferential direction which is greater than the angle θ 6 .

7. The pneumatic tire according to claim 6 , wherein the difference (θ 7 -θ 6 ) of the angle θ 7 from the angle θ 6 is in a range from 10 to 30 degrees, the angle θ 6 is in a range from 45 to 70 degrees, and the angle θ 7 is in a range from 65 to 90 degrees.

8. The pneumatic tire according to claim 7 , wherein
the in-between shoulder lateral groove segment comprises an inner portion connected to the axially inner straight shoulder lateral groove segment, and an outer portion connected to the axially outer straight shoulder lateral groove segment,
the inner portion is inclined in the same direction as the axially outer straight shoulder lateral groove segment, and
the outer portion is inclined at an acute angle with respect to the inner portion.

9. The pneumatic tire according to claim 8 , wherein
the axially inner straight shoulder lateral groove segment has a substantially constant groove width W 7 , and
the axially outer straight shoulder lateral groove segment has a substantially constant groove width W 8 greater than the groove width W 7 .

10. The pneumatic tire according to claim 9 , wherein the tread portion is further provided with narrow grooves each extending straight from the axially inner straight shoulder lateral groove segment of one of the shoulder lateral grooves to the outer portion of the in-between shoulder lateral groove segment of the adjacent shoulder lateral groove so that the outer portion and the narrow groove extend in line.

11. The pneumatic tire according to claim 2 , wherein each of the shoulder main grooves is composed of axially outer shoulder main groove segments parallel with the tire circumferential direction, axially inner shoulder main groove segments parallel with the tire circumferential direction, first oblique shoulder main groove segments, and second oblique shoulder main groove segments,
the axially outer shoulder main groove segments and the axially inner shoulder main groove segments are arranged alternately in the tire circumferential direction,
the first oblique shoulder main groove segments are inclined with respect to the tire circumferential direction to one tire axial direction at an angle θ 1 , and connect between the axially outer shoulder main groove segments and the axially inner shoulder main groove segments,
the second oblique shoulder main groove segments are inclined with respect to the tire circumferential direction to the other tire axial direction at an angle θ 2 , and connect between the axially outer shoulder main groove segments and the axially inner shoulder main groove segments,
the axially inner shoulder main groove segments are respectively connected to axially outermost points of the crown main groove on both sides in the tire axial direction, and
the axially outer shoulder main groove segments are respectively connected to the shoulder lateral grooves.

12. The pneumatic tire according to claim 11 , wherein each of the shoulder lateral grooves is composed of an axially inner straight shoulder lateral groove segment, an axially outer straight shoulder lateral groove segment, and an in-between shoulder lateral groove segment connecting therebetween and the in-between shoulder lateral groove segment is bent in a V-shape having an acute angled portion.

13. The pneumatic tire according to claim 12 , wherein the tread portion is further provided with narrow grooves each extending obliquely from the in-between shoulder lateral groove segment of one of the shoulder lateral grooves to the axially inner straight shoulder lateral groove segment of the adjacent shoulder lateral groove.

14. A pneumatic tire comprising:
a tread portion having tread edges and provided with a plurality of main grooves extending zigzag continuously in the tire circumferential direction, and a plurality of lateral grooves extending in the tire axial direction,
the main grooves including a pair of shoulder ma

Assignees

• Sumitomo Rubber Ind

Inventors

• Murata Takehiko

Classifications

• B60C2011/036

  Narrow grooves, i.e. having a width of less than 3 mm · CPC title

• B60C2011/0353

  characterised by width · CPC title

• B60C2011/1209

  straight at the tread surface · CPC title

• B60C2011/0381

  Blind or isolated grooves · CPC title

• B60C2200/14

  for off-road use · CPC title