Motorcycle pneumatic tire

Patent metadata

Field	Value
Publication number	US-10500901-B2
Application number	US-201615131789-A
Country	US
Kind code	B2
Filing date	Apr 18, 2016
Priority date	May 1, 2015
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

A motorcycle pneumatic tire includes a tread portion including a crown region, a pair of middle regions and a pair of shoulder regions upon a tread development width of the tread portion being divided equally into five regions. The tread portion is provided with a pair of circumferentially and continuously extending crown main grooves within the crown region to include a tire equator therebetween and a plurality of inclined grooves each extending from the crown region to the shoulder region in each side of the tire equator without communicating with the crown main grooves. Each of the inclined grooves includes a straight portion extending straightly in the middle region and an arc portion extending in an arc shape in the shoulder region while increasing an angle with respect to a circumferential direction of the tire axially outwardly.

First claim

What is claimed is:

1. A motorcycle pneumatic tire comprising:
a tread portion comprising a crown region, a pair of middle regions and a pair of shoulder regions upon a tread development width of the tread portion being divided equally into five regions;
the tread portion being provided with a pair of circumferentially and continuously extending crown main grooves which extends straight in parallel with a circumferential direction of the tire within the crown region to include a tire equator therebetween, a rib defined between the pair of crown main grooves, and a plurality of inclined grooves each extending from the crown region to the shoulder region in each side of the tire equator without communicating with the crown main grooves, wherein no circumferential groove is provided on the rib; and
each of the inclined grooves comprising a straight portion extending straightly in the middle region and an arc portion extending in an arc shape in the shoulder region,
wherein an angle of the arc portion with respect to the circumferential direction of the tire increases from an axially inner side of the arc portion to an axially outer side of the arc portion, and
a shoulder sub-groove is provided between a pair of circumferentially adjacent inclined grooves in each shoulder region,
the shoulder sub-groove has both ends terminating within the shoulder region, and
the shoulder sub-groove has a depth in a range of from 60% to 90% of depths of the crown main grooves,

wherein the shoulder sub-groove extends in an arc manner along one of the arc portions of the inclined grooves, and
wherein the shoulder sub-groove consists of a main portion having a pair of parallelly extending groove edges and two end portions connected to respective groove-longitudinal ends of the main portion, the main portion having a constant groove width, the end portions each having a semi-circular shape such that a groove width of the end portions gradually decreases toward respective ends of the shoulder sub-groove.

2. The motorcycle pneumatic tire according to claim 1 ,
wherein a middle land portion is defined between straight portions of a pair of circumferentially adjacent inclined grooves in each middle region, and a width of the middle land portion in a direction perpendicular to the straight portions is in a range of from 115% to 165% of widths of the straight portions.

3. The motorcycle pneumatic tire according to claim 1 ,
wherein a shoulder land portion is defined between arc portions of a pair of circumferentially adjacent inclined grooves in each the shoulder region, and a circumferential length of the shoulder land portion increases toward a tread edge.

4. The motorcycle pneumatic tire according to claim 1 ,
wherein each of the inclined grooves comprises a first groove edge extending in a straight shape with an inclination, a second groove edge facing the first groove edge and a third groove edge forming the axially inner end of the inclined groove, and the third edge extends in a straight shape along the circumferential direction of the tire.

5. The motorcycle pneumatic tire according to claim 4 ,
wherein the second groove edge intersects with the third groove edge in an acute angle, and an axially inner portion of the second groove edge extends in an arc manner such that an angle of the axially inner portion with respect to the circumferential direction of the tire decreases gradually to the third edge.

6. The motorcycle pneumatic tire according to claim 4 ,
wherein a circumferential length of the third groove edge is greater than a width of the straight portion in each inclined groove.

7. The motorcycle pneumatic tire according to claim 4 ,
wherein a circumferential length of the third groove edge is in a range of from 2.5 to 4.5 times of a width of the straight portion.

8. The motorcycle pneumatic tire according to claim 1 ,
wherein a groove width of the shoulder sub-groove is narrower than that of the inclined grooves.

9. The motorcycle pneumatic tire according to claim 1 ,
wherein a groove width of the shoulder sub-groove is substantially half of that of the inclined grooves.

10. The motorcycle pneumatic tire according to claim 1 ,
wherein the shoulder sub-groove extends in an arc manner along one of the arc portions of the inclined grooves, and a radius of curvature of the shoulder sub-groove is greater than that of the arc portion of each of the inclined grooves.

Assignees

• Sumitomo Rubber Ind

Inventors

• Matsumoto Takuro

Classifications

• B60C2011/0376

  characterised by width · CPC title

• B60C2011/0388

  provided at the equatorial plane · CPC title

• B60C2200/10

  for motorcycles, scooters or the like · CPC title

• B60C2011/0365

  characterised by width · CPC title

• B60C2011/0344

  provided at the equatorial plane · CPC title