Pneumatic tire with tread having lateral grooves and sub grooves

A pneumatic tire comprising:

• a single first main groove extending in tire circumferential directions and disposed on a tire equator of a tread surface wherein the tread surface defines a tire-contact patch;
• and
• single second main grooves extending in the tire circumferential directions and disposed respectively on both sides, in tire width directions, of the first main groove, wherein
• lateral grooves extending between the first main groove and the respective second main grooves as well as sub grooves extending halfway from the second main grooves toward the first main groove are disposed one by one alternately with each other at predetermined pitches in the tire circumferential directions,
• blocks are formed each of which is defined by the first main groove, the second main groove and the lateral grooves,
• each of the left-side lateral grooves positioned on the left side of the tire equator on the tread surface region includes:
• a first groove portion LG1 extending from the first main groove in one direction of the tire circumferential directions;
• and
• a second groove portion LG2 extending from the second main groove inwardly in the tire width direction while curving toward the one direction of the tire circumferential directions, and being connected to one side edge portion of the first groove portion LG1,
• the first groove portion LG1 has:
• an inclined groove portion LG1a extending from the first main groove outwardly in the tire width direction while inclined toward the one direction of the tire circumferential directions;
• and
• a circumferential-direction groove portion LG1b extending, in the one direction of the tire circumferential directions, from the inclined groove portion LG1a up to a position where the circumferential-direction groove portion LG1b overlaps the adjacent sub groove when seen from a tire side surface,
• the left-side sub grooves extend from the second main groove inwardly in the tire width direction while curving toward the one direction of the tire circumferential directions, and are set apart from the first groove portions LG1,
• the left-side sub grooves and the second groove portions LG2 are disposed alternately with each other in the tire circumferential directions,
• each of the right-side lateral grooves positioned on the right side of the tire equator on the tread surface region includes:
• a first groove portion RG1 extending from the first main groove in the other direction of the tire circumferential directions;
• and
• a second groove portion RG2 extending from the second main groove inwardly in the tire width direction while curving toward the other direction of the tire circumferential directions, and being connected to an opposite side edge portion of the first groove portion RG1,
• the first groove portion RG1 has:
• an inclined groove portion RG1a extending from the first main groove outwardly in the tire width direction while inclined toward the other direction of the tire circumferential directions;
• and
• a circumferential-direction groove portion RG1b extending, in the other direction of the tire circumferential directions, from the inclined groove portion RG1a up to a position where the circumferential-direction groove portion RG1b overlaps the adjacent sub groove when seen from a tire side surface,
• the right-side sub grooves extend from the second main groove inwardly in the tire width direction while curving toward the other direction of the tire circumferential directions, and are set apart from the first groove portions RG1,
• the right-side sub grooves and the second groove portions RG2 are disposed alternately with each other in the tire circumferential directions,
• apertures at both ends of each of the lateral grooves are opened to the first main groove and the second main grooves, respectively, and are shifted from one another in the tire circumferential directions,
• the left- and right-side lateral grooves are offset from each other in the tire circumferential directions, and
• the apertures of both the left- and right-side lateral grooves are shifted from one another in the tire circumferential directions and wherein each of the left-side sub grooves and the right-side sub grooves remain open in the tire-contact patch and each of the curving groove portions LG2, RG2, inclined groove portions LG1a, RG1a and circumferential direction groove portions LG1b, RG1b remain open in the tire-contact patch.

A pneumatic tire comprising:

• single first main grooves extending in tire circumferential directions and disposed respectively on right and left sides of a tire equator of a tread surface wherein the tread surface defines a tire-contact patch;
• and
• single second main grooves extending in the tire circumferential directions and disposed respectively on outer sides, in tire width directions, of the first main grooves, wherein
• lateral grooves extending between each pair of the first main grooves and the second main grooves as well as sub grooves extending halfway from the second main grooves toward the respective first main grooves are disposed one by one alternately with each other at predetermined pitches in the tire circumferential directions,
• blocks are formed each of which is defined by the first main groove, the second main groove and the lateral grooves,
• each of the left-side lateral grooves positioned on the left side of the tire equator on the tread surface region includes:
• a first groove portion LG1 extending from the first main groove in one direction of the tire circumferential directions;
• and
• a second groove portion LG2 extending from the second main groove inwardly in the tire width direction while curving toward the one direction of the tire circumferential directions, and being connected to one side edge portion of the first groove portion LG1,
• the first groove portion LG1 has:
• an inclined groove portion LG1a extending from the first main groove outwardly in the tire width direction while inclined toward the one direction of the tire circumferential directions;
• and
• a circumferential-direction groove portion LG1b extending, in the one direction of the tire circumferential directions, from the inclined groove portion LG1a up to a position where the circumferential-direction groove portion LG1b overlaps the adjacent sub groove when seen from a tire side surface,
• the left-side sub grooves extend from the second main groove inwardly in the tire width direction while curving toward the one direction of the tire circumferential directions, and are set apart from the first groove portions LG1,
• the left-side sub grooves and the second groove portions LG2 are disposed alternately with each other in the tire circumferential directions,
• each of the right-side lateral grooves positioned on the right side of the tire equator on the tread surface region includes:
• a first groove portion RG1 extending from the first main groove in the one direction of the tire circumferential directions;
• and
• a second groove portion RG2 extending from the second main groove inwardly in the tire width direction while curving toward the one direction of the tire circumferential directions, and being connected to one side edge portion of the first groove portion RG1,
• the first groove portion RG1 has:
• an inclined groove portion RG1a extending from the first main groove outwardly in the tire width direction while inclined toward the one direction of the tire circumferential directions;
• and
• a circumferential-direction groove portion RG1b extending, in the one direction of the tire circumferential directions, from the inclined groove portion RG1a up to a position where the circumferential-direction groove portion overlaps the adjacent sub groove when seen from the tire side surface,
• the right-side sub grooves extend from the second main groove inwardly in the tire width direction while curving toward the one direction of the tire circumferential directions, and are set apart from the first groove portions RG1,
• the right-side sub grooves and the second groove portions RG2 are disposed alternately with each other in the tire circumferential directions, and
• apertures at both ends of each of the lateral grooves are opened to the first main grooves and the second main grooves, respectively, and are shifted from one another in the tire circumferential directions,
• the left- and right-side lateral grooves are offset from each other in the tire circumferential directions,
• the apertures of both the left- and right-side lateral grooves are shifted from one another in the tire circumferential directions, and
• the tread surface is provided with a directional pattern designating a tire rolling direction and wherein each of the left-side sub grooves and the right-side sub grooves remain open in the tire-contact patch and each of the curving groove portions LG2, RG2, inclined groove portions LG1a, RG1a and circumferential direction groove portions LG1b, RG1b remain open in the tire-contact patch.

A pneumatic tire comprising:

• single first main grooves extending in tire circumferential directions and disposed respectively on right and left sides of a tire equator of a tread surface wherein the tread surface defines a tire-contact patch;
• and
• single second main grooves extending in the tire circumferential directions and disposed respectively on outer sides, in tire width directions, of the first main grooves, wherein
• lateral grooves extending between each pair of the first main grooves and the second main grooves as well as sub grooves extending halfway from the second main grooves toward the respective first main grooves are disposed one by one alternately with each other at predetermined pitches in the tire circumferential directions,
• blocks are formed each of which is defined by the first main groove, the second main groove and the lateral grooves,
• each of the left-side lateral grooves positioned on the left side of the tire equator on the tread surface region includes:
• a first groove portion LG1 extending from the first main groove in one direction of the tire circumferential directions;
• and
• a second groove portion LG2 extending from the second main groove inwardly in the tire width direction while curving toward the one direction of the tire circumferential directions, and being connected to one side edge portion of the first groove portion LG1,
• the first groove portion LG1 has:
• an inclined groove portion LG1a extending from the first main groove outwardly in the tire width direction while inclined toward the one direction of the tire circumferential directions;
• and
• a circumferential-direction groove portion LG1b extending, in the one direction of the tire circumferential directions, from the inclined groove portion LG1a up to a position where the circumferential-direction groove portion LG1b overlaps the adjacent sub groove when seen from a tire side surface,
• the left-side sub grooves extend from the second main groove inwardly in the tire width direction while curving toward the one direction of the tire circumferential directions, and are set apart from the first groove portions LG1,
• the left-side sub grooves and the second groove portions LG2 are disposed alternately with each other in the tire circumferential directions,
• apertures at both ends of each of the lateral grooves are opened to the first main grooves and the second main grooves, respectively, and are shifted from one another in the tire circumferential directions,
• the left- and right-side lateral grooves are offset from each other in the tire circumferential directions, and
• the apertures of both the left- and right-side lateral grooves are shifted from one another in the tire circumferential directions,
• each of the right-side lateral grooves positioned on the right side of the tire equator on the tread surface region includes:
• a first groove portion RG1 extending from the first main groove in the one direction of the tire circumferential directions;
• and
• a second groove portion RG2 extending from the second main groove inwardly in the tire width direction while curving toward the one direction of the tire circumferential directions, and being connected to one side edge portion of the first groove portion RG1,
• the first groove portion RG1 has:
• an inclined groove portion RG1a extending from the first main groove outwardly in the tire width direction while inclined toward the one direction of the tire circumferential directions;
• and
• a circumferential-direction groove portion RG1b extending, in the one direction of the tire circumferential directions, from the inclined groove portion RG1a up to a position where the circumferential-direction groove portion overlaps the adjacent sub groove when seen from the tire side surface,
• the right-side sub grooves extend from the second main groove inwardly in the tire width direction while curving toward the one direction of the tire circumferential directions, and are set apart from the first groove portions RG1,
• the right-side sub grooves and the second groove portions RG2 are disposed alternately with each other in the tire circumferential directions, and
• the tread surface is provided with a directional pattern designating a tire rolling direction and wherein each of the left-side sub grooves and the right-side sub grooves remain open in the tire-contact patch and each of the curving groove portions LG2, RG2, inclined groove portions LG1a, RG1a and circumferential direction groove portions LG1b, RG1b remain open in the tire-contact patch.