Pneumatic tire
AssigneeBridgestone Corporation
InventorsTakeshi Iwatani, Kento Hashimoto
Life of this patent
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Abstract
A pneumatic tire, having in a ground contact surface of a tread a plurality of main grooves extending in the tread circumferential direction and a plurality of land portions demarcated by the main grooves and tread ends, wherein, provided that two land portions adjacent to the central land portion on the respective sides in the tread width direction of the central land portion each represent an adjacent land portion, rigidity in the tread circumferential direction of the central land portion is lower than rigidity in the tread circumferential direction of the adjacent land portion.
Claims9
A pneumatic tire, having in a ground contact surface of a tread a plurality of main grooves extending in the tread circumferential direction and a plurality of land portions demarcated by the main grooves and tread ends, wherein:
- provided that i) when the ground contact surface of the tread has a central main groove extending on the tire equatorial plane or a central main groove extending at a widthwise position away in the tread width direction from the tire equatorial plane by a distance of ≤0.2×a tread width TW, two land portions demarcated by the central main groove and two other main grooves adjacent thereto on respective sides thereof in the tread width direction each represent a central land portion, ii) otherwise than i), a land portion demarcated by the two main grooves closest to the tire equatorial plane represents a central land portion, and iii) a land portion adjacent to the central land portion on the outer side in the tread width direction of the central land portion represents an adjacent land portion,
- rigidity in the tread circumferential direction of the central land portion is lower than rigidity in the tread circumferential direction of the adjacent land portion;
- tread rubber is constituted of two tread rubber layers, and one of the tread rubber layers has smaller elastic modulus than the other tread rubber layer located on the inner side in the tire radial direction of the one rubber layer;
- and
- the adjacent land portion has a spew formed in a tire vulcanization process in a tire width direction vicinity of the main groove adjacent on the inner side in the tire width direction of the adjacent land portion, and provided that a distance in the tire width direction between the spew and an end portion, on the inner side in the tire width direction, of the adjacent land portion is D and a rubber gauge of the tread rubber at a tire widthwise position where the spew exists is G, a first expression 0.3×G≤D≤0.55×G is satisfied,
- wherein the only spew or spews that exist on the adjacent land portion satisfy the first expression.
Dependencies are inferred from the claim text.