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US 2010/0300588 A1Published application
Pneumatic tire
AssigneeSumitomo Rubber Industries, Ltd.
InventorHideki Otsuji
Life of this patent
Estimating the term…
Abstract
A land ratio of a shoulder portion Sh of a tread portion 2 is 57 to 72%, and a land ratio of a center portion Ce is 40 to 55%. In the center portion Ce, one row block made up of center blocks 6 is formed. Each of the center blocks 6 has its width gradually reduced from a position establishing an axial maximum width BW toward both a leading end and a trailing end relative to the tire rotating direction, each of the center blocks being provided with, at the leading end thereof, a tip portion 6a that sharpens toward the leading end, and being provided with, at the trailing end thereof, a concave portion 6b that smoothly concaves toward the leading end. In each of the center blocks 6, a ratio (BL/BW) between the axial maximum width BW and a maximum length BL in the circumferential direction is 1.00 to 1.20.
Claims17
A pneumatic tire, comprising:
- a tread portion having a tread pattern being formed by repetitive arrangement of substantially identically patterned pattern pitches in the circumferential direction of the tire, wherein
- the tread portion has a center portion making up 50% of a tread ground-contact width whose center is a tire equator, and shoulder portions respectively situated on opposite sides of the center portion,
- in each of the shoulder portions, shoulder main grooves extending inwardly from an outside relative to a tread ground-contact edge in the axial direction of the tire are arranged at certain intervals in the circumferential direction of the tire, whereby a shoulder land portion is established between the shoulder main grooves, a land ratio in each of the shoulder portion between the tread ground-contact edge and an outer edge of the center portion being 57 to 72%,
- in the center portion, between the shoulder land portions being arranged on opposite sides in the axial direction of the tire, at least one center block row having center blocks arranged in the circumferential direction at certain intervals is provided, a land ratio of the center portion being 40 to 55%,
- the center block row is formed one in number,
- each of the center blocks has its width gradually reduced from a position establishing a maximum width BW in the axial direction of the tire BW toward both a leading end and a trailing end relative to the tire rotating direction, each of the center blocks being provided, at the leading end thereof, with a tip portion that sharpens toward the leading end, and being provided, at the trailing end thereof, with a concave portion that smoothly concaves toward the leading end, so as to be substantially heart-shaped in its entirety, and
- in each of the center blocks, a ratio (BL/BW) between the axial maximum width BW and a maximum length BL in the circumferential direction is 1.00 to 1.20.
4 more elements
A pneumatic tire, comprising:
- a tread portion having a tread pattern being formed by repetitive arrangement of substantially identically patterned pattern pitches in the circumferential direction of the tire, wherein
- the tread portion has a center portion making up 50% of a tread ground-contact width whose center is a tire equator, and shoulder portions respectively situated on opposite sides of the center portion,
- in each of the shoulder portions, shoulder main grooves extending inwardly from an outside relative to a tread ground-contact edge in the axial direction of the tire are arranged at certain intervals in the circumferential direction of the tire, whereby a shoulder land portion is established between the shoulder main grooves, a land ratio in each of the shoulder portion between the tread ground-contact edge and an outer edge of the center portion being 57 to 72%,
- in the center portion, between the shoulder land portions being arranged on opposite sides in the axial direction of the tire, at least one center block row having center blocks arranged in the circumferential direction at certain intervals is provided, a land ratio of the center portion being 40 to 55%,
- when the pattern pitches are each constituted of one of the shoulder main grooves and one of the shoulder land portions being adjacent to the one shoulder main groove, the pattern pitches each have a high land ratio region in which a sum of length in the axial direction of the tire of portions contacting the road surface on a tire axial line passing through the pattern pitch is 78 to 93% of the tread ground-contact width, and
- the high land ratio region is continuous in the circumferential direction of the tire by 20 to 35% of a length in the circumferential direction of the tire of each of the pattern pitches.
3 more elements
A pneumatic tire, comprising:
- a tread portion having a tread pattern being formed by repetitive arrangement of substantially identically patterned pattern pitches in the circumferential direction of the tire, wherein
- the tread portion has a center portion making up 50% of a tread ground-contact width whose center is a tire equator, and shoulder portions respectively situated on opposite sides of the center portion,
- in each of the shoulder portions, shoulder main grooves extending inwardly from an outside relative to a tread ground-contact edge in the axial direction of the tire are arranged at certain intervals in the circumferential direction of the tire, whereby a shoulder land portion is established between the shoulder main grooves, a land ratio in each of the shoulder portion between the tread ground-contact edge and an outer edge of the center portion being 57 to 72%,
- in the center portion, between the shoulder land portions being arranged on opposite sides in the axial direction of the tire, at least one center block row having center blocks arranged in the circumferential direction at certain intervals is provided, a land ratio of the center portion being 40 to 55%,
- the center blocks are adjacent to the respective shoulder land portions, with a longitudinal groove-like portion extending in the circumferential direction of the tire being interposed therebetween, and
- the longitudinal groove-like portion has a narrowed width portion whose width in the axial direction of the tire is 3 to 6 mm thereby establishing a minimum width, and increased width portions whose respective widths in the axial direction of the tire are gradually increased from the narrowed width portion toward the opposite sides in the circumferential direction of the tire.
3 more elements
Dependencies are inferred from the claim text.