Pneumatic tire
AssigneeSumitomo Rubber Industries, Ltd.
InventorMasahiro Yao
Life of this patent
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Abstract
A pneumatic tire includes a tread portion, sidewall portions, a pair of bead portions embedded with bead cores, and a carcass. The carcass includes a turned up ply including a main body portion extending between the bead cores, and a pair of turned up portions turned up around the bead cores from axially inside to outside. Each bead portion is provided with an inner apex rubber extending radially outward from the bead core between the main body portion and the turned up portion and an outer apex rubber arranged axially outside the turned up portion. The inner apex rubber has a radial height of from 18 to 30 mm. A buttress thickness D, a maximum width thickness E, and a bead thickness F satisfy expressions E≥4.5 mm, F≥9.0 mm, E/D=0.6 to 0.9, and F/E=1.7 to 2.2.
Claims20
A pneumatic tire comprising:
- a tread portion;
- a pair of sidewall portions;
- a pair of bead portions in each of which a bead core is embedded;
- and
- a toroidal carcass;
- wherein the carcass includes a turned up ply,
- the turned up ply includes a main body portion extending between the bead cores in a toroidal manner, and a pair of turned up portions, each turned up portion turned up around a respective one of the bead cores from an inside to an outside in a tire axial direction,
- each bead portion of the pair of the bead portions is provided with an inner apex rubber, extending from the respective bead core outward in a tire radial direction between the main body portion and the respective turned up portion of the turned up ply, and an outer apex rubber arranged adjacent to and axially outside the respective turned up portion,
- a height in the tire radial direction of each inner apex rubber is in a range of from 18 to 30 mm, and
- wherein on each axial side of the tire, a buttress thickness D which is the shortest distance from a tire outer surface to the carcass at a position P1 radially inwardly away from a maximum tire diameter position by 23% of a tire section height,
- a maximum width thickness E which is the shortest distance from the tire outer surface to the carcass at a maximum tire width position, and
- a bead thickness F which is the shortest distance from the tire outer surface to the carcass at a position P2 radially outwardly away from a bead baseline by 25 mm satisfy the expressions E≥4.5 mm, F≥9.0 mm, E/D=0.6 to 0.9, and F/E=1.7 to 2.2.
Dependencies are inferred from the claim text.