US 2026/0225409 A1Published application

Pneumatic tire

AssigneeSumitomo Rubber Industries, Ltd.

InventorsChisato OMORI, Masahiro NAGASE, Hiroshi KIKUCHI

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Abstract

A pneumatic tire having a protruding portion including a top portion and a rim fit profile. In each axial half of a tire meridian section of the pneumatic tire in a standard state, a parameter X relating to rim chafing resistance performance, defined by X=(A+10)×B×Hs×E/105, is 34 or more, where A: the shortest distance from the top portion to a rim flange; B: a distance from the top portion to a tire radial direction line defining a rim width; Hs: a rubber hardness of a bead apex rubber; E: a modulus (N/%×number of cords/5 cm) of a carcass ply calculated by E=(F/G)×H; G: an intermediate elongation (%) of a carcass cord under a constant load F; F: the constant load (N) applied when obtaining the intermediate elongation G; and H: ends of the carcass cords.

Claims19

Dependent claims

A pneumatic tire comprising:

a tread portion;
a pair of bead portions each having a bead core embedded therein;
a carcass extending from one bead portion of the pair to the other bead portion of the pair;
and
bead apex rubbers each extending outward in a tire radial direction from the bead core in a respective one of the bead portions, wherein
each of the bead portions has an outer surface in a tire axial direction provided with a protruding portion formed thereon,
the protruding portion protrudes axially outward and extends in a tire circumferential direction,
the protruding portion includes a top portion convex axially outward and a rim fit profile extending radially inward from the top portion,
the carcass includes at least one carcass ply in which a plurality of carcass cords is arranged,
in each axial half of a tire meridian section of the pneumatic tire in a standard state where the pneumatic tire is mounted on a rim, inflated to a standard inner pressure, and loaded with no tire load, a parameter X relating to rim chafing resistance performance, defined by the following Formula (1), is 34 or more:
X
=
(
A
+
10
)
×
B
×
Hs
×
E
/
10
5
(
1
)
where,
A:
a shortest distance (mm) in the tire radial direction from the top portion to a rim flange of the rim;
B:
a distance (mm) in the tire axial direction from the top portion to a tire radial direction line defining a rim width of the rim;
Hs:
a rubber hardness of the bead apex rubbers;
E:
a modulus (N/%×number of cords/5 cm) of the at least one carcass ply calculated by E=(F/G)×H;
G:
an intermediate elongation (%) of the carcass cords under a constant load applied according to Japanese Industrial Standards JIS L1017;
F:
the constant load (N) applied when obtaining the intermediate elongation G;
and
H:
ends (number of cords/5 cm) of the carcass cords.

42 more elements

A pneumatic tire comprising:

a tread portion;
a pair of bead portions each having a bead core embedded therein;
a carcass extending from one bead portion of the pair to the other bead portion of the pair;
and
bead apex rubbers each extending outward in a tire radial direction from the bead core in a respective one of the bead portions, wherein
each of the bead portions has an outer surface in a tire axial direction provided with a protruding portion formed thereon,
the protruding portion protrudes axially outward and extends in a tire circumferential direction,
the protruding portion includes a top portion convex axially outward and a rim fit profile extending radially inward from the top portion,
the carcass includes at least one carcass ply in which a plurality of carcass cords is arranged,
in each axial half of a tire meridian section of the pneumatic tire in a standard state where the pneumatic tire is mounted on a rim, inflated to a standard inner pressure, and loaded with no tire load, a parameter X relating to rim chafing resistance performance, defined by the following Formula (1), is in a range from 100 to 110:
X
=
(
A
+
10
)
×
B
×
Hs
×
E
/
10
5
(
1
)
wherein,
A is a shortest distance (mm) in the tire radial direction from the top portion to a rim flange of the rim, and is in a range from 0 to 3 mm;
B is a distance (mm) in the tire axial direction from the top portion to a tire radial direction line defining a rim width of the rim, and is in a range from 7 to 12 mm;
Hs is a rubber hardness of the bead apex rubbers, and is in a range from 80 to 100;
E is a modulus (N/%×number of cords/5 cm) of the at least one carcass ply calculated by E=(F/G)×H, and is in a range from 400 to 900;
G is an intermediate elongation (%) of the carcass cords under a constant load applied according to Japanese Industrial Standards JIS L1017;
F is the constant load (N) applied when obtaining the intermediate elongation G;
and
H is ends (number of cords/5 cm) of the carcass cords.

35 more elements

Dependencies are inferred from the claim text.

Facts

Application: 19/453,036Filed 20 Jan 2026
Priority: JP 2025-01542231 Jan 2025
Published: 6 Aug 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

B60C 15/0242
Bead contour, e.g. lips, grooves, or ribs: with bead extensions located radially outside the rim flange position, e.g. rim flange protectors
B60C 15/0603
Flipper strips, fillers, or chafing strips and reinforcing layers for the construction of the bead: characterised by features of the bead filler…
B60C 9/0238
Carcasses: characterised by special physical properties of the carcass ply
B60C 9/04
Carcasses: the reinforcing cords of each carcass ply arranged in a substantially parallel relationship