US 11,752,809 B2
Pneumatic tire
Toshiaki Hamada, Kobe (JP); Masahiro Tatsuta, Kobe (JP); Hiroki Uno, Kobe (JP); and Hiroto Takenaka, Kobe (JP)
Assigned to Sumitomo Rubber Industries, Ltd., Hyogo (JP)
Filed by Sumitomo Rubber Industries, Ltd., Hyogo (JP)
Filed on Jun. 24, 2019, as Appl. No. 16/450,766.
Claims priority of application No. 2018-123182 (JP), filed on Jun. 28, 2018.
Prior Publication US 2020/0001665 A1, Jan. 2, 2020
Int. Cl. B60C 15/06 (2006.01); B60C 15/00 (2006.01)
CPC B60C 15/0603 (2013.01) [B60C 15/0009 (2013.01); B60C 15/0607 (2013.01); B60C 2015/061 (2013.01); B60C 2015/0614 (2013.01); B60C 2015/0617 (2013.01); Y10T 152/10828 (2015.01); Y10T 152/10837 (2015.01); Y10T 152/10846 (2015.01)] 7 Claims
OG exemplary drawing
 
1. A pneumatic tire comprising:
a tread;
a pair of sidewalls connected to edges of the tread;
a pair of beads each having a core extending in a circumferential direction and an apex located radially outward of the core;
a carcass extending from one bead to the other bead at an inner side of the tread and the pair of sidewalls; and
a pair of clinches located radially inward of the sidewalls, wherein
the carcass includes a carcass ply having a main body portion that extends on and between one core and the other core and a pair of turned-up portions that are connected to the main body portion and turned up around the cores from an inner side toward an outer side in an axial direction,
in each bead a length from a center in the axial direction of a boundary between the core and the apex to an outer edge of the apex is not less than 10 mm and not greater than 15 mm, and
in a state where the tire is mounted on a normal rim and an internal pressure of the tire is adjusted to 10% of a normal internal pressure,
in each bead the main body portion extending along an inner surface of the apex is tilted relative to the axial direction, and an angle of the main body portion relative to the axial direction is not less than 40° and not greater than 60°,
a reinforcing layer is provided between the carcass and each clinch,
the respective reinforcing layer is a respective rubber reinforcing layer formed from a crosslinked rubber,
a loss tangent of the respective rubber reinforcing layer is equal to a loss tangent of the respective apex or lower than the loss tangent of the respective apex,
a complex elastic modulus of the respective rubber reinforcing layer is not greater than 100 MPa,
the complex elastic modulus of the respective rubber reinforcing layer is equal to a complex elastic modulus of the respective apex or higher than the complex elastic modulus of the respective apex, and
the main body portion extends linearly at a respective portion axially inward with respect to a straight line that extends in a radial direction and passes through a radially outer edge of a respective contact surface of the tire and the normal rim.