Pneumatic tire

Patent metadata

Field	Value
Publication number	US-10252573-B2
Application number	US-201515110475-A
Country	US
Kind code	B2
Filing date	Jan 16, 2015
Priority date	Feb 13, 2014
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

A tire, wherein, in a cross section in the tire width direction thereof in a state where the tire has substantially not been inflated with no load applied thereon, provided that the maximum height in the tire radial direction of the carcass is h, a radius of curvature of the carcass within a height range 0.91 h-h measured from the radially innermost position of the carcass is R 7 , an acute inclination angle specifically defined in the height range 0.91 h-h is θ 7 , the intermediate value of a radius of curvature in the height range 0.82 h-0.91 h is R 6 , a radius of curvature in the height range 0.63 h-0.82 h is R 5 , and an acute inclination angle specifically defined in the height range 0.63 h-0.82 h is θ 5 , R 7 ≥0.26h, θ 7 ≥14°, R 6 <R 7 , R 5 >R 6 , and θ 5 ≤23°.

First claim

The invention claimed is:

1. A pneumatic tire having a pair of bead portions, a pair of bead cores embedded in the bead portions, respectively, and a carcass including at least one layer of carcass ply extending in a toroidal shape across the pair of bead cores, wherein:
in a cross section in the tire width direction of the tire in a state where the tire has been assembled with a prescribed rim but substantially has not been inflated, with no load applied thereon, provided that the maximum height in the tire radial direction of the carcass, measured from the innermost position in the tire radial direction thereof, is h and that positions distanced on the outer side in the tire radial direction from the innermost position in the tire radial direction of the carcass by h, 0.91 h, 0.82 h, and 0.63 h, respectively, are a 7 th height position H 7 , a 6 th height position H 6 , a 5 th height position H 5 , and a 4 th height position H 4 , respectively,
further provided that a radius of curvature of the carcass within a 7 th height range h 7 ranging from the 6 th height position H 6 to the 7 th height position H 7 is R 7 , R 7 ≥0.26 h;
further provided that an imaginary point on the carcass at the 6 th height position H 6 is P 6 , an imaginary point on the carcass at a tire widthwise position distanced by 0.4 h on the inner side in the tire width direction from the outermost position in the tire width direction of the carcass is P 0.4 h , a line linking the imaginary points P 6 and P 0.4 h is L 7 , and an acute inclination angle formed by the line L 7 with respect to the tire width direction is θ 7 , θ 7 ≥14°;
further provided that the intermediate value of a radius of curvature of the carcass within a 6 th height range h 6 ranging from the 5 th height position H 5 to the 6 th height position H 6 is R 6 , R 6 <R 7 ;
further provided that a radius of curvature of the carcass within a 5 th height range h 5 ranging from the 4 th height position H 4 to the 5 th height position H 5 is R 5 , R 5 >R 6 ;
further provided that a line linking the innermost and the outermost positions in the tire radial direction, on the carcass, in the 5 th height range h 5 is L 5 and an acute inclination angle formed by the line L 5 with respect to the tire radial direction is θ 5 , θ 5 ≤23°, and
wherein the radius of curvature R 5 of the carcass within the 5 th height range h 5 is ≥0.82 h.

2. The pneumatic tire of claim 1 , wherein the intermediate value R 6 of a radius of curvature of the carcass within the 6 th height range h 6 is in the range of 0.13 h to 0.26 h.

3. The pneumatic tire of claim 1 , wherein, provided that a position distanced on the outer side in the tire radial direction from the innermost position in the tire radial direction of the carcass by 0.48 h is a 3 rd height position H 3 and that a radius of curvature of the carcass within a 4 th height range h 4 ranging from the 3 rd height position H 3 to the 4 th height position H 4 is R 4 , R 4 ≥0.39 h, and
the maximum width position of the carcass is located within the 4 th height range h 4 .

Assignees

• Bridgestone Corp

Inventors

• Okazaki Naoto

Classifications

• B60C2200/06

  for heavy duty vehicles · CPC title

• B60C3/04

  characterised by the relative dimensions of the section, e.g. low profile (B60C3/06 takes precedence) · CPC title

• B60C15/0027

  with low ply turn-up, i.e. folded around the bead core and terminating at the bead core · CPC title

• B60C9/0292 Primary

  Carcass ply curvature (sidewall curvature B60C13/003) · CPC title

• B60C13/003

  characterised by sidewall curvature · CPC title