Pneumatic radial tire for aircraft

Patent metadata

Field	Value
Publication number	US-11241920-B2
Application number	US-201816772804-A
Country	US
Kind code	B2
Filing date	Dec 19, 2018
Priority date	Dec 20, 2017
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

Provided is a pneumatic radial tire for an aircraft including a bead core, a radial carcass and a stiffener, the radial carcass including one or more turn-up plies and one or more down plies, wherein in tire axial direction cross-sectional view, when an intersection point of a virtual circle with a ply closest to a tire axial direction inner side of the stiffener among the plies intersecting with the virtual circle having a radius that is twice as large as a diameter D of the bead core from a center O of the bead core is a point A, an intersection point of the virtual circle with a ply closest to a tire axial direction outer side of the stiffener is a point B, and a midpoint between the point A and the point B is a reference point C, then a line segment OC connecting the center O of the bead core to the reference point C has an inclination angle θ of 17° or less to a tire radial direction line passing the center O of the bead core on the tire axial direction outer side.

First claim

The invention claimed is:

1. A pneumatic radial tire for an aircraft, comprising a bead core including a pair of cable beads, a radial carcass including a plurality of plies toroidally extending between the bead cores, and a stiffener disposed adjacent to the bead core on a tire radial direction outer side of the bead core,
the radial carcass comprising one or more turn-up plies including a windup portion wound up around the bead core from an inner side to an outer side in a tire axial direction, and one or more down plies that cover the windup portion and extend to a radial direction inner side of at least the bead core, wherein
in tire axial direction cross-sectional view in a state where the tire is mounted to a rim, is not filled with an internal pressure, and is unloaded,

when an intersection point of a virtual circle with a ply closest to a tire axial direction inner side of the stiffener among the plies intersecting with the virtual circle having a radius that is twice as large as a diameter D of the bead core from a center corresponding to a center O of the bead core is a point A, an intersection point of the virtual circle with a ply closest to a tire axial direction outer side of the stiffener is a point B, and a midpoint between the point A and the point B is a reference point C,
then a line segment OC connecting the center O of the bead core to the reference point C has an inclination angle θ of 17° or less to a tire radial direction line passing the center O of the bead core on the tire axial direction outer side.

2. The pneumatic radial tire for the aircraft according to claim 1 , wherein the inclination angle θ is 0° or more.

3. The pneumatic radial tire for the aircraft according to claim 1 , wherein the diameter D (mm) of the bead core and a prescribed load E (N) determined for each tire satisfy a relation of Formula (I) as follows:
520 ≤E/D 2 ≤940  Formula (I).

4. The pneumatic radial tire for the aircraft according to claim 2 , wherein the diameter D (mm) of the bead core and a prescribed load E (N) determined for each tire satisfy a relation of Formula (I) as follows:
520 ≤E/D 2 ≤940  Formula (I).

Assignees

• Bridgestone Corp

Inventors

• Ogawa Gaku
• Matsumoto Takuya

Classifications

• B60C2015/046

  Cable cores, i.e. cores made-up of twisted wires · CPC title

• B60C15/0054

  with ply turn-up portion parallel and adjacent to carcass main portion · CPC title

• B60C15/0072

  with ply reverse folding, i.e. carcass layer folded around the bead core from the outside to the inside · CPC title

• B60C15/0018 Primary

  not folded around the bead core, e.g. floating or down ply · CPC title

• B60C9/08

  the cords extend transversely from bead to bead, i.e. radial ply (B60C9/07 takes precedence) · CPC title