In a pneumatic tire, bead cores have a wire arrangement. In a cross-sectional view in a tire meridian direction, a tangential line and a contact point are defined. The tangential line contacts an innermost layer in a radial direction and the wire cross sections innermost and outermost in a lateral direction in the wire arrangement from a rim fitting surface side. The contact point of the tangent line is on the wire cross section on the outermost side. A gauge Wh in the lateral direction from the contact point to the rim fitting surface and an outer diameter φ of the bead wire have a relationship 2.0≤Wh/φ≤15.0. A radial height H2 of a contact portion between a body portion and a turned back portion of a carcass layer has a relationship 0.80≤H2/H1≤3.00 to a radial height H1 of the bead cores.

A tire includes a carcass ply extending from one bead structure to another bead structure. Each bead structure includes a plurality of circumferentially wound sheath layers surrounding a bead core with a triangular cross-section. The cross-section has two radially inner vertices and a radially outer vertex. The radially outer vertex and one of the radially inner vertices are an angular amount radially offset from a directly radial direction of the tire.

The outer diameter of the pneumatic tire is 350 mm or more and 600 mm or less, and the tire width is 125 mm or more and 255 mm or less. An aspect ratio of the pneumatic tire is 40% or more and 75% or less, a rim diameter of a rim wheel is 10 inches or more and 22 inches or less, and a rim width of the rim wheel is 3.8 inches or more and 8 inches or less. The pneumatic tire satisfies the relationship of 0.78≤RW/SW≤0.99 and 0.56≤RD/OD≤0.75. The carcass has a plurality of carcass cords arranged at intervals, the carcass cords are formed of prescribed organic fibers, and the breaking strength of the carcass cords is ≥2.2 kN/cm.

With a pneumatic tire not mounted on a rim, in a meridian cross-section a first line is parallel with an innermost bottom side of a bead core in a radial direction and passes through an outermost projection of the bead core in a lateral direction, a second line is orthogonal with the first line at the outermost projection, a third line is orthogonal with the first line and passes through an intersection of a rim cushion rubber, a distance between the second and third lines is 2.0 to 4.0 mm, a shortest distance between an innermost projection of the bead core in the lateral direction and a cord of a carcass layer is 0.6 to 1.4 mm, and a shortest distance between an innermost end of the bottom side of the bead core in the lateral direction and the cord of the carcass layer is 1.2 to 2.2 mm.

A pneumatic tire having a bead filler molded over a bead bundle to form an over-molded bead. The bead bundle may include at least one bead wire. The bead bundle may be over-molded with the bead filler, forming an over-molded bead. The over-molded bead may be formed into a variety of shapes and may be constructed from a variety of materials.

A pneumatic radial tire for aircraft in the present disclosure includes a bead core formed by a pair of cable beads embedded in a respective pair of bead portions, a pair of bead fillers respectively arranged outward in a tire radial direction from the pair of bead cores, and a carcass formed by two or more carcass plies that extend toroidally between the pair of bead cores. In a tire widthwise cross-sectional view, an end of a carcass ply, among the two or more carcass plies, closest to the bead filler in a region inward in a tire width direction from the bead filler is located in a region corresponding to 45° to 90° inward in the tire width direction when 0° is defined as outward in the tire radial direction from a center of the bead core.

In a cross-section of a pneumatic tire, a contour of the bead core is a polygon formed by tangent lines of circumferential portions of a bead wire, the contour includes a vertex with an acute angle and a bottom side opposite the vertex, the carcass layer is folded back along a circumference of the bead core in a bead portion, a folded back portion of the carcass layer from an outer end of the bead core extends in the radial direction, and a distance in the radial direction between a center of an arc profile of a tire outer surface and a straight line extending in the lateral direction through the vertex is within 20% of a radius r of the arc, and a distance in the lateral direction between the center of the arc and a straight line extending in the radial direction through the vertex is within 2r±0.4r.

In a tire 2, on a cross-section, three or more rows in each of which cross-sections 30 of a wire are aligned almost in the axial direction, are layered in the radial direction. The cross-sections 30 of the wire in a first row disposed on an innermost side in the radial direction and the cross-sections 30 of the wire in a second row layered outward of the first row are staggered. On a cross-section obtained by the tire 2 being cut at a plane perpendicular to the circumferential direction, an outline of a heel surface 36 of a bead 8 portion has an arc C that projects toward an outside of the bead 8 portion. A radius R of curvature of the arc C is greater than or equal to 8 mm and not greater than 12 mm.

The present invention has an object of providing a pneumatic tire that exhibits better uniformity by improving the wire wound body for constituting the bead core. The pneumatic tire 1 comprises a bead core 5 comprising a wire wound body 10 in which one bead wire 10a is spirally wound in a continuous around a tire rotational axis CL so that a plurality of layers of the bead wire are formed in a radial direction of the tire. The wire wound body 10 comprises a first part 13 and a second part 14. The first part 13 comprises a plurality of layers of the bead wire 10a each circumferentially extending with a constant radius from the tire rotational axis CL. The second part comprises a plurality of layers of the bead wire 10a each circumferentially extending while changing its radius from the tire rotational axis CL.

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.