A tire (10) for a vehicle comprises a radially outermost working layer (41) which comprises at least one undulation (412) in line with a central rib (251) of the tread (2). The undulation (412) is radially on the outside of the points of the working layer (41) in line with the bottom face (243) of the circumferential groove (24) closest to the undulation (412) and has an amplitude of at least 1 mm. The undulation (412) is vertically in line above at least one local reinforcing layer (6) comprising reinforcing elements that are mutually parallel and make with the circumferential direction (XX′) of the tire an angle of which the absolute value is at most equal to 5°.

Tire for an aeroplane and, in particular, the crown thereof which comprises a tread (1), a textile crown reinforcement (2) and a textile carcass reinforcement (4). In order to optimize the number of landings, in the equatorial plane, the thickness (E1) of the tread is at least equal to 1.1 times the thickness of the working reinforcement and the thickness (E5) of the carcass is at least equal to 1.5 times the thickness (E3) of the working reinforcement, the reinforcing elements of the working layers (31, 32, 33) having a tenacity at least equal to 90 cN/tex.

The tire comprises a tread, a crown reinforcement and at least one crown layer. The crown layer has an axial width (L.sub.2) that is at least two-thirds of a maximum axial width (L.sub.1) of the tire and has a concave portion with axial limits (M.sub.2, M′.sub.2) on either side of an equatorial plane (XZ). The tire further includes a carcass reinforcement which has at least one carcass layer with a concave portion that has axial limits (M.sub.3, M′.sub.3) on either side of the equatorial plane (XZ). The radial distance (d) between the respective concave portions is at a maximum in the equatorial plane (XZ) and decreases continuously from the equatorial plane (XZ) as far as the axial limits (M.sub.2, M′.sub.2) of the said concave portions axially closest to the equatorial plane (XZ), where it reaches a minimum value (d.sub.M).

A radial tire for an aircraft, the radial tire having a rim diameter of 20 inches or less includes a pair of bead portions; a pair of sidewall portions extending outward from the bead portions in a substantially radial direction; a tread portion that couples together respective radial outer ends of the sidewall portions; a toroidal carcass layer reinforcing a portion between bead cores embedded in the bead portions; a belt layer and a tread that are sequentially laminated on an outer side of the carcass layer in the radial direction, wherein a value M obtained by dividing a tire external diameter D by a distance L between bead heels of the bead portions is in a range of from 4.1 to 5.4.

The invention is a tyre comprising, in the central part of its crown, at least one undulation (51) of the radially outermost crown layer, having a radial amplitude A at least equal to 1 mm. At least one bead comprises, aside from the radial carcass layer and the bead wire, a radial reinforcing element that is such that the axial distance between the radial reinforcing element and the axially innermost carcass layer is at least equal to 1 mm and at most equal to 12 mm at the point of the radial reinforcing element that is situated 30 mm from the radially innermost point of the bead wire, for a better trade-off between the stiffness of the undulating crown and of the bead.

A pneumatic tire is provided where a profile line in a tire meridian cross section of a center land portion defined by circumferential grooves and located on a tire equator is curved projecting outward in a tire radial direction. A carcass layer and a reinforcing layer include a recess portion curved projecting inward in the tire radial direction in a bottom region of the center land portion.

A tire comprises, in the central part of its crown, at least one undulation (51) with a radial amplitude A of the radially outermost crown layer, circumferential furrows (24) and open grooves (25), some of these grooves being radially on the outside of the undulation (51). At least 50% of these grooves (25) are said to be adapted to the undulation. An open groove adapted to the undulation which it is radially on the outside of is such that the intersection points Ps of the bottom curve Cf of said groove and of the furrows (24) are at a distance from the radially outermost point Pext of said bottom curve Cf by a radial distance d2 at least equal to one third of the radial amplitude (A/3) of the undulation (51) and such that the curve Cf increases radially from the intersection points Ps to the point Pext.

A heavy duty pneumatic tire 1 has provided in a buttress region 10 thereof a protrusion 11 extending in the tire circumferential direction. In a tire meridian cross-section, the maximum protrusion height h.sub.max of the protrusion 11 from an imaginary buttress surface J is 3.0 mm or greater and is in the range of 0.025-0.050 times a half tread width Wt. The cross-sectional area Sa of the protrusion 11 protruding from the imaginary buttress surface J is 20 mm.sup.2 or greater.

Provided is a pneumatic tire having at least one carcass layer as a skeleton extending in toroidal shape over a pair of bead portions, at least one belt layer and a tread disposed on an outer side in the radial direction of a crown portion of the carcass. In a tire section in the widthwise direction in state where the tire is assembled to an application rim, ratio BD/BW of radius difference BD between radius at a center portion and radius at an end portion in the widthwise direction of an innermost layer of the belt layer, to width BW of the innermost layer, ranges from 0.01 to 0.04, and ratio TD/TW of radius difference TD between radius at a center portion and radius at an end portion of the tread in the widthwise direction of a tread ground surface, to tread ground-contact width TW, satisfies BD/BW<TD/TW.

A tire 2 has a nominal cross-sectional width not less than 355 mm and a nominal aspect ratio not greater than 70%, and includes a tread 8 having a tread surface 4 that comes into contact with a road surface, and a belt 18 located radially inward of the tread 8. A ratio of a width of the tread surface 4 to a camber amount of the tread surface 4 at an end of the tread surface 4 is not less than 20 and not greater than 30. Regarding a thickness from the belt 18 to the tread surface 4, a ratio of a thickness at an equator plane to a thickness at an end 36 of the belt 18 is not less than 0.95 and not greater than 1.05.