Abstract: In a pneumatic tire of the type wherein both end portions of a carcass layer are supported by a pair of right and left bead cores, respectively, and at least two belt layers are disposed on the outer periphery of a tread of the carcass layer, a cord reinforcing layer having a cord weight per unit width of not greater than 1.30 g/mm on a radial section and a cord angle of not greater than 80.degree. with respect to a tire circumferential direction is disposed at a buttress portion between a maximum width portion of a tire section and the end portion of the belt layers in a tire width-wise direction.

Abstract: A pneumatic tire to be fitted on a wheel wherein a position, in which a disc is connected to a rim, is offset from the cneter of width of the rim toward the outer surface of the wheel, characterized in that a ratio (Ho/Hi) of an attenuation coefficient Ho (=Go.times.tan.delta.o) determined on the basis of an average thickness Go of an outer side wall of the tire on the outer side of the wheel and a loss factor tan.delta.o of the rubber of this side wall to that Hi (=Gi.times.tan.delta.i) determined on the basis of an average thickness Gi of an inner side wall of the tire on the inner side of the wheel and a loss factor tan.delta.i of the rubber of this side wall is set in the range of 1.2-6.5.

Abstract: A pneumatic radial tire for passenger cars having a plurality of grooves formed in the tread and extending at least circumferentially of the tire, the tread being provided with two belt plies therein in such a manner that their belt cords extend in a crisscross pattern. The grooves have a depth in the range of 6.0 to 8.5 mm, with the thickness of the under-groove rubber layer from the bottom of the grooves to the outer belt ply being fixed within the range of 0.5 to 2.0 mm. The belt plies are placed one over another with the both edge portions left unfolded. At least one of the plies is made from aramid fiber cords and at least the both edge portions of the belt plies are covered with at least one belt cover ply which has a cord angle of no greater than 30 deg with respect to the circumference of the tire. The belt cover ply is made of organic fiber cords no larger than 0.7 mm in diameter at a picking density of 35 to 90 percent.

Abstract: A pneumatic tire characterized in that an average thickness G.sub.U of the region of each of side walls which extends from a position corresponding to a widest portion of the tire toward a tread and that G.sub.L of the region of the side wall which extends from the same position toward a bead are set different from each other, the average thickness G.sub.U of the tread-side region being set to not less than 2.5 mm with the average thickness G.sub.L of the bead-side region set to less than 2.5 mm and not less than 1.0 mm.

Abstract: A pneumatic tire having a tread surface comprised of a plurality of pitches of different lengths arranged to extend around the circumference of the tire and which includes a pitch of the shortest pitch length P.sub.min and a pitch of the longest pitch length P.sub.max, a period of the pitches begins with a pitch of P.sub.min and contains at least one pitch of P.sub.max between the pitch of P.sub.min and a pitch of P.sub.min in a next period, a fundamental period begins with the pitch of P.sub.min and ends with a pitch located immediately before the pitch of P.sub.min located first in the next period. In a pitch arangement within the fundamental period, the proportion of components of each higher order in the range of a second order to a fourth order relative to the first-order component is 80 to 200% when Fourier expansion of a stepped waveform comprising the reciprocal of the pitch length and the pitch length is conducted. The number of the fundamental periods is 1 to 4.

Abstract: A pneumatic radial tire for a passenger car, which includes a plurality of grooves provided on the surface of a tread and extending at least in a tire circumferential direction and a belt having a double layer structure and provided within the tread, characterized in that the depth of the grooves is in the range of 6.0 to 8.5 mm, the thickness of a rubber under the groove defined as the distance from the bottom of the groove to the outermost belt layer is in the range of 0.5 to 2.5 mm, one of the belt layers comprises aramid fiber cords with the other belt layer comprising steel cords, and the total sectional area, .alpha., of steel wires per 50 mm width of the belt layer comprising steel cords is 5 to 14 mm.sup.2.

Abstract: In a pneumatic tire which is to be fitted to a wheel of the type in which connecting position of a disc to a rim is offsetted to a wheel outer side from a center of a rim width, and which has a plurality of blocks on a tread thereof, a pneumatic tire wherein a total contact area C.sub.2 of shoulder blocks on the tire outer side disposed on the offset side of the disc and a total contact area C.sub.1 of shoulder blocks on the tire inner side disposed on the opposite side to the offset side of the disc satisfy the relation, C.sub.1 /C.sub.2 =1.2 to 2.0.

Abstract: A pneumatic radial tire for a passenger car, which includes a plurality of grooves provided on the surface of a tread and extending at least in a tire circumferential direction and a belt having a double layer structure and provided within the tread, characterized in that the depth of the grooves is in the range of 6.0 to 8.5 mm, the thickness of a rubber under the groove defined as the distance from the bottom of the groove to the outermost belt layer is in the range of 0.5 to 2.5 mm, and at least one layer of the belt comprises aramid fiber cords coated with a coat rubber having a modulus of elasticity at 50% elongation of 30 to 55 kgf/cm.sup.2.

Abstract: A pneumatic tire having a bead in which an end portion of a carcass layer is bent from an inner portion to an outer portion of the tire so as to be turned up around a bead core, a reinforcing layer which consists of reinforcing cords covered with coating rubber being provided so as to extend along a turnup portion of the carcass layer, the hardness of the coating rubber in the reinforcing layer is set in the range of JIS Hs 65-95.

Abstract: A pneumatic radial tire for passenger cars having a plurality of grooves formed in the tread and extending at least circumferentially of the tire, the tread being provided with two belt plies therein. The grooves have a depth in the range of 6.0 to 8.5 mm, with the thickness of the under-groove rubber layer from the bottom of the grooves to the outer belt ply being fixed within the range of 0.5 to 2.5 mm. The belt plies are both made from aramid fiber cords, or either belt ply is made from aramid fiber cords and the other ply from steel cords. The both edge portions of at least one of the belt plies are folded back toward the center of the tread at a fold percentage of 8 to 100 percent.

Abstract: A pneumatic radial tire to be fitted on a wheel in which a position wherein a disc is joined to a rim is offset from the center of the width of the rim toward the outer surface of said wheel, characterized in that the tire comprises an asymmetric structure in which a belt layer is provided between a tread and a carcass layer, an outer circumferential portion of the belt layer being covered with at least one belt covering layer, the at least one belt covering layer being disposed so that an average position of the center(s) of the width(s) thereof from the equator of the tire is deviated toward the opposite side of the offset side of the disc, a ratio e/w of the deviating distance e to the width w of a ground contacting portion of the tread being set to 0.05-0.13.

Abstract: A pneumatic radial tire for a passenger car, which includes a plurality of grooves provided on the surface of a tread and extending at least in a tire circumferential direction and a belt layer having a double layer structure and provided within the tread, characterized in that the total sectional area, .alpha., of steel wires per 50 mm width of the belt layer is in a range satisfying 5.ltoreq..alpha..ltoreq.9 mm.sup.2, the depth, d, of the grooves is in a range satisfying 6.0.ltoreq.d.ltoreq.8.0 mm, and the thickness, t, of rubber under the grooves defined as the distance from the bottom of the groove to the outermost belt layer is in a range satisfying 1.0.ltoreq.t.ltoreq.2.5 mm.

Abstract: Pneumatic radial tires for automotive use are constructed with a belt layer reinforced with a steel cord of a unique structure. The steel cord results from the preformation of a single steel wire into a spiral shape meeting specified spiral parameters as determined by specified spiral diameters, specified wire diameters and specified spiral pitches. Significant weight saving is attainable with sufficient driving performance.

Abstract: A pneumatic tire wherein two to ten periods of 3 to 8 types of pitches different from each other in the length constitute the whole circumference of a tread surface, and the proportion .alpha..sub.i of each pitch in the whole circumference of the tread surface is specified in a particular range.

Abstract: A pneumatic radial tire characterized in that at least two belt layers reinforced with cords of a high elastic modulus extending at an angle of 14.degree.-33.degree. with respect to the circumferential direction of the tire are arranged between a tread and a carcass, at least one of these belt layers being folded back at both end portions thereof toward the equator of the tire so as to wrap both end portions of any remaining belt layers, at least one reinforcing layer which is reinforced with thermally contractible organic fiber cords which extend at substantially 0.degree. with respect to the circumferential direction of the tire being inserted inside of each of the folded portions of the at least one folded belt layer, the width of the reinforcing layers being set to 10-70% of that of each of the folded portions.

Abstract: A pneumatic tire wherein a plurality of pitches different from each other in the length constitute the whole circumference of a tread surface, the total period length of each period is divided into a former half period length and a latter half period length, and (1) in every period, the ratio of either of the two half period lengths to the total period length is 15 to 30%, or (2) in the whole circumference of the tread surface, the average value of the ratio of a smaller half period length to the total period length is 15 to 30%.

Abstract: A pneumatic tire having a tread pattern formed on the surface of the tire by using at least two types of main pattern elements having a length in the circumferential direction of the tire equal to at least 1.0% of that of the outer periphery of the tire and a subpattern element having a length in the circumferential direction of the tire of at least 0.5 mm and equal to 0.6% or less of that of the outer periphery of the tire, combining one of the main pattern elements with the subpattern element to prepare a plurality of types of combination pattern elements different from each other in the length of the circumferential direction of the tire and the pattern, and periodically disposing these pattern elements along the circumferential direction of the tire.

Abstract: A pneumatic tire for automobiles which has a carcass reinforced with polymeric monofilaments of the same or different diameter which are interconnected by radially inwardly curved peripheral extensions thereof to form a cord having a substantially flat transverse cross-sectional configuration as a whole.

Abstract: A pneumatic tire characterized in that a carcass layer is constructed by arranging non-twisted polyamide monofilament cords each having a flat cross-section such that the major axis of said flat cross-section is disposed along the surface direction of said carcass layer, that said carcass layer is fold up from the inside to the outside of said tire around a bead portion, and that the folded-up end portions are constructed such that the thickness thereof becomes smaller toward the distal end thereof.

Abstract: A pneumatic tire wherein the shoulder width of a pitch having a larger length is smaller than that of a pitch having a smaller length and there exists a particular relationship between the length ratio .alpha. of the longest pitch to the shortest pitch and the ratio .beta. of the maximum value of P.sub.i .times.L.sub.i to the minimum value of P.sub.i .times.L.sub.i.