Abstract: A pneumatic tire has a sidewall rubber insert axially inward of at least one carcass ply. Such insert may, for example, be an apex extending radially outward from the bead core region of the tire into the sidewall. Alternatively, it may be positioned higher in the sidewall portion of the tire and away from the bead core. Such insert is a rubber composition containg a dispersion of an ultra high molecular weight polyethylene and a dispersion of a starch composite.

Abstract: A two-ply radial runflat tire having a belt structure, a ply structure, two inextensible beads and two wedge-insert reinforced sidewalls. The outer ply is reinforced by high-modulus, light-weight aramid. The aramid reinforcement material of the outer ply is clamped around the beads. The outer ply is prestressed in tension during manufacture of the tire. The resultant tire is light in weight and resists upward buckling of the tread during runflat operation.

Abstract: A tire 10 has a composite ply 40. The composite ply 40 has a primary ply 40A reinforced with parallel inextensible cords 41 and a pair of ply extensions 40B having synthetic cords. The method of manufacturing the tire 10 is described. The tire 10 can be made as a runflat type tire.

Abstract: Pneumatic vehicle tires comprising a carcass which extends between two bead rings, a belt arrangement provided between the carcass and a tread strip, and also rubber reinforcing plies arranged in the sidewall regions, which adopt a supporting function when the tire is deflated, are characterized in that a single rubber reinforcing ply is arranged radially within a first carcass ply and its maximum thickness is disposed in the upper half of the sidewall height; with the rubber reinforcing ply extending from the bead apex region up to and beneath the edge region of the belt ply, and with the bead apex, which extends approximately up to the half sidewall height, being surrounded by the first carcass ply.

Abstract: A pneumatic tire, includes at least one carcass ply folded turned up around a bead cord, a belt layer arranged on an outer side of a crown portion of the carcass ply to have an overlapping portion with the folded portion of the carcass, a first reinforcing rubber layer arranged between body portion of the carcass ply and the folded portion of the carcass ply, and a second reinforcing rubber layer arranged inside the body portion of the carcass ply, wherein overlapping width W2 from an upper end position RF of the second reinforcing rubber layer to an end BE of the belt layer is 7% to 33% of the width BW of the belt layer; and cross sectional widths G1W, G2W, and G3W satisfy the following relations: G3W/G1W=0.85 to 0.95, and G2W/G1W=1.0 to 1.05.

Abstract: An all terrain vehicle tire (10) has an annular tread (12) and a casing (11) radially inward of the tread (12). The tread (12) has a plurality of tread lugs (92, 94) and a central rib (95). The plurality of tread lugs (92, 94) are disposed on each tread half and spaced axially from the equatorial plane of the tire (10). The spacing from the equatorial plane of the tire (10) is a distance of at least 10% of the tread width. The central rib (95) is located between the plurality of tread lugs (92) on each tread half. The central rib (95) has a nonskid depth as measured from the inner tread surface of less than the maximum nonskid depth of the tread lugs (92, 94). The preferred embodiment tire (10) has a pair of inserts (42), one insert (42) being in each sidewall (18, 20) of the tire (10) and a third insert (70) disposed between a breaker reinforcing structure (36) and at least one ply reinforcing structure (38) of the casing (11).

Abstract: The invention relates to pneumatic tires for a motor vehicle comprising a multi-layer carcass. Said multi-layer carcass extends between two bead rings, a set of bracing plies provided between the layers of the carcass and a tire tread, and rubber reinforcement layers arranged in the side wall areas which support the tire when it is deflated. The invention is characterized in that a first rubber reinforcement layer is arranged radially within a first carcass layer and a second rubber reinforcement layer is arranged between the first carcass layer and a second carcass layer. The two rubber reinforcement layers extend from the bead filler area to a position under the edge area of the bracing plies. The two rubber layers vary in thickness across the height of the side walls.

Abstract: A pneumatic radial ply tire with an aspect ratio of less than 50 has a ground contacting tread radially outward of a circumferential belt structure which in turn is radially ourtward of a carcass structure. The carcass structure has a pair of bead areas that include a bead foot compatible with a conventionally-shaped wheel rim having flanges with laterally extending portions. The carcass structure has a cord-reinforced elastomeric ply layer extend laterally between the two bead areas and radially inward of the belt structure. The tread area is directly connected to the bead areas without a sidewall. Rim flange protectors comprising a continuous circumferential elastomeric projection extend laterally outward from each bead/tread area and thereby radially outward of the rim flanges.

Abstract: The tire of the invention has an optimized path of the outermost carcass designed to maximize the extent of tensile stress in the sidewall and bead portions of the tire. The invention further provides separate reinforcement structures in the bead portion for anchoring the carcass or carcasses in the bead and for retaining the bead on the mounting rim during deflated operation, and said anchoring reinforcement also facilitates the maintenance of the desirable carcass profile.

Abstract: A pneumatic tire with an increased load carrying capacity (extended load index) but compatible with conventional, commercially available wheel rims, has a modified carcass ply line. The pneumatic tire (746) has a tread area (712) and a carcass structure (728) including two bead areas (750a,750b), at least one cord-reinforced elastomeric ply (730) extending through sidewalls (726a,726) between the bead areas (750a,750b) and the tread area (712), and a belt structure (718) between the tread area (712) and the carcass structure (728). The tire (746) has bead areas (750a,750b) containing a triangular shaped beads so that the ply line (PL′″) that causes the bead areas to better secure the tire to the rim during high stress conditions.

Abstract: A first stage tire building drum for building a run flat tire has a cylindrical central portion for receiving the strip components thereon for fabricating a first stage body ply carcass and has a pair of bead receiving areas adjacent the central portion for receiving bead rings thereon. The central portion and bead areas preferably are formed by a plurality of moveable arcuate segments. A spacer or sleeve is formed by a plurality of arcuate segments and is mounted on the center of the cylindrical drum portion and forms a pair of adjacent recesses. The spacer has a smooth outer cylindrical surface. The spacer has a height equal to the thickness of run flat tire sidewall inserts and a width equal to the distance between the inside edges of the opposed sidewall inserts.

Abstract: A pneumatic radial ply runflat tire 1000 for a vehicle has a tread 1012, a carcass 1022 comprising at least one radial ply 1030 and two sidewalls 1016 each reinforced by a circumferentially disposed crescent-shaped wedge insert. Each insert has an elastomeric porous section 1042 embedded in an elastomeric stiffer layer 1044 of the insert 1040. When the tire is normally inflated, the porous section 1042, and hence the insert as a whole, is flexible, thereby providing comfortable driving characteristics. Under runflat (deflated tire) conditions, the pores in the porous section 1042 collapse, and the porous section 1042 stiffens, and hence the insert as a whole becomes stiff enough to support the load of the vehicle.

Abstract: A pneumatic tire with an increased load carrying capacity (extended load index) but compatible with conventional, commercially available wheel rims, has a modified carcass plyline. The tire has a tread area, a carcass structure including two bead areas each comprising a bead, at least one cord-reinforced elastomeric ply extending between the two bead areas, and two sidewalls, one sidewall extending between the tread area and each bead area.

Abstract: A runflat pneumatic tire has a tread stiffening member radially inward of the tread 12. The tire has a deflected section height H30 under load at 30 psi inflation and a deflected section height H0 at 0 psi wherein the deflection D30 are equal to or less than D0−D30 and the net contact area at 0 psi has a perimeter dynamic contact shape of at least U shaped or rectangular.

Abstract: A motorcycle tire having excellent belt cord durability, high-speed durability, impact force absorbability, running stability and uniformity performances is produced by constituting a belt with a low-cost steel cord member having a specified twisting construction of 2 to 7 filaments and a specified space between the mutual filaments over a full length of the cord in the belt.

Abstract: A run flat tire has a plurality of reinforcing wedges located in the tire sidewall with the hardness of each wedge generally diminishing in the radially inward direction of the sidewall. Since the bead filler is harder than the radial innermost wedge, the hardness at generally the top of the bead filler increases in the radial inward direction. The reinforcing wedges partially overlap each other and can generally have any configuration. The changing of hardness of the radial wedges results in a wedge sequence and thus a more even strain distribution throughout the tire sidewall. This strain distribution extends the run flat life of the tire and also provides a good balance with other tire performance parameters.

Abstract: The present invention provides a pneumatic safety tire comprising a pair of left and right bead cores, a carcass layer, a multi-layer belt portion, a tread portion, and a pair of side wall portions disposed at the left and right of said tread portion, wherein at least one sheet of a rubber-filament fiber composite formed from filament fibers and a rubber component is disposed at said side wall portions in a vicinity of said carcass layer. The safety tire of the present invention maintains the properties during ordinary use under the inflated condition at high levels, has a light weight, and shows remarkably improved properties during use under the run-flat condition.

Abstract: A passenger tire having a tread, a casing with two sidewalls, one or more radial plies extending from and wrapped about two annular beads and a belt reinforcement structure located radially between the tread and the piles. The tread has a central rib with a first contour-defining curve extending outwards from the mid centerline of the tire towards the sidewalls and a pair of side ribs each having a second contour-defining curve disposed between the central rib and the sidewalls. The first and second contour-defining curves each have first and second radii disposed such that the meeting point of first and second adjacent contour-defining curves cannot contain a single line that is mutually tangential to the first and second adjacent contour-defining curves.

Abstract: A pneumatic tire, in which a concave portion adjacent to a convex mark is provided on a surface of a sidewall portion, and a ratio of a volume v of the concave portion to a volume V of the convex mark is set as: 0.8V≦v≦1.2V, alternatively, a convex portion adjacent to a concave mark is provided on the surface of the sidewall portion, and a ratio of a volume w of the convex portion to a volume W of the concave mark is set as: 0.8W≦w≦1.2W, thus suppressing a bend of a carcass layer located under a mark spot of the sidewall portion, and making it possible to maintain a carcass line approximately uniformly on a circumference thereof.

Abstract: A chipper (40, 43, 54) for use in a pneumatic radial ply runflat tire (49) comprises cord reinforcements (42, 42′) making an angle, &agr;′ of between 30° and 50° relative to the circumferential direction. The radially outermost edge (46, 50) of the chipper is located between 10 and 15 millimeters above the wheel rim flange (56) of the wheel-mounted tire and between 5% and 20% of the section height SH of the tire. The chipper is disposed axially inward of the ply turnup end (58). The chipper (40) may comprise a single layer of cords (42), or the chipper (43) may comprise two layers (47, 47′) with the -cords (42, 42′) in the two layers being crossed to form mirror images across a radial reflection axis.

Abstract: A pneumatic tire constituting part or all of the part members constituting the pneumatic tire by a rubber composition containing, based on a total 100 parts by weight of a rubber containing at least 70 parts by weight of an ethylenic unsaturated nitrile-conjugated diene-based highly saturated rubber having a content of conjugated diene units of not more than 30 percent by weight, 0 to 120 parts by weight of zinc methacrylate and 0 to 60 parts by weight of carbon black and having a total of formulations of zinc methacrylate and carbon black of 10 to 120 parts by weight, and providing, between the above part members and the adjoining diene-based rubber layer, a bonding rubber layer comprising of a rubber composition containing, based on a total 100 parts by weight of a predetermined diene-based rubber and acrylonitrile butadiene copolymer rubber, 5 to 80 parts by weight of a predetermined aromatic petroleum resin.

Abstract: Runflat tires are generally made by including a stiff insert in the sidewall thereof. This insert should be as stiff as possible to help support the weight of the vehicle to which the tire is mounted in situations where there is a loss of air pressure. During periods of operation after loss of air pressure the stiff insert carries most of the load on the tire which leads to the generation of heat. Heat build-up can then lead to thermal degradation in the insert. A reduction in crosslink density and a change in the distribution of crosslink types is the result of this thermal degradation. This invention is based upon the discovery that thermal degradation in the inserts of runflat tires can be inhibited by including a bis-citraconimido compound therein as an antireversion agent.

Abstract: A pneumatic radial tire which can run in a flat tire condition comprising: a side reinforcing layer disposed on a carcass layer of the side region and having a generally crescent sectional shape; and a belt layer composed of a belt ply in which metal wire bundles (each bundle containing untwined plural metal wires arranged in parallel) are arranged planarly in parallel to each other and being spaced from each other with a distance therebetween in the tire widthwise direction, and an inner liner has a thickness of 0.1 to 0.3 mm. The light run-flat tire can run to a safe place while supporting the load of the vehicle even if the tire is punctured so that the internal pressure thereof is lowered or even becomes zero, and can effect a comfortable ride and a low rolling resistance when it is filled with a normal internal pressure.

Abstract: The run-flat tire (10) of this invention includes spaced apart bead areas (30) having a unique design to include first (34) and second (36) bead fillers adjacent a bead core (32). The second bead filler (36) is bounded by the first bead filler (34) and bead core (32). The method for manufacturing the tire to eliminate voids at the bead core (32) of the cured tire is also provided. The bead fillers are made to be resilient so that the tire can be easily mounted on a rim, particularly improving the ability to mount a run-flat tire (10) on a rim (80). The bead core (32) and fillers (34, 36) are designed for helping to sustain the run-flat tire (10) on the rim (80) with a loss of inflation pressure and to improve the running performance of the tire.

Abstract: A pneumatic radial ply runflat tire (200) has a tread (210), belt structure (212), a carcass (216), and an underlay (234) disposed between the belt structure and the carcass. The carcass (216) comprises two sidewalls (226), two beads (220), and one or more radial plies (222,224). The tire (200) is characterized by the underlay (234) having reinforcement cords (236) with turns aligned parallel to the tire's equatorial plane, the cords (236) exhibiting negligible modulus of elasticity (“modulus”) below a threshold elongation and high modulus above the threshold elongation. The underlay (234) stiffens the tire during runflat operation but not during normal inflated operation.

Abstract: Runflat tires are generally made by including a stiff insert in the sidewall thereof. This insert should be as stiff as possible to help support the weight of the vehicle to which the tire is mounted in situations where there is a loss of air pressure. During periods of operation after loss of air pressure the stiff insert carries most of the load on the tire which leads to the generation of heat. Heat build-up can then lead to thermal degradation in the insert. A reduction in crosslink density and a change in the distribution of crosslink types is the result of this thermal degradation. This invention is based upon the discovery that thermal degradation in the inserts of runflat tires can be reduced by including a 1,6-bis(N,N′-dibenzylthiocarbamoyldithio)-hexane therein as an antireversion agent.

Abstract: A pneumatic tire comprises a tread portion, a pair of sidewall portions, a pair of bead portions, and at least one carcass ply toroidally extending between a pair of bead cores and wound around the bead core to form a turnup portion, in which a reinforcing rubber having substantially a crescent shape at its lateral section is disposed at an inside of the sidewall portion and a cord reinforcing layer containing cord(s) extending in a direction of approximately 90° with respect to a radial line segment is disposed in at least a bead portion.

Abstract: A pneumatic radial ply tire (50) having a tread (52), a carcass (60) with two sidewalls (77, 78), one or more radial plies (70, 72), two annular beads (36a′, 36b′), a belt structure (56) located radially between the tread and the radial ply structure (58), a fabric underlay (54), deployed radially inward of the belt structure, and a tread insert (66) deployed between the belt structure and the fabric underlay. Said underlay (66) contains circumferentially aligned high-modulus fibers or cords (88) which, in combination with metal belt structure (56) and the tread insert (66), contribute to circumferential tread rigidity. Insert (66), in conjunction with the belt structure (56) and the radial ply structure (58), contributes to lateral tread rigidity. The circumferential and lateral stiffening of the tread (52) enhances high-speed runflat handling and contributes to improved runflat operational life.

Abstract: The invention relates to pneumatic tires for a motor vehicle comprising a multi-layer carcass. Said multi-layer carcass extends between two bead rings, a set of bracing plies provided between the layers of the carcass and a tire tread, and rubber reinforcement layers arranged in the side wall areas which support the tire when it is deflated. The invention is characterized in that a first rubber reinforcement layer is arranged radially within a first carcass layer and a second rubber reinforcement layer is arranged between the first carcass layer and a second carcass layer. The two rubber reinforcement layers extend from the bead filler area to a position under the edge area of the bracing plies. The two rubber layers vary in thickness across the height of the side walls.

Abstract: A tire having at least one crescent-shaped rubber composition as an insert in its sidewall region which is comprised of at least one diene-based elastomer, carbon black and, optionally, silica and at least one of dithiodipropionic acid, benzoic acid and salicylic acid.

Abstract: A run-flat tire comprises a tread portion, a pair of sidewall portions, a pair of bead portions with a bead core therein, a carcass ply extending between the bead portions through the tread portion and sidewall portions and turned up around the bead cores to be secured thereto, and a pair of axially spaced rigid rings each disposed inside the carcass ply in one of shoulder regions. Each of the ring is embedded in a bulge of rubber formed on the inside of the tire.

Abstract: A run-flat tire, i.e., a tire capable of running for a while even when it is flat or uninflated due to a puncture, includes a carcass ply or layer having a turned-up end which reaches one end of a belt layer underlying the tire tread. A crescent-shaped side-reinforcing rubber pad includes a outer-surface-side rubber pad and an inner-surface-side rubber pad arranged which sandwich a fibrous layer therebetween. The inner-surface-side pad, i.e., the one situated inward of the outer-surface-side pad, is thicker than the outer-surface-side pad. The upper end (the end close to the tread) and the lower end (the end close to a bead portion) of the fibrous layer extend slightly beyond the upper and lower ends of the side-reinforcing rubber pad, respectively.

Abstract: A radial ply pneumatic tire has a carcass with a bead portion, a carcass reinforcing structure, and a bead filler. The carcass reinforcing structure has at least two structures with cords which extend to each bead. In a preferred embodiment of the invention, the tire carcass includes elastomeric first and second fillers, the first filler being located between the first ply structure and the innerliner of the tire, and the second filler being located between the first and second ply structures. The fillers stiffen the sidewalls to permit the tire to be driven while uninflated. The tire further includes an aramid overlay radially outwardly of the reinforcing belt.

Abstract: A run-flat tire comprises a carcass ply extending between the bead portions, and a sidewall reinforcing layer disposed axially inside said carcass ply in each sidewall portion, wherein in a normally inflated unloaded state, a profile line from a tire equator point (P) to a maximum tire section width point (D) is curved substantially along an involute curve so as to have a radius of curvature decreasing continuously from the tire equator point towards the sidewall portion, the basic circle of the involute curve is an ellipse whose major axis extends in the tire radial direction, the radial distance (h) between the tire equator point (P) and the maximum tire section width point (D) is more than 34% but less than 50% of the tire section height (H).

Abstract: A tire having at least one crescent-shaped rubber composition as an insert in its sidewall region which is comprised of at least one diene-based elastomer, carbon black and, optionally, silica and at least one of dithiodipropionic acid, benzoic acid and salicylic acid.

Abstract: A pneumatic tire for passenger cars comprises bead cores, a carcass layer, a tread portion, and side wall portions, wherein a rubber reinforcing layer having a crescent-shaped cross-section and at least one sheet of a rubber-filament fiber composite having a thickness measured under a pressure of 20 g/cm2 of 0.05 to 2.0 mm which is formed from a rubber component and filaments having a diameter or a maximum cross-sectional dimension of 0.0001 to 0.1 mm and a length of 8 mm or more are disposed in said side wall portions. Reinforcing cords of carcass plies are made of an aliphatic polyamide fiber having a melting point of 250° C. or higher.

Abstract: A pneumatic tire has a sidewall rubber insert axially inward of at least one carcass ply. Such insert may, for example, be an apex extending radially outward from the bead core region of the tire into the tire sidewall. Alternatively, it may be positioned higher in the sidewall portion of the tire and away from the bead core. Such insert is a rubber composition containing a dispersion of an ultra high molecular weight polyethylene and a dispersion of a starch composite.

Abstract: A run-flat tire comprises a carcass composed of an inner ply and an outer ply each made of organic fiber cords, a belt disposed radially outside the carcass in the tread portion, and three sidewall reinforcing rubber layers disposed in each sidewall portion. The inner and outer carcass plies are turned up around the bead cores from the inside to the outside of the tire, and the turnup portions of the inner carcass ply extends into between the belt and the carcass so that the radially outer end thereof is secured therebetween. The sidewall reinforcing layers include: an inside layer disposed axially inside the main portion of the inner ply; a middle layer disposed between the main portion of the inner ply and the main portion of the outer ply; and an outside layer disposed axially outside the main portion of the outer ply. At least one of the sidewall reinforcing rubber layers has a radially outer end located beneath the belt.

Abstract: A pneumatic tire for a passenger car having a pair of bead portions, a toroidal carcass portion extending over both bead portions, at least two belt layers provided in a crown portion of the carcass, a tread portion positioned at an outer peripheral side of the belt layer, and side wall portions provided at the right and left sides of the tread portion, and which further includes a steel cord as a reinforcing material for reinforcing at least one layer of the carcass portion and the belt layer. The steel cord is formed by plying a plurality of filaments each having a strand diameter of 0.125 to 0.275 mm, and has an inflection point on an S—S curve. A reduction rate of a diameter of the steel cord under a load stress which is one third of breaking strength in comparison with a no load condition is equal to or more than 20%.

Abstract: A run flat tire has a plurality of reinforcing wedges located in the tire sidewall with the hardness of each wedge generally diminishing in the radially inward direction of the sidewall. Since the bead filler is harder than the radial innermost wedge, the hardness at generally the top of the bead filler increases in the radial inward direction. The reinforcing wedges partially overlap each other and can generally have any configuration. The changing of hardness of the radial wedges results in a wedge sequence and thus a more even strain distribution throughout the tire sidewall. This strain distribution extends the run flat life of the tire and also provides a good balance with other tire performance parameters.

Abstract: There is disclosed a safety pneumatic tire comprising a tire shell which is equipped with a toroidal carcass extending over a pair of bead portions and also functioning as a reinforcing material for a side wall portion connected to the bead portions and further for a tread portion, and which has a side-reinforcing layer on the internal surface of the side-wall portion; a rim which hermetically seals and supports the bead portions of the tire shell; and closed cell-based elastic foam which is filled in the internal hollow portion encompassed by the tire shell and the rim, wherein the constructional material of the elastic foam is butyl rubber or halogenated butyl rubber. The above safety pneumatic tire is markedly improved in run-flat durability, can reconcile favorable riding comfort chacteristic with the run-flat durability, is minimized in adverse influence upon the tire performances such as rolling resistance, and enables the production of a lightweight pneumatic tire.

Abstract: A tire 10 has a composite ply 40. The composite ply 40 has a primary ply 40A reinforced with parallel inextensible cords 41 and a pair of ply extensions 40B having synthetic cords. The method of manufacturing the tire 10 is described. The tire 10 can be made as a runflat type tire.

Abstract: A run-flat tire comprises a tread portion, a pair of bead portions, a pair of sidewall portions, a carcass comprising at least one carcass ply extending between the bead portions, a belt disposed radially outside the carcass in the tread portion, and a tread reinforcing layer disposed between carcass plies or alternatively between the carcass and belt, the tread reinforcing layer made of a high elastic modulus rubber compound having a complex elastic modulus E* of from 10 to 30 MPa, a thickness t of from 0.8 to 2.5 mm, and an axial width WA of 0.7 to 1.0 times the tread width TW of the tire.

Abstract: A pneumatic tire comprises a carcass of at least one rubberized ply of a radial arrangement, a belt comprised of two or more cross cord layers, a pair of thick reinforcing strip rubbers located at an inner face side of the carcass and a bead filler rubber, in which the reinforcing strip rubber and bead filler rubber have specified JIS hardness and rebound resilience, hardness ratio and maximum gauge ratio.

Abstract: A runflat radial ply pneumatic tire 10 has a carcass 30 which has a pair of sidewalls 20, each sidewall being reinforced with at least two sidewall fillers or runflat inserts 42, 46 and at least two cord reinforced plies 38, 40 and a bead core 26. The tire has one or more reinforcing belts 36. Each sidewall has at least one ply 38 or 40 reinforced with cords, the cords have a modulus E of X, X being at least 10 GPa. At least one ply has a turnup end 32 wrapped around the bead core 26. A first ply 38 or 40 is reinforced with substantially inextensible cords having a modulus E greater than X of the cords of the other ply. The second ply 38 or 40 is spaced from the first ply 38 or 40 by the second filler or runflat insert in the sidewall 20.

Abstract: A pneumatic tire (10) has a pair of sidewall portions (20), a pair of bead regions (22) and a carcass (30) reinforced with at least two sidewall fillers or inserts (42), (46) for each sidewall portion and at least one cord reinforced ply (38) and two bead cores (26) one in each bead region and a reinforcing belt structure (36). This tire is preferably a runflat radial ply tire. The at least one cord reinforced ply (38) has a pair of turnup ends (32) wrapped around the pair of bead cores (26). The turnup ends (32) each extend radially outwardly to a terminal end (33) at a radial height of at least 40% of the tire section height (SH). The first insert for each sidewall portion lies radially inward and adjacent the at least one ply (38). The second insert (46) for each sidewall portion is a bead filler insert radially above the bead core (26) and between the at least one ply (38) and its turnup end (32).

Abstract: In a pneumatic tire for run-flat running comprising a stiffener rubber, viewing a cross-section of the tire-rim assembly inflated under an air pressure corresponding to 15% of a maximum air pressure of the tire, a top of the stiffener rubber is located inward from a specified line segment PA in a radial direction of the tire.

Abstract: A runflat radial ply passenger or light truck pneumatic tire 10 has a carcass 30 reinforced with at least one sidewall insert or filler 42 and one substantially inextensible cord reinforced ply 38, the ply being wrapped about two bead cores 26 and located radially inward of a belt reinforcing structure 36. The sidewall insert or filler 42 is located radially inward of the ply 38. The cord 43 has a minimum modulus E of 10 Gpa and is generally inextensible and less heat sensitive than conventional synthetic cords used in passenger and light truck tires.

Abstract: The run-flat tire of this invention includes a pair of bead regions, a crown region with a tread and a tread reinforcing package including a cap ply and self supporting sidewalls between each bead region and the crown region. An innerliner ply maintains air within the inflated tire. The self supporting sidewalls each include a first crescent-shaped reinforcing member, an inner carcass layer, an inner sidewall supporting complex and an outer sidewall and bead protecting complex. The supporting sidewalls effectively have a plurality of crescent-shaped reinforcing members and a plurality of carcass layers. The sidewall supporting complexes are realized by providing first and second partial carcass layers along with a filler rubber portion and a second crescent-shaped reinforcing member, which can be formed by a separate tire building operation. The sidewall protecting complexes can be formed in a similar operation.

Abstract: A pneumatic tire, more particularly a run flat tire, comprises at least three radial carcass plies each extending between bead portions through a tread portion and sidewall portions, the tread portion is provided between the radially outermost carcass ply and radially inner next carcass ply with a crown reinforcing rubber layer so that at least two carcass plies are disposed radially inside the crown reinforcing rubber layer, and each of the sidewall portions is provided between the axially innermost carcass ply and axially outer next carcass ply with a side reinforcing rubber layer so that at least two carcass plies are disposed axially outside the side reinforcing rubber layer. The reinforcing rubber layers are preferably made of a low heat generation rubber having a complex elastic modulus of 8 to 15 Mpa, and a loss tangent of 0.03 to 0.08. The complex elastic modulus of the side reinforcing rubber layer is preferably less than that of the crown reinforcing rubber layer.