Abstract:
The bead durability of the heavy duty pneumatic radial tire for truck and bus is improved by arranging a rubber stock composed of three rubbers A, B and C each having particular properties between a carcass ply and its turnup portion in the bead portion and/or rendering the turnup portion of the carcass ply in the bead portion into a particular arrangement.
Abstract:
A radial tire for motorcycle has a belt layer of cords with modulus of elasticity of 600 kg/mm.sup.2 or more wound spirally on a carcass nearly parallel to the tire equator, and a bead apex rubber disposed on a bead core between a carcass main portion extending from a tread to a bead core and a carcass turned up portion. The bead apex rubber consists of a soft apex part SA with JISA hardness of 50 to 60 degrees extending radially outward from the bead core, and a hard apex part HA with JISA hardness of 70 to 95 degrees extending radially outward from the soft apex part SA. A height h1 the soft apex part SA from a bead base is 0.20 to 0.40 times a height h0 of the tread end, and a height h2 of the hard apex part HA is 0.50 to 1.25 times the height h0 of the tread end.
Abstract:
Highly durable, lightweight tires of a pneumatic radial type for passenger cars are constructed with a tread portion having on its outer peripheral surface a plurality of grooves arranged circumferentially of the tire and a belt layer formed from an array of steel cords and disposed in the tread. Each of the steel cords results from twisting a selected number of steel filaments each of specified contents of C, Si and Ni and has a specified level of tensile strength. The distance of rubber from a bottom end of each of the grooves to an outer surface of the steel cord array is defined to be of a specified range as determined cross-sectionally of the tire.
Abstract:
A heavy duty high speed cross ply tire has a carcass composed of at least one aromatic polyamide fiber cord ply, the product T.sqroot.D of the cable twist number T (turns/10 cm) of the belt cord and the square root of the total denier number D (deniers) of the cord is 2.466.times.10.sup.3 to 3.036.times.10.sup.3 and the elongation E (%) at breakage of the belt cord divided by the total denier number D is 7.78.times.10.sup.-4 to 12.22.times.10.sup.-4.
Abstract:
A rubber composition for the manufacture of automotive vehicle tires suitably as a bead filler therefor. The composition comprises specified proportions of carbonblack, a modified novolak phenolic resin, hexamethylenetetramine and a polymeric cardanol based on a starting rubber component such that the resulting rubber composition has a relatively low rigidity prior to vulcanization and a relatively high dynamic modulus after vulcanization.
Abstract:
A pneumatic tire comprises a radial carcass of at least one carcass ply wound around each of bead cores from inside toward outside to form a turnup portion, an outer ply inclusive of the turnup portion containing cords each having a modulus of elasticity of not less than 2500 kg/mm.sup.2 and a diameter d, and a rubber stiffener arranged at its radially inward portion between the carcass ply and the outer ply. In a bead structure of such a pneumatic tire, the stiffener is divided into an inner stiffener portion and an outer stiffener portion around a specified boundary plane, and each of these stiffener portions is comprised of rubber having a given Shore A hardness, and a volume ratio of the outer stiffener portion in the stiffener is not less than 10%.
Abstract:
The invention is directed to a tire for mounting on the wheel rim of a vehicle. The tire comprises a pair of bead portions each reinforced by a bead hoop, at least one bead portion of the tire having an additional retention zone positioned axially inwards of and integral with the main bead portion, the retention zone having an axially inner tip or toe substantially inwards of the main bead portion and the construction of the bead portion and the additional retention zone between the bead hoop and tip providing substantial resistance to compressive forces therebetween. The portion between the bead hoop and the tip can include reinforcement and can comprise an elastomeric material having a hardness of 80 to 95 degrees I. R. H. The tip is formed from an elastomeric material having a set property at 70.degree. C. of greater than 40% so that when the tip is fitted to a wheel rim having sharp teeth in the region contacted by the tip, the material of the tip engages the teeth. The tip may be provided by means of a strip of material positioned at the axially and radially innermost point of the tire toe. The tire can also comprise a chafer layer extending around the outer periphery of the bead in which case the strip of material providing the tip is positioned on the outside of the chafer.
Abstract:
A pneumatic radial tire having a rubber sheet incorporated in a region lying between a bead core and at least an outer surface portion of the bead portion which is in contact with a rim on which the tire is mounted, to suppress the noise generation. The rubber sheet has a dynamic modulus of elasticity at 20.degree. C., E'(20.degree. C.), of 6.0 MPa to 14.0 MPa and a ration of the dynamic modulus E'(20.degree. C.) to a dynamic modulus of elasticity at 60.degree. C., E'(60.degree. C.), namely E'(20.degree. C.)/E'(60.degree. C.), of at least 1.2 but less than 1.4.
Abstract:
A radial tire for high load which possesses excellent vibration damping performance, wherein a carcass cord reinforcing layer composed of fiber cords laid at a bias angle of between 30 and 90 degrees with respect to the radial direction of the tire is arranged adjacent to a carcass ply of a radial arrangement so that both edges thereof in the radial direction overlap with a belt and a bead reinforcing layer respectively by a certain amount.
Abstract:
A high speed tire for heavy duty vehicles includes a carcass in a radial structure, a belt layer, tapered bead apex rubbers, side packing rubbers of small thickness, and side wall rubbers. The carcass has a main body part extending from a tread part through side wall parts to a bead core in each of two bead parts, and folding-back parts each being folded back around the bear core at each edge of the main body. Each of the bead apex rubbers extends outward in the radial direction between the main body part and the folding-back part from the bead core. Each of the side packing rubbers is disposed along the outside surface in the tire axial direction of the carcass. Each of the side wall rubbers covers the packing rubber and extends from the bead part to the side wall part so as to form the outside surface of the tire. Furthermore, the 100% modulus MP of the side packing rubber is 53 to 95 kg/cm.sup.2, the 100% modulus MA of the bead apex rubber is 78 to 120 kg/cm.sup.2, the 100% modulus MS of the side wall rubber is 14 to 50 kg/cm.sup. 2, and these 100% modulus MP, MA, MS are in the relation of MS