Abstract: Runflat tire construction is optimized for tire ride comfort by reducing tire wall gauges in the tread-shoulder-to-upper-sidewall transition region and compensating with supporting sidewalls that constantly increase in thickness (gauge) from the transition region to a bead/flange area where a chafer extends above a wheel rim flange. Thus the bead and lower sidewall area are reinforced to a maximum and the shoulder area gets only the minimum stiffness necessary to achieve the required runflat performance. Within the context of wall gauges that constantly increase from the transition region to the bead/flange area, a mid-sidewall gauge ratio MSGR, being equal to a mid-sidewall gauge G2 divided by a shoulder gauge G1, is approximately within the range of 1.1 to 1.4, preferably approximately equal to 1.3; and a bead/flange gauge ratio BFGR, being equal to a bead/flange gauge G3 divided by a shoulder gauge G1, is approximately within the range of 1.5 to 1.8, preferably approximately equal to 1.7.

Abstract: Runflat tire construction is optimized for tire ride comfort by reducing tire wall gauges in the tread-shoulder-to-upper-sidewall transition region and compensating with supporting sidewalls that constantly increase in thickness (gauge) from the transition region to a bead/flange area where a chafer extends above a wheel rim flange. Thus the bead and lower sidewall area are reinforced to a maximum and the shoulder area gets only the minimum stiffness necessary to achieve the required runflat performance. Within the context of wall gauges that constantly increase from the transition region to the bead/flange area, a mid-sidewall gauge ratio MSGR, being equal to a mid-sidewall gauge G2 divided by a shoulder gauge G1, is approximately within the range of 1.1 to 1.4, preferably approximately equal to 1.3; and a bead/flange gauge ratio BFGR, being equal to a bead/flange gauge G3 divided by a shoulder gauge G1, is approximately within the range of 1.5 to 1.8, preferably approximately equal to 1.7.

Abstract: A pneumatic radial ply tire (50) having a tread (52), a carcass (60) with two sidewalls (77, 78), two 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), one or more circumferentially deployed high-modulus incompressible belt reinforcements (66) and/or two or more circumferentially deployed high-modulus tensile-stress-bearing fabric reinforcements (59). Belt reinforcement(s) (66) and/or fabric reinforcement(s) (59) work to increase the lateral and circumferential rigidity of the tread (52) and underlying structures of the carcass (60). The lateral and circumferential stiffening of the tread (52) enhances high-speed runflat handling and contributes to improved runflat operational life.

Abstract: A radial ply runflat 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′), and a belt structure (56) located radially between the tread and the radial ply structure (58). The tread has laterally disposed tread ribs (64a,64b) whose contours are defined by circular curves intersecting nontangentially with the circular curve that defines the contour of the central portion of the tread. Each sidewall portion (77,78) has a rib (63a,63b) that is out of contact with the road during normal inflation operation and that engages the road during runflat operation. The tread ribs (64a,64b) are separated from the respective sidewall ribs (63a,63b) by decoupling grooves (65a,65b) which overlie the point of nontangential intersection of the circular curves that define the respective contours of the sidewall ribs and the laterally disposed tread ribs.

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 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 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.