Sumitomo Rubber Industries Limited

Saneto Saitou

Hiroyuki Noma

Masaharu Ono

The present invention relates to a radial tire and a radial tire-rim assembly. The radial tire (1) has a pair of beads (2), each bead having a bead core (3) and a bead apex (5), a carcass (4), with both edges thereof folded back around said bead core and fastened to said bead core, a tread (6), a belt layer (7), and an aspect ratio smaller than 60%. The tread is wider (in the axial direction) than the maximum width of said carcass and the edges of said tread are positioned within a range of 50-100% of the height of the cross-section of the carcass. This structure provides the tire side with rigidity and permits the tread to deform so that is supports the weight of the car and runs safely even when the tire pressure is decreased. The radial tire-rim assembly is characterized in that the bead of the radial tire has a toe (9) extending inward (in the radial direction of the tire) and is further provided with a hump groove (10) corresponding paramently,, the rim (20 ) has an annular groove (22) and hump (23) which fit into the toe and groove, respectively. These arrangements prevent the bead from separating from the rim when the tire pressure is decreased or at a time of sharp cornering.

Radial tire which runs safe after a loss of tire pressure

The present invention relates to a radial tire and a radial tire-rim assembly. The radial tire (1) has a pair of beads (2), each bead having a bead core (3) and a bead apex (5), a carcass (4), with both edges thereof folded back around said bead core and fastened to said bead core, a tread (6), a belt layer (7), and an aspect ratio smaller than 60%. The tread is wider (in the axial direction) than the maximum width of said carcass and the edges of said tread are positioned within a range of 50-100% of the height of the cross-section of the carcass. This structure provides the tire side with rigidity and permits the tread to deform so that it supports the weight of the car and runs safely even when the tire pressure is decreased. The radial tire-rim assembly is characterized in that the bead of the radial tire has a toe (9) extending inward (in the radial direction of the tire) and is further provided with a hump groove (10). Correspondingly, the rim (20) has an annular groove (22) and hump (23) which fit into the toe and groove, respectively. These arrangements prevent the bead from separating from the rim when the tire pressure is decreased or at a time of sharp cornering.

Wide tread radial tire-rim assembly with bead-rim interlock

A safety tire having a carcass turned up in both edges around bead cores, a tread thereon, a belt, a pair of bead apexes, wherein, in a state that the tire is assembled on a specified rim and inflated to a specified pressure, the aspect ratio of the tire is not more than 80%, the axial width WT of the tread is greater than the maximum width WC of the carcass, each edge of the tread is positioned at a height within a range of 50 to 100% of the sectional height HC of the carcass, the carcass provided on each side of the tire equator with a convex arc part with a radius R1 and a concave arc part with a radius R2 smoothly connected each other at an inflection point therebetween, the convex arc part has the center positioned inward of the tire and is extended radially inwardly from the point of the maximum width WC of the carcass to the inflection point, the concave arc part has the center positioned outward of the tire and is extended radially inwardly from the inflection point to the vicinity of a contact point at which the carcass contacts with the bead core, and the radius R2 of the concave arc part is greater than the radius R1 of the convex arc part.

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Hyogo, Japan

Saneto Saitou