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US 4,262,724 AGranted
Low pressure and run-flat warning system for a pneumatic tire
AssigneeUniroyal, Inc.
InventorBerge Sarkissian
Life of this patent
Estimating the term…
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AssigneeUniroyal, Inc.
InventorBerge Sarkissian
Estimating the term…
A pneumatic run-flat insert for a pneumatic tire is provided with circumferential sections having different radii. During vehicle operation in a run-flat condition the different insert radii cause a vibratory disturbance at a wheel axle that alerts the driver of the existence of a run-flat condition or an abnormally low-pressure condition in the tire. During normal driving conditions there is clearance between the insert and the tire liner and no warning vibrations will occur in the wheel axle. In various embodiments of the invention the different insert radii correspond to two or more ply sections in an insert ply having different cord angles. A relatively high cord angle ply section will furnish a relatively larger radius than the ply section with a relatively low cord angle. In further embodiments of the invention a pneumatic or non-pneumatic run-flat insert includes one or more bumps on the insert crown formed of rubber strips for example that furnish the insert with an out-of-round condition that causes a similar vibrating disturbance to warn the driver of a low-tire pressure or run-flat condition.
A pneumatic insert for a pneumatic tire wherein the tire and insert are arranged to be supported on a wheel rim having an axis of rotation and an annular support surface, said insert comprising a generally toroidal-shaped hollow member with a pair of sidewall portions and a crown portion joining the sidewall portions, said insert further including an axis of rotation substantially coaxial with said wheel axis and an equatorial plane perpendicular to said insert axis, said insert being formed of at least one annular ply of cord material comprising at least two sections of predetermined circumferential extent joined together such that one of said sections is a continuation of the other said section, said one section having cords at a first bias angle only with said equatorial plane and said other section having cords at a second bias angle only with said equatorial plane, said first and second bias angles being dissimilar to furnish said insert crown with an out-of-round condition wherein the radial distance from the wheel axis to the insert crown at said one section is unequal to the radial distance from the wheel axis to the insert crown at said other section, said inequality being governed by the difference in bias angle of the cords in the first and second insert ply sections.
Dependencies are inferred from the claim text.