US 5,427,166 A · Run-flat tire with three carcass layers

Abstract

The weight, space and convenience advantages of a run-flat tire can be substantial. This is especially true for the urban-economy car or family type vehicles which have limited space available for a spare tire and inadequate space for the removed flat tire. These vehicles also have higher comfort requirements that must be addressed. The mini-spare solution to the flat tire problem has very limited performance capabilities. Other solutions include major modifications in the rim and/or the tire, which are not cost effective or compatible with a conversion to standard tires on the same rims. The run-flat tire of this invention includes thickened sidewall portions, a belt package with a cap ply, lower sidewall rubber support portions, a specially designed bead seat area with a rim seat ply and three carcass layers. The classical problems of inflated vs. deflated performance tradeoffs in ride comfort, handling, radial stiffness and endurance of the tire are substantially improved. This is accomplished with a run-flat tire having relatively small weight increases over a standard tire and a rim that can be used interchangeably with the standard tire. The run-flat tire system of this invention is capable of maximum lateral accelerations under nominal operations of approximately 0.90 g.sup.S and extended operating efficiency (i.e., handling and durability) at higher speeds for longer distances.

Claims21

Dependent claims

A tire for mounting on a rim of a vehicle capable of sustaining vehicle loads at a contact patch in an effective manner with the loss of inflation pressure comprising:

a crown portion having a tread;
a belt package located radially inward of said tread;
an innerliner portion on the interior surface of the tire;
a pair of bead portions axially spaced apart and having a bead core and a bead filler;
a pair of axially spaced apart load bearing sidewall portions wherein each sidewall portion is disposed radially between a respective lateral edge of said crown portion of the tire and a respective bead portion, each sidewall portion having first and second crescent-shaped reinforcing members disposed outside said innerliner portion;
a middle carcass layer radially inward of the belt package and extending between each bead portion with turned-up portions from inside to outside around each bead core in such a manner to at least partially encompass said bead core and a respective bead filler;
an outer carcass layer disposed outside said middle carcass layer and each carcass turned-up portion and extending radially inward to at least a point axially outward and adjacent to each said bead core;
an inner carcass layer disposed to the inside of said middle carcass layer and extends under the crown portion then radially inward between the first member and the second member of the crescent-shaped reinforcing members in each sidewall to at least a point axially inward and adjacent to each said bead core, said carcass layers each having a plurality of substantially parallel reinforcing members and a curvilinear configuration.

5 more elements

A tire and rim system capable of sustaining vehicle loads in an effective manner with the loss of inflation pressure comprising:

a crown portion of the tire having a tread;
a pair of tire bead portions each having a bead core, a bead filler, a rim seat ply in contact with the rim, a first rubber seat portion and a second rubber toe portion located axially and radially inward of the bead core;
a tire middle carcass layer having carcass turned-up portions from inside to outside around each bead core in such a manner to at least partially encompass said core and a respective bead filler;
a tire outer carcass layer disposed outside said middle carcass layer and each carcass turned-up portion and extending radially inward to at least the radial extent of said bead core;
a pair of axially spaced apart tire load bearing sidewall portions wherein each sidewall portion is disposed radially between a respective edge of said crown portion of the tire and a respective bead portion, each sidewall portion having first and second crescent-shaped reinforcing members disposed between said middle carcass layer and an innerliner portion;
an inner carcass layer disposed inside said middle carcass layer and positioned between the first member and the second member of the crescent-shaped reinforcing members in each sidewall and extending radially inward to at least a point axially interior and adjacent to each bead core, said carcass layers each having a plurality of substantially parallel reinforcing members and a curvilinear configuration and each carcass layer being continuous from bead to bead, wherein the position of said inner carcass layer produces a stepwise radial stress distribution between said first and second crescent-shaped reinforcing members axially across the inner carcass layer on a median plane adjacent to a central radial plane of a contact patch and reduces counter deflection of a surface of the tread;
and
a rim having a hump disposed at the axially innermost end of the rim seat ply of the mounted tire, wherein said hump may engage the rim seat ply and whereas the tire remains seated on said rim of the vehicle during vehicle maneuvers as well as during straight ahead running.

5 more elements

Dependencies are inferred from the claim text.

Run-flat tire with three carcass layers

Life of this patent

Run-flat tire with three carcass layers

Life of this patent

Abstract

Claims21