Pneumatic tire
AssigneeBridgestone Corporation
InventorHiroyuki Yokokura
Life of this patent
Estimating the term…
Abstract
A pneumatic tire having a reduced weight and improved durability is provided. In this pneumatic tire, at least one of the carcass ply and belt plies or the belt-reinforcement layer is constituted of reinforcing cords being para-aramid cords, and the para-aramid cords satisfy the relationship represented by the following formulae (I) to (III): E≦32.14×T−236 (I) E≧150 (II) T≦19 (III) (where E represents a modulus of elasticity (cN/dtex) at 25° C. under a load of 49 N, and T represents a tensile strength (cN/dtex)).
Claims9
A pneumatic tire comprising a pair of left and right annular bead portions, a pair of left and right side walls connected to the bead portions, a tread provided between the side walls, a reinforcing carcass layer composed of at least one toroidal carcass ply extending between the bead portions, and a reinforcing belt layer composed of two or more belt plies arranged on the outer periphery of crown of the carcass layer, wherein
- the carcass ply is a rubber coated fabric obtained by arranging para-aramid cords in parallel, and the para-aramid cords satisfy the relationship represented by the following formulae (I) to (III):
- E≦32.14×T−236 (I)
- E≧150 (II)
- T≦19 (III)
- (where E represents a modulus of elasticity (cN/dtex) at 25° C. under a load of 49 N, and T represents a tensile strength (cN/dtex)).
A pneumatic tire comprising a pair of left and right annular bead portions, a pair of left and right side walls connected to the bead portions, a tread provided between the side walls, a reinforcing carcass layer composed of at least one toroidal carcass ply extending between the bead portions, and a reinforcing belt layer composed of two or more belt plies arranged on the outer periphery of crown of the carcass layer, wherein
- at least one of the belt plies is a rubber coated fabric obtained by arranging para-aramid cords in parallel so that the para-aramid cords are at an oblique angle with respect to the equator of the tire, the remaining belt ply is a rubber coated fabric obtained by arranging steel cords in parallel so that the steel cords are at an oblique angle with respect to the equator of the tire and that the steel cords cross the para-aramid cords, and the para-aramid cords satisfy the relationship represented by the following formulae (I) to (III):
- E≦32.14×T−236 (I)
- E≧150 (II)
- T≦19 (III)
- (where E represents a modulus of elasticity (cN/dtex) at 25° C. under a load of 49 N, and T represents a tensile strength (cN/dtex)).
A pneumatic tire comprising a pair of left and right annular bead portions, a pair of left and right side walls connected to the bead portions, a tread provided between the side walls, a reinforcing carcass layer composed of at least one toroidal carcass ply extending between the bead portions, and a reinforcing belt layer composed of two or more belt plies arranged on the outer periphery of crown of the carcass layer, as well as a belt-reinforcement layer consisting of rubber coated fabric obtained by arranging reinforcing cords substantially in parallel with the circumference of the tire, in which a cap layer is positioned on a tire radial outer side of the belt layer so as to cover the full width of the belt layer and/or layering layers are positioned at both ends of the belt layer, wherein
- the reinforcing cords constituting the belt-reinforcement layer are para-aramid cords, and the para-aramid cords satisfy the relationship represented by the following formulae (I) to (III):
- E≦32.14×T−236 (I)
- E≧150 (II)
- T≦19 (III)
- (where E represents a modulus of elasticity (cN/dtex) at 25° C. under a load of 49 N, and T represents a tensile strength (cN/dtex)).
Dependencies are inferred from the claim text.