Bridgestone Corporation

Yoichi Okamoto

Yoshihide Kohno

Toshiya Miyazono

Hiroyuki Koseki

Tread portion of an automobile tire

A heavy duty pneumatic radial tire comprises a radial carcass and a belt superimposed about an outer periphery of the carcass and comprised of at least three rubberized cord layers, cords of two adjacent layers among these layers being crossed with each other at an acute cord angle with respect to an equatorial plane of the tire to form cross cord layers, in which a narrow-width cord layer among the cross cord layers is provided with an end cover rubber having a particular 100% modulus and a space cushion rubber having a particular 100% modulus.

Heavy duty pneumatic radial tires with particular belt rubber configuration

A heavy duty pneumatic radial tire comprises a radial carcass extending between a pair of bead cores, and a belt comprised of three rubberized cord layers, among which cord layers an innermost cord layer and a middle cord layer being laminated to form a cross belt layer by crossing cords of these cord layers with each other with respect to a plane including a circumference of the tire, in which an inclination cord angle with respect to the plane in the innermost cord layer and the middle cord layer is within a given range, and cords in an outermost cord layer have a given inclination cord angle as measured from the plane toward a direction of measuring the inclination cord angle of the middle cord layer, and a coating rubber for the outermost cord layer has a given modulus of elasticity.

Heavy duty pneumatic radial tires with specified coating rubber of

Heavy duty pneumatic radial tires with particular belt rubber

A pneumatic tire comprises various tire components each comprised of a rubber-coated layer containing a given number of reinforcing elements. In at least one of these rubber-coated layers, not less than 30% of all reinforcing elements are divided into plural groups each comprised of a combination of m-steps and n-rows viewing in a thickness direction of the rubber-coated layer, in which each of m and n is an integer of 2 or more representing the number of the reinforcing elements, and a distance between mutually adjacent and opposite reinforcing elements not grouped with each other is wider than a distance between mutually adjacent reinforcing elements in the group.

Pneumatic tires including a tire component containing groups of

A tire component used in a pneumatic radial tire is a rubber-coated layer comprised of a given number of reinforcing elements separately arranged in parallel with each other, in which the reinforcing elements corresponding to at least 30% of all reinforcing elements included in the rubber-coated layer are divided into plural groups, and a distance between mutually adjoining and opposite reinforcing elements not grouped with each other is wider than a distance between mutually adjoining reinforcing elements separately arranged at equal spaces in the group. Thus, the occurrence of cracking at cut ends of the reinforcing elements is prevented to improve the tire durability.

Pneumatic radial tires including a tire component containing groups of

A tire component used in a pneumatic radial tire is a rubber-coated layer comprised of a given number of reinforcing elements separately arranged in parallel with each other, in which the reinforcing elements corresponding to at least 30% of all reinforcing elements included in the rubber-coated layer are divided into plural groups, and a distance between mutually adjoining and opposite reinforcing elements not grouped with each other is wider than a distance between mutually adjoining reinforcing elements separately arranged at equal spaces. Thus, the occurrence of cracking at cut ends of the reinforcing elements is prevented to improve the tire durability.

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Kodaira, Japan

Yoichi Okamoto