Bridgestone Corporation

Atsushi Miyasaka

Yasuo Himuro

John J Regallis

Sotaro Iwabuchi

Shungo Fujita

Yuichiro Ogawa

Daita Itoi

Francis J Byrne

Makoto Tsuruta

Richard J Wright

Masashi Yamaguchi

Arata Tomita

Hajime Nakamura

Naota Yamagishi

Richard W Gillmore

Yasuo Osawa

Syu Nagai

Seiichirou Kawai

A tire including a pattern region and plural unit patterns. The pattern region is formed at an outer surface of a tire and includes a base. The plural unit patterns are formed within the pattern region, and each unit pattern is formed including extension portions having a projection height from the base of from 0.1 mm to 1.0 mm. The extension portions extend in plural directions from a bend point in plan view. A spacing between the bend points of adjacent unit patterns out of the unit patterns is from 0.2 mm to 1.0 mm.

Tire

A tire includes an annular decoration printing portion, at least a portion thereof being provided on an outer surface of a side portion further toward a tire radial direction outer side than a tire maximum width position. The decoration printing portion includes an annular design portion and an annular gradation portion provided at least on the tire radial direction outer side of the design portion. The gradation portion incrementally decreases in value outward in the tire radial direction, with a value of 100% being a pure color and a value of 0% being pure black in an HSV color space.

Pneumatic tire

The present invention includes a run-flat tirecomprising a plurality of turbulence generation ridgeswhich extend on a surface of a tire side portionin a tire-radial direction and which are arranged at a pitch in a tire-circumferential direction and relationship Si&#x3e;So is satisfied. Si is the sum of sidewall areas of all the turbulence generation ridges located at the inner side, in the tire-radial direction, of a maximum width position of the pneumatic tire. So is the sum of sidewall areas of all the turbulence generation ridges located at the outer side, in the tire-radial direction, of the tire maximum width position.

A pneumatic tireaccording to the present invention includes a plurality of turbulence generation ridgeswhich extend on a surface of a tire side portionin a tire-radial direction and which are arranged at a pitch in a tire-circumferential direction. A protrusionrising from the surfaceof the tire side portionis formed in the tire side portion. Either an inner end portionA of the turbulence generation ridgeor an outer end portionB of turbulence generation ridgeis smoothly continuous to a surface of the protrusion. An inner end height (H), which is a height of the inner end portionA from the surfaceof the tire side portion, is larger than an outer end height (H), which is a height of the outer end portionB from the surfaceof the tire side portion

Sidewall portion of an automobile tire

A pneumatic tire having a tread surface provided with a plurality of circumferential grooves and lateral grooves each having one end opened into that circumferential groove and the other end terminating in a land portion. At least one lateral groove is always included completely in the ground contact surface of the tread. The groove width of the lateral grooves is at least locally not less than 30% of the groove width of the circumferential grooves. Each lateral groove has an extending length not less than 40% of an extending length of the circumferential grooves in the ground contact surface and is provided with a region having a cross-sectional area which increases from its side of opening into the circumferential groove toward its terminal end, and including a starting end with a minimum cross-sectional area that is situated closer to the circumferential groove in which the lateral groove opens.

A pneumatic tire has a tread pattern wherein a circumferential groove continuously extending in a circumferential direction is formed in at least a first half part of a treading face within a range of 10-30% of a treading face width from an end of the treading face and a plurality of curvedly slant grooves extending from the circumferential groove toward a side of a central part of the treading face so as to make an angle at an acute angle side with respect to the circumferential direction gradually small away from the circumferential groove are arranged at intervals in the circumferential direction, in which a land row consisting of tapered land portions defined between the circumferentially adjoining curvedly slant grooves and having a width gradually decreased toward the side of the central part of the treading face is formed in the treading face, and sipes linearly extending at two large and small inclination angles with respect to the circumferential direction without crossing with each other are alternately arranged in the circumferential direction, and first type of the sipes has an angle at the acute angle side with respect to the circumferential direction of 75-90&#xb0; and second type of the sipes has an angle at the acute angle side of 30-60&#xb0;.

Pneumatic tire with tread having first type of sipes and second type of sipes

Tire sidewall

A pneumatic tire having improved wet performance without sacrificing steering stability. A pair of central circumferential main groovesand a pair of side circumferential main groovesare arranged on a tread, to obtain a fundamentally high level of wet performance. A plurality of central land portion row lateral groovesis formed at both sides of a central land portion rowto be spaced away from each other substantially at a constant distance, to enhance wet performance. Central land portion row chamfer portionsare formed at obtuse angle portions of the central land portion row. The central land portion row chamfer portionsdrain water between a tread surface and a ground-contact surface into the respective central circumferential main groovesadjacent thereto, whereby wet draining performance is enhanced. Drainage is conducted by the central land portion row chamfer portions, so that it is unnecessary to use multiple central land portion row lateral grooves, thus making it possible to secure land portion rigidity of the central land portion row, and also steering stability.

Pneumatic tire with tread including chamfer portions

Tread portion of an automobile tire

To provide a pneumatic tire for a motorcycle in which both wear resistance and wet steering stability can be attained. Since a pair of zigzag circumferential direction groovesare positioned at the center of a tread central regionC and has an amplitude, even when a certain camber angle is exceeded, an occurrence of a sudden separation of the zigzag circumferential direction groovefrom a road-contact surfacecan be prevented, whereby deterioration of wet steering stability can be suppressed. When the camber angle increases, water in a road-contact surfaceis drained by inclining grooveswhich are arranged at an external side of the zigzag circumferential direction groove. Since sharp inclining groove portionsA of the inclining groovesare positioned in the tread central regionC, and no lug groove components are employed, circumferential direction rigidities of land portions in the tread central regionC are high and exhibits excellent wear resistance. Since loose inclining groove portionsB and sub-inclining groovesof the inclining groovesare positioned in tread side regionsS, rigidities of land portionsresisting to inputs at the time of a large camber angle are high, and accordingly, wear resistance is high.

Growing community of inventors

Kodaira, Japan

Atsushi Miyasaka