Bridgestone Corporation

Takaaki Kojima

Yukihiro Kiwaki

Keiichi Kato

Shungo Fujita

Soutarou Iwabuchi

Naoya Ochi

Sotaro Iwabuchi

Yusuke Nobunaga

Keigo Saito

Kenjiro Yamaya

Futoshi Oki

Kensuke Dobashi

Shu Nagai

Tire tread

Plural lug grooves are formed that extend from an outermost circumferential direction groove towards a tire equatorial plane side and are disposed sloped with respect to the tire equatorial plane at intervals along the tire circumferential direction. Arc shaped communication grooves are formed in segment land portions arising from a land portion being segmented in the tire circumferential direction by the lug grooves. The communication grooves communicate between the lug grooves adjacent to each other in the tire circumferential direction.

Pneumatic tire

A pneumatic tire which comprises a land portion () and a land portion (). A main groove () extending along the tire circumferential direction is formed between the land portion () and the land portion (). The land portion () comprises a groove wall () that forms the main groove (). The land portion () comprises a groove wall () that forms the main groove (). The groove wall () and the groove wall () are serpentine along the tire circumferential direction (R) when seen from a plane of the tread surface, and the groove width of the main groove () in the tread width direction (W) varies in a predetermined repetition interval (&#x3bb;) along the tire circumferential direction. The ratio of the minimum width (W) of the groove to the maximum width (W) of the groove satisfies a relation of 35%&#x2266;W/W&#x2266;85%.

Pneumatic tire with main groove having serpentine groove walls

A pneumatic tire comprises a tread provided with at least two circumferential main grooves and a rib defined in a tread central portion by the circumferential main grooves, wherein an auxiliary groove is formed in the tread central portion, the auxiliary groove having a circumferential groove portion extending in a tire equator direction and an axial groove portion extending from an end of the circumferential groove portion in such a manner that the axial groove portion is bent at an acute angle to the circumferential groove portion, and at least an end of the auxiliary groove is open into the circumferential main groove.

Pneumatic tire with tread having chamfered circumferential groove portion of bent auxiliary groove

A pneumatic tire comprises, in a tread portion, at least two block groups Gto Gwhose block number density is within a range of 0.003 pieces/mmto 0.04 pieces/mm. At least one block group Gincludes blockin which lateral length BWis larger that its longitudinal length BL.

A tirecomprises rib-shaped land portionsextending in a tire circumferential direction TC and has a circumferential grooveadjacent to the land portionsand extending in the tire circumferential direction TC. Tread contact surfacesof the land portionsform smooth surfaces with no gap when a normal load is applied and the tread contact surfaces are in contact with a road surface. The circumferential grooveincludes a shallow groove portionextending in the tread-width direction TW, and a deep groove portionadjacent to the shallow groove portionin the tire circumferential direction and extending in the tread-width direction. A deep groove portionis recessed more inwardly in a tire radial direction TR than the shallow groove portionwith a groove bottomof the shallow groove portionbeing an upper end of the deep groove portion

Tire having a circumferential groove including a first groove portion and a second groove portion

A pneumatic tire () comprises a tread (), side walls (), and buttress portions (). In a cross-section of the pneumatic tire () in the tread width direction (TW), if the point at which a first curved line (R) which follows the curvature of the surface of the tread () and a second curved line (R) which follows the curvature of the surface of a buttress portion () intersect is defined as an imaginary point (IP) and also if the point at which a straight line (L) passing through the imaginary point (IP) and substantially perpendicular to the carcass () intersects the surface of the pneumatic tire () is defined as an intersection point (NP), the pneumatic tire () has a recessed shoulder region (US) including the intersection point (NP) and having a predetermined width. The recessed shoulder region (US) is provided with recesses () recessed from the surface of the pneumatic tire () and also with a surface portion () in which no recess () is formed. The recessed shoulder region (US) extends in the tire circumference direction (TC).

Tire with recessed portions formed on buttress portion

A pneumatic tire () provided with: a rib-like land portion (), a rib-like land portion (), and a rib-like land portion () which are divided by circumferential grooves () extending in the circumferential direction of the tire; and resonators which are recessed inward in the radial direction of the tire, which each form a predetermined space when the rib-like land portion () makes contact with the road surface, and which communicate with circumferential grooves. The resonators include first resonators which are provided in the circumferential direction of the tire, and also include second resonators which are, when the tire is mounted on a vehicle, located further toward the inboard side than the first resonators and are arranged in the circumferential direction of the tire. The number of the second resonators is greater than the number of the first resonators.

Tire

A pneumatic tire () provided with a rib-like land portion () having first resonators formed therein, and also with a rib-like land portion () located, when the tire is mounted on a vehicle, on the side of the tire closer to the vehicle than the rib-like land portion () and having second resonators formed therein. Each of the first and second resonators includes an air chamber recessed inward in the radial direction of the tire, and also includes a narrow groove communicating with the air chamber and a circumferential groove. The volume of the air chamber of the first resonator is greater than the volume of the air chamber of the second resonator.

Growing community of inventors

Tokyo, Japan

Takaaki Kojima