Sumitomo Rubber Industries Limited

Tomoyuki Kujime

Hiroshi Okagawa

Minoru Nishi

Naoki Sugiyama

Koji Matsuura

Kosuke Nakano

A tire comprises a tread portion provided with two circumferential grooves disposed one each side of the tire equator and extending continuously in the tire circumferential direction, and a shoulder land region defined on the axially outside of each of the two circumferential grooves. The shoulder land region is provided with oblique grooves inclined with respect to the tire axial direction. The oblique grooves include first oblique grooves having axially inner ends, and second oblique grooves having axially inner ends positioned axially outside the axially inner ends of the first oblique grooves.

Tire

A tire includes an outboard tread edge and an inboard tread edge to be located on an outboard side and an inboard side of a vehicle, respectively, circumferentially and continuously extending main grooves, and land portions divided by the main grooves. The land portions include an outboard shoulder land portion, an outboard middle land portion, an inboard shoulder land portion, and an inboard middle land portion. Each of the outboard shoulder land portion, the inboard shoulder land portion, and the inboard middle land portion is provided with axially extending lateral grooves. The outboard middle land portion is provided with outboard middle lateral grooves extending from an edge of the outboard middle land portion on the outboard tread edge side toward the inboard tread edge. The outboard middle lateral grooves are inclined with respect to a tire circumferential direction at angles smaller than those of the lateral grooves.

A tire comprises a tread portion provided with two circumferential grooves disposed one each side of the tire equator and extending continuously in the tire circumferential direction, and a crown land region between the two circumferential grooves. The crown land region is provided with first crown sipes extending from one of the circumferential grooves and terminating within the crown land region, and second crown sipes extending from the other circumferential groove and terminating within the crown land region.

The pneumatic tire comprises a tread portionprovided with first sipesand second sipesand having a first tread half portionand a second tread half portion. The first sipesare smoothly continued from a crown land regionin the second tread half portionto a shoulder land regionin the first tread half portionthrough a crown main grooveand a shoulder main groove. The second sipesextend from the crown land regionin the second tread half portiontoward a second tread edge Te

Pneumatic tire

A pneumatic tire includes a tread portion provided with a crown land region and middle land regions provided with only sipes, and shoulder land regions provided with shoulder rug grooves and connecting sipes. The tread portion is provided with a crown tread profile having a radius of curvature, a middle tread profile having a radius of curvature, and a shoulder tread profile having a radius of curvature which satisfy a magnitude relation Rc&#x3e;Rm&#x3e;Rs. First interconnecting positions at which the crown tread profile connects with the middle tread profiles are positioned in the respective middle land regions. Second interconnecting positions at which the middle tread profiles connect with the shoulder tread profiles are positioned in the respective shoulder land regions and axially inside the inner ends of the shoulder rug grooves.

A run-flat tire comprises a tread portion, sidewall portions, bead portions, and a carcass ply extending between the bead portions. The sidewall portions are each provided therein with a sidewall reinforcing rubber layer having a crescent-shaped cross sectional shape and disposed on the axially inside of the carcass ply. The sidewall portions are each provided in the axially outer surface thereof with a rim protector which projects radially outward most on the radially outside of the radially inner edge of the sidewall reinforcing rubber layer. The bead portions are each provided therein with an axially inside core and an axially outside core between which each radially inner edge portion of the carcass ply is secured. When measured along a normal line drawn normally to the carcass ply from an apex of the rim protector, the thickness of the sidewall reinforcing rubber layer is in a range of from 29% to 35% of the thickness of the tire.

Run-flat tire

A vehicle tire includes a tread portion provided in the tread surface with a circumferentially continuously extending groove having a bottom and a pair of opposite side walls, wherein at least one of the side walls is provided with protrusions protruding into the groove and arranged in the tire circumferential direction. The protrusion has a gradually increasing part in which the area of the cross section of the protrusion being parallel with the tread surface is gradually increased toward the radially outer side of the tire.

A pneumatic tire comprises a carcass formed of a carcass ply extending between a pair of bead portions in a toroidal shape, and a bead core disposed in a respective one of the bead portions, the bead core comprising an axially inner core and an axially outer core respectively disposed on an axially inner side and the axially outer side of the carcass ply. The bead portion comprises an inner bead apex rubber extending radially outward from the inner core, and an outer bead apex rubber extending radially outward from the outer core. An outer apex height Ho from a bead base line to a outer end of the outer bead apex rubber is in a range of from 120% to 150% of an inner apex height Hi from the bead base line to the outer end of the inner bead apex rubber.

Tire for automobile

A pneumatic tire having a designated orientation for mounting to a vehicle includes a tread, sidewalls, beads including bead cores, respectively, and a carcass including a carcass ply. Each bead includes a rubber apex, an outer bead and an inner bead, the rubber apex includes an outer apex portion and an inner apex portion, the outer apex portion includes a first outer apex portion positioned inward from the carcass ply in the axial direction and a second outer apex portion positioned outward from the carcass ply in the axial direction, the inner apex portion includes a first inner apex portion positioned inward from the carcass ply in the axial direction and a second inner apex portion positioned outward from the carcass ply in the axial direction, and the second outer apex portion has height which is greater than height of the second inner apex portion in the radial direction.

A pneumatic tire has a tread portionprovided with: an outboard shoulder main grooveand an outboard crown main grooveextending circumferentially of the tire; first outboard shoulder axial groovesextending from an outboard tread edge Teo to the outboard shoulder main groove; second outboard shoulder axial groovesextending from the outboard tread edge Teo and terminating without reaching to the outboard shoulder main groove; first outboard middle axial groovesextending from the outboard shoulder main grooveand terminating without reaching to the outboard crown main groove; and second outboard middle axial grooveextending from the outboard crown main grooveand terminating without reaching to the outboard shoulder main groove. The first outboard middle axial groovesare aligned with the first outboard shoulder axial grooves, respectively, so as to smoothly continue to the first outboard shoulder axial groovesthrough the outboard shoulder main groove

A middle land portion includes middle sipes and middle lateral grooves. A shoulder land portion includes shoulder lateral grooves and shoulder sipes. A ratio Ems/Ema is smaller than a ratio Ess/Esa. Ems denotes a total of elements of edge lengths of the middle sipes in an axial direction of the tire. Ema denotes a total of elements of edge lengths of the middle sipes and the middle lateral grooves in the axial direction. Ess denotes a total of elements of edge lengths of the shoulder sipes in the axial direction. Esa denotes a total of elements of edge lengths of the shoulder sipes and the shoulder lateral grooves in the axial direction.

Growing community of inventors

Kobe, Japan

Tomoyuki Kujime