Sumitomo Rubber Industries Limited

Kabushiki Kaisha Kobe Seiko Sho

Tetsuya Yamamoto

Takashi Okada

Maki Hamaguchi

Tetsuo Suzuki

Yasuo Hirano

Hideki Yamamuro

Hiroshi Chosokabe

Tatsuhiko Iwa

Takeshi Watase

A pneumatic tire includes a tread portion, a pair of sidewall portions, a pair of bead cores, a carcass layer, a pair of first bead apex rubber components, and a belt layer disposed outward of the carcass layer. In an unloaded condition where the tire is mounted onto a standard rim and inflated with an internal pressure at 50 kPa, the carcass layer has a profile that includes an outer side portion extending from a position (A) where the carcass layer separates from the belt layer to a maximum width position (B) of the carcass layer, and the pair of outer side portion is located outside a virtual arc (C) having a single radius (R) of curvature passing through the position (A), the maximum width position (B), and an outermost ends in the tire radial direction of one of the pair of first bead apex rubber components.

Pneumatic tire

The tire includes a tread portion having circumferential grooves extending in a tire circumferential direction and land regions demarcated by the circumferential grooves. The circumferential grooves include a first circumferential groove and a second circumferential groove adjacent to the first circumferential groove and having a width larger than the first circumferential groove. The land regions include a first land region demarcated between the first circumferential groove and the second circumferential groove. The first land region has lateral grooves extending in a tire axial direction and lateral sipes extending in the tire axial direction and each having a width smaller than that of each of the lateral grooves. A total value of the widths of the lateral grooves and the lateral sipes connected to the second circumferential grooves is smaller than a total value of the widths of the lateral grooves and the lateral sipes connected to the first circumferential grooves.

Tire

A tire comprises a tread portion provided with a tread profile. The axial distance Lfrom the tire equator to a contact point Pbetween the tread profile and a tangential line thereto at which the angle &#x3b8; of the tangential line becomes 3 degrees with respect to the tire-axial-direction line, is smaller than 65% of a half tread width Tw. The difference (&#x3b8;&#x2212;&#x3b8;) of an angle &#x3b8;of the tangential line at an axial position Papart from the tire equator by 90% of the half tread width Tw, from an angle &#x3b8;of the tangential line at an axial position Papart from the tire equator by 60% of the half tread width Tw, is in a range from 7 to 12 degrees.

A pneumatic tire includes a tread portion having a pair of central block rows arranged on both sides of a tire equator. Each of the central block rows includes a plurality of central blocks arranged in a circumferential direction of the tire. Each of the central blocks includes a ground contacting face with an axially inner block edge facing the tire equator. The inner block edge includes a first inclined edge and a second inclined edge inclined in an opposite direction to the first inclined edge so that the inner block edge protrudes toward the tire equator. The first inclined edge includes a first circular arc portion with a center located on the side of the tire equator.

Tire for automobile

A carbon substrate is prepared from a molded article of thermosetting resin by heat-treating in an inert atmosphere. The resin is characterized in that the content of Fe, Al, Ni, Co, Cr, and Mg insoluble in the resin is less than 1 ppm each and the content of Ca and Si insoluble in the resin is less than 2 ppm each. The thermosetting resin is further characterized in that the water content is less than 3 wt % and the ratio of the methylene carbon (CH.sub.2) connected to the hydroxyl group (OH) is less than 3% (based on the total carbon number). The carbon substrate prepared in this manner is almost free of defects and voids. It is suitable for use as the substrate of magnetic recording medium. The thermosetting resin may be a powdery or granular one which fluidizes and then cures on heating. A molded article of thermosetting resin is prepared by introducing the resin melt into a mold and curing it with heating under pressure. It is subsequently heat-treated in an inert atmosphere to give a molded article of glass-like carbon.

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Kobe, Japan

Tetsuya Yamamoto