Sumitomo Rubber Industries Limited

Fumikazu Yamashita

Yasuaki Kuniyasu

Akio Yamamoto

Tadao Matsumoto

Takaaki Ishida

Hiroaki Ninomiya

Kenji Tagashira

Yasutaka Iwata

Mitsushige Idei

Yurie Tanami

Kentaro Yagyu

Akira Kamigoro

Shingo Umekita

In the tire, fillersare layered over clinchesin portions outward of a carcassin the axial direction. A carcass plyis turned up around cores. Turned-up portionsare disposed between the fillersand apexes. Each clinchhas a maximum thickness Tcx that is measured along a line normal to an inner surface, in the axial direction, of the clinch. A ratio of a thickness Tfof the fillerto a sum of the thickness Tfand the thickness Tcx is greater than or equal to 0.1 and not greater than 0.6. A percentage of a complex elastic modulus E*f of the fillerrelative to a complex elastic modulus E*a of the apexis greater than or equal to 70% and not greater than 125%.

Pneumatic tire

A pneumatic tire comprises a sidewall reinforcing rubber disposed axially inside the carcass in each of the sidewall portion, and in order improving the ride comfort during normal running without deteriorating runflat performance, the axially inner surface of the sidewall reinforcing rubber is provided with a circumferentially extending groove. When the tire is deflated, the groove in the ground contacting patch is closed and the sidewall reinforcing rubber supports the tire load. When the tire is inflated-normally, as the sidewall portion can be bent around the groove, the ride comfort is improved.

Runflat tire

A runflat tire having an improved ride comfort performance without impairing the runflat durability, and comprising a carcassand sidewall-reinforcing rubber layershaving a crescent-shaped cross section disposed axially inward of carcassin sidewall portion, wherein each sidewall-reinforcing rubber layercomprises at least a radially outermost first rubber portionand a second rubber portionwhich is contiguous to the first rubber portionand extends toward a bead portion, and the second rubber portionhas a complex modulus E*of at least 1.1 times the complex modulus E*of the first rubber portion

Pneumatic tire for passenger cars having specified harshness factor

A pneumatic tire, which is improved in high speed durability, maintaining the required tread rubber thickness for mud and snow tires, is disclosed. The tire comprises a radial carcass and a belt including a breaker. The breaker comprises an inner ply and an outer ply, each composed of steel cords laid at an angle of 16 to 26 degrees to the tire equator. The outer breaker ply has a width WB2 of 0.7 to 0.75 times the tire cross sectional width TW. The inner breaker ply has a width WB1 of 1.03 to 1.10 times said width WB2 of the radially outer breaker ply. The tread profile comprises a crown portion defined by a circular arc having a single radius Rc of curvature of 1.4 to 2.6 times the tire cross sectional width TW and having the center on the tire equatorial plane, and a pair of tread shoulder portions continuing from the axially outer ends of said tread crown portion, each defined by a circular arc having a single radius Rs of curvature of 0.10 to 0.20 times the tire cross sectional width TW. The tread rubber thickness Ts at the axially outer edges of the radially outer breaker ply to a tread rubber thickness Tc at the tire equator being 0.7 to 0.9. The tread portion is provided with a block pattern comprising circumferential grooves having a groove depth D of 9 to 13 mm.

Pneumatic tire with specified tread profile and circumferential groove

A radial tire with reduced running noise, which comprises a belt comprising two cross plies of cords laid an angle of 10 to 40 degrees with respect to the tire equator, and a pair of axially spaced narrow dampers disposed radially outside of the belt. Each damper has a width L of 0.1 to 0.36 times the width WBO of the outer belt ply. The dampers are centered on two points P, respectively, each point P being spaced apart from the tire equator towards each side of the tire equator by a distance H of 0.1 to 0.25 times the width WBO of the outer belt ply. The axially inner edge of each damper is spaced apart from the the tire equator by a distance D of 0.05 to 0.2 times the width WBO of the outer belt ply. Each damper is formed by spirally winding a cord so that the windings or turns are substantially in parallel to the tire equator.

Pneumatic tire with reduced running noise

A tire which is provided on a sidewall with an embossed mark (3), the embossed mark has an indent portion (5) and an outline portion (6), the outline portion has a top surface (6A) having a light color different from a dark color of the sidewall surface (2S) the bottom (5A) of the indent portion is provided with a rough surface to have a less luster than the sidewall surface, and preferably, the radial height of the mark is in the range from 15 mm to 60 mm, and the bottom of the indent portion is provided with a cross mesh pattern whose mesh pitches are 0.01 to 0.1 times the radial height H of the mark.

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Kobe, Japan

Fumikazu Yamashita