Sumitomo Rubber Industries Limited

Yoshiaki Uemura

Masanao Yoshida

Kenji Tagashira

Kouji Shibata

A pneumatic tire, which comprises a tread portion provided with a circumferential groove having a pair of side walls, in the axial direction of the tire the circumferential groove is disposed within the ground contacting width of the tread under a standard loaded state, the standard loaded state is such that the tire is mounted on its regular rim and inflated to 70% of its maximum air pressure and then loaded with 88% of its maximum load, the axial width of the circumferential groove is in the range of from 0.2 to 0.35 times the ground contacting width, and at least one of the side walls has a nonrectilinear configuration having a plurality of axially deviated parts, whereby the conditions of the resonance of the air in the circumferential groove are continuously changed during running to decrease air resonance noise thereby effectively reducing the tire noise.

Pneumatic tire having circumferential groove

A pneumatic tire with an improved tread portion capable of reducing a pass-by noise with improving wet performances is disclosed, wherein a central region Y1 of the tread between a pair of first circumferential lines X1 is provided with a wide circumferential groove having a width W1 of from 0.05 to 0.15 times the ground contacting width TW; a pair of middle regions Y2 between the first circumferential lines X1 and second circumferential lines X2 and a pair of shoulder regions Y3 axially outward of the second circumferential lines X2 are not provided with a circumferential groove but axial grooves, the axial grooves extending from the central region Y1 to tread edges and intersect the first circumferential lines X1 at an angle .theta.1 of from 10 to 25 degrees and the second circumferential lines X2 at an angle .theta.2 of from 30 to 45 degrees; and each first circumferential line X1 drawn on each side of the tire equator at an axial distance L1 of 0.1 to 0.15 times the width TW, and each second circumferential lines X2 drawn on each side of the tire equator at an axial distance L2 of from 0.325 to 0.375 times the width TW.

Pneumatic tire

A pneumatic tire, which comprises a tread portion provided with a circumferential groove having a pair of side walls, in the axial direction of the tire the circumferential groove is disposed within the ground contacting width of the tread a standard loaded state, the standard loaded state is such that the tire is mounted on its regular rim and inflated to 70% of its maximum air pressure and then loaded with 88% of its maximum load, the axial width of the circumferential groove is in the range of from 0.2 to 0.35 times the ground contacting width, and at least one of the side walls has a nonrectilinear configuration having a plurality of axially deviated parts, whereby the conditions of the resonance of the air in the circumferential groove are continuously changed during running to decrease air resonance noise there by effectively reducing the tire noise.

Pneumatic tire including circumferential groove

A tire and rim combination including a flanged rim and a pneumatic tire. The tire includes a pair of bead parts each provided with a plurality of, preferably at least 8, pieces of exhaust ribs projecting from a bead outside surface and extending outwardly in a radial direction so as to form air passages for escape of air between a rim flange and the bead outside surface during rim assembly. A distance F1 from an inner end of the exhaust rib to a bead base line is in a range of 0.7 to 1.5 times a flange height FH measured from the bead base line, and a distance F2 from an outer end of the exhaust rib to the bead base line is not less than 1.1 times the flange height FH. The exhaust rib has a triangular sectional shape having a width of 0.5 to 1.0 mm and a height of 0.5 to 2.0 mm.

Tire and rim combination with exhaust ribs in tire bead

A pneumatic tire to be mounted on a normal rim, has a pair of bead parts each having a bead bottom surface seating on a rim seat of the normal rim and bead outside surface connecting with the bead bottom surface and abutting against a rim flange of the normal rim. The bead outside surface is provided with an exhaust extending outward in the radial direction from an inner end of the exhaust so as to form the air passage for escape of air between the rim flange and bead outside surface at the time of rim assembly. The inner end of the exhaust is positioned within a region remote from a bead base line by a distance of 0.5 to 1.5 times a separating point height Fh defined as a height in the radial direction from the bead base line to a separating point at which the bead outside surface separates from the rim flange.

Tire and rim combination with exhaust means in tire bead

A pneumatic tire, which comprises a tread portion provided with a circumferential groove having a pair of side walls, in the axial direction of the tire the circumferential groove is disposed within the ground contacting width of the tread under a standard loaded state, the standard loaded state is such that the tire is mounted on its regular rim and inflated to 70% of its maximum air pressure and then loaded with 88% of its maximum load, the axial width of the circumferential groove is in the range of from 0.2 to 0.35 times the ground contacting width, and at least one of the side walls has a nonrectilinear configuration having a plurality of axially deviated parts, whereby the conditions of the resonance of the air in the circumferential groove are continously changed every moment during running to decrease air resonance noise thereby effectively reducing the tire noise.

A pneumatic tire, in which, in a cross section including the tire axis, the bead profile is made of a curved line between a locus of

Pneumatic tire having a rim interfacing bead profile for improved fit

A pneumatic tire to be mounted on a normal rim, has a pair of bead parts each having a bead bottom surface seating on a rim seat of the normal rim and bead outside surface connecting with the bead bottom surface and abutting against a rim flange of the normal rim. The bead outside surface is provided with exhaust extending outward in the radial direction from an inner end of the exhaust so as to form the air passage for escape of air between the rim flange and bead outside surface at the time of rim assembly. The inner end of the exhaust is positioned within a region remote from a bead base line by a distance of 0.5 to 1.5 times a separating point height Fh defined as a height in the radial direction from the bead base line to a separating point at which the bead outside surface separates from the rim flange.

A PCI rim comprising a bead seat and a flange each engaging a tire bead of a tire T wherein flange radius of the flange is set in a range from 7.5 mm to 12 mm, flange height of the flange is set in a range from 14 mm to 25 mm, and bead seat radius of the bead seat is set in a range from 4.5 mm to 7.0 mm. The gap F in practical engagement can be significantly reduced compared with the case of a conventional PCI rim. This brings unified circumferential engagement of the tire T with the rim 9 for a practical vehicle so that FV can be inhibited to be significantly small. Further, vibration problems caused by tire rotation are prevented and the displacement of the rim for the practical vehicle can be reduced.

PCI rim

Automobile tire

A radial tire comprises: a pair of bead cores disposed one in each bead portion of the tire; a carcass having radially arranged cords turned up around the bead cores form the axially inside to the outside thereof; a rubber tread disposed radially outside the carcass; a belt comprising a wider ply and a narrower ply disposed adjacently between the carcass and the tread, each belt ply comprising parallel metallic cords each composed of at most five metallic strands, each strand having a diameter of in a range of 0.10 mm to 0.22 mm, the cord count in each belt plies being in a range of 25 to 45 cords/5 cm in a direction at a right angle to the cord direction; and a rubber damper layer disposed between said adjacent belt plies, the damper layer having a substantially uniform thickness so that the distance between the cords of one belt ply and the cords of the other belt ply is in a range of 2.0 mm to 3.0 mm, and the damper layer having a width being not more than the wider belt ply width and not less than the narrower belt ply width.

Growing community of inventors

Kobe, Japan

Yoshiaki Uemura