Bridgestone Corporation

Bridgestone Tire Company Limited

Shigeo Makino

Yasutaka Enoki

Tetsuhito Tsukagoshi

Yasutoshi Aoki

Shigeo Watanabe

Tamotsu Matsunuma

Noboru Sugimura

Hiroshi Kojima

Toshio Hayakawa

Tsutomu Tanaka

Shigeoki Usami

Keizou Okita

Kiyoharu Kurihara

Akio Sato

Toshiyuki Sogi

Norio Iwata

Iwao Arimura

Kazuyuki Endo

Hironori Hirano

Shigeta Aoki

Shinji Murase

Hideki Matsuda

Norboru Sugimura

A re-treading method and an apparatus therefor can detect a deviation amount of the position distant by a required tread length from the leading edge of the tread material from a predetermined pattern position near that position planned to be cut, cut the tread material at the at the predetermined position, wind the cut-out tread material on the outer circumference of the base tire while adjusting the length of the tread material by applying thereto a substantially uniform tensile or compressive force, and unite the leading and trailing edges of the tread material wound on the base tire.

Re-treading method and apparatus

A re-treading method and an apparatus. An image of a zone of the tread material including its cut position is compared with a stored tread pattern image to detect a deviation amount. The tread material or the cut position are moved relative to each other by the deviation amount. The tread material is cut at the cut position after the relative movement. The tread material is wound on a base tire, and the leading and trailing edges of the tread material are united. The tread material or cut position may not be moved relative to each other if the deviation amount is within an allowable range.

Automobile tire

The uneven wear produced in the tread side rib in the heavy duty pneumatic radial tire is prevented by arranging a peripheral fine groove on a particular region of the side face of the tread portion in a particular form.

Heavy duty pneumatic radial tires including a bent groove in the side

A main circumferential groove for a pneumatic tire having asymmetrical side walls. One of the side walls has three segments each inclined differently to a line normal to the tread surface. The angle of the inner segment is larger than that of an outer segment.

Pneumatic tire having asymmetrical groove cross section

A pneumatic tire having a tread of a lug type pattern is disclosed. In this type of the tire, the tread rubber has a composite structure of a cap rubber and a base rubber having a heat build-up property lower than that of the cap rubber and arranged on at least a shoulder portion of the tread just beneath the cap rubber. The base rubber has a thickness that an average thickness just beneath the lug is larger than that just beneath the lug groove in a conical plane imaged by taking as a general line a normal line drawn from the tread end to the inner surface of the tire in the radial section inclusive of a rotational axis of the tire.

Base-cap tread

A pneumatic radial tire comprising a belt portion disposed between the tread portion and the carcass portion wherein the belt portion is constituted by at least a pair of first belts, a second belt and a third belt which are arranged from radially inward to outward, the first, second and third belts having a first series, second series and third series of parallel cords embedded therein, respectively. The first belts being laterally spaced apart a predetermined lateral space symmetrically with respect to the mid-circumferential centerline and the cords thereof are disposed at an angle of between 40 to 60 degrees with respect to the mid-circumferential centerline. The spaced-apart first belts have opposite lateral ends which are located within less than 5 percent of a belt width of the third belt from the corresponding opposite lateral ends of the third belt, respectively. The first series of the cords of the first belt and the second series of the cords of the second belt are oriented in same directions, while the second series of the cords of the second belt and the third series of the cords of the third belt are oriented in opposite directions with each other.

Pneumatic radial tire

A combination radial tire for heavy load vehicles comprising a thread portion consisting of a combination of a belt composed of at least two metal cord layers and a carcass composed of at least two organic textile cord plies. In the lower half region of the carcass located at a bead portion, at least one additional reinforcing layer is interposed between the carcass plies and/or another additional reinforcing layer is interposed between the carcass ply and rubber stocks sandwiched between the carcass ply and its turn-up portion, these additional reinforcing layers being extended in parallel with the carcass ply cords and including organic textile cords.

Combination radial tire for heavy load vehicles

A heavy duty pneumatic radial tire comprises a carcass of a substantially radial construction composed of at least one rubberized ply layer containing cords embedded therein and a belt superimposed about said carcass for stiff reinforcement beneath a tread and composed of at least two rubberized ply layers each containing metal cords embedded therein, said metal cords of which being crossed with each other at a relatively small angle with respect to the circumferential direction of tire, and said tread being provided with a plurality of continuous or discontinuous zigzag circumferential ribs defined along the widthwise direction of tire by at least three, substantially zigzag main grooves extending circumferentially of said tread, said main grooves comprising one or a pair of central circumferential grooves located at a substantially central region of said tread and a pair of outside circumferential grooves defining each of outermost ribs of said tread. In this tire, the central circumferential groove has such a symmetrical cross-sectional shape with respect to a center line of said groove that an inclination angle of a groove wall of said groove with respect to a normal line drawn from an outer surface of said tread and passing an edge of said groove in the cross section perpendicular to said groove wall is made relatively large in a region extending from the groove bottom to at least 50% of groove depth, and the outside circumferential groove has such an unsymmetrical cross-sectional shape with respect to a center line of said groove that an inclination angle of an outer groove wall of said groove in the rotation axial direction of tire is made relatively large and an inclination angle of an inner groove wall of said groove in a region extending from the outer surface of said tread to at least 10% of groove depth is made smaller than that of said outer groove wall.

Heavy duty pneumatic radial tires

A heavy duty pneumatic low-sectional radial tire having an aspect ratio of not more than 0.8 is disclosed, which comprises a pair of bead portions, a pair of side portions, a tread portion extending across the side portions, and a reinforcement for a tire casing composed of at least one carcass ply extending across two bead cores and turning up around the bead core and containing cords embedded therein in a substantially radial direction of the tire, each cord having a modulus of not less than 4,000 kg/mm.sup.2, and a belt of at least two layers, each layer containing metal cords embedded therein, superimposed around a crown portion of the carcass and crossing with each other at a relatively small angle with respect to the equatorial line of the tire. In this tire, a carcass line of the tire casing at a temporarily mounted posture on a normal rim under an internal pressure of 0.5 kg/cm.sup.2 depicts a bow-shaped profile in tire section defined by a curved line, whose curvature being smaller with distance from a chord PQ at the outside thereof, where the PQ is a line segment connecting a point P to a point Q, the point P is an intersection of the carcass line and a normal line of the carcass line passing an alienating point of the bead portion from a rim flange or an inflection point of the carcass line when the intersection is located inside the inflection point and the point Q is an intersection of the carcass line and a radial line of the tire passing the point P. The bow-shaped profile of the carcass line is substantially symmetrical with respect to a substantially perpendicular bisector of the chord PQ as a symmetrical axis inside and outside thereof.

Heavy duty pneumatic low-sectional radial tire

A pneumatic radial tire for heavy load vehicles comprising a body reinforcement and a bead portion reinforcement, in which the bead portion reinforcement substantially continuously covers the carcass ply wound around a bead core up to the inside of the tire, the upper end of the turn-up portion of the carcass ply and the outside upper end of the bead portion reinforcement covering the upper end of the carcass ply are arranged at an area other than a bead portion flexible region defined by two segments BC and AD as shown in attached FIG. 3, the bead portion reinforcement makes use of a cord having a modulus which corresponds to 15 to 60% of that of the ply cord of the carcass, and a tension at 100% elongation of a soft stiffener corresponds to 5 to 30% of that of a hard stiffener, the soft and hard stiffeners being disposed on the bead core one upon the other.

Growing community of inventors

Tokorozawa, Japan

Shigeo Makino