Patents Assigned to Bridgestone Tire Company Limited
  • Patent number: 4527606
    Abstract: A pneumatic radial tire for passenger cars having a low rolling resistance and an excellent wet skid resistance is disclosed. The radial tire comprises a carcass of a radial construction toroidally extending between a pair of bead cores with the ends turned thereover, a tread portion arranged outside a crown portion of the carcass and having a two laminate structure of tread base rubber and tread cap rubber, and a reinforcing belt layer embedded in the tread base rubber and superimposed about the crown portion of the carcass. The tread base rubber and tread cap rubber have resiliences of not less than 65% and not more than 60%, respectively. The tread portion has a sectional ratio of a sectional area of the tread cap rubber occupied in the equatorial section of tire to a total sectional area of the tread portion of not less than 50% and a negative ratio of not more than 45%. The belt layer has a flatness of not more than 15%.
    Type: Grant
    Filed: November 14, 1983
    Date of Patent: July 9, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Toshio Kita, Nobumasa Ikeda, Takashi Takusagawa, Yoshiharu Goto, Hiroshi Hayakawa, Minoru Togashi
  • Patent number: 4526934
    Abstract: A branched styrene-butadiene copolymer and a pneumatic tire using the same as a tread base rubber are disclosed. This copolymer is produced by coupling an active styrene-butadiene copolymer anion, which is obtained by polymerizing styrene and butadiene in a hydrocarbon solvent in the presence of ether or a tertiary amine and an initiator of an organolithium compound, with a tin halide compound. In the copolymer, the ratio of branched copolymer connected with tin-butadienyl bond is at least 20% by weight, and the content of bound styrene is not less than 3% by weight but less than 25% by weight, and the content of vinyl bond in butadiene portion is not less than 30% but less than 50%.
    Type: Grant
    Filed: March 8, 1983
    Date of Patent: July 2, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Noboru Oshima, Isamu Shimizu, Yoshito Yoshimura, Tatsuo Fujimaki, Seisuke Tomita
  • Patent number: 4526217
    Abstract: A heavy duty pneumatic radial tire is disclosed, which comprises a carcass composed of at least one rubberized ply containing cords arranged substantially in a radial plane of the tire and a belt superimposed about a crown portion of the carcass just beneath a tread and composed of at least three rubberized belt plies. In this tire, metal cords of a first belt ply nearest to the carcass among the above belt plies are arranged at an angle of 25.degree.-50.degree. without crossing with metal cords of a second belt ply near the carcass next to the first belt ply with respect to a central circumferential line of the tire, and metal cords of the second belt ply and a third belt ply near the carcass next to the second belt ply, a tensile strength of each of which being 1.5-2 times that of the metal cord of the first belt ply, are arranged at an angle of 10.degree.-30.degree.
    Type: Grant
    Filed: April 30, 1984
    Date of Patent: July 2, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Muneyoshi Maeda, Kazuyuki Endo, Hikaru Tansei
  • Patent number: 4521269
    Abstract: The tire building apparatus was an axially elongated drive shaft which is rotatable about its center axis. The tire building drum of the apparatus includes an axially elongated retainer sleeve which is interchangeably received on the drive shaft and rotatable with the drive shaft about the center axis of the drive shaft. A slider sleeve is slidably received on the retainer sleeve and is rotatable with the drive shaft about the center axis of the drive shaft. A plurality of link members are provided each being pivotally connected at its one end to the slider sleeve. A plurality of arcuate drum segments are provided each being equiangularly spaced apart from one another about the center axis of the axially elongated drive shaft and pivotally connected with the other end of each of the link member.
    Type: Grant
    Filed: December 23, 1983
    Date of Patent: June 4, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventor: Chiaki Ozawa
  • Patent number: 4520857
    Abstract: A high-durable pneumatic radial tire is disclosed. In the tire of this type, steel cords each made from particular steel filaments are used in at least one of belt and carcass. This steel filament has a pearlite structure having an average value of interlamellar distance between cementites of 300-500 .ANG., and a tensile strength of not less than 220 kgf/mm.sup.2.
    Type: Grant
    Filed: November 8, 1983
    Date of Patent: June 4, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Takao Ogino, Yoichi Watanabe, Shigehisa Sano
  • Patent number: 4519431
    Abstract: A styrene-butadiene copolymer having a high styrene content is disclosed, which is obtained by polymerizing styrene and butadiene in a hydrocarbon solvent in the presence of an organolithium compound and, if necessary, a Lewis base and then coupling with a tin halide compound. This copolymer contains in its main chain at least 30 wt % of polymer having a tin-carbon bond and has a bound styrene content of more than 25 wt % but not more than 60 wt % and a content of vinyl bond in butadiene portion of not less than 30% but less than 50%.
    Type: Grant
    Filed: July 19, 1984
    Date of Patent: May 28, 1985
    Assignees: Bridgestone Tire Company Limited, Japan Synthetic Rubber Co., Ltd.
    Inventors: Yoshito Yoshimura, Noboru Oshima, Isamu Shimizu, Shinsuke Yamaguchi, Tatsuo Fujimaki, Tomoharu Yamada, Seisuke Tomita
  • Patent number: 4518023
    Abstract: A pneumatic tire includes a tread, a pair of sidewalls and a pair of bead portions and further a carcass and a belt for reinforcing the tread, sidewalls and bead portions. The carcass consists of at least one layer of rubber coated cord ply whose organic fiber cords are arranged in parallel with each other in substantially radial surfaces of the tire. The belt consists of a rubber coated metal cord layer folded at least at one edge, whose metal cords are arranged in parallel with each other at relatively small angles with respect to an equatorial line of the tire.According to the invention, a reinforcing layer of at least one rubber coated layer is arranged in an inside of and in substantially intimate contact with the folded edge of the rubber coated metal cord layer of the belt and extending at least 7% of an overall width of the belt from a folded position of the belt. Cords of the reinforcing layer are organic fiber cords and are in parallel with each other at angles of 0.degree.-40.degree.
    Type: Grant
    Filed: April 7, 1983
    Date of Patent: May 21, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Yutaka Yamaguchi, Nobuyuki Koizumi, Masami Hirano, Tamio Araki, Koichi Kojima
  • Patent number: 4518024
    Abstract: A pneumatic radial tire having an improved durability in the running on bad road is disclosed, which comprises a carcass composed of at least one rubberized cord ply containing cords arranged substantially perpendicular to the equatorial plane of the tire and a belt superimposed around the crown portion of the carcass and composed of at least two rubberized cord layers each containing cords inclined at a relatively small angle with respect to the equatorial plane of the tire, the cords of which being crossed with each other. In this tire, the outermost layer of the belt contains cords having a flexural rigidity lower than that of the remaining layer and arranged at an end count higher than that thereof.
    Type: Grant
    Filed: February 7, 1984
    Date of Patent: May 21, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventor: Tamotsu Matsunuma
  • Patent number: 4516451
    Abstract: For cutting an elongate rubbery strip, there is disclosed an apparatus which largely comprises transmitting means operative to transmit the elongate rubbery strip to a predetermined position, an anvil located underneath the predetermined position and formed with an elongated groove extending at angle with respect to the transverse direction of the rubbery strip, the angle between the longitudinal direction of the elongated groove and the transverse direction of the rubbery strip being variable by means of adjusting means. The apparatus for cutting the elongate rubbery strip further comprises a cutting mechanism operative to cut the elongate rubbery strip on bias throughout the width thereof in cooperation with the anvil.
    Type: Grant
    Filed: April 21, 1983
    Date of Patent: May 14, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Masaru Takeshita, Toshio Tokunaga, Yuichiro Ogawa
  • Patent number: 4515502
    Abstract: A marine fender is disclosed, which comprises a hollow cylindrical body composed of rubber or rubbery elastic material, each end of which being provided with a flange for a quay wall or a shock receiving member, an annular rigid reinforcing plate embedded in each flange, and a fillet reinforcement provided on a foot portion of each flange. In the marine fender, an annular groove is further formed in a region adjacent to the fillet reinforcement at each end of the body.
    Type: Grant
    Filed: October 16, 1981
    Date of Patent: May 7, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Shinichi Kajigaya, Mitsuo Nakaya
  • Patent number: 4515922
    Abstract: A rubber composition having improved wet skid resistance and rolling resistance is disclosed, which comprises (A) 10-90% by weight of polybutadiene rubber having a content of cis-1,4-bond at least 80% and an average chain length of cis-1,4-bond of not less than 110, and (B) 10-90% by weight of random styrene-butadiene copolymer rubber obtained by copolymerization in the presence of an organic metal catalyst and having a content of bound styrene of not more than 40% by weight and a content of 1,2-bond in total butadiene unit of 30-95%.
    Type: Grant
    Filed: January 27, 1984
    Date of Patent: May 7, 1985
    Assignees: Bridgestone Tire Company Limited, Japan Synthetic Rubber Co., Ltd.
    Inventors: Mitsuhiko Sakakibara, Masao Yoshizawa, Masaki Ogawa, Yasushi Hirata, Shigeru Tomihira
  • Patent number: 4515197
    Abstract: A novel tread pattern is disclosed, which can give high performances on wet road at both the straight running and the cornering under a low load, particularly no load, to a heavy duty pneumatic radial tire without sacrificing the performances on wet road under normal load. The tread pattern comprises at least 4 lands defined by at least 3 main grooves, wherein a pair of first group lands arranged on the outermost side regions of the tread have substantially continuous along the the circumferential direction of the tread and the remaining lands located between the first group lands have notches arranged thereon in their lateral direction.
    Type: Grant
    Filed: May 4, 1983
    Date of Patent: May 7, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Kenichi Motomura, Hiroshi Ogawa, Akira Yamamoto, Noriyuki Hagita
  • Patent number: 4513802
    Abstract: A pneumatic radial tire is adapted to improve or reduce the rolling resistance and simultaneously to improve the steering stability and riding comfortability against vibration during running without adversely affecting the wet performance and durability by making higher the carcass maximum width position and the carcass curvature reverse position, or enlarging the curvature of the carcass in the radially outer zone of the carcass maximum width position and simultaneously the carcass curvature reverse extent in the radially inner zone of the sidewalls so as to intentionally deviate from the naturally equilibrated configuration.A method of manufacturing a reduced rolling resistance pneumatic radial tire uses a mold for vulcanizing and forming the tire therein, which mold has a particular shape of cavity having a foot width 20-50% wider than a rim width and diverging progressively from shoulder corresponding portions to the wider foot portion of the cavity.
    Type: Grant
    Filed: December 29, 1982
    Date of Patent: April 30, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Minoru Togashi, Kenshiro Kato, Shin-ichi Furuya
  • Patent number: 4510983
    Abstract: A pair of pneumatic belted tires for use in motorcycle are disclosed, each of which comprises a tread extending over a width corresponding to the maximum width of the tire, a pair of sidewalls, a pair of bead portions each containing a bead core therein, a carcass composed of at least one rubberized ply containing organic fiber cords inclined at an angle of 50.degree.-90.degree. with respect to the equatorial plane of the tire, and a belt composed of at least two rubberized plies each containing cords arranged at a certain inclination angle with respect to the equatorial plane. In such a tire pair, an inclination angle .alpha. of cord in the belt for rear wheel tire and an inclination angle .beta. of cord in the belt for front wheel tire satisfy the following relationship:(.alpha.-.beta.).gtoreq.4.degree.when15.degree..ltoreq..alpha..ltoreq.26.degree.,or(.alpha.-.beta.).gtoreq.-0.3.alpha.+11.8.degree.when26.degree..ltoreq..alpha..ltoreq.36.degree..
    Type: Grant
    Filed: September 30, 1983
    Date of Patent: April 16, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Shinichiro Ohkuni, Yoichi Kitazawa
  • Patent number: 4511627
    Abstract: A sandwich glass comprising glass plates and an intermediate layer interposed therebetween is disclosed. The intermediate layer is formed by crosslinking or photocrosslinking a resin composition comprising an ethylenevinyl acetate copolymer and an organic peroxide or a photosensitizer under heating of the resin composition above the melting point of the copolymer.
    Type: Grant
    Filed: October 7, 1982
    Date of Patent: April 16, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Itsuo Tanuma, Hideo Takeichi, Yukio Fukuura, Tomio Ohyachi, Kazuo Naito
  • Patent number: 4510011
    Abstract: A strip deforming apparatus for deforming a flexible strip into a looped endless band, comprising a first conveyor assembly comprising an endless belt having an upper travelling path, a second conveyor assembly positioned below the first conveyor assembly and comprising an endless belt having an upper travelling path parallel with and spaced apart downwardly from the belt of the first conveyor assembly, and a third conveyor assembly positoned between the first and second conveyor assemblies and comprising a pair of conveyor rolls elongated in longitudinal directions of the apparatus and each rotatable about the center axis thereof. At least one of the first and second conveyor assemblies is movable toward and away from the other conveyor assembly and the conveyor rolls are spaced apart in parallel from each other in a lateral direction of the apparatus.
    Type: Grant
    Filed: December 23, 1983
    Date of Patent: April 9, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Yusaku Azuma, Yoshifumi Kitayama, Shinji Kawaida
  • Patent number: D278224
    Type: Grant
    Filed: June 27, 1983
    Date of Patent: April 2, 1985
    Assignee: Bridgestone Tire Company, Limited
    Inventors: Masao Nakamura, Hiroshi Kojima, Hideaki Nishio
  • Patent number: D278994
    Type: Grant
    Filed: September 8, 1983
    Date of Patent: May 28, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Hideaki Nishio, Yuji Tateo
  • Patent number: D279090
    Type: Grant
    Filed: September 8, 1983
    Date of Patent: June 4, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Hiroshi Kojima, Kiyoshi Takase
  • Patent number: D279465
    Type: Grant
    Filed: May 9, 1983
    Date of Patent: July 2, 1985
    Assignee: Bridgestone Tire Company Limited
    Inventors: Hideaki Nishio, Hiroshi Kojima, Akira Kurima