Bridgestone Corporation

Tokyo Keiki Inc.

Tokimec Inc.

Nobuyuki Okamura

Hiroomi Arakane

Takao Sagawa

Michio Itoh

Kazunori Shinohara

Masahiro Hojo

Kojiro Yamaguchi

Hisao Yamamoto

Koji Yamauchi

Eiji Nakamura

Tadashi Saito

Masaaki Tsuchihashi

Isao Nishi

Yasuharu Hashimoto

Yutaka Iseda

Hirohiko Takagi

Toyoori Yoshida

Shioto Tanaka

Kazuki Kaya

Masayuki Funayama

Akinobu Uchida

An automatic steering system for a working vehicle, for automatic maneuvering of the working vehicle running on a working ground surface along a desired running path, in which the influences of various ground surface environments and of any aging degradation and/or individual variation of the working vehicle may be minimized, and the automatic steering operation may be conducted with improved stability. The automatic steering system includes a measurement section for acquiring measurements including those of the position, velocity, heading direction, and attitude of the vehicle and a data processing section. The data processing section includes a vehicle related parameter estimator for determining a value of a vehicle related parameter and a ground surface related parameter estimator for determining a value of a ground surface related parameter.

Automatic steering system for working vehicle

A position output device for outputting position data indicating a current position of an object, is based on position data of a determined current position of the object as determined by a satellite navigation system. When a position jump has occurred in the position data from the satellite navigation system, an appropriate current position is outputted. An estimated current position is generated based on the output position outputted at the latest update time. It is determined whether or not a position jump has occurred, based on the distance between the estimated position and the satellite navigation system-based determined position, which is being updated by the satellite navigation system. When it is determined that a position jump has occurred, a position adjustment vector is generated by calculation, which is then used to generate an adjusted position.

Position output device using satellite navigation system

The sensor successively calculates a rolling angle, pitch angle and azimuth from the coordinate transformation matrix with the level error and azimuth error compensated. It calculates azimuth error compensatory values using the GPS direction signal and calculates a difference between the GPS direction signal and magnetic azimuth signal under a condition wherein the reliability of the GPS direction signal is high, whereas it calculates azimuth error compensatory values using the calculated difference between the GPS direction signal and magnetic azimuth signal and the magnetic azimuth signal under a condition wherein the reliability of the GPS direction signal is not high and under a condition wherein the reliability of the magnetic azimuth signal is not low.

Azimuth/attitude detecting sensor

Pneumatic tire

A pneumatic tire having a tread layer. A rubber composition of the tread layer includes a specific diene-based rubber component, and either a specific zinc dithiophosphate vulcanization accelerator, or a specific zinc dithiophosphate vulcanization accelerator and a benzothiazole vulcanization accelerator. The zinc dithiophosphate vulcanization accelerator is contained in an amount of 0.2 to 5.0 parts by weight per 100 parts by weight of the rubber component. A molar amount of the benzothiazole vulcanization accelerator is one-half or more of a molar amount of the zinc dithiophosphate vulcanization accelerator. Further, the rubber composition contains a white filler in an amount of 15 parts by weight or more per 100 parts by weight of the rubber component. Produceability of the pneumatic tire is excellent, and a low heat build-up performance thereof is improved without any adverse effects on gripping performance.

The present invention provides a rubber composition for a tire tread which comprises 100 parts by weight of a rubber component comprising 50 parts by weight or more of SBR and the remaining amount of a synthetic rubber and/or natural rubber, 25 parts by weight or more of a softener, and 0.5 to 5.0 parts by weight of a vulcanization accelerator, such as bis(4-methylbenzothiazolyl-2)-disulfide, bis(5-methylbenzothiazolyl-2)-disulfide, mercapto-4-methylbenzothiazole, and mercapto-5-methylbenzothiazole, and a pneumatic tire produced by using this rubber composition. A tire having excellent controllability and ride quality throughout tire life can be provided.

Rubber composition containing SBR rubber, softener and a bis benzothiazolyl disulfide vulcanization accelerator

Provided are a rubber composition improved in an anti-static property and a pneumatic tire using the same for its tread part, wherein the rubber composition comprises natural rubber and/or diene base synthetic rubber and a white filler as a filler, and further comprises an anionic anti-static agent or a polyoxyalkylene glycol compound represented by the flowing formulas (I), (II) or (III): ##STR1## wherein R.sup.1 and R.sup.3 each represent a linear or branched, saturated or unsaturated aliphatic hydrocarbon group having 1 to 21 carbon atoms, or an aryl group; R.sup.4 and R.sup.5 each represent a hydrogen atom, a linear or branched, saturated or unsaturated aliphatic hydrocarbon group having 1 to 21 carbon atoms, or an aryl group; R.sup.1 and R.sup.3 in the above formula (I), R.sup.4 and R.sup.3 in the above formula (II) and R.sup.4 and R.sup.5 in the above formula (III) in one same molecule may be the same as or different from each other; R.sup.2 is a methylene, ethylene, propylene or tetramethylene group, and all R.sup.2 's may be the same or different; and n is an integer of 100 or less.

Rubber composition improved in anti-static property and pneumatic tire

A pneumatic tire in which a foamed rubber layer having closed cells is provided at a surface of a tire tread which substantially contacts at least a road surface, wherein the foamed rubber layer has closed cells whose average diameter is about 1 .mu.m to about 120 .mu.m and has an expansion ratio of about 1% to about 100%, a solid-phase rubber portion of the foamed rubber layer has a rubber composition in which at least both of a diene-type rubber and silica are mixed, and an amount of the silica is about 10 to about 80 parts by weight based on 100 parts by weight of the diene-type rubber. The pneumatic tire exhibits excellent traction and braking abilities and controllability on snowy, icy and wet road surfaces.

Pneumatic tire having foamed rubber

A pneumatic tire in which a foamed rubber layer having closed cells is provided at a surface of a tire tread which substantially contacts at least a road surface, wherein the foamed rubber layer has closed cells whose average diameter is about 1 m to about 120 m and has an expansion ratio of about 1% to about 100%, a solid-phase rubber portion of the foamed rubber layer has a rubber composition in which at least both of a diene-type rubber and silica are mixed, and an amount of the silica is about 10 to about 80 parts by weight based on 100 parts by weight of the diene-type rubber. The pneumatic tire exhibits excellent traction and braking abilities and controllability on snowy, icy and wet road surfaces.

A pneumatic tire having improved heat resistance and gripping performance is obtained by using as a tread rubber a rubber composition containing particular amounts of specified p-phenylene diamine derivative and specified carbon black.

Pneumatic tires

A rubber-cord composite body used for cord reinforcing rubber articles is produced by embedding fiber cords treated with an epoxy compound and further with a particular resorcin-formaldehyde-rubber latex adhesive into a particular rubber composition containing 0.5.about.10 parts by weight of each of a bismaleimide compound and sulfur.

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Tokyo, Japan

Nobuyuki Okamura