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公开(公告)号:JPH05286307A
公开(公告)日:1993-11-02
申请号:JP9311092
申请日:1992-04-13
Applicant: BRIDGESTONE CORP
Inventor: MATSUSHITA NORINAGA
IPC: B60C9/08 , B60C9/18 , B60C9/20 , B60C11/04 , B60C11/117
Abstract: PURPOSE:To prevent the generation of the groove bottom cracks of branch grooves and inclination lug grooves provided at spheres that exceed the specific ratio of the maximum width of a periphery tread. CONSTITUTION:The cords 22A of the 1st belt ply 22 of a pneumatic radial tire 10 for a two wheeler are inclined at an angle alpha1 in regard to the equatorial plane S, and the cords 24A of the 2nd belt ply 24 and the cords 22A of the 1st belt ply cross each other, and the cords 24A of the 2nd belt ply 24 are inclined at an angle alpha2 in regard to the equatorial plane S. Directional inclination lug grooves 27 are formed at the tread 18 of the pneumatic radial tire 10, and branch grooves 28 are made to diverge at, spheres RW that exceed 65% from the center of a periphery tread width TW of inclination lug grooves 27. Also, the sphere SW of the center of the tread width where the 1st belt ply 22 and the 2nd belt ply 24 accumulate, goes over the spheres where branch grooves 28 exist.
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公开(公告)号:JPH0281707A
公开(公告)日:1990-03-22
申请号:JP23225388
申请日:1988-09-19
Applicant: BRIDGESTONE CORP
Inventor: KADOTA KUNINOBU , MATSUSHITA NORINAGA , KONO YOSHIHIDE
Abstract: PURPOSE:To obtain a pneumatic tire with necessary and sufficient rigidity distribution with no increase of any member by making reinforcing elements for strips having distribution in width direction so as to give the maximum value at the side edges of a belt, to a ratio of amplitude to wave length of the corrugation. CONSTITUTION:Strips B1-B5 making plural numbers of cord or filament arranged in corrugation all together around a toroidal carcass 2 as reinforcing elements and coated with high polymer material lower in its elastic modulus are used as a belt 3 contributing to strengthen a crown. It is possible to control both rigidity and envelope capability by arranging reinforcing elements for strips B1-B5 in distributions in width direction having the maximum values, at side edges of the belt 3, of a ratio a/lambda of amplitude (a) to wave length lambdaof corrugations, and especially by arranging the same in distribution increasing gradually toward the side edges of the belt 3, so it is possible to realize improved durability of the belt and to suppress partial wear while securing maneuvering performance as it is.
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