Pneumatic radial tire
AssigneeSumitomo Rubber Industries, Ltd.
InventorNaoki Yukawa
Life of this patent
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Abstract
A belt layer is provided at its outer side with a band layer comprising edge bands on left and right sides. When a cross sectional area of one band cord is defined as S (unit; mm2) and a modulus of the band cord when its elongation is 2% is defined as M (unit; N/mm2) and disposition density of the band cord per 1 cm of the band layer is defined as D (unit; the number of band cords/cm), an elongation resistance value K (unit; N·the number of band cords/cm) of the band layer which is determined by the following equation (1) is set to 270 or higher and 830 or lower: K=S×M×D/100. (1) An elongation percentage T(%) of the band cord in a tire in its natural state in which the tire is not assembled to a rim is set to 0.75% or higher and 1.2% or lower.
Claims5
A pneumatic radial tire comprising a belt layer disposed inside a tread portion and outside a carcass in a radial direction of the tire, and a band layer consisting of a pair of edge bands disposed radially outward of the belt layer and at opposite edge portions of the belt layer, wherein when a cross sectional area of one band cord is defined as S (unit;
- mm2) and a modulus of the band cord when its elongation is 2% is defined as M (unit;
- N/mm2) and the disposition density of the band cord per 1 cm of the band layer edge bands, is defined as D (unit;
- the number of band cords/cm), an elongation resistance value K (unit;
- N·the number of band cords/cm) of the edge bands, which is determined by the following equation (1) is set to greater than 700 and 830 or lower:
- K=S×M×D/100 (1)
- and elongation percentage T(%) of the edge band cord in the tire in its natural state in which the tire is not assembled to a rim is set to 0.75% or higher and 1.2% or lower.
Dependencies are inferred from the claim text.