【発明の名称】空気入りラジアルタイヤ

Japanese Patent JP2953533

B2

PURPOSE:To prevent separation of a belt and improve durability of the edge portion of the belt by composing the belt of a belt trunk layer in which two kinds of wide and narrow, metallic cords are buried adjacently and crosswise, and respectively specifying a ratio of hardness between coating rubbers of both belt layers and an elongation of the wide belt layer when its coating rubber is broken. CONSTITUTION:A belt truck layer 4 is composed of a truck layer 4A consisting of four layers 41 to 44 located inside in the radial direction of a tire. A belt trunk layer 42 defined as a belt layer P which forms a free end is sandwiched by belt layers 41Q and 43Q from inside and outside. An elongation of the belt truck layer 42 is set to be 300 percent or more when the coating rubber is broken. Further, when JIS spring type hardness (A type) of coating rubber of the belt layer 42 is assigned to HA, and the same hardness of the belt layers 41 and 43 is assigned to HB, a ratio of both hardness HB/HA is set to be 1.0