Patent attributes
At least one belt layer in which one or plural rubber-coated belt cords are arranged to be spirally wound almost in parallel with a tire circumferential direction on the outer circumference of a body ply. The belt cord is small in the increase rate of tensile load to stretch rate in the range of a predetermined stretch rate or less, but becomes large in the increase rate of the tensile load in another range exceeding the predetermined stretch rate. Therefore, during a vulcanizing and forming process, the belt cord is expanded together with unvulcanized compounded rubber under a small tensile load, and it does not occur to prevent body ply cords from being expanded, so that a green tire is vulcanized and formed with respective parts thereof being adhered as a result of being expanded to keep a correct shape.
