| abstract |
The present invention provides structure of steel cord in heavy duty tires, in which the adhesive strength between filament and rubber, and penetrating property of rubber are improved by making the twist direction of core and strand different in the steel cord comprising core and strand filament, and by making the pitch or the twist period of core and strand different. In particular, this structure is applied to steel cord of 3+8*d(HT) which is used in heavy duty tires. In this application, twist direction of core filament is in the S direction and twist direction of strand filament is in the Z direction, and the ratio of the pitch of core filament (CP) and the pitch of strand filament (SP) is between 0.50 and 0.94. |