Pneumatic tyre

Abstract

Abstract PURPOSE:To contrive to improve the durability especially at running under low inflation pressure by a structure wherein reinforcement cords of carcass cord layers laminated in two layers or an upper and a lower layers are crossed each other peripherally and symmetrically with a specified angle and yet the total number of single strands per unit length of the lower layer is rendered to be specified times as many as that of the upper layer. CONSTITUTION:The reinforcement cords of the upper carcass cord layer 5u and of the lower carcass cord layer 5d are rendered to intersect each other at an angle of 60-80 deg. with respect to the peripheral direction of the tyre and at the same time are arranged substantially symmetrical to the direction of the meridional cross section of the tyre. Due to the arrangement as described above, the rigidity of the carcass part is improved better than ever, resulting in obtaining excellent driving stability and improving the durability at high speed running by preventing the upper part of a side wall from being pushed up during high speed running. Furthermore, the total denier per 50m/m of the lower carcass cord layer 4d is made 1.1-1.5 times as many as that of the upper carcass cord layer 4u. Consequently, the difference between the stretch applied to the reinforcement cords in the cord layer 4u and that in the layer 4d during molding and vulcanizing processes can be made smaller, resulting in obtaining the excellent durability at running even under low inflation pressure.

Inventors

• 👤 Isamu Irie
• 👤 入江　勇
• 👤 Yasuo Morikawa
• 👤 森川　庸雄

Bibliographic Details