ZM9774A1 - Improvements in or relating to pneumatic tyres - Google Patents

Abstract

1478660 Pneumatic tyres INDUSTRIE PIRELLI SpA 13 June 1974 [18 June 1973] 26353/74 Heading B7C A pneumatic tyre provided with an inner and an outer carcass ply the cords of which are of substantially uniform diameter and dispersed in radial or substantially radial planes, includes, in each sidewall, an elastomeric insert 13 between the plies. The insert between points A, B is of substantially uniform thickness, the thickness being greater than the diameter of a single carcass cord. Preferably the inserts are of an elastomer having a modulus of elasticity at 100% elongation between 150 g./mm.<SP>2</SP> and 900 g./mm.<SP>2</SP>. In the preferred embodiment which shows groups 4, 5 of carcass plies the diameter of each cord (of nylon) is 0À81 mm. and each insert is 6 mm. thick. The modulus of elasticity of the inserts is 300 g./mm.<SP>2</SP> at 100% elongation. Chafers 11 comprise metal cords. The carcass cords may alternatively be of metal, cotton, rayon or polyester fibres. The number of plies in the groups 4 and 5 may differ, and the cords of one group may differ from the cords of the other group. An intermediate carcass ply or plies may divide each insert into a plurality of components.