Pneumatic safety tire

Claim 1

In a pneumatic safety tire having a carcass composed of at least one radial cord ply toroidally extending from a tread portion, through two sidewall portions, to two inner bead portions; a belt arranged on the carcass layer so as to cover the crown portion thereof between two shoulder portions of the tire; an inner liner extending throughout between the both bead portions on the inner surface of the carcass; and a pair of crescent-shaped cross-section reinforcing layers located between the carcass and the inner liner in each of the sidewall portions, wherein each of said reinforcing layers has a thickest portion thereof at substantially the middle of each of the sidewall portions extending from the shoulder portion to the head portion the improvement wherein each of said crescent-shaped cross-section reinforcing layers comprises: (a) a higher elastic rubber layer G 1 having an elastic modulus of 25 to 60 kg/cm 2 in tensile stress when elongation strain is 100% and combined with the inner surface of said carcass at the sidewall portion of the tire; and (b) an anticrack rubber layer G 2 having an elastic modulus of 10 to 30 kg/cm 2 in tensile stress in said condition but smaller than that of said elastic rubber layer G 1 and arranged such that at least part of an outer surface thereof is combined with said elastic rubber layer G 1 and an inner surface thereof is combined with said inner liner, respectively at a volume ratio of said higher elastic rubber layer G 1 to said anticrack rubber layer G 2 as 1<G 1 /G 2 <10.