PNEUMATIC TYRE FOR VEHICLE WHEEL

摘要

1398621 Pneumatic tyres INDUSTRIE PIRELLI SpA 20 July 1972 [30 July 1971] 33917/72 Heading B7C A pneumatic tyre comprises elastomeric side walls extending between a reinforced tread 15 and beads 21 and having midlines 28 which are convex with respect to the tyre inflation chamber. When the tyre is inflated and in use the side walls are under compression. The zones 30, 32, 34 have greater flexibility than the zones 31, 33, and this differing flexibility may be achieved by forming, e.g. by injection moulding, the side walls wholly of one rubber having, e.g. a modulus of elasticity of 40 kg./cm.2 with the zones being of different thicknesses, by forming the zones of elastomers having different moduli, e.g. 5-60 kg./cm.2 in zones of greater flexibility and 20-150 kg./cm.2 in zones of lesser flexibility, or by forming the sidewalls of an elastomer with the zones of lesser flexibility being reinforced, e.g. by oriented glass fibres. The tread reinforcement 18 may comprise at least two layers of parallel textile or metal cords, with the cords of adjacent layers crossing. The edges of the reinforcement may be folded to provide stiffer edge regions, or additional inextensible strips may be provided in the edge regions. Instead of cord fabric layers, layers in the form of foils may be used. The beads may include cores, and the tread may be removable.