GB1361981A - Radialply tyres - Google Patents

Abstract

1361981 Pneumatic tyres PNEUMATIQUES CAOUTCHOUC MANUFACTURE ET PLASTIQUES KLEBER-COLOMBES 22 July 1971 [24 July 1970] 34546/71 Heading B7C In a pneumatic tyre comprising a radial-ply carcass 10, a tread 17, and a reinforcing belt 16 located between the carcass and the tread, one sidewall of the carcass 10 has adhered to one of its surfaces over part of its radial dimension an annular strip 19 made from a rubber mixture with a modulus elasticity of at least 40 kg./cm.<SP>2</SP> at 100% elongation, the strip 19 extending from the radially outer part of the associated tyre bead region to, as shown in Fig. 2, a point C located at 2/3 H or to a point beoynd the point C, and the remaining part of the carcass sidewall between the radially outer part of the strip 19 and the adjacent edge of the belt 16 being covered with a rubber mixture whose modulus of elasticity is less than that of the strip 19. There may, as shown in Fig. 2, be a strip 19 on the axially outer surface of each sidewall of the carcass, the remaining parts of the carcass sidewalls being covered by members 20 and by edge regions 18 of the tread 17, the tread 17 and members 20 being made from a rubber with a modulus of elasticity less than 25 kg./cm.<SP>2</SP> at 100% elongation. In a modification of the Fig. 2, embodiment (Fig. 1, not shown) the strips 19 are extended to replace the members 20, and in a modification of this modified embodiment (Fig. 4, not shown) only one carcass sidewall is provided with a strip 19 the other carcass sidewall having applied to its outer surface a strip (19 1 ) made of a rubber with a modulus of elasticity of 15 kg./cm.<SP>2</SP> at 100% elongation. Alternatively a strip 19 may be applied to the axially inner surface of each carcass sidewall (Fig. 3, not shown), and in this case the outer surface of each sidewall may have a strip (21) of supple rubber applied to it. Specific examples of rubber mixtures suitable for the strip or strips 19 are given in the Specification. The belt 16 may comprise plies of cords laid at a cord-angle of 20 degrees; the carcass 10 may have portions 11 turned-up to envelop bead cores 12, filler strips 13 and flipper strips 14 in the bead regions; and chafer strips 15 may be provided on the outer surfaces of the bead regions.