GB1477845A - Belted pneumatic tyres - Google Patents

Abstract

1477845 Pneumatic tyres PNEUMATIQUES CAOUTCHOUC MANUFACTURE ET PLASTIQUES KLEBER-COLOMBES 26 June 1974 [4 July 1973] 28413/74 Heading B7C A pneumatic tyre having an aspect ratio less than or equal to 0À8 is provided with a tread reinforcement belt, the belt comprising a first, non-folded ply 16 of parallel steel or glass cords having an elastic modulus at least equal to 200 gms/denier, the edges of the non-folded ply being enveloped by the folded margins of a second ply 17 including parallel, aromatic polyamide cords of elastic modulus at least equal to 330 gms/denier. The cords of the first ply extend in one direction and make an angle of 10‹-20‹ with the midcircumferential plan and the cords of the second ply extend in opposite direction and make a larger angle (e.g. 25‹- 30‹) with the plane. Margin 17<SP>1</SP> of the second ply may turn outwardly (as shown) or inwardly to envelop the edges of the first ply (Fig. 2, not shown). The tyre includes a radial carcass ply 10 having rayon, nylon, polyester, fibre-glass or metal cords. Strengthening annular elements of rubber 18 having a higher modulus of elasticity in the circumferential direction may be provided radially outwardly or inwardly of the edges of the first ply. There may be more than one first ply and/or more than one second ply. In an alternative embodiment two superimposed first plies are enveloped at their edges (Fig. 4, not shown) by a second ply comprising two axially spaced half plies (17a, 17b).