GB1386879A - Spiked tyre - Google Patents

Abstract

1386879 Tyre treads INDUSTRIE PIRELLI SpA 18 May 1972 [28 May 1971] 23407/72 Heading B7C A spiked radial tyre comprises a stiffening structure 4 between the carcass 2 and the tread 3, and the radially inner end 16 of each spike 12 extends partially or completely through the structure, the structure comprising one or more plies of rubberized parallel cords. The tyre also includes an elastomeric strip 10 positioned radially inwardly of the ply or at least one of the plies and radially outwardly of the carcass. The radial distance of each of the ply or plies and the strip from the radially outer surface of the tread being substantially uniform. As illustrated in Fig. 1, folded parallel cord plies 5, 6 are positioned radially inwardly and radially outwardly respectively of the strip 10, and a head 16 and a collar 17 of each spike are situated inwardly and outwardly respectively of the ply 6. As illustrated in Fig. 2, the plies 5 and 6 are positioned outwardly of the elastomeric strip and the head 16 and collar 17 of each spike are positioned respectively in the strip 10 and outwardly of the plies. The cords in each ply makes an angle of 15-20 degrees with the mid-circumferential plane and may be constituted of natural or artificial fibres (e.g. rayon), or of metal (e.g. steel). The material of the strip may be the same as that used for rubberizing the cords, and preferably has a hardness not less than 80‹ Shore and a thickness of 2-4 mm.