TYRE BUILDING USING COMPONENTS PRE-CURED BY ELECTRON RADIATION

1448532 Manufacturing pneumatic tyres GOODYEAR TIRE & RUBBER CO 13 March 1974 [9 April 1973] 11150/74 Heading B7C Partial curing of a tyre component or components is effected prior to building the toroidal tyre blank by subjecting the component or components to electron radiation, e.g. of between 1-10 megarads, such radiation causing a higher degree of partial cure within the component than on its surface. In the illustrated tyre, which may be a radial or cross-ply tyre, the shoulder pads 42, 44, the lateral edges of the belt plies 38, 40, and the shoulder regions of the carcass plies 26, 28 are so treated. Also, the liner 16 may be so treated. A ply may be treated by passing the ply beneath an electron radiation source (63), (Fig. 4, not shown). The width (W) of the ply so treated may be adjusted, e.g. by rotating the source about a vertical axis (64). The source may be rectangular or elliptical in section perpendicular to the vertical axis. A tyre casing (i.e. the bead assemblies, liner and carcass plies) may be shaped prior to or after the addition of the belt plies, shoulder pads and tread and side wall rubbers. Finally, the shaped green tyre is cured.