Process for making a radial tire

Claim 1

A process for making a radial tire comprising the steps of: transforming a cylindrical tire carcass assembly including a carcass ply layer, bead portions, and side wall rubbers into a toroidal shape, laying over a given number of belts in an endless form on the upper surface thereof, winding a plurality of synthetic fiber threads over the top of the given number of belts in the circumferential direction, with a space of 5 mm to 15 mm left between each adjacent thread, in the range of more than 70% of the width of the belts, laying over a tread cap thereon, retaining said tire carcass assembly by sandwiching bead portions thereof between rims of outer flanges and inner flanges provided at a tire building machine, bringing the bead portions toward each other, contacting the upper surface of the tire carcass assembly substantially all over the lower surface of the lowest given number of the belts so that deformation of the belts and the tread cap is lessened, resulting in diminution of wrinkles, joining integrally the tire carcass assembly, the belts, the threads, and the tread cap to form a green tire having an equatorial diameter larger by about 2% than an equatorial diameter of a vulcanizing mold, so that less slipping of the green tire occurs in the vulcanizing mold, subjecting said green tire to vulcanization in the vulcanizing mold; whereby uniformity of the radial tires produced is greatly improved.