METHOD OF BUILDING A PNEUMATIC TIRE AND A TIRE BUILDING FORMER THEREFOR

摘要

ABSTRACTAn improved method and apparatus for buildingradial tyres which lends itself to automatic productionof tyres is disclosed herein. The method of buildinga pneumatic tyre comprises separately building anunexpanded carcass assembly and an annular tread assemblycomprising tread rubber, breaker reinforcement and sidewallrubbers, positioning the tread assembly and the carcassassembly in coaxial relationship with the unexpandedcarcass disposed centrally within the tread assembly,expanding the carcass into engagement with the treadassembly and consolidating the two assemblies together.The apparatus is in the form of a building former for atread assembly comprising an expansible central portionand a pair of expansible side portions, the central portionbeing arranged to expand to a greater diameter than theside portions so as to hold said side portions in a frusto-conical shape.