GB128777A - Improvements in Methods of Making Casings of Pneumatic Tires. - Google Patents

Abstract

128,777. Hopkinson, E. July 30, 1918. Vulcanizing tyres.-Relates to the manufacture of pneumatic-tyre covers and consists in subjecting the formed cover to the action of an interiorlyapplied expansible member adapted to expand the cover and stretch the threads until substantially the final size is attained, retaining the cover in the expanded condition until set and afterwards vulcanizing under direct internal fluid pressure. A cover 10, Fig. 1, after warming on a steamheated pulley 1, is placed upon a rim 9, Fig. 3, over an inflatable core 8, and is expanded by the inward movement of rings 7 by screws 12, and the simultaneous inflation of the core 8. When expanded, the rings 7 are locked to the rim 9 by spring locking-rings 5, Fig. 5. and the rim is removed with the cover, which is then enclosed by mould shells 13. Further pressure is then applied to the core 8 to expand the cover into the mould, and the cover is allowed to cool under pressure. After cooling, the cover is removed from the mould 13 and core 8 its edges are closed by a sealing-member 16, Fig. 8, furnished with grooves 20 containing unvulcanized rubber packing, and the cover is enclosed by mould members 21, which are forced together in a press and are secured by clamps 22. Fluid, such as carbon dioxide, is then forced in under pressure through a valved tube 23, and the mould is placed in a suitable vulcanizer. Instead of using the inflatable core 8, the cover may be expanded mechanically.