摘要 |
1,170,759. Pneumatic tyre manufacture. DEERING MILLIKEN RESEARCH CORP. 17 Oct., 1966 [18 Oct., 1965], No. 46371/66. Heading B7C. [Also in Division D1] A method of making pneumatic tyres comprises the steps of forming a carcass in band form, applying to the carcass an extensible breaker strip comprising rubber-coated continuous tyre cord 4 disposed across the breaker strip from one side to the other with reversals of the cord direction at the edges, applying sidewall and tread rubber in flat band form, and finally vulcanizing and shaping this assembly to toroidal form under heat and pressure, whereby the breaker strip's circumference is increased and its width reduced. To achieve its extensibility, the breaker strip consists either of a cellulosic tyre cord which has been exposed while in the relaxed state to the action of liquid ammonia, or a polyester tyre cord which has been treated with a halogenated methane solvent. Rubber shoulder portions may be formed on the sidewall and tread rubber between the lateral edges of the breaker strip and the carcass so that in the finished tyre the strip lies parallel to the plane of the tread surface. |