Centrifugal casting of pneumatic tyres - using core with inflatable zenith portion for locating reinforcement plies

摘要

Reinforced pneumatic tyres are made from a polyurethane elastomer by a centrifugal casting process. The core has tread parts which can be deformed outward by compressed air or hydraulic fluid so that they fix the reinforcement plies by friction in the desired final position. When this outer layer has been injected and has fixed the plies, the core tread parts are deflated and the rest of the elastomer is filled into the remaining space. This is a reliable way of embedding reinforcement plies in polyurethane elastomer tyres without risk of internal flaking.