Heavy duty tires with low aspect ratios mounted on trucks, buses and the like demonstrate reduction of tire radial growth in the center region, and demonstrate uniformity of contact pressure distribution in the tire width direction, due to the disposition of a circumferential reinforcing layer in the belt layer. Conventional pneumatic tires that are configured in this manner are disclosed in Japanese Patent Nos. 4642760B, 4663638B and 4663639B, as well as in Japanese Unexamined Patent Application Publication Nos. 2009-1092A, 2006-111217A and 2006-183211A.
Also, in recent years, there has been increased interest in retreading tires from the cost and environmental aspects. Retreaded tires are tires in which the tread rubber of the tire is replaced when the residual grooves reach the end of their life, and are manufactured by one of two methods: the precure method or the remold method. Retreaded tires made by the precure method are manufactured by forming a base tire by removing the used tread rubber by a buffing process, and laminating a vulcanized precured tread having the tread pattern of a new product onto the base tire. Retreaded tires made by the remolding method are manufactured by forming a base tire by removing the used tread rubber by a buffing process, wrapping unvulcanized tread rubber around the base tire, and vulcanization molding using a forming mold having the tread pattern.
In these retreaded tires, there is a demand to increase the yield of base tires.
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USPTO Backgrounds