| 摘要 |
<p>A process for injection molding a crown of a vehicle tire from one composition and the sidewalls from a different composition involves the steps of shaping the reinforcing structure in the mold, injecting a first composition over one side of the reinforcing structure to form a crown with a tread and injecting a second composition to form the sidewalls with an interface within the proximity of the edges of the reinforcing structure. In a preferred embodiment, the tire has the configuration of the one disclosed in U.S. Patent 3,805,868. The annular reinforcing structure is shaped to be generally convex but concave towards the tread along its edges. Also disclosed is apparatus for carrying out the above process, comprising a rigid core formed of several elements, to be split or collapsed for its removal after injection, a female element constituted by a plurality of pieces and provided with openings for the simultaneous injection of two different compounds for the tread and for the sidewalls, and means for the volumetric dosing of said two compounds.</p> |
