Abstract: A tire tread with good noise characteristics according to the invention includes at least one circumference in which a composed sequence of a plurality of design elements, are consecutively disposed in succession. Each design element having varying circumferential lengths, or pitches wherein the pitches are reduced in number, less than or equal to 3 and preferably 2, and are disposed in a random and disordered succession is present. Also disclosed is a design method which generates automatically, in a random or pseudo-random mode, one or more sequences in which the greatest part of the obtained sequences presents good sonorous properties and are selectable across the various characteristic values obtainable from the same sequences.

Abstract: A pneumatic tire for motor vehicles having a low power absorption and a high directional control stability is disclosed. The tire has a tread formed by two superimposed elastomeric layers and has a H/L ratio of less than 0.6; H is the sidewall height and L is the width of the tire section.

Abstract: An apparatus is provided for injection molding a pneumatic tire having corresponding symmetrical parts such as the sidewalls of the tire which are geometrically symmetrical and have substantially the same physical characteristics. The apparatus involves means for providing a feed stream of suitable plastic or elastomeric compound such as rubber, separating the feed stream into intermediate streams and remixing the intermediate stream before injection into the mold. The compound is injected into the mold cavities at uniformly spaced points along at least one of the annular zones of the cavity. The feed stream is preferably separated into two streams, one of which comes primarily from the outer portion of the stream and the other predominantly from near the center of the stream and then these streams are intermixed to provide a stream which is substantially uniform in composition throughout.

Abstract: A process and apparatus are provided for injection molding a pneumatic tire having corresponding symmetrical parts such as the sidewalls of the tire which are geometrical symmetrical and have substantially the same physical characteristics. The process involves providing a feed stream of suitable plastic or elastomeric compound such as rubber, separating the feed stream into intermediate streams and remixing the intermediate stream before injection into the mold. The compound is injected into the mold cavities at uniformly spaced points along at least one of the annular zones of the cavity. The feed stream is preferably separated into two streams, one of which comes primarily from the outer portion of the stream and the other predominantly from near the center of the stream and then these streams are intermixed to provide a stream which is substantially uniform in composition throughout.