Industrie Pirelli S.p.a.

Giovanni Calori

Giorgio Tangorra

A pneumatic tire for motor vehicles having a generally trapezoidal section with a top portion which is generally convex towards the outside and wider than any other part of the tire, beads, and two sidewalls. The sidewalls spread outwardly from the beads to zones which connect the sidewalls with the top portion. The top portion has a central tread portion which is normally in contact with the ground when the tire is under load, and lateral shoulders which are spaced from the ground during rectilinear running of the vehicle. The sidewalls have zones which are less resistant to bending adjacent to the shoulders and adjacent to the beads than the parts which are intermediate the shoulders and beads. The less resistant zones act as hinges under load on the tread. A generally annular reinforcing structure for the tread, which is substantially inextensible in the axial and circumferential direction, is folded at its ends about reinforcing annular straps arranged in each shoulder. In any radial section, the cincture connection angle, which is the angle between a straight line drawn through the center of the hinge adjacent to each shoulder and parallel to the tire axis and a straight line drawn through the center of the shoulder hinge and the center of the strap, is between -10.degree. and 30.degree..

Pneumatic tires for vehicle wheels

A process is provided for injection molding a vehicle tire such as the one disclosed in U.S. Pat. No. 3,805,868 having a bead of elastomeric material. The mold has an outer envelope and an inner body having a core formed of radially collapsible sectors which combine to enclose a mold cavity. The inner body member has at least two annular elements, an upper and lower one, which are separable from one another and from the core along the direction of the core axis. The annular elements have surfaces which form axially inner surfaces of the tire's beads. The inner body member is also provided with members for blocking the annular elements with the core and with the envelope. The core of the mold is divided into two series of alternate collapsible sectors which are displaced radially inwardly when the tire is released from the mold.

Process for injection molding a vehicle tire

A mold is provided for injection molding a vehicle tire such as the one disclosed in U.S. Pat. No. 3,805,868 having a bead of elastomeric material. The mold has an outer envelope and an inner body member having a core formed of radially collapsible sectors which combine to enclose a mold cavity. The inner body member has at least two annular elements, an upper and lower one, which are separable from one another and from the core along the direction of the core axis. The annular elements have surfaces which form axially inner surfaces of the tire's beads. The inner body member is also provided with members for blocking the annular elements with the core and with the envelope. The core of the mold is divided into two series of alternate collapsible sectors which are displaced radially inwardly when the tire is released from the mold. Apparatus is provided for actuating the mold parts to disassemble and assemble the mold.

Molding apparatus for injection molding a vehicle

A mold is provided for injection molding a vehicle tire such as the one disclosed in U.S. Pat. No. 3,805,868 having a bead of elastomeric material. The mold has an outer envelope and an inner body member having a core formed of radially collapsible sectors which combine to enclose a mold cavity. The inner body member has at least two annular elements, an upper and lower one, which are separable from one another and from the core along the direction of the core axis. The annular elements have surfaces which form axially inner surfaces of the tire's beads. The inner body member is also provided with members for blocking the annular elements with the core and with the envelope. The core of the mold is divided into two series of alternate collapsible sectors which are displaced radially inwardly when the tire is released from the mold.

Tire molding apparatus

The beads of a pneumatic tire having sidewalls of a cross-sectional shape, wherein upon inflation the midline thereof between the tread reinforcement and bead is convex with respect to the interior of the tire, are gripped by a rim having an annular channel generally elliptically shaped in cross-section and having its open side directed radially outwardly with respect to the axis of the wheel and inwardly directed annular flanges only partially closing the open side of the channel.

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Milan, Italy

Giovanni Calori