Industrie Pirelli S.p.a.

Societa Pneumatici Pirelli S.p.a.

Giorgio Bertoldo

Antonio Pacciarini

Franco Bottasso

An apparatus for feeding elastomeric strips used to form an annular tread reinforcing structure of a vehicle pneumatic tire provided with reinforcing metal cords to a drum which forms the strips into the annular reinforcing structure is disclosed. The apparatus comprises an endless belt looped about spaced pulleys which transfers cut lengths of an elastomeric strip for making an annular tread reinforcing structure from bobbins of the strip to a drum which shapes an annular tread reinforcing member therefrom. The cut lengths of elastomeric strip are maintained in the desired position on the belt and drum by the action of two separate magnetic fields. One of the magnets is stationary and is placed under the belt. The other magnet is adjacent to the belt pulley nearest the drum. Apparatus is provided for laying automatically the two ends of the elastomeric strip on the belt.

Apparatus for feeding reinforcing layers in tire manufacture

This invention provides a method and apparatus for making vehicle tires wherein the annular, reinforcing structure and the tread band are manufactured on two drums, one drum having a comb-shaped surface, and the other drum having sectors. The comb-shaped drum is co-axial and can be slipped off with respect to the drum having sectors. Means are provided for rotating the two drums independently of one another in a slipped position, and for centering the teeth of the comb when the two drums are one around the other. After centering, the sectors are expanded, from the inside towards the outside of the comb, for sustaining the annular structure previously disposed on the comb in a slipped position from the sectors and for receiving the tread band.

Process and apparatus for manufacturing vehicle tires

A process is provided for manufacturing radial tires for a motor vehicle having a radial carcass, a reinforcing structure with at least two layers of criss-crossed symmetrically arranged metallic cords forming a belt, and a tread. The process involves a series of steps which comprise: building up a carcass in a cylindrical configuration on a first expandable building drum and shaping the carcass into a toroidal configuration. A reinforcing belt is also formed by winding two layers of metallic cords on an auxiliary expandable drum with a diameter equal to the external diameter of the toroidal shaped carcass. The belt is maintained in slidable contact on the drum and shaped toroidally by expanding the auxiliary drum. The belt is then removed from the auxiliary drum and transferred with a tread band to the carcass on the first drum. The carcass is toroidal shaped again to assemble the carcass and belt. The assembly is vulcanized under pressure in a mold.

Process and apparatus for manufacturing radial tires

An expandible tire-building drum for making toric shaped tire carcasses built in the form of cylindrical sleeves is provided. The cylindrical sleeves have at their extremities, annular bulges which are circumferentially inextensible and are radially developed towards the inside. These bulges form the beads on the carcass. The height of the bead is one-half the difference between the internal diameter of the said sleeve and the internal diameter of the said bead. The drum comprises two co-axial discs, constituted substantially by a hub and an annular flange fixed to the hub, axially slidable reciprocally and fixed with each other in rotation. The said discs are supported on a rotating shaft which projects in cantilever fashion from a driving device. The discs comprise a radially external surface having a first part, capable of receiving the beads of the sleeve, and being defined as 'bead-seat'. The discs also have an annular co-axial ridge with an external diameter greater than the diameter of the said bead-seat disposed alongside the said seat on the part that is axially inside with respect to the said drum. The drum is characterized by the fact that in the said discs, the radially external surface comprises a second part having a frustoconical form that converges axially outside the drum, coinciding also along its axial inner border, with the axially outer border of the said bead-seat. The annular ridge, projects in cantilever fashion, from the disc axially towards the drum interior, the plane perpendicular to drum axis and tangent to the border axially inside the annular ridge resulting axially innermost of the plane perpendicular to the drum axis and tangent to the axially inner surface of the annular flange.

Growing community of inventors

Arese, Italy

Giorgio Bertoldo