B29D30/12

Process and expandable forming drum for building tyres for vehicle wheels

A forming drum has circumferentially consecutive sectors that are radially movable between a contracted condition and an expanded condition in which the sectors are radially moved away from a geometric axis in order to define a radially external abutment surface. Each sector has circumferentially opposite coupling portions, each having circumferential projections alternated with circumferential cavities. The projections of each sector are slidably engaged in the respective cavities of circumferentially adjacent sectors. From at least one of the projections, at least one support wing is extended having a first side and a second side that are respectively opposite. The first side coincides with a portion of the abutment surface and the second side at least partially overlaps one of the projections belonging to an adjacent sector. A process for building tyres employing the drum is also described.

Process and expandable forming drum for building tyres for vehicle wheels

A forming drum has circumferentially consecutive sectors that are radially movable between a contracted condition and an expanded condition in which the sectors are radially moved away from a geometric axis in order to define a radially external abutment surface. Each sector has circumferentially opposite coupling portions, each having circumferential projections alternated with circumferential cavities. The projections of each sector are slidably engaged in the respective cavities of circumferentially adjacent sectors. From at least one of the projections, at least one support wing is extended having a first side and a second side that are respectively opposite. The first side coincides with a portion of the abutment surface and the second side at least partially overlaps one of the projections belonging to an adjacent sector. A process for building tyres employing the drum is also described.

Drum for producing a tire, provided with retractable sectors

A drum for building a green tire casing having: sectors that form a circumferential face of the drum, and at least one cam for controlling a radial movement of the sectors with respect to a rotation axis of the drum. The cam has two main faces and is designed such that a monotonous movement of the cam first of all causes the radial movement of some of the sectors by virtue of ramps situated on its first face without modifying a radial position of the other sectors, and then causes the radial movement of the other sectors by virtue of ramps situated on its second face, the movement of all of the sectors then being simultaneous.

Drum for producing a tire, provided with retractable sectors

A drum for building a green tire casing having: sectors that form a circumferential face of the drum, and at least one cam for controlling a radial movement of the sectors with respect to a rotation axis of the drum. The cam has two main faces and is designed such that a monotonous movement of the cam first of all causes the radial movement of some of the sectors by virtue of ramps situated on its first face without modifying a radial position of the other sectors, and then causes the radial movement of the other sectors by virtue of ramps situated on its second face, the movement of all of the sectors then being simultaneous.

Expandable forming drum, and process for building tyres

A toroidal forming drum and a process for budding tyres. The toroidal forming drum is expanded within a shaped carcass sleeve for supporting the carcass sleeve against an abutment surface externally provided by the forming drum. An elementary semi-finished product is applied around the shaped carcass sleeve by pressing the elementary semi-finished product toward the abutment surface. The abutment surface has circumferential rows of solid portions alternated with hollow portions. The solid portions, arranged along axially opposite circumferential edges of the abutment surface, have a transverse size between 10% and 60% of a transverse size presented by the solid portions arranged in proximity to an axial centreline plane of the abutment surface.

Expandable forming drum, and process for building tyres

A toroidal forming drum and a process for budding tyres. The toroidal forming drum is expanded within a shaped carcass sleeve for supporting the carcass sleeve against an abutment surface externally provided by the forming drum. An elementary semi-finished product is applied around the shaped carcass sleeve by pressing the elementary semi-finished product toward the abutment surface. The abutment surface has circumferential rows of solid portions alternated with hollow portions. The solid portions, arranged along axially opposite circumferential edges of the abutment surface, have a transverse size between 10% and 60% of a transverse size presented by the solid portions arranged in proximity to an axial centreline plane of the abutment surface.

FACILITY AND METHOD FOR MANUFACTURING AN ANNULAR TIRE ON A LIGHTWEIGHT MONOLITHIC CORE

The facility comprises a tire-building station that is configured to form an uncured tire on a core. A curing station is configured to cure the assembly formed by the core and the uncured tire so as to obtain a cured annular tire. An extraction station is configured to separate, after the curing operation, the cured tire from the core. The curing station has a first, heating, thermal source which presses against the exchange face of the core for the curing operation and is then dissociated from the core and remains in the curing station in order to leave the exchange face free again when the core and the cured tire are transferred to the extraction station so that a second, refrigerating, thermal source of the extraction station takes the place of the first thermal source in contact with the exchange face of the core so as to cool the core.

FACILITY AND METHOD FOR MANUFACTURING AN ANNULAR TIRE ON A LIGHTWEIGHT MONOLITHIC CORE

The facility comprises a tire-building station that is configured to form an uncured tire on a core. A curing station is configured to cure the assembly formed by the core and the uncured tire so as to obtain a cured annular tire. An extraction station is configured to separate, after the curing operation, the cured tire from the core. The curing station has a first, heating, thermal source which presses against the exchange face of the core for the curing operation and is then dissociated from the core and remains in the curing station in order to leave the exchange face free again when the core and the cured tire are transferred to the extraction station so that a second, refrigerating, thermal source of the extraction station takes the place of the first thermal source in contact with the exchange face of the core so as to cool the core.

Rigid core mold removal device and tire manufacturing method

A method for manufacturing a tire T comprises a step for forming a green tire on the outside of a rigid core mold 2, a step for vulcanization-molding and obtaining a tire-accompanying rigid core mold G, a step for setting, at an assembly station P3, a core 5 taken out from the tire-accompanied rigid core mold G, and a removal and assembly step for removing one core segment 3 from the tire T by moving in inwardly in the tire radial direction from the tire-accompanying rigid core mold G and mounting it on the core 5 set at the assembly station. The removal and assembly step is performed for every core segment in the tire, whereby a rigid core mold 2 is assembled at the assembly station P3, while removing the rigid core mold 2 from the tire T.

Rigid core mold removal device and tire manufacturing method

A method for manufacturing a tire T comprises a step for forming a green tire on the outside of a rigid core mold 2, a step for vulcanization-molding and obtaining a tire-accompanying rigid core mold G, a step for setting, at an assembly station P3, a core 5 taken out from the tire-accompanied rigid core mold G, and a removal and assembly step for removing one core segment 3 from the tire T by moving in inwardly in the tire radial direction from the tire-accompanying rigid core mold G and mounting it on the core 5 set at the assembly station. The removal and assembly step is performed for every core segment in the tire, whereby a rigid core mold 2 is assembled at the assembly station P3, while removing the rigid core mold 2 from the tire T.