An intermediate article of manufacture formed as a first stage bead area subassembly for a split ply pneumatic tire carcass is disclosed. The bead area subassembly has an annular bead core; a bead apex; a ply strip; and preferably a sidewall affixed to the ply strip. The subassembly is formed into a disk-shaped bead area monocomponent. The ply strip is wrapped about the bead core and the apex to form a ply turnup and both the ply strip and the ply turnup extend radially outwardly from the bead core. The bead area subassembly when formed into the disk-shaped bead area monocomponent is placed on an annular holder device.

To form a tire carcass, a body ply is wound about a drum, which has two half-drums movable axially in opposite directions to and from a center plane of the drum, and having respective turn-up bladders, on each of which is laid a respective annular lateral portion of the body ply; each annular lateral portion being turned up about a respective bead bundle and onto a sidewall of a toroidal-shaped annular central portion of the body ply by inflating the relative turn-up bladder and controlling distension of a given annular portion of the turn-up bladder so that, when inflation is completed, the annular portion assumes a given final position, in which an intermediate portion of the turn-up bladder rolls outwards along the relative sidewall of the annular central portion of the body ply.

A carcass ply is applied around an outer surface of a building drum according to an application diameter larger than the fitting diameter of a tyre. Coaxially engaged around each of the end flaps is an annular anchoring structure defining the fitting diameter. A pair of sidewalls is manufactured by laying of a continuous elongated element in the form of approached coils on the carcass sleeve. An outer sleeve, including at least one belt structure possibly associated with a tread band, is coaxially centered around the carcass sleeve. Through axial approaching of two halves forming the building drum, the carcass sleeve is shaped into a toroidal configuration to determine application of same against a radially internal surface of the outer sleeve.

A carcass ply is applied around an outer surface of a building drum according to an application diameter larger than the fitting diameter of a tire. Coaxially engaged around each of the end flaps is an annular anchoring structure defining the fitting diameter. A pair of sidewalls is manufactured by laying of a continuous elongated element in the form of approached coils on the carcass sleeve. An outer sleeve, including at least one belt structure possibly associated with a tread band, is coaxially centered around the carcass sleeve. Through axial approaching of two halves forming the building drum, the carcass sleeve is shaped into a toroidal configuration to determine application of same against a radially internal surface of the outer sleeve.

A tyre carcass building drum (1) having a longitudinal axis (3) and two half-drums (6) movable along the longitudinal axis (3) in opposite directions away from and towards a centre plane (4) of the drum (1), each one comprising a bead carrying device (16) defining a saddle and a turn-up device (41) designed to turn up a annular side portion (42) of a carcass ply around, and on the outside of a respective bead ring; the turn-up device (43) having an end portion arranged, at rest, along a peripheral annular portion (18) of the saddle (17) and shaped so as to define an extension of the curvilinear profile of the saddle (17); and thrust means (50) being provided to directly and independently exert an axial thrust and a radial thrust on the turn-up device (43). The invention also relates to an operating method of said drum.

The present disclosure provides a tire building method and a mechanical drum. The tire building method includes: controlling an attaching mechanism to roll a bead filler to attach the bead filler on a carcass of the tire; while attaching the bead filler or during a process of attaching the bead filler, controlling a turn-up mechanism to support a sidewall of a tire; and after the bead filler is attached, controlling the turn-up mechanism to roll the sidewall of the tire. The tire building method according to the present disclosure solves problems of long time of building the tire and low efficiency of building the tire in the related art.