The machine includes a tire-building zone for producing, on a drum, a carcass entity that includes a carcass ply with carcass reinforcers. The machine also includes a finishing zone for producing a crown entity that includes a tread, a shaping system for causing the carcass entity to expand radially in order to give it a toroidal shape. In an assembling zone, the crown entity is assembled on the carcass entity. A biasing system interacts, during the shaping, with the carcass reinforcers so as to modify the angular orientation of the carcass reinforcers with respect to the circumferential direction of the drum. An automatic control unit allows a biased-crown tire to be manufactured in this way.

A process and a plant for producing tyres for vehicle wheels are described. Building of a crown structure of the tyre includes building a crossed belt structure on a substantially cylindrical first forming drum, transferring the crossed belt structure from the first forming drum to an annular holding member, positioning a second forming drum in a radially inner position with respect to the annular holding member, transferring the crossed belt structure from the annular holding member to the second forming drum by radially expanding the second forming drum until it is brought into contact with the crossed belt structure so as to toroidally shape the crossed belt structure, and depositing at least one zero degrees belt layer on the second forming drum in a radially outer position with respect to the toroidally-shaped crossed belt structure.

A process and a plant for producing tyres for vehicle wheels are described. Building of a crown structure of the tyre includes building a crossed belt structure on a substantially cylindrical first forming drum, transferring the crossed belt structure from the first forming drum to an annular holding member, positioning a second forming drum in a radially inner position with respect to the annular holding member, transferring the crossed belt structure from the annular holding member to the second forming drum by radially expanding the second forming drum until it is brought into contact with the crossed belt structure so as to toroidally shape the crossed belt structure, and depositing at least one zero degrees belt layer on the second forming drum in a radially outer position with respect to the toroidally-shaped crossed belt structure.

A method for building belt assemblies for tyres for vehicle wheels is described. The method includes building a crossed belt structure on a forming drum. Depending on the type of tyre to be produced, the method selects whether to build a belt assembly having a cylindrical shaping or a belt assembly having a toroidal shaping. In order to build a belt assembly having a cylindrical shaping, zero degrees belt layer is deposited on the forming drum in a radially outer position with respect to the crossed belt structure. In order to build a belt assembly having a toroidal shaping, the crossed belt structure is picked up from the forming drum. The crossed belt structure is then toroidally shaped and transferred onto another forming drum. A zero degrees belt layer is then deposited on the other forming drum in a radially outer position with respect to the toroidally shaped crossed belt structure.

A method for building belt assemblies for tyres for vehicle wheels is described. The method includes building a crossed belt structure on a forming drum. Depending on the type of tyre to be produced, the method selects whether to build a belt assembly having a cylindrical shaping or a belt assembly having a toroidal shaping. In order to build a belt assembly having a cylindrical shaping, zero degrees belt layer is deposited on the forming drum in a radially outer position with respect to the crossed belt structure. In order to build a belt assembly having a toroidal shaping, the crossed belt structure is picked up from the forming drum. The crossed belt structure is then toroidally shaped and transferred onto another forming drum. A zero degrees belt layer is then deposited on the other forming drum in a radially outer position with respect to the toroidally shaped crossed belt structure.

A first ply and then a second ply, which is superposed on the first ply, are produced on a hoop-type first support. The hoop-type first support has a first receiving surface, to form a laminate. The first and second plies forming the laminate are transferred onto an annular second receiving surface of a core so that the laminate is wrapped on the core until each ply is closed on itself and the laminate is thus closed on itself in a ring about the central axis of the core.

Crown reinforcement of an aircraft tire comprises a working reinforcement (2) radially inside of tread (3) and radially outside of carcass reinforcement (4). Working reinforcement (2) comprises two working bi-plies (21, 22) radially superposed with respective axial widths (L.sub.1, L.sub.2), from first axial end (I.sub.1, I.sub.2) to second axial end (I.sub.1, I.sub.2). Each working bi-ply (21, 22) comprises two working layers (211, 212; 221, 222) radially superposed and respectively made up of axially juxtaposed portions of strip (5) of axial width W extending circumferentially in periodic curve (6) that forms, in the equatorial plane (XZ) of the tire and with the circumferential direction (XX) of the tire, a non-zero angle A and has a radius of curvature R at its extrema (7). The difference DL between the respective axial widths (L.sub.1, L.sub.2) of the radially superposed working bi-plies (21, 22) is at least equal to 2(W+(RW/2)(1cos A)).

Crown reinforcement of an aircraft tire comprises a working reinforcement (2) radially inside of tread (3) and radially outside of carcass reinforcement (4). Working reinforcement (2) comprises two working bi-plies (21, 22) radially superposed with respective axial widths (L.sub.1, L.sub.2), from first axial end (I.sub.1, I.sub.2) to second axial end (I.sub.1, I.sub.2). Each working bi-ply (21, 22) comprises two working layers (211, 212; 221, 222) radially superposed and respectively made up of axially juxtaposed portions of strip (5) of axial width W extending circumferentially in periodic curve (6) that forms, in the equatorial plane (XZ) of the tire and with the circumferential direction (XX) of the tire, a non-zero angle A and has a radius of curvature R at its extrema (7). The difference DL between the respective axial widths (L.sub.1, L.sub.2) of the radially superposed working bi-plies (21, 22) is at least equal to 2(W+(RW/2)(1cos A)).

An object is to improve durability without increasing the tire mass. An aircraft pneumatic tire (10) includes: a carcass ply (12) that straddles between a pair of bead portions (24); an inside belt layer (14) that is provided at a tire radial direction outer side of a crown portion of the carcass ply (12); an outside belt layer (16) that is provided at the tire radial direction outer side of the inside belt layer (14) and that is configured by a cord of cord configuration elements that have been twisted together; a belt protection layer (18) that is provided at the tire radial direction outer side of the outside belt layer (16) and that is configured by a cord of cord configuration elements that have been twisted together; and a low elasticity portion that is provided at at least one of the cord of the belt protection layer (18) or the cord of the outside belt layer (16), and that has a lower elasticity than other length direction portions of the cord (32).

An object is to improve durability without increasing the tire mass. An aircraft pneumatic tire (10) includes: a carcass ply (12) that straddles between a pair of bead portions (24); an inside belt layer (14) that is provided at a tire radial direction outer side of a crown portion of the carcass ply (12); an outside belt layer (16) that is provided at the tire radial direction outer side of the inside belt layer (14) and that is configured by a cord of cord configuration elements that have been twisted together; a belt protection layer (18) that is provided at the tire radial direction outer side of the outside belt layer (16) and that is configured by a cord of cord configuration elements that have been twisted together; and a low elasticity portion that is provided at at least one of the cord of the belt protection layer (18) or the cord of the outside belt layer (16), and that has a lower elasticity than other length direction portions of the cord (32).