In the building of a carcass structure for tyres of vehicle wheels, the step of reinforcing with a loop at least one annular anchoring structure (10) associated at the axially opposite end edges of a carcass ply is carried out. Said reinforcement step is carried out on at least one radially expandable/contractable service drum (107a, 107b) and comprises the steps of: setting the service drum (107a, 107b) to a predetermined radial dimension selected according to the fitting diameter of the tyre to be manufactured, depositing the loop (5) on the service drum (107a, 107b), loading the annular anchoring structure (10) onto the service drum (107a, 107b) in a radially outer position with respect to the loop (5), radially expanding the service drum (107a, 107b) up to lock in position the annular anchoring structure (10), rotating the service drum (107a, 107b) about a longitudinal axis (X-X) thereof and, during such a rotation, turning the loop (5) up about the annular anchoring structure (10).

In the building of a carcass structure for tyres of vehicle wheels, the step of reinforcing with a loop at least one annular anchoring structure (10) associated at the axially opposite end edges of a carcass ply is carried out. Said reinforcement step is carried out on at least one radially expandable/contractable service drum (107a, 107b) and comprises the steps of: setting the service drum (107a, 107b) to a predetermined radial dimension selected according to the fitting diameter of the tyre to be manufactured, depositing the loop (5) on the service drum (107a, 107b), loading the annular anchoring structure (10) onto the service drum (107a, 107b) in a radially outer position with respect to the loop (5), radially expanding the service drum (107a, 107b) up to lock in position the annular anchoring structure (10), rotating the service drum (107a, 107b) about a longitudinal axis (X-X) thereof and, during such a rotation, turning the loop (5) up about the annular anchoring structure (10).

An annular bead core forming former is for manufacturing a bead core including a wire array in which a bead wire is helically wound in a width direction of the bead core. The bead core forming former comprises a main body portion having an outer circumferential surface with a circumferential groove extending in a circumferential direction for winding the bead wire and at least one width adjusting portion which moves relatively to the main body portion to changes a width of the circumferential groove.

An annular bead core forming former is for manufacturing a bead core including a wire array in which a bead wire is helically wound in a width direction of the bead core. The bead core forming former comprises a main body portion having an outer circumferential surface with a circumferential groove extending in a circumferential direction for winding the bead wire and at least one width adjusting portion which moves relatively to the main body portion to changes a width of the circumferential groove.

A bead retaining member includes a body having a concave first concave edge and one or more retaining elements which are distributed over the body along said first concave edge for retaining a first bead of a first size along a first retaining curve having a first retaining radius and for retaining a second bead of a second size along a second retaining curve having a second retaining radius larger than the first retaining radius. The first retaining curve intersects with the second retaining curve at a first intersection point and a second intersection point. The first concave edge is non-circular and is located radially outside of the second retaining curve in a center region of the first concave edge between the first intersection point and the second intersection point and radially outside of the first retaining curve in a first lateral region and a second lateral region.

A bead retaining member includes a body having a concave first concave edge and one or more retaining elements which are distributed over the body along said first concave edge for retaining a first bead of a first size along a first retaining curve having a first retaining radius and for retaining a second bead of a second size along a second retaining curve having a second retaining radius larger than the first retaining radius. The first retaining curve intersects with the second retaining curve at a first intersection point and a second intersection point. The first concave edge is non-circular and is located radially outside of the second retaining curve in a center region of the first concave edge between the first intersection point and the second intersection point and radially outside of the first retaining curve in a first lateral region and a second lateral region.

A method for verifying the correct formation of the beads in a process and a plant for building tyres for vehicle wheels, includes: loading a plurality of annular anchoring structures in a storage, disposing them in two groups separated by an opening; positioning a building drum provided with a carcass sleeve in a tyre bead-forming machine; picking up two of the annular anchoring structures from the storage and loading them on the tyre bead-forming machine. In a work area of the tyre bead-forming machine, on each of two axially opposite zones of the carcass sleeve, a respective annular anchoring structure is fit and each of the abovementioned zones is turned up around the respective annular anchoring structure to form the beads. The aforesaid opening allows an operator to conduct a visual inspection of the work area and/or access the work area during the entire work cycle of the machine.

A pneumatic tire includes a pair of bead portions, a pair of bead cores each disposed in a respective one of the pair of bead portions, a carcass extending between the pair of bead cores, the carcass including a carcass ply that includes a main portion extending between the pair of bead cores and a pair of turn-up portions each turned up around a respective one of the pair of bead cores from axially inside to outside of the tire and extending outwardly in a tire radial direction, and a reinforcing rubber layer disposed in each bead portion and being adjacent to an axially outside of the turn-up portion, wherein the reinforcing rubber layer has a laminated body in which a plurality of sheet-shaped rubber members having different radial lengths are laminated in the tire axial direction.

A tire 22 includes a pair of bead portions 66 to be fitted to a rim R. Each bead portion 66 includes a bead 30 having a core 52 and an apex 54. An outer surface 68 of the bead portion 66 includes a seat face 70 and a flange face 72 disposed radially inward and axially outward, respectively, of the bead 30, a heel face 74 disposed between the seat face 70 and the flange face 72, and a plurality of vent lines 78 projecting from the heel face 74 and extending in the circumferential direction. A contour of the heel face 74 is represented by an arc on a cross-section, of the tire 22, taken along a plane including a rotation axis of the tire 22, and a radius Rh of the arc is not less than 8 mm and not greater than 15 mm.

A tire 22 includes a pair of bead portions 66 to be fitted to a rim R. Each bead portion 66 includes a bead 30 having a core 52 and an apex 54. An outer surface 68 of the bead portion 66 includes a seat face 70 and a flange face 72 disposed radially inward and axially outward, respectively, of the bead 30, a heel face 74 disposed between the seat face 70 and the flange face 72, and a plurality of vent lines 78 projecting from the heel face 74 and extending in the circumferential direction. A contour of the heel face 74 is represented by an arc on a cross-section, of the tire 22, taken along a plane including a rotation axis of the tire 22, and a radius Rh of the arc is not less than 8 mm and not greater than 15 mm.