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.

An improved bead setting assembly includes at least one bead setter. The bead setter in turn includes a frame member and magnetic segments pivotally mounted on the frame member at positions about an opening in the frame member. Means are provided to selectively rotate the magnetic segments radially inwardly to a bead retaining position and radially outwardly from the bead retaining position. A plurality of clamp segments are pivotally mounted on the frame member at positions about the frame opening, and each clamp segment in turn includes a clamp arm with a multi-piece construction. Means are provided for selectively rotating the clamp segments radially inwardly into engagement with the bead and radially outwardly from the bead engagement. A rotary encoder is mounted on the frame member and is operatively connected to a selected one of the clamp segments for determining a disposition of the bead.

An apparatus for manufacturing a pneumatic tire, comprises: a cylindrical former for forming a tire base from rubber members, a carcass and bead cores; and bead lock devices arranged at both ends of the former in its axial direction. Each bead lock device is expandable and contractable in diameter, and comprises a holding portion for supporting the bead core from the inside in the radial direction when expanded. The holding portion comprises an axially inner flange, an axially outer flange, and a bottom surface connecting therebetween. The height of the axially inner flange is greater than the height of the outer flange by 5 mm or more.

The invention relates to a calibration tool and a method for calibrating a laser-triangulation measuring system, wherein the calibration tool comprises a tool body that defines a reference plane and that is rotatable relative to the measuring system about a rotation axis perpendicular to said reference plane, wherein the tool body is provided with one or more calibration surfaces that define a pattern of calibration positions, wherein the pattern comprises at least three columns extending in a radial direction away from the rotation axis and at least three rows extending in a circumferential direction about the rotation axis, wherein for each column the calibration positions within said respective column vary in height relative to the reference plane in a height direction perpendicular to said reference plane and wherein for each row the calibration positions within the respective row vary in height in the height direction relative to the reference plane.

A process for manufacturing tyres for vehicle wheels, comprising the step of building on a forming support a carcass structure comprising at least one carcass ply and, at least one end edge of the carcass ply, at least one annular anchoring structure comprising at least one substantially circumferential annular insert and at least one filling insert associated to said at least one substantially circumferential annular insert. The step of building the carcass structure comprises the steps of positioning the annular anchoring structure on the carcass ply by moving the annular substantially circumferential insert into contact with an end edge of the carcass ply by means of a special positioning member, pulling down the filling insert on the end edge of the carcass ply and turning up a free end portion of the end edge of the carcass ply so as to form a turned up end portion of the carcass ply including said annular anchoring structure. The pulling down of the filling insert on the end edge of the carcass ply is carried out by a special pulling down member while the substantially circumferential annular insert is retained into a contact position with the end edge of the carcass ply by said positioning member.

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 process for manufacturing tyres for vehicle wheels, comprising the step of building on a forming support a carcass structure comprising at least one carcass ply and, at at least one end edge of the carcass ply, at least one annular anchoring structure comprising at least one substantially circumferential annular insert and at least one filling insert associated to said at least one substantially circumferential annular insert. The step of building the carcass structure comprises the steps of positioning the annular anchoring structure on the carcass ply by moving the annular substantially circumferential insert into contact with an end edge of the carcass ply by means of a special positioning member, pulling down the filling insert on the end edge of the carcass ply and turning up a free end portion of the end edge of the carcass ply so as to form a turned up end portion of the carcass ply including said annular anchoring structure. The pulling down of the filling insert on the end edge of the carcass ply is carried out by a special pulling down member while the substantially circumferential annular insert is retained into a contact position with the end edge of the carcass ply by said positioning member.

A method and a device for the production of a green tire, in which at least two materials in strip form are positioned on a tire building drum. At least two cores are set in place. The tire building drum is equipped both with a core clamping device and with a core fixing device. The tire building drum is composed of a central part and of two drum halves arranged adjacent to the central part on both sides. The drum halves are arranged such that they can be positioned in an axial direction. The central part is equipped with a variable diameter in a radial direction. A radial enlargement of the diameter of the central part is performed before the cores are set in place.

A tire manufacturing method comprises causing a bead member having a bead core region and a bead filler region to be wrapped cylindrically about the outer circumferential surface of a carcass ply member which is wrapped cylindrically about a drum, and causing an outer zone of the carcass ply member to be folded back upon itself by way of a folded region so as to envelop the bead member, the bead filler region comprises a first rubber region that is contiguous with the bead core region, and a second rubber region that is contiguous with the first rubber region, and when the bead member is wrapped about the outer circumferential surface of the carcass ply member, the second rubber region is already contiguous with the first rubber region.