A process and an apparatus for building tyres for vehicle wheels includes assembling at least one tyre component through laying of strip-like elements disposed circumferentially close to each other on a deposition surface radially external to the forming drum, wherein laying of each strip-like element includes: radially moving the strip-like element close to the deposition surface; locking a central portion of the strip-like element against the deposition surface; and pulling the strip-like element in opposite directions starting from the central portion toward the opposite ends thereof, while the central portion is maintained in a locked condition against the deposition surface, so as to progressively lay down the strip-like element against the deposition surface.

A process and an apparatus for building tyres for vehicle wheels includes assembling at least one tyre component through laying of strip-like elements disposed circumferentially close to each other on a deposition surface radially external to the forming drum, wherein laying of each strip-like element includes: radially moving the strip-like element close to the deposition surface; locking a central portion of the strip-like element against the deposition surface; and pulling the strip-like element in opposite directions starting from the central portion toward the opposite ends thereof, while the central portion is maintained in a locked condition against the deposition surface, so as to progressively lay down the strip-like element against the deposition surface.

The present invention has an object of providing a pneumatic tire that exhibits better uniformity by improving the wire wound body for constituting the bead core. The pneumatic tire 1 comprises a bead core 5 comprising a wire wound body 10 in which one bead wire 10a is spirally wound in a continuous around a tire rotational axis CL so that a plurality of layers of the bead wire are formed in a radial direction of the tire. The wire wound body 10 comprises a first part 13 and a second part 14. The first part 13 comprises a plurality of layers of the bead wire 10a each circumferentially extending with a constant radius from the tire rotational axis CL. The second part comprises a plurality of layers of the bead wire 10a each circumferentially extending while changing its radius from the tire rotational axis CL.

The tool which contains: a support, and an arm bearing a strip extrusion member and a strip applicator roller, wherein the arm is articulated with respect to the support about a first axis parallel to a geometric axis of the roller and about a second axis tangential to a circumference of the roller, of the first and second axes at least one passing through a centre of gravity of the arm.

A method for controlling the thickness of a continuous elongated element made of elastomeric material, applied according to coils wound on a forming support, includes: advancing a head end of the continuous elongated element toward the forming support; subjecting, during the advancement, the continuous elongated element to a first stretching with a first stretch coefficient before applying on the forming support; and subjecting, during the advancement, the continuous elongated element to a second stretching with a second stretch coefficient during the application on the forming support. During the first stretching, a span of the continuous elongated element adjacent to the head end is stretched with a supplementary stretch coefficient greater than the first stretch coefficient, in a manner so as to confer, also to the span adjacent to the head end, a stretch and a section similar or substantially equivalent to those of the rest of the continuous elongated element.

A method for controlling the thickness of a continuous elongated element made of elastomeric material, applied according to coils wound on a forming support, includes: advancing a head end of the continuous elongated element toward the forming support; subjecting, during the advancement, the continuous elongated element to a first stretching with a first stretch coefficient before applying on the forming support; and subjecting, during the advancement, the continuous elongated element to a second stretching with a second stretch coefficient during the application on the forming support. During the first stretching, a span of the continuous elongated element adjacent to the head end is stretched with a supplementary stretch coefficient greater than the first stretch coefficient, in a manner so as to confer, also to the span adjacent to the head end, a stretch and a section similar or substantially equivalent to those of the rest of the continuous elongated element.

A method for forming a belt-like rubber sheet S by extruding rubber on a drum outer peripheral surface 3a by an extruder 2 includes: a front end forming step for forming a front end S1 having a wedge-shaped cross section; an intermediate part forming step for forming an intermediate part S2 having a desired thickness; and a rear end forming step for forming a rear end S3 having a wedge-shaped cross section by gradually decreasing an extrusion amount of the rubber to zero from a predetermined extrusion amount in a predetermined time, gradually decreasing the rotational speed of the drum outer peripheral surface 3a to zero from a predetermined rotational speed in the predetermined time, and gradually decreasing a distance from the drum outer peripheral surface 3a to a die 21 to an extrusion end distance from a predetermined distance in the predetermined time.

Disclosed is a guiding device having a guide roller that is rotatable about a roller axis and that has an exterior guide surface extending in a circumferential direction about the roller axis, wherein the guide roller includes a plurality of roller segments juxtaposed in an axial direction along the roller axis for forming the exterior guide surface, wherein the plurality of roller segments are movable relative to each other to enable the guide roller to be positioned in a maximum bend state in which the roller axis extends along an arc, wherein the plurality of roller segments are interlocked to rotate together about the roller axis in a maximum bend state, wherein the plurality of roller segments extend over an arc length along the arc of the roller axis, wherein the arc length is at least ninety degrees in the maximum bend state.

A tire production device includes a supply unit to supply a ribbon strip molded into a ribbon shape; and a tire molding unit to stick the ribbon strip onto an outer periphery of a drum having an inner peripheral shape of a tire, while rotating the drum, in which the supply unit has a sticking position at which the ribbon strip is stuck onto the outer periphery of the drum. The tire molding unit includes: the drum with a horizontal rotation axis; a turning table that turns the drum around a vertical axis while maintaining a horizontal rotation axis of the drum; and a parallel movement mechanism provided on the turning table to move the drum in parallel along a horizontal surface set to the turning table, and in which the rotation axis extends in a tangential direction centered on the axis line about which the turning table turns.

A tire production device includes a supply unit to supply a ribbon strip molded into a ribbon shape; and a tire molding unit to stick the ribbon strip onto an outer periphery of a drum having an inner peripheral shape of a tire, while rotating the drum, in which the supply unit has a sticking position at which the ribbon strip is stuck onto the outer periphery of the drum. The tire molding unit includes: the drum with a horizontal rotation axis; a turning table that turns the drum around a vertical axis while maintaining a horizontal rotation axis of the drum; and a parallel movement mechanism provided on the turning table to move the drum in parallel along a horizontal surface set to the turning table, and in which the rotation axis extends in a tangential direction centered on the axis line about which the turning table turns.