A method for building tyres is described. An elementary semifinished product is deposited on a building drum rotated by an output end effector of a robotized arm in form of coils forming a component of a tyre. A processor determines a target rotation speed of the building drum and a target value for a speed parameter associated with the rotation. If the target value is not an integer number, the processor: i) determines a drive interval shorter than the effector settling time; ii) calculates first and second values corresponding to integer numbers immediately preceding and immediately following the target value; iii) calculates a speed parameter PWM profile with minimum and maximum values corresponding to the first and second values; and iv) controls the effector according to the PWM profile.

A method for building tyres is described. An elementary semifinished product is deposited on a building drum rotated by an output end effector of a robotized arm in form of coils forming a component of a tyre. A processor determines a target rotation speed of the building drum and a target value for a speed parameter associated with the rotation. If the target value is not an integer number, the processor: i) determines a drive interval shorter than the effector settling time; ii) calculates first and second values corresponding to integer numbers immediately preceding and immediately following the target value; iii) calculates a speed parameter PWM profile with minimum and maximum values corresponding to the first and second values; and iv) controls the effector according to the PWM profile.

A carcass sleeve is situated in a radially external position with respect to a toroidal forming drum, arranged in a first radially contracted operative condition. The carcass sleeve is shaped according to a toroidal configuration while the forming drum is positioned inside the carcass sleeve. During shaping of the carcass sleeve, the forming drum is radially expanded up to a second radially expanded operative condition. Upon completed shaping, the carcass sleeve is coupled to the forming drum in the second operative condition. The forming drum, coupled to the shaped carcass sleeve, is arranged in proximity to at least one device for building at least one belt layer at a radially external position relative to the shaped carcass sleeve.

The present disclosure is directed to a process and an apparatus for cutting a continuous rubber-covered belt in a process for building tyres for vehicle wheels, wherein the apparatus comprises a cutting group, in turn comprising: a knife formed by a first half-part and a second half-part and movable along a cutting direction that is tilted with respect to a supply direction of a rubber-covered belt placed beneath the knife. The process comprises: lifting a lifting element placed below the continuous rubber-covered belt and at the cutting zone, until a portion of rubber-covered belt is lifted, and lowering the single first-half part of the knife, making it slide with respect to the second half-part.

The present disclosure is directed to a process and an apparatus for cutting a continuous rubber-covered belt in a process for building tyres for vehicle wheels, wherein the apparatus comprises a cutting group, in turn comprising: a knife formed by a first half-part and a second half-part and movable along a cutting direction that is tilted with respect to a supply direction of a rubber-covered belt placed beneath the knife. The process comprises: lifting a lifting element placed below the continuous rubber-covered belt and at the cutting zone, until a portion of rubber-covered belt is lifted, and lowering the single first-half part of the knife, making it slide with respect to the second half-part.

A loading station for forming a fiber mass for micronaire testing. The loading station has a hopper for receiving an unformed fiber mass. A forming chamber receives the unformed fiber mass from the hopper. The forming chamber includes a non-movable back wall and a non-movable bottom plate with ports formed therein. The ports draw an airflow from the hopper into the forming chamber. A selectively movable isolation plate isolates the forming chamber from the hopper, and a selectively movable horizontal forming wall horizontally compacts the fiber mass into a desired horizontal cross-section. A selectively movable vertical forming wall vertically compacts the fiber mass into a desired vertical cross-section. A selectively movable plunger presses axially along the shaped fiber mass.

A tire 2 includes a tread 4 on which at least three circumferential grooves 24 continuously extending in a circumferential direction are formed, and a belt 14 located radially inward of the tread 4. A ratio of a center stretch, at a center portion of the belt, indicated by the follow/Mg formula (2) to a shoulder stretch, at an end portion of the belt, indicated by the following formula (1) is not less than 1 and not greater than 3, and the shoulder stretch is not less than 1%.

(Shoulder stretch)

100×(Rsa−Rsb)/Rsb  (1)

(Center stretch)

100×(Rca−Rcb)/Rcb  (2)

A tire 2 includes a tread 4 on which at least three circumferential grooves 24 continuously extending in a circumferential direction are formed, and a belt 14 located radially inward of the tread 4. A ratio of a center stretch, at a center portion of the belt, indicated by the follow/Mg formula (2) to a shoulder stretch, at an end portion of the belt, indicated by the following formula (1) is not less than 1 and not greater than 3, and the shoulder stretch is not less than 1%.

(Shoulder stretch)

100×(Rsa−Rsb)/Rsb  (1)

(Center stretch)

100×(Rca−Rcb)/Rcb  (2)

A plant for building different models of green tyres for vehicle wheels, including a plurality of workstations using elementary semi-finished products is described. A first carcass structure of a first model of tyre is built on a first forming support, in a first workstation, the first carcass structure including at least one first carcass ply obtained from a first elementary semi-finished product, and at least one first pair of annular reinforcing inserts. The first forming support is delivered to a bypass device to go beyond at least one second workstation without transiting through it.

A plant for building different models of green tyres for vehicle wheels, including a plurality of workstations using elementary semi-finished products is described. A first carcass structure of a first model of tyre is built on a first forming support, in a first workstation, the first carcass structure including at least one first carcass ply obtained from a first elementary semi-finished product, and at least one first pair of annular reinforcing inserts. The first forming support is delivered to a bypass device to go beyond at least one second workstation without transiting through it.