With a pneumatic tire mounted on a regular rim, inflated to a regular internal pressure, and in an unloaded state, in a tire meridian cross-sectional view, electrically conductive rubber is formed in a region corresponding to a bulging land portion except for a region with a width of 5% of a width of the bulging land portion and being centered at a bulging apex position bulging most toward an outer side of the bulging land portion in a tire radial direction.

In a process for building tyres for vehicle wheels, at least one tread band (9) or other elastomeric component of a tyre (2) is made by applying at least one continuous elongated element (14) according to a plurality of turns (C) around a forming drum (15) rotating around a geometric rotation axis (X) thereof. The continuous elongated element (14) is made by the action of extruding a first material through an extrusion nozzle (16), to form an inner core (33) of said continuous elongated element (14) exiting from an outlet opening (18) of the extrusion nozzle (16). During the extrusion, a second material different from the first material is conveyed around the first material, at the extrusion nozzle (16) and upstream of the outlet opening (18), to form a coating layer (32) which entirely surrounds the inner core (33).

A method for forming a composite tread, the method comprising the steps of: forming a coextruded strip of a first compound and a second compound, wherein the first compound is a tread compound, and the second compound is formed from a second compound, wherein the tread is formed from winding the coextruded strip onto the tire building drum while varying the ratio of the first compound to the second compound

The invention relates to a method for producing a tread (20), comprising the steps: extruding the tread (20), which has an outer side (22) and an inner side (24), opposite the outer side (22), and a carrying region (26) made of a carrying region rubber material and a guide strip (28) made of a guide strip rubber material, wherein the guide strip (28) extends from the outside (22) to the inside (24) and a specific electrical guide strip resistance (W.sub.28) of the guide strip rubber material is smaller than a specific electrical carrying region resistance of the carrying region rubber material. The steps according to the invention are: determining an electrical guide strip resistance (W.sub.28) of the guide strip (28) between the outer side (22) and the inner side (24) and outputting a warning signal when the electrical resistance (W) exceeds a specified maximum resistance (W.sub.28,max).

A method for manufacturing a tire includes a rubber layer forming step of helically wrapping non-conductive strip rubber supplied from an extruder around an outer circumferential side of a conductive case main body to form a plurality of rubber layers. The rubber layer forming step includes: a non-conductive strip rubber wrapping step of wrapping the non-conductive strip rubber around; and a conductive strip rubber wrapping step of superposing conductive rubber on the non-conductive strip rubber to wrap around as conductive strip rubber. The conductive strip rubber wrapping step includes: wrapping pieces of the conductive rubber around in a layered manner so as to overlap each other in a tire radial direction; and forming a conductive portion reaching up to a tire surface.

A method for the cold retreading of a tyre (1) comprising the following steps: —a removal step, during which the old, worn tread is removed from the tyre in order to expose an equatorial surface (2) of a casing (3) of the tyre (1); —a deposition step, during which a cushion (4) and a pre-cured tread strip (6) provided with a tread pattern are deposited around the equatorial surface (2) of the casing (3); and—a curing step, during which the cushion (4) arranged between the casing (3) and the pre-cured tread strip (6) is cured. The retreading method also comprises a conductive interposition step, during which a conductive adhesive compound (5) is deposited between said cushion (4) and said pre-cured tread strip (6) and/or between said cushion (4) and said casing (3). The conductive adhesive compound (5) comprises at least one conductive material in a quantity ranging from 5 to 20% by weight and chosen among graphene, graphite and a carbon black having a surface area which is greater than or equal to 300 m.sup.2/gr. The curing step comprises a connection operation, during which said conductive adhesive (5) compound is connected either to a heat source (S) or to a power source (S) so as to transmit the heat to the cushion (4).

A method of making a tire includes placing substantially circular sheets of polymeric material on top of each other until a tire is built to a predetermined width. A predetermined tread shape is formed along a circumference of the substantially circular sheets of polymeric material.

A tire includes a circumferential tread disposed in a crown region of the tire and an undertread disposed below the circumferential tread. The tire also has a pair of bead regions, including a first bead region and a second bead region, and a body ply extending from the first bead region to the second bead region. The tire further has a pair of sidewalls, including a first sidewall extending between the first bead region and the circumferential tread and a second sidewall extending between the second bead region and the circumferential tread. The tire also has a sidewall antenna adjacent to the first sidewall. The sidewall antenna has a first end contacting the undertread and a second end contacting the body ply.

A pneumatic tire is provided in the tread portion with a land portion including a conductive portion made of a conductive rubber. The conductive portion has a radially inner end electrically connected to a conductive tire internal structural to be connected to a wheel rim, and a radially outer end exposed in a ground contacting top surface of the land portion. The conductive portion extends from its radially inner end to outer end while inclining toward a first side surface of the land portion. The first side surface comprises a radially inner part, and a radially outer part extending radially outwardly from the radially inner part while inclining to the radially outer end of the conductive portion at an angle greater than the radially inner part.

A pneumatic tire includes a tread portion including main grooves and land portions. In a cross-sectional view of the tire, one of the land portions includes a first edge, a second edge, a ground contact surface extending between the first edge and the second edge and having an arc-shaped profile protruding radially outwardly, and conductive portion made of conductive rubber. The conductive portion extends from a radially inner end to a radially outer end exposed at the ground contact surface with an inclination toward the first edge. The inner end is connected to a tire internal structural member to be electrically connected to a rim when the tire is mounted on the rim. On the ground contact surface, a central position of the outer end is located on a central position of the land portion in a tire axial direction, or on a side of the first edge.