Abstract: An expandable bladder has at least one first layer of butyl material and one second layer of silicone material, radially external to the first layer. The first and second layers have an undulated interface profile defining mechanical-engagement elements between the first and second elastomer materials. A process for manufacturing bladder as well as a tire molding and vulcanizing apparatus incorporating the bladder.

Abstract: An expandable bladder has at least one first layer of butyl material and one second layer of silicone material, radially external to the first layer. The first and second layers have an undulated interface profile defining mechanical-engagement elements between the first and second elastomer materials. A process for manufacturing bladder as well as a tyre moulding and vulcanising apparatus incorporating the bladder.

Abstract: An expandable bladder has at least one first layer of butyl material and one second layer of silicone material, radially external to the first layer. The first and second layers have an undulated interface profile defining mechanical-engagement elements between the first and second elastomer materials. A process for manufacturing bladder as well as a tire molding and vulcanising apparatus incorporating the bladder.

Abstract: A method for manufacturing a tire includes making at least one semi-finished elementary product of elastomeric material and depositing it in adjacent turns on a toroidal support. Making the at least one elementary product includes extruding the elastomeric material through an extruder head including a bushing defining a tapered extrusion channel. An extruder includes a chamber, at least one helical screw disposed in the chamber, and the extruder head. The head includes an outer tubular body attached by one end to the chamber, a bushing disposed inside the body to define the tapered extrusion channel, and a die disposed inside the body. A ratio of an area of the inlet section to an area of the outlet section is greater than 5:1 and less than 100:1 and a ratio of a diameter of the inlet section to a length of the bushing is greater than 0.1 and less than 1:1.

Abstract: A pneumatic tire has a carcass structure having at least one carcass ply and at least one annual reinforcing structure associated with the carcass ply, a tread band made of an elastomeric material at a radially outer position with respect to the carcass structure, a belt structure interposed between the carcass structure and the tread band and a pair of axially opposite side walls on the carcass structure, wherein the tread band has i) at least one first sector, radially extending, substantially of a first elastomeric material; ii) a plurality of second sectors radially extending, positioned at axially opposite sides of the at least one first sector and substantially of a second elastomeric material; iii) at least one longitudinal groove formed in the at least one first sector and extending substantially for the entire circumferential development of the tread band, wherein the first elastomeric material has a modulus of elasticity under compression at 23° C.

Abstract: A vehicle wheel tire includes a carcass structure, at least one annular reinforcing structure, a tread band, and a pair of sidewalls. The carcass structure includes at least one carcass ply, each including a plurality of elongated elements disposed around a cross-section profile of the tire. Each elongated element includes two side portions at mutually-spaced-apart positions and a crown portion that extends between the side portions. The at least one annular reinforcing structure includes at least one bead core. A fraction of the elongated elements is turned up around the at least one bead core. A method of manufacturing the tire includes preparing the elongated elements, disposing each elongated element on a toroidal support, applying at least one bead core at a region close to side portions of the elongated elements, and turning up ends of a fraction of the elongated elements around the at least one bead core.

Abstract: An apparatus for building pneumatic tyres includes a forming support and an assembling device to assemble components of elastomeric material on the forming support. The assembling device includes a feeding unit to deliver a continuous elongated element of elastomeric material, a conveyor having a moving surface along a predetermined direction and toward a proximal end thereof close to the forming support, and an application device positioned at the proximal end. The continuous elongated element is moved forward on the moving surface as far as the proximal end and the forming support is rotated to enable application of the continuous elongated element in the form of coils wound up on the forming support itself. A retaining device co-operates with the conveyor to brake the continuous elongated element at the end of the application, while the forming support goes on rotating, until it causes stretching and severing of the continuous elongated element.

Abstract: A method for manufacturing a tyre for vehicle wheels, includes a carcass structure having at least one carcass ply associated with axially opposite annular anchoring structures. The method includes the steps of manufacturing at least one pair of annular anchoring structures of the carcass structure and associating the pair of annular anchoring structures with the at least one carcass ply at axially opposite end flaps of the carcass ply. The step of manufacturing each annular anchoring structure includes the steps of manufacturing a bead core and coating the bead core with a reinforcement tape through an apparatus. The step of coating the bead core includes the steps of winding the reinforcement tape onto the bead core moving a tape deposition member with respect to the bead core. The step of manufacturing the annular anchoring structure further includes a step of loading the reinforcement tape onto the tape deposition member.

Abstract: During manufacture of a tyre for motor vehicles, one or more structural elements of elastomeric material, such as a tread band provided with a respective under-layer, are manufactured by laying a continuous elongated element on the carcass structure or other forming support, which elongated element is longitudinally divided into a first and second mutually-coupled portions that are obtained through extrusion of two different elastomeric materials coming from respective extruders leading to a common extrusion die. Laying of the coils takes place in such a manner that the first and second materials form a first layer and a second layer overlapping the first layer, respectively.

Abstract: A method for manufacturing a tire includes forming a carcass structure, forming a tread band, placing the tire in a curing mold, and molding and curing the tire. The carcass structure includes a crown portion defined between two axially opposed sidewalls that extend radially toward an axis of rotation of the tire and terminate in a circumferential portion comprising an annular reinforcing structure for mounting the tire on a rim. The tread band extends circumferentially around the carcass structure and includes a molded relief pattern. Forming the tread band includes producing a strip of elastomeric material and winding it onto the crown portion. The strip includes an elongated right cross-section that is asymmetrical in a transverse direction. The strip is wound in a plurality of axially consecutive turns until the tread band is formed. At least one turn is at least partly overlapped onto a previously deposited, axially consecutive turn.

Abstract: One or more components of elastomer material in a tyre are formed by dispensing elastomer material through a nozzle of an extruder to form a continuous elongated element of flattened section that is laid in the form of coils disposed close to each other on a laying surface carried by a support element, while said support element is driven in rotation and suitably moved adjacent to a die of the nozzle. The nozzle is drivable in rotation by an actuator so as to modify orientation of the nozzle itself during formation of the tyre component.

Abstract: A method for producing a vehicle tire belt structure includes forming at least one belt strip including at least one circumferential edge with a profile extending along a broken line. A vehicle tire includes a carcass structure, tread band, and belt structure. At least one carcass ply of the carcass structure includes reinforcing cords oriented substantially along radial planes of the tire. The belt structure includes at least one pair of radially superimposed belt strips including a plurality of reinforcing cords parallel to each other. The reinforcing cords of a first belt strip cross those of a radially adjacent belt strip. The reinforcing cords of the first and radially adjacent belt strips are obliquely oriented in opposite directions with respect to an equatorial plane of the tyre. At least one of the belt strips includes at least one circumferential edge with a profile extending along a broken line.

Abstract: A process for manufacturing a tyre which has at least one structural element including at least one first portion made of a first crude elastomeric material, and at least one second portion made of the first crude elastomeric material, the second portion being axially spaced apart from the first portion. The process includes the steps of forming a crude tyre on a supporting device and moulding and curing the crude tyre, wherein the step of forming the crude tyre includes the step of providing the structural element.

Abstract: A pneumatic tire includes a carcass structure, at least one annular reinforcing structure, a tread band, a belt structure, and axially opposite sidewalls. The tread band includes at least one radially inner layer and a radially outer layer. The at least one radially inner layer includes a first modulus of elasticity under compression, the radially outer layer includes a second modulus of elasticity under compression, and the first modulus is greater than the second. The at least one radially inner layer includes a plurality of circumferential abutment elements that radially extend into the radially outer layer and are axially distributed along a transverse development of the tread band. A related process includes making carcass and belt structures, disposing the at least one first layer in a radially outer position with respect to the belt structure, and disposing the at least one second layer on the at least one first layer.

Abstract: A pneumatic tire includes a carcass structure, tread band, belt structure, and sidewalls. The carcass structure includes at least one carcass ply and at least one annular reinforcing structure associated with the at least one carcass ply. The tread band includes first and second sectors. The first sectors are axially spaced apart from each other and tapered along a radially inner direction. The second sectors are axially spaced apart from each other and tapered along a radially outer direction. The first and second sectors are disposed axially side-by-side, one after the other, along a transverse development of the tread band. A ratio of Shore A hardness at 23° C. of the elastomeric material of the first sectors to Shore A hardness at 23° C. of the elastomeric material of the second sectors is greater than 1.10:1. A process for manufacturing the tire is also disclosed.

Abstract: An expandable bladder has at least one first layer of butyl material and one second layer of silicone material, radially external to the first layer. The first and second layers have an undulated interface profile defining mechanical-engagement elements between the first and second elastomer materials. A process for manufacturing bladder as well as a tyre moulding and vulcanising apparatus incorporating the bladder.

Abstract: A pneumatic tire has a carcass structure having at least one carcass ply and at least one annual reinforcing structure associated with the carcass ply, a tread band made of an elastomeric material at a radially outer position with respect to the carcass structure, a belt structure interposed between the carcass structure and the tread band and a pair of axially opposite side walls on the carcass structure, wherein the tread band has i) at least one first sector, radially extending, substantially of a first elastomeric material; ii) a plurality of second sectors radially extending, positioned at axially opposite sides of the at least one first sector and substantially of a second elastomeric material; iii) at least one longitudinal groove formed in the at least one first sector and extending substantially for the entire circumferential development of the tread band, wherein the first elastomeric material has a modulus of elasticity under compression at 23° C.

Abstract: A vehicle wheel tyre includes a carcass structure, at least one annular reinforcing structure, a tread band, and a pair of sidewalls. The carcass structure includes at least one carcass ply, each including a plurality of elongated elements disposed around a cross-section profile of the tyre. Each elongated element includes two side portions at mutually-spaced-apart positions and a crown portion that extends between the side portions. The at least one annular reinforcing structure includes at least one bead core. A fraction of the elongated elements is turned up around the at least one bead core. A method of manufacturing the tyre includes preparing the elongated elements, disposing each elongated element on a toroidal support, applying at least one bead core at a region close to side portions of the elongated elements, and turning up ends of a fraction of the elongated elements around the at least one bead core.

Abstract: A pneumatic tyre for a vehicle wheel includes a toroidal carcass, a tread band, a belt structure, and at least one reinforcing layer associated with the carcass. The carcass includes at least one carcass ply having a substantially continuous right-section profile. The carcass has a central crown portion and two axially opposite sidewalls. Each sidewall terminates with a bead for mounting the tyre on a corresponding rim. Each bead includes at least one reinforcing core. The tread band is disposed crownwise, coaxially extending around the carcass, and includes a raised pattern for rolling contact with the ground. The belt structure is coaxially interposed between the carcass and the tread band. The tyre has a size ratio f/H less than 0.2:1. The at least one reinforcing layer is disposed radially external to a point of maximum axial width of the carcass and axially external to the belt structure.

Abstract: A tyre for a vehicle wheel includes a toroidal carcass, a tread band, and a belt structure. The carcass includes a central crown portion and two axially opposite sidewalls. The axially opposite sidewalls end in a pair of beads for mounting the tyre on a corresponding rim. Each bead includes at least one annular reinforcing core. The tread band is disposed at the central crown portion of the carcass, coaxially extends about the carcass, and includes a relief pattern for rolling contact with the ground. The belt structure is coaxially interposed between the carcass and the tread band. The carcass further includes at least one carcass ply. Ends of the at least one carcass ply are anchored to the annular reinforcing cores. The at least one carcass ply includes a portion that encloses at least one insert in proximity to the annular reinforcing cores.