Abstract:
A tyre for a wheel of a vehicle comprises a toroidal carcass provided with axially opposite sidewalls and beads for anchoring the tyre to a rim of the wheel, a tread band located crownwise on the carcass, comprising a surface with a plurality of hollows and grooves defining a raised tread pattern, and a belt structure interposed between the carcass and the tread band, axially extending between the sidewalls. The tread band comprises at least first and second circumferential axially-contiguous portions arranged to contact a road surface. The first portion is formed of a first composition comprising a reinforcing filler having at least 40%-by-weight carbon black and at least some white filler, the second portion is formed of a second composition comprising a reinforcing filler having at least 20%-by-weight white filler, and the first composition is different from the second composition. A difference of compositions between the at least first and second portions achieves a tyre operating temperature lower than a reference temperature.
Abstract:
A process for continuously producing an elastomeric composition includes metering at least one elastomer, at least one filler, and at least one minor ingredient; feeding the at least one elastomer, the at least one filler, and the at least one minor ingredient into at least one extruder; mixing and dispersing the at least one filler and the at least one minor ingredient into the at least one elastomer using the at least one extruder; obtaining a subdivided product from a resulting elastomeric composition discharged from the at least one extruder; accumulating an amount of the subdivided product; and stirring the accumulated amount of the subdivided product. An apparatus for continuously producing an elastomeric composition includes at least one extruder, at least one first metering device, at least one second metering device, at least one device for obtaining a subdivided product, and at least one accumulating and stirring device.
Abstract:
A first carcass ply (3) is formed by depositing onto a toroidal support (11), strip-like lengths (13) cut to size from a continuous strip-like element and each comprising longitudinal thread-like elements (14) incorporated into a layer of elastomer material (17). The strip-like lengths are laid down sequentially in mutual circumferential side by side relationship, to form side portions (25) partly superposed on each other and crown portions (24) in mutual circumferential side by side relationship. Associated with the carcass ply (3) are annular structures (4) comprising a first and a second circumferentially inextensible annular inserts (27, 28) and an elastomer filling (29) interposed therebetween. A second carcass ply (31) is made in superposed position to the first carcass ply (3) and the annular structures (4). A belt structure (5), a tread band (8) and sidewalls (9) are combined with the carcass structure (2) thus formed, to define a tire (1) to be vulcanized.
Abstract:
A method of moulding and curing tires for vehicle wheels includes the steps of disposing a tire being processed on a toroidal support, enclosing the tire and the toroidal support inside a moulding cavity defined in a vulcanization mould, pressing the outer surface of the tire against the moulding cavity walls, and administering heat to the tire to cause molecular crosslinking of the tire. The pressing step includes the steps of compressing side portions of the tire between the moulding cavity walls and the outer surface of the toroidal support, concurrently with the closing step, and imposing an expansion to a radially-outer portion of the tire to bring the radially-outer portion of the tire against the walls of the moulding cavity.
Abstract:
A tyre for a vehicle wheel includes a carcass structure, a belt structure, a tread band, and sidewalls laterally applied to opposite sides of the carcass structure. The carcass structure includes at least one carcass ply with a first and second series of strip segments and a pair of annular reinforcing structures. In one embodiment, each of the pair of annular reinforcing structures includes a first annular insert having opposed axial surfaces and being positioned between respective lateral portions of the first series of strip segments and respective diverging lateral portions of the second series of strip segments. In this embodiment, no filling body is positioned between the respective lateral portions of the first series of strip segments and the respective diverging lateral portions of the second series of strip segments. In an alternative embodiment, each of the pair of annular reinforcing structures includes a first annular insert and a filling body, the first annular insert and the filling body each having opposed axial surfaces and being positioned between the respective lateral portions of the first series of strip segments and the respective diverging lateral portions of the second series of strip segments.
Abstract:
Method of allowing control of a vehicle provided with at least two wheels in case of puncture of a tire, each wheel having a rim and a tire associated therewith, including the steps of inflating each tire to an operating pressure at a reference temperature; admitting a fluid compressed to a first pressure higher than the operating pressure of the tire at the reference temperature into at least one tank associated with at least one of the rims; bringing the tire into communication with the tank when the inner pressure of the tire is lower than the operating pressure by a predetermined first threshold value; measuring the inner pressure of the tire with a predetermined frequency; calculating a variation of the inner pressure in the time unit; generating an alarm signal when the variation of the inner pressure corresponds to a reduction and is higher than a predetermined value; and transmitting the alarm signal to the driver.
Abstract:
A wheel having a controlled and compensated pressure includes a rim associated with a tank adapted to be filled with a fluid to a first pressure; a tyre mounted on the rim and having an inner volume inflated to an operating pressure, the operating pressure being lower than the first pressure; at least one valve adapted to regulate a communication between the tank and the inner volume of the tyre, the valve having at least one elastic element operatively associated with a closure member designed to open and close a port of the valve to bring the tank into communication with the tyre when the pressure of the tyre is lower than the operating pressure, the elastic element having an elastic constant showing a variation of 10% to 40% within a temperature range of about −50° C. to about 50° C.
Abstract:
A method for monitoring deformations in a tyre of a vehicle wheel, the wheel including the tyre and a rim, the method including: providing the wheel with at least two magnetic-field emitters mutually disposed so as to yield a composite magnetic field having one or more space portions where at least one component of the composite magnetic field is substantially null; disposing at least one main magnetic-field sensor substantially in one of the one or more space portions; monitoring variation of the at least one component of the composite magnetic field; and correlating the variation with tyre deformations. At least one of the magnetic-field emitters is disposed in contact with the tyre. A system for monitoring deformations in a tyre of a vehicle wheel includes the wheel, the at least two magnetic-field emitters, and the at least one main magnetic-field sensor.
Abstract:
A tyre for a vehicle wheel includes a carcass structure, a belt structure, a tread band, and sidewalls. The carcass structure includes at least one first and second carcass ply and a pair of annular reinforcing structures. The carcass plies are formed of strip sections extending in a substantially U-shaped conformation, including at least two parallel thread elements at least partly coated with elastomer material. The at least one first (second) carcass ply includes a first (third) and second (fourth) series of strip sections arranged in mutually-alternating sequence along a circumferential extension of the carcass structure. The annular reinforcing structures include first and second primary portions. The first (second) primary portion includes an axially-inner side turned towards end flaps of the strip sections of the first (third) series and an axially-outer side turned towards end flaps of the strip sections of the second (fourth) series.
Abstract:
A tire for a vehicle wheel is provided which comprises a carcass structure, and a belt structure applied to the carcass structure at a circumferentially-outer position of the carcass structure. A tread band is also provided which is circumferentially superposed on the belt structure, and sidewalls are laterally applied to opposite sides of the carcass structure. The carcass structure comprises at least one carcass ply, and a pair of annular reinforcing structures, wherein the at least one carcass ply comprises a first series and a second series of strip segments consecutively arranged along a circumferential development of the carcass structure, and each strip segment extends according to a substantially U-shaped conformation. In addition, each strip segment comprises at least two filiform elements, positioned longitudinally and parallel to each other, and at least partially coated by at least one layer of elastomer material. Also, each annular reinforcing structure is engaged in proximity to a respective inner circumferential edge of the at least one carcass ply. Each annular reinforcing structure comprises at least one primary portion, and at least one additional portion, wherein the at least one primary portion comprises an axially-inner side oriented toward terminal edges of the first series of strip segments, and the at least one primary portion comprises an axially-outer side oriented toward terminal edges of the second series of strip segments. Further, the at least one primary portion comprises a first circumferentially-inextensible annular insert, a filling body, and at least one second circumferentially-inextensible annular insert, wherein the first annular insert is substantially annulus-shaped, is positioned coaxially to the carcass structure, adjacent to the respective inner circumferential edge of the at least one carcass ply, and is formed by at least one elongated element extending in concentric turns. Moreover, the filling body is made of elastomeric material, and is joined to the first annular insert. The at least one second annular insert is substantially annulus-shaped, and is positioned coaxially to the carcass structure, axially side-by-side to the filling body and laterally opposite relative to the first annular insert, wherein the at least one second annular insert is formed by at least one elongated element extending in concentric turns, the at least one additional portion is positioned against the terminal edges of the second series of strip segments on a side opposite to the at least one primary portion, the at least one additional portion comprises at least one third circumferentially-inextensible annular insert, the at least one third annular insert is substantially annulus-shaped, the at least one third annular insert is positioned coaxially to the carcass structure, adjacent to the respective inner circumferential edge of the at least one carcass ply, and the at least one third annular insert is formed by at least one elongated element extending in concentric turns,