Abstract:
The carcass structure of a tire comprises one or more carcass plies each formed of strip lengths comprising longitudinal thread elements incorporated in a layer of elastomer material. The strip elements have respective crown portions disposed circumferentially in mutual side-by-side relationship, and side portions extending radially at the tire sidewalls. The side portions of each carcass ply are each at least partly covered with at least one of the side portions belonging to an adjacent deposition length. Associated with the carcass plies are annular structures comprising a pair of inextensible inserts in the form of an annulus which are anchored to the first and second carcass plies respectively and axially separated by an elastomeric filling body. A belt structure, a tread band, and sidewalls are combined with the carcass structure to define the tire.
Abstract:
A tread for motor vehicle tires having circumferential grooves (3) and transverse grooves (4), a plurality of tread blocks (5, 6) circumferentially spaced apart to form two shoulder rows (5) and at least one central row (6) located between the shoulder rows. Each block (5, 6) is provided with one or more sipes or slits (11, 12) that are rectilinear and inclined with respect to the axis of rotation of the tire (2). The sipes (11, 12) of the blocks (5, 6) which constitute each of the shoulder and central rows are parallel to one another. The sipes (12) of the central rows (6) have an inclination, with respect to the axis of rotation, that is greater than the inclination of the sipes (11) of the blocks (6) which constitute the shoulder rows. This arrangement of the sipes (11, 12) substantially reduces the rolling noise of the tire.
Abstract:
In the manufacture of a tire having a metal bead core, a covering structure (6) is associated with each bead core, which structure consists of a sheet (7) made of unvulcanized elastomeric material wrapped around the bead core and a strip of unvulcanized rubberized fabric (8), reinforced with heat-shrinkable material cords, wound around the elastomeric material sheet (7). The bead cores (3) are subsequently assembled with other tire components, and afterwards a tire vulcanization step is carried out. During this step the chemical bonding between the elastomeric sheet (7) and the bead core (3) is achieved, which bonding is promoted by the simultaneous shrinkage of the cords provided in the rubberized fabric strip (8).
Abstract:
A process for continuously producing an elastomeric composition includes providing at least one extruder, metering and feeding at least one elastomer, at least one filler, and ingredients different from elastomers and fillers into the at least one extruder, mixing and dispersing the at least one filler and the ingredients different from elastomers and fillers into the at least one elastomer using the at least one extruder, and extruding a resulting elastomeric composition. The at least one extruder includes the housing and at least one screw rotatably mounted in the housing. The housing includes at least one feed opening and a discharge opening. At least one of the ingredients different from elastomers and fillers includes a subdivided product including one or more minor ingredients dispersed in at least one thermoplastic binding agent. An apparatus for continuously producing the elastomeric composition is also disclosed.
Abstract:
A method of molding 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 molding cavity defined in a vulcanization mould, pressing the outer surface of the tire against the molding 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 molding 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 molding cavity.
Abstract:
A pneumatic tyre for vehicle wheels with a radially inner surface of a substantially toroidal conformation, includes at least one antenna provided with an electrically conductive elongated body in engagement with the radially inner surface through a plurality of constraint elements. Each pair of consecutive constraint elements identifies an orthodromic distance smaller than the length of the elongated-body portion between this pair of elements. Also described is a method of setting the antenna on the inner surface of the tyre.
Abstract:
A method of allowing control of a vehicle with at least two-wheels in case of puncture of a tyre, each wheel including a rim and a tyre associated therewith, includes the steps of: inflating each tyre to an operating pressure; admitting a fluid compressed to a first pressure higher than the operating pressure of the tyre into at least one tank associated with at least one of the rims; bringing the tyre into communication with the tank when the inner pressure of the tyre is lower than a predetermined first threshold value; detecting a variation of an inner pressure of the tank; activating a pressure measuring device when the inner pressure variation corresponds to a reduction and is higher than a first predetermined value; measuring the inner pressure of the tank with a predetermined frequency by means of (through) the pressure measuring device; calculating a variation in the inner pressure in a time unit; generating an alarm signal when the calculated inner pressure variation corresponds to a reduction and is higher than a second predetermined value; and transmitting the alarm signal to the driver.
Abstract:
A method for determining the force at the hub of a wheel of a vehicle while traveling. The wheel includes a rim and at least one deformation sensor directly associated with the rim in at least one predetermined position and arranged according to at least one predetermined orientation. The method includes the steps of detecting at least one deformation component of the rim during travel through the at least one deformation sensor; applying to the at least one deformation component, during travel, a correlation parameter characteristic of the rim, between the force at the hub and the relative deformation of the rim to determine at least one force component at the hub correlated with the at least one deformation component of the rim. The determining of the correlation parameter preferably takes place through experimental tests that include the steps of providing a sample wheel having a rim substantially the same as that of the wheel and determining at least one correlation coefficient between at least one force component acting upon the sample wheel at the hub along at least one predetermined direction and at least one respective deformation component of the rim of the wheel.
Abstract:
A wheel having a controlled 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 at a reference temperature, the operating pressure being lower than the first pressure; and at least one valve assembly adapted to establish a communication between the tank, the inner volume of the tyre and the external environment. The valve assembly includes a command valve, an exhaust valve and a compensation valve operatively associated with each other. The command valve controls communication between the tank and the inner volume of the tyre. The exhaust valve is connected to the external environment, to the inner volume, to the command valve and to the compensation valve. The compensation valve is connected to the exhaust valve and the command valve. The command valve includes an inner chamber connected with the exhaust valve and the compensation valve in such a manner that the command valve is operated by the exhaust valve and the compensation valve through a pressure variation of the inner chamber in response to a variation of the inner pressure of the tyre.
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.