Abstract: A method of control to determine the comfort level of a tire of a wheel for a vehicle is based on a dynamic tire model with a rigid ring having concentrated parameters that represent construction characteristics of the tire. Some concentrated parameters are measured, others are determined by parametric identification through a test of passing over an obstacle of the tire. From testing eight curves of natural frequencies and dampenings are obtained that are compared with as many calculated curves obtained from the model. By checking the coincidence between the eight calculated curves and the eight experimental curves, the values of the other concentrated parameters are determined that cause the calculated frequencies and dampenings to coincide with the experimental ones.

Abstract: In a process for producing a vulcanizable rubber composition containing silica and having a low content of carbon black, at least a silica-based reinforcing filler and ad least a silane-based coupling agent are added to and intimately mixed with other ingredients of the composition in subsequent steps, at a temperature of from 165.degree. and 180.degree. C. and between 110.degree. and 160.degree. C. respectively. The rubber composition so obtained has an improved silica dispersion, constant physico-mechanical characteristics and a better drawability and is particularly suitable for the manufacture of treads for tires with low rolling resistance.

Abstract: A method and apparatus for applying a ribbon-like coating structure to the outer surface of a tire bead core. A bead core (2) is coaxially placed around a support drum (6) carrying an inflatable air bag (7) disposed in a deflated condition. Clasping sectors (14) circumferentially distributed in the drum are radially moved close to the inner surface of the bead core (2) to make a central portion of a ribbon-like coating structure (3) arranged about the inflatable air bag (7), adhere against the bead core itself. The air bag is inflated so as to form, on opposite axial sides relative to the bead core (2), two lobes (17, 18) each of them being enclosed between the outer surface of the drum (6) and a respective annular opposition bell (19, 20) coaxially encircling the drum. By axially moving the opposition bells (19, 20), a first and a second side flap of the coating structure (3) are applied to respective surfaces of the bead core (2).

Abstract: A method of foreseeing and controlling wearing in the tread of a tire based on the use of cuts of a limited depth (in the order of tenth parts of one millimeter) formed on the external surface of the tread, in the thickness of the elastomeric material. The cut is preferably made by a laser beam. Rotation of the tire on a road or on any other friction surface enables both the uneven wearing of the tread, highlighted by localized spots devoid of cuts, to be quickly verified by inspecting the maintenance state of the cuts. Also, and the wear rate of the tread can be drawn from calculation of the time, during the rotation, elapsing between the disappearance of two groups of cuts of different depth.

Abstract: A tire tread band for medium/heavy duty motor-vehicles having circumferential grooves confining three pairs of respectively center, intermediate and shoulder ribs. Respective tread blocks are defined along the center and intermediate ribs and they are confined by transverse cuts. The center cuts impart a cusp-shaped end conformation and a hollow-shaped end conformation to the respective blocks, and the shapes of said end portions mutually match. The intermediate cuts run in the linear extension of the center cuts to give the respective blocks a rhomboidal configuration. The tire can be alternately associated with a driving axle or a driven axle, by merely reversing its direction of rotation, so that the following results are selectively achieved: an increase in the traction capability by the intermediate blocks or an increase in the directional capability as a result of the mutual wedging between the center blocks at the ground-contacting area.

Abstract: A database of reversion cure constants is provided by measuring a physical property of a rubber formulation at two different temperatures as a function of time, calculating a set of cure constants for the rubber formulation which account for reversion, and storing the constants for later use either to optimize cure for a given process or of a given compound, or to assure quality of a raw compound. The invention also provides a curing press for optimizing cure including a mold, a heater, a temperature transducer, a computer and the database.

Abstract: A device for a braking and traction test of a wheel integral with a hub that is free to rotate, comprises a road-wheel, a crank integral with the hub and a connecting rod that causes the reciprocating movement of a piston sealingly sliding in a chamber of a cylinder containing air. The piston exerts on the wheel and on the tire a sinusoidal torque consisting in a braking torque during its compression stroke and in a traction torque during its expansion stroke. The device also comprises a first deformation transducer associated with the hub and a second and a third speed transducer associated with the hub and with the road-wheel, respectively.

Abstract: A tire (1) having sidewalls (3) with an annular strip (8) within which a plurality of ribs (9) is formed. The ribs are disposed in mutual side by side relation and circumferentially distributed. The annular strip (8) is made in the form of a hollow on a sidewall (3) of the tire (1) and is designed to display informative inscriptions (12) the characters of which (13) are defined by projections (19) projecting from the surface of the annular strip.

Abstract: To determine the carbon black distribution two measurements of spectral intensities of separately produced plasmas are carried out with different time delays relative to a particular laser pulse, the time delay for the second measurement for determining the spectral line intensities of a reference element carbon (I.sub.C') and at least one analysis element (I.sub.A.n') being smaller than for the first measurement; for determining the spectral line intensities of the reference element (I.sub.C) and the other analysis elements (I.sub.A.n).Evaluation of the measurements is performed by reference to calibration information based on reference measurements, which information shows the magnitude of the concentration ratio of the other analysis elements or the at least one analysis element to the reference element (c.sub.A.n /c.sub.C or c.sub.A.n /c.sub.R) as a function of the appurtenant intensity ratio values.

Abstract: A torsional vibrator comprises a direct-current electric motor provided with induced windings supplied with direct current through inverter means capable of changing their polarity in an alternating manner with a preselected frequency. To a shaft of the electric motor a wheel is made integral that is formed by a rim and by a tire and acceleration transducers are associated with the rim and with the tire of the wheel. The shaft of the motor is driven to execute angular oscillations that torsionally excite said wheel and cause it to vibrate in rotational direction. The acceleration transducers detect rotational vibrations and provide measurements of acceleration of the rim and of the tire.

Abstract: A metal wire, having a steel core and being provided with a layer of cladding of a zinc/manganese alloy containing between 5% and 80% of manganese. The wire is used as a reinforcement structure for tires or other products of elastomer material. Several embodiments of a process for applying the cladding on the steel core by electrodeposition of the zinc/manganese alloy are also described.

Abstract: A database of reversion cure constants is provided by measuring a physical property of a rubber formulation at two different temperatures as a function of time, calculating a set of cure constants for the rubber formulation which account for reversion, and storing the constants for later use either to optimize cure for a given process or of a given compound, or to assure quality of a raw compound. The invention also provides a curing press for optimizing cure including a mold, a heater, a temperature transducer, a computer and the database.

Abstract: An apparatus for plotting a tread pattern on a vulcanized tire (2 ) which is mounted to a rim (7 ) rotatably supported by a primary framework (5 ) and oscillatable about two axes (Z, X) perpendicular to each other and to the axis of rotation (Y) of the tire (2 ). A signal from an electronic computer into which a base data sequence relating to a trace pattern to be reproduced on the tire is stored, is fed with a detection data sequence relating to the surface extension of said tire. The base data are processed depending on the detection data sequence for creating an application data sequence, so that, based on said application data, the electronic computer operates a laser beam emitter (10 ) carrying out plotting of the required trace pattern on the outer surface of the tire, as the sum of subsequent distinct portions, each of them being plotted, while the tire is stationary, through oscillations of the laser beam within a cone of predetermined width.

Abstract: A method and apparatus for applying a ribbon-like coating structure to the outer surface of a tire bead core. A bead core (2) is coaxially placed around a support drum (6) carrying an inflatable air bag (7) disposed in a deflated condition. Clasping sectors (14) circumferentially distributed in the drum are radially moved close to the inner surface of the bead core (2) to make a central portion of a ribbon-like coating structure (3) arranged about the inflatable air bag (7), adhere against the bead core itself. The air bag is inflated so as to form, on opposite axial sides relative to the bead core (2), two lobes (17, 18) each of them being enclosed between the outer surface of the drum (6) and a respective annular opposition bell (19, 20) coaxially encircling the drum. By axially moving the opposition bells (19, 20), a first and a second side flap of the coating structure (3) are applied to respective surfaces of the bead core (2).

Abstract: The distribution of a specific pressure in the ground-contacting area of a tire (4) under examination is detected by means of a plurality of sensing cells (7) distributed on a plate-like support (8) applied to a rest surface (2) acted upon by the tire through its rolling surface (5). Each sensing cell (7) sends an electric signal correlated with the specific pressure applied thereto to a processing unit (10) through which the processed signals are sent to a display device (12) graphically representing the distribution of the specific pressure in the ground-contacting area. By causing the tire (4) to roll on the rest surface (2) and therefore the sensing cells (7), the dynamic variation of the specific pressures in the ground-contacting area can be detected. A protection sheet (11) interposed between the rolling surface of the tire (4) and the sensing cells (7) protects the latter against risks of damages due to tangential shearing stresses produced at the ground-contacting area.

Abstract: A toroidal semifinished product (5) made of raw elastomeric material is semivulcanized in a semivulcanization chamber (4) defined between two half-molds (2, 3) disposed close to each other. A pressure, preferably equal to the pressure exerted by the gases generated in the semifinished product (5), is created in the mold (1a). The half-molds (2, 3) are moved apart from each other and pressure in the mold is gradually reduced, thereby giving rise to the expansion and consequent transferring of the semifinished product (5) from the semivulcanization chamber (4) to a surrounding final vulcanization chamber (6). When the inner diameter of the semifinished product (5) is larger than the inner diameter of the final vulcanization chamber (6), said chamber is closed at its inner circumferential edge and then, after possible pressure increase in the mold, at its outer circumferential edge, in order to integrally enclose the semifinished product and enable completion of the vulcanization process.

Abstract: A storage reel (2) carrying a cord (5) wound up on a core (3). The end portion (7) of the cord (5) slidably passes through a hole (6) and is fastened to the outer surface (4b) of the flange (4) by a clip (8) comprising a substantially "W" shaped elongated element (11) made of harmonic steel which is provided with terminal appendages (10) rotatably engaged to articulation seats (9a) defined in corresponding tabs (9) projecting externally of the flange (4). The elongated element (11) is bent according to consecutively opposite portions (11a) so as to form a pair of retaining loops (12) acting on a cord end portion (7) for holding it against the flange (4), as well as a counter-loop (13) acting against the flange (4) in order to generate an elastic reaction in the clip (8) thereby causing the end portion (7) to be held fast by friction under the retaining loops.

Abstract: A process for the manufacture of tire for high speed two-wheeled vehicles comprising making a cylindrical sleeve, attaching annular bead wires to the axial ends of said sleeve and shaping the sleeve into a toroidal configuration. A belt structure made of coils of cords is applied to the crown of said toroidal configuration. The belt is reinforced with HE cords which can be deformed to enable the tire carcass to be so largely expanded into the mold to achieve completely molding of a tread band.