Abstract:
A tyre for a vehicle wheel includes a carcass structure, belt structure, tread band, and at least one pair of sidewalls. The carcass structure includes at least one first carcass ply and at least two annular reinforcing structures. The at least one first carcass ply includes elongated sections circumferentially distributed around the tyre's geometric rotation axis. Each elongated section extends in a U-shaped configuration around a cross-section outline of the carcass structure to define two side portions and one crown portion. Each elongated section substantially lies in a plane parallelly offset relative to a meridian plane of the carcass structure. The crown portion of each elongated section is oriented, relative to a radial reference plane passing through a transition region between the crown portion and at least one corresponding side portion, at an angle having a different value from an inclination of the at least one corresponding side portion.
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 method of manufacturing a carcass structure for vehicle tires includes the steps of making at least one carcass ply by deposition of elongated sections circumferentially distributed on a toroidal support and applying annular reinforcing structures to a region close to inner circumferential edges of the at least one carcass ply. Each of the elongated sections extends in a U-shaped configuration around a cross-sectional outline of the toroidal support to define two side portions mutually spaced apart in an axial direction and one crown portion extending at a radially outer position between the side portions. Each of the elongated sections is laid down substantially in a plane parallelly offset relative to a meridian plane of the toroidal support. A related carcass structure and tire are also disclosed.
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:
A method of making a tire includes forming at least one first carcass ply of a structure, forming at least one circumferentially-inextensible annular structure, and applying the at least one circumferentially-inextensible annular structure to a region close to inner cicumferential edges of the at least one first carcass ply. Forming the at least one first carcass ply includes preparing first strip lengths, each first strip length including longitudinal and parallel thread elements at least partly coated with at least one layer of raw elastomer material, and depositing the first strip lengths onto a toroidal support to define two side portions and a crown portion. The crown portions are disposed consecutively in side-by-side relationship along a circumferential extension of the toroidal support. The side portions of each first strip length cover in part or are partly covered by a side portion of at least one circumferentially-consecutive first strip length.
Abstract:
A tire for a vehicle wheel includes a carcass structure having at least one first carcass ply, a pair of circumferentially inextensible annular structures, a belt structure applied to the carcass structure, a tread band applied to the belt structure, and at least one pair of sidewalls applied to the carcass structure. The at least one first carcass ply includes a plurality of strip lengths each including at least two thread elements. Each strip length defines two side portions and a crown portion. The crown portions are disposed side-by-side along a circumferential extension of the tire. The side portions of each strip length partly cover or are partly covered by a side portion of at least one adjacent strip length. Each annular structure includes at least a first circumferentially inextensible annular insert formed by at least one first elongated element extending in concentric coils.
Abstract:
A method of making pneumatic tyres for vehicle wheels in which during building of the tyre on a toroidal support at least one step of a partial vulcanisation is introduced, the step enabling the overall production time to be reduced by lowering the overall time of the final moulding and vulcanisation step, while maintaining the features of the bead and the carcass ply/plies linked thereto as stated in the design specifications. More particularly, by building at least one carcass structure on the toroidal support and submitting the latter to a first vulcanisation step while exerting a pressure from the outside to the inside of the structure itself, an at least partly vulcanised carcass structure is obtained that is stable in its geometry and suitable for completing the tyre building. Subsequently, a second vulcanisation step accompanied by moulding of the tread band and the sidewalls allows a finished tyre in a more reduced overall period of time to be obtained.
Abstract:
An apparatus for manufacturing components for a tire being worked is provided. The apparatus includes a toroidal support for carrying the components of a tire being worked. The toroidal support has an outer surface substantially matching an inner shape of the tire. The apparatus also includes means for feeding at least one elongated element through at least one delivery member disposed adjacent to the outer surface of the toroidal support. The apparatus also includes means for circumferential distribution arranged to drive the toroidal support in rotation around a geometric axis of rotation of the toroidal support so that the at least one elongated element is circumferentially distributed on the toroidal support. The apparatus also includes means for transverse distribution arranged to give controlled relative displacements between the toroidal support and the delivery member for distributing the at least one elongated element to form a plurality of coils disposed in side-by-side relationship in order to define a tire component. The transverse distribution means operates on the toroidal support for moving the toroidal support relative to the delivery member, and the circumferential distribution means and the transverse distribution means are integrated into a robotized arm.
Abstract:
A method for moulding and curing a tyre for a vehicle wheel includes building a tyre on a toroidal support, placing the tyre carried by the toroidal support into a moulding cavity, pressing an outer surface of the tyre against walls of the moulding cavity using a working fluid under pressure, and heating the working fluid. The toroidal support includes an outer surface whose shape substantially matches the tyre's inner surface. The walls of the moulding cavity conform in shape to an outer surface of the tyre when vulcanization is completed. The working fluid flows in at least one diffusion gap between the toroidal support and the tyre. The working fluid in contact with the tyre has a critical temperature lower than a vulcanization temperature and the working fluid is submitted to circulation. An apparatus for moulding and curing a tyre for a vehicle wheel is also disclosed.
Abstract:
A process for manufacturing elastomeric components of a tire for a vehicle wheel includes feeding a continuous elongated element from a delivery member by exerting a feeding pressure inside the delivery member, rotating a building support around a geometrical rotation axis of the support, carrying out controlled relative displacements between the delivery member and the support to form a tire component, stopping the feeding of the elongated element when formation of the tire component is complete, and exerting a counter-pressure inside the delivery member after stopping the feeding. Rotating the support assists circumferential distribution of the elongated element on the support. Carrying out controlled relative displacements assists transverse distribution of the elongated element on the support. The tire component is defined by a plurality of coils laid in a pre-established deposition pattern depending on a predetermined cross-section outline to be given to the tire component.