摘要:
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.
摘要:
An apparatus for manufacturing a vehicle tire includes means for preparing and toroidally shaping a carcass structure, preparing and arranging a belt structure as a crown around the carcass structure, and wrapping a tread around the belt structure. The means for preparing the belt structure includes an extrusion apparatus for forming a sheet of rubber-coated fabric including a plurality of reinforcing cords substantially parallel to one another, means for conveying the sheet, a first cutting device for cutting the sheet to obtain a plurality of strips, a device for transferring the strips, a device for splicing the strips to form a substantially continuous belt assembly, means for conveying the strips and the belt assembly, second and third cutting devices, means for conveying the belt strips and portions of the belt strips, and at least one assembly drum adapted to support the portions of the belt strips.
摘要:
A process for molding and curing tires, includes introducing a green tire into a curing mold, the mold including a first sidewall plate and a second sidewall plate, a ring of circumferential sectors circumscribing a mold cavity, an expandable bladder delimited by a membrane, and at least one bead molding ring which is movable between a first contracted operating position and a second extended operating position; and molding and curing the green tire in the curing mold; and between introducing the green tire and molding and curing it, the process includes extending the at least one bead molding ring from the first contracted operating position to the second extended operating position; forming a circumferential bearing surface which bears against a first axially inner surface portion of a first annular fixing structure of the green tire; pressing a second axially inner surface portion of the first annular fixing structure by expanding the membrane at a pre-molding pressure which is lower than a molding pressure, so as to bring the first annular fixing structure into contact with the first sidewall plate thus shaping an axially outer surface portion of the first annular fixing structure by means of the first sidewall plate and shaping the first axially inner surface portion of the first annular fixing structure by means of the circumferential surface of the at least one bead molding ring.
摘要:
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.
摘要:
An apparatus for moulding and vulcanisation of tyres for vehicle wheels includes a vulcanisation press and a vulcanisation mould associated with the press. The apparatus includes a pair of plates and a plurality of mould sectors that are mutually movable between an open condition and a closed condition; at least one plurality of sector carriers designed to support the mould sectors and movable together with the sectors; and a plurality of guide means on which the plurality of sector carriers slide for movement of the mould sectors from the closed condition to the open condition and vice versa, at least part of the sector carriers having at least one spring device designed to exert a thrust action adapted to ensure sliding of the sector carrier on the guide element in a substantially parallel direction.
摘要:
A green tyre is either directly formed or, when building is over, engaged on an expandable toroidal support to be then introduced into a vulcanisation mould. The expandable toroidal support includes an expandable bladder and a pair of pressure rings, each including fast and second pressure sectors circumferentially distributed and operating at axially opposite positions on the expandable bladder. Driving devices act on the pressure rings to selectively translate them between a work condition at which the pressure sectors of each pressure ring, circumferentially aligned with each other, extend radially away from the geometric axis, and a rest condition at which the pressure sectors are disposed close to the geometric axis. Kinematic synchronisation members operatively associated with the driving devices mechanically mutually constrain the pressure rings, so as to impose a simultaneous and mutually symmetric movement on them.
摘要:
A method for controlling the deformation of a surface of a sail of a sailing boat during a direction change manoeuvre, includes arranging at least one inflatable batten into a respective seat formed on a side surface of the sail, the at least one batten being inflated at a predetermined working pressure as to impart to said at least one inflatable batten a bending stiffness having, with no bending load, a predetermined value, carrying out a manoeuvre, for changing the direction of the sailing boat, wherein in a first part of manoeuvre the at least one batten is subjected to the action of an increasing bending load, and in a second part of the manoeuvre, the bending load ends its action on the at least one batten, during the manoeuvre the mechanical properties of the at least one batten being changed so that as the bending load increases in the first part of the manoeuvre, the value of the bending stiffness of the at least one batten decreases considerably, and as the action of the bending load ends in the second part of the manoeuvre, the bending stiffness of the at least one batten returns to the predetermined value.
摘要:
There is described a method for controlling the deformation of a surface of a sail (1) of a sailing boat (100) during a direction change manoeuvre, said method comprising the step of arranging at least one inflatable batten (10) into a respective seat (3) formed on a side surface (2a) of the sail (1), said at least one batten (10) being inflated at a predetermined working pressure, said working pressure being such as to impart to said at least one batten (10) a bending stiffness having, with no bending load, a predetermined value and the step of carrying out a manoeuvre for changing the direction of the sailing boat (100), wherein in a first part of said manoeuvre said at least one batten (10) is subjected to the action of an increasing bending load and in a second part of said manoeuvre, said bending load ends its action on said at least one batten (10), during said manoeuvre the mechanical properties of said at least one batten (10) being changed so that as said bending load increases in said first part of the manoeuvre, the value of the bending stiffness of said at least one batten (10) decreases considerably, and as the action of said bending load ends in said second part of the manoeuvre, the bending stiffness of said at least one batten (10) returns to said predetermined value. Such method is carried out by using a sail (1) provided with at least one batten (10) comprising a fluid impervious wrapping (31) adapted to be inflated by a fluid under pressure and a reinforcing structure (33) associated externally with said wrapping (31) and comprising a plurality of reinforcing thread-like elements (34a, 34b) arranged crossed with an angle comprised between about 65° and about 115°.
摘要:
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 primary valve adapted to regulate communication between the tank and the inner volume of the tyre; the primary valve including at least one elastic element operatively associated with a closure member designed to open and close a port of the primary 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 between about −50° C. and about 50° C. A one-way valve hinders the fluid from flowing back from the tyre to the tank in the absence of pressure within the tank.
摘要:
A method for manufacturing a belt structure of a vehicle tire includes the steps of preparing a belt assembly, cutting the belt assembly to obtain first and second substantially-continuous belt strips, supplying the first and second belt strips to at least one assembly drum, and superposing on the at least one assembly drum portions of the first and second belt strips to obtain a belt structure comprising radially-superposed portions of the first and second belt strips.