Abstract:
A manufacturing method includes the steps of: (A) preparing first and second sheet pieces 20a and 20b made of unvulcanized rubber; and (B) winding a long sheet 26 on a drum 6. The long sheet 26 includes the first and second sheet pieces 20a and 20b, and the second sheet piece 20b has a front edge joined to a rear edge of the first sheet piece 20a. Preferably, the step (B) includes the steps of: (B′1) joining the front edge of the second sheet piece 20b to the rear edge of the first sheet piece 20a to obtain the long sheet 26; and (B′2) feeding the sheet 26 from a servicer 4 to the drum 6 while rotating the drum 6 to wind the sheet 26 on the drum 6.
Abstract:
A tyre for vehicle wheels includes a carcass structure with at least one carcass ply formed by strip-like elements consecutively adjacent one after the other along a circumferential extension and having overlap zones along respective longitudinal edges superimposed on each other. Each overlap zone has, along a longitudinal extension thereof, terminal sections that are laterally opposite with respect to an intermediate section. The intermediate section of each overlap zone has an intermediate overlap width greater than a terminal overlap width of the terminal sections.
Abstract:
In a process for building tires, a carcass structure which includes at least one carcass ply and a belt structure, is formed. Manufacture of the belt structure includes: forming a first portion of at least one cushion insert through spiralling of a continuous elongated element; forming at least one first belt layer in a radially external position to the first portion in such a manner that the first portion axially projects from one of the axially opposite side edges of the first belt layer, forming a second portion of the cushion insert through spiralling of a continuous elongated element in a radially external position to the side edge of the first belt layer and to a stretch of the first portion projecting from the side edge itself, so as to enclose the side edge between the first and second portions of the cushion insert.
Abstract:
A process for manufacturing tires for vehicle wheels includes associating at least one reinforcing structure with at least one surface portion of at least one tire component laid on a forming support, wherein associating the at least one reinforcing structure includes bringing, through a handling and deposition member, at least one reinforcing element to the forming support and depositing, through said handling and deposition member, the reinforcing element on a respective deposition part defined on a surface portion of the component. The depositing includes gradually laying the reinforcing element on the deposition part following the profile of the deposition part in a circumferential direction.
Abstract:
Side portions of a plurality of strip-shaped members to be arranged on a drum are positioned accurately and joined with accuracy while sufficient joint strength is assured. The drum is rotated each time the strip-shaped member is arranged by arranging means, and a plurality of the strip-shaped members are sequentially arranged in a drum peripheral direction. The side portions of the adjacent strip-shaped members are joined by joining means so as to manufacture a constituent member of a tire. A joint portion whose thickness is relatively small is provided on one of the side portions of the strip-shaped member, and the plurality of strip-shaped members are arranged by overlapping the joint portion on one of the side portions and the other side portion. A width between the side portions is measured, the drum is rotated based on the measurement, and the positions of the side portions are matched.
Abstract:
A pneumatic tire includes an inner liner layer formed from a laminate sheet obtained by laminating: a sheet made from a thermoplastic resin or a thermoplastic resin composition which is a blend of the thermoplastic resin and an elastomer; and a rubber bonded by curing to the thermoplastic resin or the thermoplastic resin composition. The pneumatic tire avoids occurrence of cracks near a splice portion of the inner liner layer after the pneumatic tire starts to be used for driving, and thereby achieves excellent durability. In the tire, an inner liner layer is formed by lap-splicing end portions of a laminate sheet which is obtained by the laminating A sheet with end portions each having a tip subjected to a tip sharpening process is used as the sheet made from the thermoplastic resin or the thermoplastic resin composition which is the blend of the thermoplastic resin and the elastomer.
Abstract:
A process and an apparatus for building tyres for vehicle wheels includes assembling at least one tyre component through laying of strip-like elements disposed circumferentially close to each other on a deposition surface radially external to the forming drum, wherein laying of each strip-like element includes: radially moving the strip-like element close to the deposition surface; locking a central portion of the strip-like element against the deposition surface; and pulling the strip-like element in opposite directions starting from the central portion toward the opposite ends thereof, while the central portion is maintained in a locked condition against the deposition surface, so as to progressively lay down the strip-like element against the deposition surface.
Abstract:
A method for manufacturing a tire for vehicle wheels includes the steps of building a carcass structure, including at least one carcass ply associated with annular anchoring structures, on a forming support, building a belt structure in a radially outer position with respect to the carcass structure and building a tread band in a radially outer position with respect to the belt structure, wherein the at least one carcass ply, the annular anchoring structures and the belt structure each include at least one reinforcing element deposited in a radially outer position with respect to the forming support. The deposition of the at least one reinforcing element includes the steps of setting a first deposition path of the at least one reinforcing element on the forming support based upon a theoretical deposition profile; detecting the deviations between an actual deposition profile and the theoretical profile along the first deposition path, defining, based upon the deviations, an actual deposition path of the at least one reinforcing element on the forming support; and depositing the at least one reinforcing element on the forming support along the actual deposition path.
Abstract:
A cord-reinforced band 2 having at least one cord 1 is cut into a plurality of cord-reinforced strips 3 of a predetermined length L. The cord-reinforced strips 3 are arranged successively such that side edge parts of adjacent cord-reinforced strips 3 overlap each other and the adjacent cord-reinforced strips are bonded together to form a tire structural member of a pre-determined length with respect to a direction perpendicular to the longitudinal side edges of the cord-reinforced strips 3. The tire structural member manufacturing method uses one and the same extrusion die 14 having an extrusion opening of a fixed width regardless of a pitch at which the cords 1 are arranged. Thus, the tire structural member manufacturing method is simpler.
Abstract:
A process and an apparatus for manufacturing tyres for vehicle wheels, includes the step of building on a substantially cylindrical forming support a carcass structure including at least one carcass ply associated, at axially opposite end edges thereof, with respective annular anchoring structures. The step of building the carcass structure further includes the step of associating, at at least one end edge of said at least one carcass ply, at least one reinforcing structure including a predetermined number of reinforcing elements having a predetermined width and same length. The reinforcing elements are preferably obtained by cutting to size, with a predetermined cutting angle, a continuous band-like reinforcing element having a predetermined width. The reinforcing elements are arranged on the end edge of the carcass ply along a deposition path at a distance from one another having a value between 0 and a predetermined value.