Abstract:
In the building of a carcass structure for tires of vehicle wheels, the step of reinforcing with a loop at least one annular anchoring structure associated at the axially opposite end edges of a carcass ply is carried out on at least one radially expandable/contractable service drum and includes the steps of: setting the service drum to a predetermined radial dimension selected according to the fitting diameter of the tire to be manufactured, depositing the loop on the service drum, loading the annular anchoring structure onto the service drum in a radially outer position with respect to the loop, radially expanding the service drum up to lock in position the annular anchoring structure, rotating the service drum about a longitudinal axis thereof and, during the rotation, turning the loop up about the annular anchoring structure.
Abstract:
On a building drum, anchoring structures to beads, carcass plies, a belt structure and/or other annular composite components are sequentially assembled with a liner, sidewalls, sidewall inserts, under-belt inserts or other annular elastomer components. Each of the sidewall inserts, sidewalls, or under-belt inserts is made as a one piece construction in a service station operating far away from the building drum for storage on a movable storing device. Actuating members operating on the movable storing device carry the annular elastomer components from the service station to the building drum. A transfer member picks up the annular elastomer components from the movable storing device to transfer them to the building drum.
Abstract:
A process and an apparatus for building tires for vehicle wheels wherein the process includes the step of assembling components of elastomeric material on a forming support, in which at least one of the components of elastomeric material is manufactured by the steps of: i) dispensing a continuous elongated element of elastomeric material; ii) applying the continuous elongated element in the form of coils disposed in side by side relationship or at least partly superposed, wound up on the forming support, so as to form the at least one component of elastomeric material of the tire; iii) exerting a first pressure on a central region of a portion of the continuous elongated element applied onto the forming support; and iv) exerting a second pressure on side regions of the portion of the continuous elongated element applied onto the forming support.
Abstract:
A plant for building tyres for vehicle wheels, includes at least one forming drum having a supporting shaft axially projecting from opposite sides relative to a central body. A handling device is adapted to engage the forming drum and transfer it between at least one loading/unloading location and a work location provided for carrying out at least one process working on the forming drum. The handling device includes a grip assembly carrying at least two grip members each engaging the supporting shaft in the vicinity of each of the end portions thereof, and at least one motor associated with at least one of said grip members for driving the forming drum in rotation while the at least one process working is being carried out in the work location.
Abstract:
A plant and a process for building green tyres for vehicle wheels. The process includes: a) building a carcass structure on a first forming drum in at least one carcass structure building line including a plurality of work stations arranged according to a sequential series, the carcass structure including at least one carcass ply and a pair of annular anchoring structures; b) building a crown structure on at least one second forming drum in at least one crown structure building line including a plurality of work stations arranged according to a sequential series, the crown structure including at least one belt structure; c) toroidally shaping the carcass structure assembling it to the crown structure in at least one shaping and assembling work station, wherein the transfers of each of the first forming drum and the second forming drum, with the respective carcass structure and crown structure being processed, from one work station to the other of the respective building lines includes at least one transfer from a first work station to a second work station not adjacent to the first one in the sequential series, and wherein each step d) of transfer takes place in such a way that the first forming drum and the second forming drum only pass in the first and second work station.
Abstract:
The constituent elements of a carcass structure of a tire are formed by laying elementary components on a building support including an inflatable bladder set in an inflated condition in which it substantially reproduces the inner configuration of the carcass structure to be obtained. A belt structure carrying a tread band, both produced separately, is coaxially disposed around the carcass structure formed on the building support and applied thereto following a radial expansion of the inflatable bladder. In a vulcanization mold, the building support is submitted to an over-inflation step to press the tire against the inner walls of the mold. The circumferential edges of the inflatable bladder are in engagement with respective anchoring flanges with possibility of movement in a radial direction, so as to be submitted to an elastic expansion during the over-inflation step.
Abstract:
A process for manufacturing tyres for vehicle wheels includes building on a forming support a carcass structure including at least one carcass ply, and, at at least one end edge of the carcass ply, at least one annular anchoring structure including at least one substantially circumferential annular insert and at least one filling insert associated with the at least one substantially circumferential annular insert. Building the carcass structure includes positioning the annular anchoring structure on the carcass ply by moving the substantially circumferential annular insert into contact with an end edge of the carcass ply by means of a special positioning member, pulling down the filling insert on the end edge of the carcass ply and turning up a free end portion of the end edge of the carcass ply so as to form a turned up end portion of the carcass ply including the annular anchoring structure. The pulling down of the filling insert on the end edge of the carcass ply is carried out by a special pulling down member while the substantially circumferential annular insert is retained in a contact position with the end edge of the carcass ply by the positioning member.
Abstract:
A pair of annular inserts of elastomeric material is circumferentially applied by spiraling around a laying surface of an auxiliary drum. Then a plurality of strip-like elements disposed in parallel side by side relationship with each other in the circumferential extension of the laying surface is applied onto the auxiliary drum, so as to form at least one first belt layer. Respectively opposite end portions of each strip-like element are radially superposed, each against one of the annular inserts, so that each of the annular inserts projects from a respective end edge of the strip-like element. The cap structure formed on the auxiliary drum is coupled to a carcass structure through toroidal conformation of the latter, in such a manner that the radially external ends of sidewall portions previously manufactured on the carcass plies are associated with the axially external ends of the annular inserts.
Abstract:
A method and a plant for manufacturing a belt structure of a green tire are described, wherein the portions (49a, 49b) of the belt strips (19a, 19b) constituting the belt structure are produced in a substantially continuous manner immediately upstream of at least one assembly drum (50, 51). Such method and plant are integrated respectively in a method and in a plant for manufacturing, in a substantially continuous manner, a belt package and a crown structure incorporating the belt structure thus obtained. The method for manufacturing the belt package comprises the subsequent formation on the belt structure of a rubber mixture layer incorporating a plurality of reinforcing cords (5), whereas the method for manufacturing the crown structure comprises the subsequent assembly of a tread (7) on the belt package thus formed. The rubber mixture layer incorporating the reinforcing cords (5) and the tread (7) are both manufactured in a substantially continuous manner immediately upstream of at least one assembly drum (66). According to the invention, a high and constant quality level of the belt structure, of the belt package and of the crown structure are ensured, achieving at the same time a reduction in production costs and an increase in the production capacity of the plant.
Abstract:
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.