EP4642632A1

EP4642632A1 - Method and apparatus for building green tyres for bicycles

Info

Publication number: EP4642632A1
Application number: EP23841535.0A
Authority: EP
Inventors: Angelo MAZZUCATO; Dario GIAMBERSIO; Enrico BIRAGHI; Stefano Testi
Original assignee: Pirelli SpA; Pirelli Tyre SpA
Current assignee: Pirelli and C SpA; Pirelli Tyre SpA
Priority date: 2022-12-28
Filing date: 2023-12-20
Publication date: 2025-11-05
Also published as: MX2025007015A; CN120435379A; WO2024141869A1

Abstract

An apparatus for building green tyres (1) for bicycles comprises a building drum (20), at least one feeding line (103) configured for feeding a first semifinished product (A1, An), a cutting device (104) operative along the feeding line (103) and configured for cutting to size a piece (C) of the first semifinished product (A1- An). The feeding line (103) comprises a motorised application conveyor belt (105) configured for thrustingly feeding the piece (C) so as to move it towards the building drum (20) up to a respective first pointing zone (106). At least one dispensing line (112) is configured for dispensing a second semifinished product (B1-Bm) directly towards the building drum (20) up to a second pointing zone (113). A grip ring (118) is configured for axially removing a built green tyre (1) from the building drum (20).

Description

METHOD AND APPARATUS FOR BUILDING GREEN TYRES FOR BICYCLES

The present invention relates to a method for building green tyres for bicycles. Also forming the object of the invention is an apparatus for building green tyres for bicycles, in particular suitable for the execution of the aforesaid method.

The terms "radial" and "axial" and the expressions "radially inner/outer" and "axially inner/outer" are used with reference to the radial direction and to the axial direction of the tyre, i.e. to a direction perpendicular to the rotation axis of the tyre and to a direction parallel to the rotation axis of the same, respectively.

The terms "circumferential" and "circumferentially" are instead used with reference to the annular extension of the tyre. In normal operating conditions such extension is circular, but in specific steps of the processing process, the tyre can take on a different configuration, in particular flattened with two main sections substantially rectilinear or curved, interconnected by U- shaped terminal sections. For the sake of simplicity, also in these cases, reference will be made to the "circumferential extension", identifying with such expression the extension taken on by the tyre along the rolling direction in operating conditions.

A radial plane of the tyre contains the rotation axis of the same.

The expressions "low", "below", "lower" or "on the lower part", and "high", "above", "upper" or "on the upper part" are used for indicating a relative position of one element with respect to another and/or of one element with respect to the ground (horizontal plane). By "rotation axis" of a green tyre it is intended the axis corresponding to the rotation axis of the vulcanised tyre when mounted in operating conditions on a respective mounting rim.

With the term "width", it is intended an axial size of the tyre or of a component thereof. With the term "length" it is intended a circumferential size of a component of the tyre.

With the term "semifinished product" it is intended a prefabricated manufactured item (i.e. fabricated before the production of the tyre and generally outside the building plant), intended to form a type of component of a tyre and extended as a continuous elongated element. The semifinished product can be made of only elastomeric material or it can be reinforced with at least one cord made of textile and/or metallic and/or hybrid material or it can be manufactured by cord made of textile and/or metallic and/or hybrid material. Preferably a semifinished product can also be formed of multiple semifinished products that are preassembled with each other.

With the term "first semifinished product" it is intended a prefabricated manufactured item, extended width-wise like the component that it is intended to form and from which a piece is cut whose length defines the circumferential extension of the respective component around the rotation axis of the tyre.

With the term "second semifinished product" it is intended a prefabricated manufactured item, extended width-wise like the component that it is intended to form or for a section smaller than the width of the component that it is intended to form, which is dispensed directly on the building drum on which it is wound and cut at the end of the winding.

With the term "component", it is intended any one portion of the tyre capable of carrying out its own function or a part thereof. For example these are the components of the tyre: liner, bead core, filler of the bead zone, carcass ply, tread band, "breaker", "chafer", "flipper", enlarged protective band or "bead to bead", elastomeric base, sidewall reinforcement strip or a part of these.

With the term "feeding" it is intended the transport of the first semifinished product and of the relative piece towards the building drum. In particular, with the term "thrustingly feeding" it is intended the transport of the first semifinished product and of the relative piece by a moving member (application conveyor belt) that pushes the first semifinished product, thus preventing the transport of the first semifinished product from taking place by a tensioning applied thereon.

With the term "dispensing" it is intended the supply of the semifinished product starting from a dispensing member in which the semifinished product itself is collected, for example through unwinding a reel, or through which the semifinished product is extruded.

With the term "pointing zone" it is intended a zone in which a head end of the piece or of the semifinished product comes into contact with the building drum in order to start the winding.

By "elastomeric material", it is intended a composition comprising at least one elastomeric polymer and at least one reinforcement filler. Preferably, such composition also comprises additives such as crosslinking agents and/or plasticising agents. Due to the presence of the crosslinking agents, such material can be crosslinked by heating, so as to form the final manufactured item. The building of a tyre for bicycles normally provides that one or more carcass plies are applied according to a cylindrical configuration around an outer surface of a building drum. Each bead core of a pair of bead cores is fit or applied around one of the axially opposite end flaps of the carcass ply.

The end flaps are then turned up around the respective bead cores. Then, there is the application of a tread band, typically made in strip form of elastomeric material cut to size, which is wound around the carcass ply lying against the building drum, in axially centred position with respect to the bead cores. At the end of the winding, the opposite ends of the tread band are slightly superimposed and mutually joined by a junction.

The mutual axial distance between the bead cores remains unchanged in the course of the entire building process, including the application of the tread band. This process aspect represents a particular characteristic that distinguishes the tyres for bicycles from the tyres for motor vehicles. For the latter, indeed, a step of mutual approaching of the bead cores is normally provided for in order to shape the carcass structure according to a toroidal configuration during coupling with a belt structure having a diameter greater than that of the bead cores.

Upon completed building, the built green tyre for bicycles is removed from the drum and transferred into a vulcanisation press, in order to be subjected to a moulding and vulcanisation treatment aimed to determine the structural stabilisation thereof through crosslinking of the elastomeric material present thereof, as well as possibly to impart a desired tread design on the tread band. Generally the operations necessary for pointing and hence the winding of the piece or of the semifinished product are manually made, i.e. the presence of an operator is requested. In many cases, in order to facilitate a correct distribution and application of the material, the operator must intervene in the cutting step, in the pointing step, in the guiding and alignment step and in the final joining step.

Therefore, at the present state of the art, the operations of assembly of the components on the building drum, even if assisted by systems of automatic or semi-automatic feeding of the semifinished products, require the use of specialised labour, in order to obtain a correct positioning, distribution, tensioning and/or cutting to size of the semifinished products themselves for the purposes of making the components on the building drum.

The Applicant has proposed automating the present abovedescribed building processes, but has observed that the machinery and the methods normally employed in manufacturing tyres for motor vehicles, such as cars and/or motorcycles, cannot be employed in manufacturing tyres for bicycles. The building operations of the tyres for bicycles in fact require the preparation and manipulation of manufactured items that are extremely thin and delicate. Many components, for example the liner, the carcass plies, and other reinforcement textile structures can have thicknesses between 0.1 mm and 1 mm, for example on the order of 0.3 mm, with extensions width-wise which can reach and exceed values of 450 mm. Also the components made of elastomeric material, such as for example the liner, can have thickness within the above-indicated interval, for example lower than 0.5 mm and with width greater than 120 mm. These size characteristics always lead to the use of semifinished products that lack a sufficient structural solidity to allow the correct manipulation thereof by the machinery normally used in the building of tyres for motorcycles or cars.

A vulcanised tyre for bicycles must be bendable and this requires specific materials for the bead cores (synthetic or natural fibres) and the absence of reinforcement belting layers. As a consequence, a green tyre for bicycles tends to be deformed under the effect of internal tensions and its own weight, and this in a random and uncontrollable manner in circumferential direction where the circular form is lost due to the low resistance of the bead cores and/or in the axial extension direction due to the shrinkage of the materials or weight itself of its components. It is therefore evident just how complex it can be to manage the semifinished products intended to make this type of tyre, when they are still free to be moved in any direction before being assembled to form a component of the green tyre.

All this involves problems relative to a reduced productivity and to a considerable increase of the production costs. In addition, it can be difficult to obtain satisfactory results in terms of precision and uniformity of production, i.e. of repeatability, especially in the production of tyres intended for sports use, where a lack of structural accuracy can impact the performances. Safety problems for the operators must also be resolved, as these are often obliged to complete different processing with their hands in the immediate vicinity and/or in direct contact with movable parts, with exposure to risks of injury. The Applicant has observed that the semifinished products used for building a tyre for bicycles are mainly subjected to two process types. On such matter, the Applicant has perceived that, in order to facilitate a mechanised management of the entire building, it is necessary to optimise the movement and the processing of the two types of semifinished products in a different manner and preferably in different zones of the building apparatus.

More precisely, the Applicant has found that by separating the semifinished products into two groups, a first group intended to manufacture pieces to be wound on the building drum and a second group dispensed directly on the building drum, it is possible to automate the building process by dedicating, to each type of semifinished product, the necessary attention in order to be reliably and repeatably manipulated with consequent improvement of the productivity, uniformity and quality level.

The Applicant has also found that by thrustingly feeding the pieces deriving from first semifinished products of a first group of semifinished products and dispensing, directly on the building drum, second semifinished products of a second group of semifinished products it is possible to obtain an automated building cycle, by cancelling the intervention of the operator or limiting it to only the safe and qualitatively less important operations, and improve the uniformity and the quality of the obtained product, reducing the building times and increasing the type of materials that can be managed by the same apparatus.

More precisely, in accordance with a first aspect, the invention relates to a method for building green tyres for bicycles.

Preferably provision is made for a) arranging a plurality of semifinished products divided into a first group and in a second group, in which each group respectively comprises at least one first semifinished product and at least one second semifinished product, and in which each first or second semifinished product is adapted to build a component of a green tyre for bicycles.

Preferably provision is made for b) arranging a building drum rotating around a rotation axis parallel to a horizontal plane.

Preferably provision is made for c) building at least one component of said green tyre for bicycles starting from said at least one first semifinished product.

Preferably the action c) comprises feeding said at least one first semifinished product along a respective feeding line, cutting to size a piece thereof and thrustingly feeding said piece by means of a respective motorised application conveyor belt of said feeding line which moves it towards said building drum up to a respective first pointing zone on said building drum.

Preferably the action c) comprises winding said piece around said building drum, continuing to feed it thrustingly towards said respective first pointing zone.

Preferably provision is made for d) building at least one component of said green tyre for bicycles starting from said at least one second semifinished product.

Preferably the action d) comprises, along a respective dispensing line, dispensing said at least one second semifinished product directly towards said building drum up to a second pointing zone on said building drum.

Preferably the action d) comprises winding said at least one second semifinished product around said building drum, continuing to dispense it towards said second pointing zone. Preferably the action d) comprises cutting said second semifinished product wound around said building drum.

Preferably provision is made for e) repeating the action c) and/or d) according to a predefined sequence as a function of the type of tyre to be built, up to completing the green tyre.

Preferably provision is made for f) axially removing said green tyre from the building drum.

The Applicant deems that by dividing the semifinished products into two groups and differentiating the management of the semifinished product and of the relative building on the drum between the two groups allows attaining a building that is versatile and adaptable for many types of tyre, identifying the specific situations that would have required the intervention of an operator and intervening in a differentiated and hence more effective manner in order to increase the automation of the building. In particular, the Applicant intervened on the pieces deriving from first semifinished products of a first group of semifinished products in order to thrustingly feed them so as to prevent involuntary and uncontrolled tensioning due to friction and/or to different reactions of the material. Such provision limits the instability of the semifinished product and of the relative piece, allowing the automation of the steps of feeding, cutting, pointing and winding. In addition, the Applicant intervened on second semifinished products, providing to dispense them directly on the building drum in order to obtain two different building modes, possibly actuatable at least in part simultaneously in order to decrease the building times and at least in part in two different areas. Considerable improvements are also verified regarding safety for the operators, by limiting the manual interventions thereof and by circumscribing areas of safe intervention, differentiated by the two groups of semifinished products.

More precisely, in accordance with a second aspect, the invention relates to an apparatus for building green tyres for bicycles.

Preferably provision is made for a building drum rotating at a rotation axis parallel to a horizontal plane.

Preferably provision is made for at least one feeding line configured for feeding a first semifinished product constituting part of a first group of a plurality of semifinished products.

Preferably provision is made for a cutting device operative along said at least one feeding line and configured for cutting to size a piece of said first semifinished product.

Preferably said at least one feeding line comprises a motorised application conveyor belt configured for thrustingly feeding said piece so as to move it towards said building drum up to a respective first pointing zone.

Preferably provision is made for at least one dispensing line configured for dispensing a second semifinished product constituting part of a second group of said plurality of semifinished products directly towards said building drum up to a second pointing zone.

Preferably provision is made for a grip ring configured for axially removing a built green tyre from the building drum.

The Applicant deems that by dividing the apparatus into feeding lines and into dispensing lines allows actuating the division discussed above with regard to the method, thus obtaining the relative above-described advantages. The present invention in at least one of the aforesaid aspects can have at least one of the following preferred characteristics.

Preferably said at least one dispensing line and the respective second pointing zone are arranged in an upper half-space with respect to a radial plane of the building drum parallel to the horizontal plane.

Preferably said at least one feeding line and the respective first pointing zone are arranged in one same lateral half-space of the two lateral half-spaces with respect to a radial plane of the building drum perpendicular to the horizontal plane, the other lateral half-space being free for the access of an operator to the building drum.

The Applicant deems that the spatial division of the areas of competence of the two groups of semifinished products allows optimising the management of the relative semifinished products and, while limiting the need for operator intervention, it improves the safety thereof during intervention.

Preferably the action c) comprises moving, at least in translation along a horizontal direction, a support structure of said application conveyor belt from a distal position to a proximal position with respect to said first pointing zone in order to bring the piece close to the building drum.

Preferably said motorised application conveyor belt is slidably mounted on a support structure that is movable at least in translation along a horizontal direction between a distal position and a proximal position with respect to said first pointing zone. The Applicant deems it advantageous to combine a first thrust movement obtained due to the motorised sliding of the application conveyor belt with respect to the support structure and a second thrust movement due to the movement of the support structure. Such aspect reduces the building times and stabilises the piece on the application conveyor belt in order to obtain an effective pointing and a correct alignment of the same. Preferably the action c) comprises adjusting a linear sliding speed of said application conveyor belt with respect to the support structure and an angular speed of said building drum in order to control the tension applied to the piece during the winding of the piece on the building drum.

The Applicant deems it advantageous to exploit the thrust movement obtained due to the motorised sliding of the application conveyor belt with respect to the support structure in order to affect the qualities of the tyre not only through the selection of the compounds and components, but also through a controlled management of the pointing and winding steps. For example, the adjustment of the linear sliding speed of the application conveyor belt and of the angular speed of the building drum allows controlling the tension applied to the piece and adapting it both to the type of tyre that one wishes to build and to possible data detected during the feeding of the first semifinished product.

Preferably the action c) comprises thrustingly feeding said first semifinished product along said feeding line by means of a motorised preparation conveyor belt which moves it towards a cutting zone configured for cutting said piece to size.

Preferably said at least one feeding line comprises a motorised preparation conveyor belt configured for thrustingly feeding the respective first semifinished product along said feeding line towards said cutting device. The Applicant deems that extending the thrusting feeding to the entire the feeding line and hence also to the first semifinished product before cutting, allows stabilising the first semifinished product during cutting and possibly obtaining a further control parameter, the speed of feeding the first semifinished product, usable for adjusting the cutting step and the subsequent separation of the relative piece.

Preferably the action c) comprises translating a support structure of said application conveyor belt from a proximal position with respect to said preparation conveyor belt to a proximal position with respect to said first pointing zone.

Preferably said motorised application conveyor belt is slidably mounted on a support structure that is movable at least in translation along a horizontal direction between a proximal position with respect to said preparation conveyor belt and a proximal position with respect to said first pointing zone.

The Applicant deems that by dividing the feeding into two steps (preparation and application), both thrustingly operated and providing for the mobility of the application conveyor belt with respect to the preparation conveyor belt, allows stabilising the first semifinished product during cutting and uncoupling the preparation from the application, enabling the at least partial time superimposition thereof in order to reduce the building time.

Preferably said first semifinished product is fed by means of said motorised preparation conveyor belt while said motorised application conveyor belt translates from the proximal position with respect to said preparation conveyor belt to the proximal position with respect to said first pointing zone, bringing a piece that has been previously separated from the first semifinished product.

The Applicant deems that the at least partial time superimposition of the preparation step of the first semifinished product and of the step of application of a relative piece allows reducing the building time.

Preferably said first group comprises at least one first semifinished product adapted to manufacture a first carcass ply and a first semifinished product adapted to manufacture a tread band, each first semifinished product being fed along a respective feeding line.

Preferably provision is made for a feeding line configured for feeding a first semifinished product adapted to manufacture a first carcass ply and a feeding line configured for feeding a first semifinished product adapted to manufacture a tread band.

Preferably said first group also comprises one or more from among: a first semifinished product adapted to manufacture a second carcass ply; a first semifinished product adapted to manufacture strips for reinforcing the sidewalls; a first semifinished product adapted to manufacture a liner; a first semifinished product adapted to manufacture an enlarged protective band or "bead to bead"; a first semifinished product adapted to manufacture reinforcement elements of the beads or "flippers"; each first semifinished product being fed along a respective feeding line.

Preferably a feeding line is also provided for, configured for feeding one from among: a first semifinished product adapted to manufacture a second carcass ply; a first semifinished product adapted to manufacture strips for reinforcing the sidewalls; a first semifinished product adapted to manufacture a liner; a first semifinished product adapted to manufacture an enlarged protective band or "bead to bead"; a first semifinished product adapted to manufacture reinforcement elements of the beads or "flippers".

The Applicant deems that the differentiation into two groups of semifinished products, dedicating specific attention and specific spaces to the management of the first semifinished products, allows obtaining methods and apparatuses that are substantially complete and adaptable to numerous types of tyres by selecting the suitable steps or tools.

Preferably each first semifinished product is fed towards a respective first pointing zone, said first pointing zones being distributed along a circumferential pointing section arranged laterally with respect to said building drum in one of the two lateral half-spaces with respect to a radial plane of the building drum perpendicular to the horizontal plane.

Preferably provision is made for a plurality of first feeding lines each configured for feeding a respective first semifinished product and a respective piece towards a respective first pointing zone, said first pointing zones being arranged along a same circumferential pointing section arranged laterally with respect to said building drum in one of the two lateral half-spaces with respect to a radial plane of the building drum perpendicular to the horizontal plane.

The Applicant deems that concentrating the management and the pointing of the first semifinished products improves the safety of the operator, both because there is the focus on zones and steps having a similar management, and because other spaces are freed that can be dedicated to the safe access of the operator.

Preferably said second group comprises at least one second semifinished product adapted to manufacture bead cores fed along a respective feeding line.

Preferably provision is made for at least one dispensing line configured for dispensing a second semifinished product adapted to manufacture bead cores.

Preferably said second group also comprises at least one second semifinished product associated with a service belt and in which dispensing said second semifinished product towards said second pointing zone comprises separating and collecting said service belt.

Preferably provision is also made for at least one dispensing line configured for dispensing a second semifinished product associated with a service belt and in which said at least one dispensing line comprises means for separating and collecting said service belt.

Preferably said second group also comprises one from among: a second semifinished product adapted to manufacture reinforcement elongated elements or "chafers"; a second semifinished product adapted to manufacture a protective band or "breaker"; a second semifinished product adapted to manufacture an elastomeric base; a second semifinished product adapted to manufacture fillers.

Preferably at least one dispensing line is also provided for, configured for dispensing one from among: a second semifinished product adapted to manufacture reinforcement elongated elements or "chafers"; a second semifinished product adapted to manufacture a protective band or "breaker"; a second semifinished product adapted to manufacture an elastomeric base; a second semifinished product adapted to manufacture fillers.

The Applicant deems that the differentiation into two groups of semifinished products, dedicating specific attention and specific spaces for the management of the second semifinished products, allows obtaining methods and apparatuses that are substantially complete and adaptable to numerous types of tyres, selecting the suitable steps or tools.

Preferably each second semifinished product is dispensed towards a respective second pointing zone, said second pointing zones being arranged along a same axial pointing section axially arranged along said building drum.

Preferably provision is made for a plurality of dispensing lines each configured for dispensing a respective second semifinished product towards a respective second pointing zone, thus defining a plurality of second pointing zones distributed along a same axial pointing section axially arranged along said building drum. The Applicant deems that concentrating the management and the pointing of the second semifinished products improves the safety of the operator both because there is the focus on zones and steps having a similar management, and because other spaces are freed that can be dedicated to the safe access of the operator.

Preferably, before each action d), provision is made for setting the respective second pointing zone along said axial pointing section.

Preferably provision is made for a shuttle which supports said at least one dispensing line and which is movable along the rotation axis of the building drum in order to position a dispensing line being processed at the respective second pointing zone along an axial pointing section axially arranged along said building drum. The Applicant deems that the rapid selection of the second semifinished products from among a wide selection readily available in the building apparatus, without requiring substitutions or adaptations, reduces the building time in particular the down times and allows quickly passing from one type of tyre to another, facilitating the processing in batches of small quantities, thus avoiding waste and the need for storage.

Preferably provision is made for executing the action c), except for winding said piece around said building drum, simultaneously with the action d).

The Applicant deems that by differentiating the approach to the two groups of semifinished products, it is possible to simultaneously execute several actions, in particular those which do not interfere with each other.

Preferably said building drum has variable diameter.

Preferably the action c) and/or the action d) comprises comparing the diameter of the building drum with a reference value of the component to be built and possibly modifying the diameter of the building drum in order to reach said reference value.

The Applicant deems it advantageous to exploit the adaptability of the diameter of the building drum in order to affect the qualities of the tyre not only through the selection of the compounds and components, but also through a controlled management of the pointing and winding steps. For example, the adjustment of the diameter of the building drum allows controlling the tension applied to the piece and/or to the second semifinished product and adapting it both to the type of tyre that one wishes to build and to possible data detected during the feeding and/or dispensing.

Preferably said building drum is arranged with fixed rotation axis. The Applicant deems it advantageous to operate with a fixed reference so as to simplify the feeding and/or the dispensing and the relative pointing.

Preferably provision is made for a plurality of feeding lines arranged at different heights, with mainly horizontal extension, at least partially superimposed along a vertical direction within the same lateral half-space.

Preferably provision is made for a plurality of feeding lines, each configured for feeding a first semifinished product and provision is made for selecting the feeding line/lines as a function of the type of tyre to be built.

Preferably provision is made for a plurality of dispensing lines, each configured for dispensing a second semifinished product and provision is made for selecting the dispensing line/lines as a function of the type of tyre to be built.

Preferably during the building of the tread band, an axially central portion of the at least one carcass ply, extended axially through an axial middle line plane equidistant from the bead cores, lies parallel to the building drum.

Preferably one or more feeding lines have a shape of a support structure and/or of relative supports such to determine a rotation or a tilt of the application conveyor belt following the translation of the support structure approaching the building drum.

Preferably a piece that is situated supported by the application conveyor belt is subjected to a first thrust movement due to the motorised sliding of the application conveyor belt and to a second thrust movement due to the movement of the support structure.

Preferably each component of the green tyre is built on the same building drum.

Preferably the building drum comprises turning up devices, e.g. movable levers.

Preferably provision is made for at least one unwinder for each feeding line comprising a motor unwinder member that is different from a motor preparation member such that the unwinder is uncoupled from the preparation conveyor belt.

Preferably provision is made for adjusting the speeds of the motor unwinder member and of the motor preparation member in order to control a loop in the first semifinished product between the unwinder and the preparation conveyor belt.

Preferably provision is made for a rolling pallet preferably arranged in a lower half-space with respect to a radial plane of the building drum parallel to a horizontal plane.

Further characteristics and advantages will be more evident from the detailed description of a preferred but not exclusive embodiment of a method and an apparatus for building green tyres for bicycles, in accordance with the present invention. Such description will be set forth hereinbelow with reference to the enclosed drawings, provided only as a non-limiting example, in which:

- figures 1 to 4 schematically show, in cross section, several operating steps aimed for building a green tyre for bicycles;

- figures 5A and 5B schematically show, in cross section, the components of a tyre for bicycles in a respective base shape thereof;

- figures 6A-6H schematically show, in cross section, the tyre of figure 5A respectively with at least one additional component;

- figure 7 schematically shows a plan view of an apparatus for building green tyres for bicycles;

- figure 8 shows a side view of the apparatus of figure 7;

- figure 9 shows a front view of the apparatus of figure 7;

- figure 10 shows a flow diagram of an example of a building cycle.

The present invention is aimed for building green tyres 1 for bicycles, e.g. for use on road, track, mountain bikes, e-bikes etc..

With reference to the figures, reference number 100 indicates an apparatus for building green tyres 1 for bicycles suitable for actuating a method for building green tyres 1 for bicycles according to the present invention.

As illustrated in figures 5A-5B, in the green tyre 1 for bicycles, a radially inner surface 2a, facing substantially towards a rotation axis "X" of the tyre, and a radially outer surface 2b facing substantially away from the rotation axis "X" are identifiable. The green tyre 1 for bicycles has a carcass structure 3 comprising at least one carcass ply 4 with cords that are mutually parallel, incorporated in an elastomeric matrix.

Figure 5A illustrates a green tyre 1 in which the carcass structure 3 comprises a (first) carcass ply 4.

Axially opposite end flaps 4a of the carcass ply 4 are bent around respective bead cores 5, i.e. around anchoring annular structures integrated in the zones normally identified with the term "beads", at which there is the mechanical engagement between the tyre in use conditions and a respective mounting rim. The bead cores 5 are for example made of composite material with natural or synthetic fibre base and/or made of metallic material. The end flaps 4a are radially superimposed on an axially central portion 4b of the carcass ply 4 and preferably also mutually with respect to each other.

Preferably, the cords of the carcass ply 4 have an extension tilted according to a predetermined angle, approximately comprised between about 35° and about 55° with respect to a circumferential extension direction of the green tyre 1. In this manner, by being superimposed on the axially central portion 4b of the carcass ply 4, the carcass structure 3 has in radial direction two layers of cords with respectively cross progression. A tread band 6, made of elastomeric material, is applied in radially outer position with respect to the carcass structure 3.

Figure 5B illustrates the green tyre 1 of figure 5A with the difference that the carcass structure 3 comprises two carcass plies 4, i.e. a first carcass ply and a second carcass ply, radially superimposed on each other, each with the respective cords extended along a direction that is tilted with respect to the circumferential extension of the green tyre 1 and according to a tilted or cross orientation with respect to the cords belonging to the other carcass ply.

Generally, the tyre for bicycles lacks a belt structure, i.e. reinforcement belt layers radially interposed between the carcass structure 3 and the tread band 6 and whose extensibility in circumferential direction is substantially null or very limited, in any case much less than that of the carcass ply/plies 3.

In addition to the components illustrated in figures 5A-5B (carcass ply/plies 4, bead cores 5, tread band 6) in the green tyre 1 for bicycles one or more additional components can also be provided for. Figures 6A-6H respectively illustrate an additional component that can return into the structure of the green tyre 1 for bicycles. Each of the components illustrated in figures 6A-6H can be present separately in the green tyre 1 or in combination with one or more of the other illustrated components or with further non-illustrated components.

For the sake of simplicity, figures 6A-6H only report the number references of the additional component illustrated and refer to a green tyre 1 in which the carcass structure 3 comprises a carcass ply 4 but any additional component, illustrated or no, can also return into the structure of green tyres with two or more carcass plies 4.

With reference to figure 6A, a green tyre 1 is illustrated comprising at least one textile reinforcement defined by at least one protective band 7, normally termed "breaker", whose task is for example that of protecting the tyre from punctures. The protective band 7 is extended circumferentially between the tread band 6 and the carcass structure 3 (continuous line) and/or between two layers of the carcass ply 4 mutually superimposed in radial direction (dashed line). Preferably the protective band 7 has textile structure incorporating cords respectively parallel or respectively cross. Preferably the protective band 7 has a thickness not greater than about 0.6 mm, preferably comprised between 0.35 mm and 0.6 mm. The axial extension of the protective band/bands 7 is smaller than that of the tread band 6 and preferably comprised between 15 mm and 50 mm.

With reference to figure 6B, a green tyre 1 is illustrated comprising at least one textile reinforcement defined by at least one enlarged protective band 8, normally termed "bead to bead", whose task is for example that of protecting the tyre from punctures. The enlarged protective band 8 is extended circumferentially preferably between the tread band 6 and the carcass structure 3. Preferably the enlarged protective band 8 has textile structure incorporating cords that are respectively parallel or respectively cross. Preferably the enlarged protective band 8 has a thickness not greater than about 0.6 mm, preferably comprised between 0.35 mm and 0.6 mm. The axial extension of the enlarged protective band 8 is greater than that of the tread band 6, e.g. comprised between 50 mm and 200 mm, preferably such to terminate axially at each of the bead cores 5. The enlarged protective band 8 can be associated with one or more protective bands 7, preferably it is associated with a protective band 7 that is extended circumferentially between the tread band 6 and the carcass structure 3, in radially inner position with respect thereto. With reference to figure 6C, a green tyre 1 is illustrated comprising at least a rubber elongated element defined by at least one elastomeric base 9 in layer form. The elastomeric base 9 is extended circumferentially preferably between the tread band 6 and the carcass structure 3. Preferably the elastomeric base 9 is arranged in radially inner position with respect to the protective band 7, if present between the tread band 6 and the carcass structure 3, and/or in radially outer position with respect to the enlarged protective band 8, if present. The elastomeric base 9 can have approximately an axial width comprised between 15 mm and 30 mm, and thickness comprised between 0.5 mm and 1.5 mm.

With reference to figure 6D, a green tyre 1 is illustrated comprising a so-called liner 10 that covers a radially inner surface of the carcass structure 3. The liner 10 consists of an air- impermeable compound layer whose thickness can be approximately comprised between 0.35 mm and 1 mm. The liner is extended from one of the beads to the other, according to an axial extension approximately between 70 mm and 120 mm and preferably is a partially wound around the bead cores 5.

With reference to figure 6E, a green tyre 1 is illustrated, comprising at least one textile reinforcement defined by two reinforcement elongated elements 11, normally termed "chafers", applied respectively in proximity to a bead core 5, outside the bead, at the radially outer surface 2b of the tyre. Each reinforcement elongated element 11 appears in textile strip form incorporating cords that are parallel to each other or respectively cross, for the purpose of protecting the beads from contact with the rim of the wheel, on which the tyre is mounted. Each reinforcement elongated element 11 can have a width comprised between 8 mm and 15 mm and a thickness comprised between 0.35 and 1 mm. The reinforcement elongated elements 11 can be built directly on the turned-up end flaps 4a or on the enlarged protective band 8, if present, or on the turned-up portion of the liner 10, if present.

With reference to figure 6F, a green tyre 1 is illustrated comprising two strips for reinforcing the sidewalls 12, each extended between the respective bead and the tread band 6 for example according to a width comprised between 30 mm and 60 mm. Preferably each reinforcement strip of the sidewalls 12 is made of rubber-covered textile material, incorporating cords that are mutually parallel or cross. Preferably the strips for reinforcing the sidewalls 12 have thickness approximately comprised between 0.35 mm and 0.8 mm. The reinforcement elongated elements 11 if present, can be built directly on the strips for reinforcing the sidewalls 12, if present. When the strips for reinforcing the sidewalls 12 are not present, portions of carcass ply 4 that are directly exposed towards the outside environment are identifiable on the radially outer surface 2b of the tyre, between the axially outer edges of the tread band 6 and the bead cores 5. The tyre for bicycles in fact typically lacks sidewalls, i.e. layers of elastomeric material applied laterally to the outside of the carcass structure 3, each extended between one of the beads and the respective axially outer edge of the tread band.

With reference to figure 6G, a green tyre 1 is illustrated comprising at least two rubber elongated elements respectively defining two fillers 13, respectively arranged at the bead cores 5, in axially inner position with respect to the bead cores themselves, in order to complete the beads. The fillers 13 are preferably manufactured with rubber compounds having hardness and strength adapted to provide stability during the mounting of the tyre on the rim and shear strength during use. In addition the fillers 13 improve the form of the border of the carcass ply 4 in the zone where it is wound around the bead core 5.

With reference to figure 6H, a green tyre 1 is illustrated comprising two reinforcement elements of the beads 14, respectively wound around the bead cores 5, normally termed "flippers", in order to complete the beads. The reinforcement elements of the beads 14 allow reducing the risk of separation of the components of the tyre in the regions of the bead. Preferably each reinforcement element of the bead 14 encloses the respective bead core 5 and the respective filler 13 and carries out the function of separating the carcass ply 4 from the bead core 5, allowing a certain degree of relative mutual movement for the purpose of reducing the disparities of stress on the carcass ply 4 and on the rubber components of the bead or adjacent thereto, e.g. the filler 13 and/or the strips for reinforcing the sidewalls 12.

Each component of the green tyre 1 is built starting from a respective semifinished product "A", "B".

Based on the type of tyre and hence on the type of components provided therein, there is a plurality of semifinished products "A", "B", possibly providing for selecting the plurality of necessary semifinished products "A", "B".

In particular, according to an action a) of the method for building green tyres for bicycles according to the present invention, provision is made for arranging a plurality of semifinished products "A", "B" divided into a first group and into a second group,

The first group comprises at least one first semifinished product Al-An (with n the number of first semifinished products). In figure 8, by way of example seven first semifinished products were indicated, respectively with the reference numbers Al to A7.

The second group comprises at least one second semifinished product Bl-Bm (with m the number of second semifinished products). In figure 9, by way of example five second semifinished products were indicated, respectively with reference numbers Bl to B5.

The set of semifinished products of the first and of the second group constitutes the aforesaid plurality of semifinished products. In other words, a component of the tyre is built starting from a first semifinished product Al-An, i.e. a semifinished product belonging to the first group, or from a second semifinished product Bl-Bn, i.e. a semifinished product belonging to the second group. Therefore each first or second semifinished product "A", "B" is adapted to manufacture a respective component of a green tyre for bicycles.

According to an action b) of the method for building green tyres for bicycles according to the present invention, provision is made for arranging a building drum 20, constituting part of the apparatus 100. Each component of the green tyre 1 is built on the same building drum 20. The building drum 20 is rotatably supported so as to be rotating around a respective rotation axis "X" parallel to a horizontal plane "0" and substantially corresponding to the rotation axis "X" of the tyre. Preferably the building drum 20 is arranged with rotation axis "X" fixed.

Preferably the building drum 20 has variable diameter.

Preferably the building drum 20 comprises turning up devices (not illustrated), e.g. movable levers for lifting the end flaps 4a and turning them up towards the axially central portion 4b.

According to an action c) of the method for building green tyres for bicycles according to the present invention, provision is made for building at least one component of the green tyre 1 starting from a first semifinished product Al-An. Such action c) comprises feeding the respective first semifinished product and cutting to size (length) a piece "C" thereof. The first semifinished product is extended width-wise like the component that it is intended to form. The action c) thus comprises feeding the piece "C" towards the building drum 20 and winding it therearound, forming a joint between the head ends of the piece itself and generating a component having a cylindrical shape. The length of the piece "C" thus defines the circumferential extension of the respective component around the rotation axis "X" of the green tyre 1 while the width of the piece "C" defines the axial size of the respective component with respect to the rotation axis "X" of the green tyre 1.

According to an action d) of the method for building green tyres for bicycles according to the present invention, provision is made for building at least one component of the green tyre 1 starting from a second semifinished product Bl-Bm. Such action d) comprises dispensing the second semifinished product directly towards the building drum 20, winding the second semifinished product around the building drum 20 and cutting the second semifinished product wound around the building drum.

The second semifinished product Bl-Bm can be extended widthwise like the component that it is intended to form (axial size with respect to the rotation axis "X" of the green tyre 1), so that a complete rotation generally suffices of the building drum 20 for building the respective component. As an alternative, the second semifinished product Bl-Bm can be extended width-wise for a smaller section of the width of the component that is intended to form, so that for building the respective component multiple complete rotations are generally necessary of the building drum 20 so as to create a plurality of turns that are axially approached and/or radially superimposed on each other up to reaching the width (axial size) of the respective component.

According to an action e) of the method for building green tyres for bicycles according to the present invention, provision is made for repeating the action c) and/or d) according to a predefined sequence as a function of the type of green tyre to be built, up to completing the green tyre 1.

According to an action f) of the method for building green tyres for bicycles according to the present invention, provision is made for axially removing the green tyre 1 from the building drum 20 in order to subject it to other process steps, for example for transferring it to a vulcanisation press.

For such purpose, the building drum 20 is radially contracted so as to facilitate the axial removal of the green tyre 1. Figure 1 to 4 schematically illustrate the building on the building drum 20 of a green tyre 1 in a base version thereof illustrated in figures 5A or 5B.

In figure 1, the carcass ply or plies 4 are built by winding around the building drum 20 of a piece "C" of a respective first semifinished product Al-An. In this case the first group comprises at least one first semifinished product adapted to manufacture a first carcass ply (for example the first semifinished product indicated with the reference Al in figure 8) and possibly a first semifinished product adapted to manufacture a second carcass ply (for example the first semifinished product indicated with the reference A2 in figure 8). The possible liner 10 can be built before the application of the carcass ply/plies 4 by winding around the building drum 20 of a piece of a respective first semifinished product. In this case the first group also comprises at least one first semifinished product adapted to manufacture a liner (for example the first semifinished product indicated with the reference A3 in figure 8).

In figure 2 the bead cores 5 are respectively built by winding around the building drum 20 of a respective second semifinished product and subsequent cut. In this case the second group comprises at least one second semifinished product adapted to manufacture bead cores (for example the second semifinished product indicated with the reference Bl in figure 9). The bead cores are built respectively around one of the axially opposite end flaps 4a of the carcass ply/plies 4 and to a predetermined mutual axial distance "D". In figure 3 the end flaps 4a of the carcass ply/plies 4 are turned up around the respective bead cores 5 and at least partially superimposed on each other.

If necessary, the turning up can be preceded by the building of one or more from among: at least one protective band 7 "breaker" (dashed line of figure 6A), the fillers 13 (figure 6G), the reinforcement elements of the beads 14 or "flippers" (figure 6H), if provided for.

The protective band 7 or "breaker" is built by winding around the building drum 20 of a respective second semifinished product and subsequent cut. In this case the second group also comprises at least one second semifinished product adapted to manufacture a protective band or "breaker" (for example the second semifinished product indicated with the reference B2 in figure 9).

The fillers 13 are built by winding around the building drum 20 of a respective second semifinished product and subsequent cut. In this case the second group also comprises at least one second semifinished product adapted to manufacture fillers (for example the second semifinished product indicated with the reference B3 in figure 9).

The reinforcement elements of the beads 14 or "flippers" are built by winding around the building drum 20 of pieces "C" of a respective first semifinished product. In this case the first group also comprises at least one first semifinished product adapted to manufacture reinforcement elements of the beads or "flippers" (for example the first semifinished product indicated with the reference A4 in figure 8). In figure 4, after the turning up, the tread band 6 is built by winding around the building drum 20 of a piece "C" of a respective first semifinished product. In this case the first group comprises at least one first semifinished product adapted to manufacture a tread band 6 (for example the first semifinished product indicated with the reference A5 in figure 8). The tread band 6 is built around the carcass ply 4, in axially centred position with respect to the bead cores 5. The tread band 6 can be built in radial superimposition with respect to the turned-up end flaps 4a. The end flaps 4a can therefore be partially arranged in axially inner position with respect to axially opposite lateral edges of the tread band 6.

During the building of the tread band 6, the axially central portion 4b of the at least one carcass ply 4, extended axially through an axial middle line plane "M" equidistant from the bead cores 5, lies parallel to the building drum 20 (figure 4). With the term "axial middle line plane" of the tyre, moulded and vulcanised or green, it is intended a plane perpendicular to the rotation axis "X" and equidistant from the axially outer portions of the tyre itself.

The tread band 6 is preferably built by maintaining the mutual axial distance "D" of the bead cores 5 substantially unchanged. More particularly, the mutual axial distance "D" between the bead cores 5 remains preferably unchanged in the course of the entire building process, including the application of the tread band 6.

In the green tyre 1 for bicycles, the thickness of the bead core 5 corresponds to half of the difference between an outer circumferential diameter "De" and a fitting diameter "De" of the bead core 5 itself (figure 2).

If necessary, the building of the tread band 6 can be preceded and/or followed by the building of at least one from among: at least one protective band 7 or "breaker" (continuous line of figure 6A), at least one enlarged protective band 8 or "bead to bead" (figure 6B), at least one elastomeric base 9 (figure 6C), the reinforcement elongated elements 11 or "chafers" (figure 6E), the strips for reinforcing the sidewalls 12 (figure 6F).

The protective band 7 or "breaker" is built as described above.

The enlarged protective band 8 or "bead to bead" is built by winding around the building drum 20 of a piece "C" of a respective first semifinished product. In this case the first group comprises at least one first semifinished product adapted to manufacture an enlarged protective band 8 or "bead to bead" (for example the first semifinished product indicated with the reference A6 in figure 8).

The elastomeric base 9 is built by winding around the building drum 20 of a respective second semifinished product and subsequent cut. In this case the second group also comprises at least one second semifinished product adapted to manufacture an elastomeric base (for example the second semifinished product indicated with the reference B4 in figure 9).

The reinforcement elongated elements 11 or "chafers" are built by winding around the building drum 20 of a respective second semifinished product and subsequent cut. In this case the second group also comprises at least one second semifinished product adapted to manufacture reinforcement elongated elements or "chafers" (for example the second semifinished product indicated with the reference B5 in figure 9).

The strips for reinforcing the sidewalls 12 are built by winding around, the building drum 20, pieces "C" of a respective first semifinished product. In this case the first group comprises at least one first semifinished product adapted to manufacture strips for reinforcing the sidewalls (for example the first semifinished product indicated with the reference A7 in figure 8). The apparatus 100 comprises at least one building area 101 and a tower 102. The building area 101 is extended transverse to the tower 102, to one end thereof (figure 7).

In the tower 102, provision is made for at least one feeding line 103 configured for feeding a first semifinished product Al-An constituting part of the first group of the aforesaid plurality of semifinished products. The above-described action c) comprises feeding the first semifinished product along a respective feeding line 103.

For the purpose of building a green tyre 1 for bicycles in its base version illustrated in figure 5A, it suffices that the tower 102 comprise at least two feeding lines 103: a feeding line 103 configured for feeding the first semifinished product adapted to manufacture a first carcass ply Al and a feeding line 103 configured for feeding the first semifinished product adapted to manufacture a tread band A5.

Therefore, each first semifinished product is fed along a respective feeding line 103.

For the purpose of building a green tyre 1 for bicycles in its base version illustrated in figure 5B and/or comprising at least one additional component, for example at least one of the additional components illustrated in figures 6B, 6D, 6F or 6H, further feeding lines 103 can be provided for that are respectively configured for feeding one or more from among: the first semifinished product adapted to manufacture a second carcass ply A2; the first semifinished product adapted to manufacture an enlarged protective band or "bead to bead" A6; the first semifinished product adapted to manufacture a liner A3; the first semifinished product adapted to manufacture strips for reinforcing the sidewalls A7; the first semifinished product adapted to manufacture reinforcement elements of the beads or "flippers" A4.

In the example illustrated in figure 8, four feeding lines 103 are provided for which, from top to bottom, the following are respectively configured for feeding the first semifinished product adapted to manufacture a tread band A5, the first semifinished product adapted to manufacture a first carcass ply Al, the first semifinished product adapted to manufacture a second carcass ply A2 (or the first semifinished product adapted to manufacture a liner A3 or the first semifinished product adapted to manufacture an enlarged protective band or "bead to bead" A6), the first semifinished product adapted to manufacture strips for reinforcing the sidewalls A7 (or the first semifinished product adapted to manufacture reinforcement elements of the beads or "flippers" A4).

All of the above-listed feeding lines can also be further provided for, selectable as a function of the type of tyre to be built, or it is possible to dedicate the feeding lines illustrated in figure 8 to different first semifinished products as a function of the type of tyre to be built or it is possible to substitute, each time, the feeding lines as a function of the type of tyre to be built.

Each feeding line 103 is associated with a respective cutting device 104.

Each cutting device 104 is operative along a respective feeding line and is configured for cutting to size a piece "C" of the first semifinished product Al-An fed through such feeding line. The cutting device 104 can comprise movable blades or other cutting bodies or operate by non-mechanical systems, e.g. laser systems, ultrasound systems or other systems.

Each feeding line 103 comprises a motorised application conveyor belt 105 preferably by a motor application member 105a, e.g. a roller or a motorised pulley, configured for sliding the application conveyor belt 105 with respect to a support structure 105b on which it is slidably mounted.

In this manner, the application conveyor belt 105 is configured for thrustingly feeding the piece "C" so as to move it towards the building drum 20 up to a respective first pointing zone 106.

The action c) comprises thrustingly feeding the piece "C" by means of the motorised application conveyor belt 105 and winding it around the building drum 20, continuing to feed it thrustingly towards the respective first pointing zone 106, so as to not subject it to uncontrolled stretching actions.

The feeding line/lines 103 and the respective first pointing zone/zones 106 are arranged in one same lateral half-space of the two lateral half-spaces SL1, SL2 defined by a radial plane R.1 of the building drum 20 perpendicular to the horizontal plane "0" (i.e. arranged vertically). With reference to the example of figure 8, each feeding line 103 and the respective first pointing zone 106 are arranged in the same lateral half-space SL1 while the other lateral half-space SL2 is free for the access of an operator to the building drum 20.

In other words the tower 102 can comprise a plurality of feeding lines 103, each configured for feeding a respective first semifinished product Al-An and a respective piece "C" towards a respective first pointing zone 106. A plurality of first pointing zones 106 is thus defined, distributed along a circumferential pointing section, arranged laterally with respect to the building drum 20 in one of the two lateral half-spaces mentioned above, e.g. the lateral half-space SL1.

Preferably the support structure 105b of the application conveyor belt 105 is movable at least in translation along a horizontal direction between a distal position and a proximal position with respect to the first pointing zone 106.

In particular, the support structure 105b of the application conveyor belt 105 can be mounted on supports 107 (e.g. pins or rollers) on which it can translate between the distal position and the proximal position with respect to the first pointing zone 106. One or more feeding lines 103, for example that/those arranged at higher heights, can have a shape of the support structure 105b and/or of the relative supports 107 such to determine a rotation or a tilt of the application conveyor belt 105 following the translation of the support structure 105b so as to be further approached to the building drum 20.

In other words, the piece "C" that is situated supported by the application conveyor belt 105, is subjected to a first thrust movement towards the first pointing zone 106 due to the motorised sliding of the application conveyor belt 105 with respect to the support structure 105b and preferably is also subjected to a second thrust movement due to the movement of the support structure 105b in the passage from the distal position to the proximal position with respect to the first pointing zone 106.

The action c) comprises translating the support structure 105b of the application conveyor belt 105 from the distal position to the proximal position with respect to the respective first pointing zone 106 in order to bring the piece "C" close to the building drum 20.

Preferably the action c) comprises adjusting a linear sliding speed of the application conveyor belt 105 with respect to the support structure 105b and an angular speed of the building drum 20 in order to control the tension applied to the piece "C" during its winding on the building drum 20.

Each feeding line 103 preferably also comprises a motorised preparation conveyor belt 108 preferably by a motor preparation member 108a, e.g. a roller or a motorised pulley, configured for sliding the preparation conveyor belt 108 with respect to a support structure 108b on which it is mounted.

In this manner the preparation conveyor belt 108 is configured for thrustingly feeding the respective first semifinished product Al-An along the feeding line 103 towards the cutting device 104. The action c) comprises thrustingly feeding the first semifinished product Al-An along a respective feeding line 103 by means of the motorised preparation conveyor belt 108, which moves it towards a cutting zone corresponding to the cutting device 104 in which the cutting to size of the piece "C" is executed. In this manner the first semifinished product Al-An is actively thrust and is not subjected to uncontrolled stretching actions.

The preparation conveyor belt 108 is upstream of the application conveyor belt 105 according to a travel sense F of the first semifinished product Al-An along the respective feeding line 103.

The support structure 105b of the application conveyor belt 105 is movable at least in translation along a horizontal direction between a proximal position with respect to the preparation conveyor belt 108, corresponding to the distal position with respect to the first pointing zone 106, and the proximal position with respect to the respective first pointing zone 106.

The action c) comprises translating the support structure 105b from the proximal position with respect to the preparation conveyor belt 108 to the proximal position with respect to the first pointing zone 106 in order to move the piece "C" close to the building drum 20.

Preferably, a first semifinished product Al-An is fed by means of the motorised preparation conveyor belt 108 while the motorised application conveyor belt 105 translates from the proximal position with respect to the preparation conveyor belt 108 to the proximal position with respect to the first pointing zone 106, bringing a piece "C" that has been previously separated from the first semifinished product Al-An.

The preparation conveyor belt 108 and the application conveyor belt 105 can comprise a single transport unit "T" as is for example illustrated in figure 7 in a continuous line. In the event in which it is requested to apply two pieces "C" at two different axial positions along the building drum 20, such as for example in the case of the reinforcement elements of the beads 14 or "flippers" and of the strips for reinforcing the sidewalls 12, the preparation conveyor belt 108 and the application conveyor belt 105 can comprise two parallel transport units Tl, T2 as is for example illustrated in figure 7 in dashed line.

The tower 102 also comprises at least one unwinder 109, in particular one unwinder 109 for each feeding line 103.

Each unwinder 109 is adapted to contain a respective first semifinished product Al-An which is dispensed towards the respective feeding line 103, preferably towards the respective preparation conveyor belt 108.

Preferably each unwinder 109 comprises a motor unwinding member 109a different from the motor preparation member 108a such that the unwinder 109 is uncoupled from the preparation conveyor belt 108 in order to prevent the first semifinished product from undergoing uncontrolled stretching actions. Indeed, by adjusting the speeds of the motor unwinding member 109a and of the motor preparation member 108a, it is possible to generate a loop 110 in the first semifinished product between the unwinder 109 and the preparation conveyor belt

108 and thus allow compensating for possible accelerations or decelerations.

Sensors 111 detect the first semifinished product in the unwinder

109 (for example the diameter of a reel) and the length of the loop 110 and allow controlling the speeds of the motor unwinding member 109a and of the motor preparation member 108a.

The action c) comprises therefore dispensing a first semifinished product Al-An towards the respective feeding line 103, unwinding it and adjusting the speeds of the motor unwinding member 109a and of the motor preparation member 108a in order to compensate for possible uncontrolled accelerations or decelerations.

In the building area 101, in addition to the building drum 20, provision is made for at least one dispensing line 112 configured for dispensing a second semifinished product Bl-Bm constituting part of the second group of the aforesaid plurality of semifinished products. The dispensing occurs directly towards the building drum 20, up to a second pointing zone 113 on the building drum itself. The action d) therefore comprises dispensing, along a respective dispensing line 112, a second semifinished product Bl-Bm directly towards the building drum 20 up to the second pointing zone 113.

The dispensing of the second semifinished product and the subsequent cut imply that the respective component is built directly on the building drum 20, by winding around the carcass ply or plies 4 the second semifinished product in a single rotation of the building drum 20 or in multiple rotations, creating a plurality of turns that are axially approached and/or radially superimposed on each other.

For the purpose of building a green tyre 1 for bicycles in a base version thereof illustrated in figure 5A or 5B, it suffices that the building area 101 comprises a dispensing line 112 configured for dispensing the second semifinished product adapted to manufacture bead cores Bl.

For the purpose of building a green tyre 1 for bicycles comprising at least one additional component, for example at least one of the textile reinforcements illustrated in figures 6A or 6E, further dispensing lines 112 can also be provided for that are respectively configured for feeding one or more from among: the second semifinished product adapted to manufacture a protective band or "breaker" B2; the second semifinished product adapted to manufacture reinforcement elongated elements or "chafers" B5.

For the purpose of building a green tyre 1 for bicycles comprising at least one additional component, for example at least one of the rubber elongated elements illustrated in figures 6C or 6G, further dispensing lines 112 can also be provided for that are respectively configured for feeding one or more from among: the second semifinished product adapted to manufacture an elastomeric base B4; the second semifinished product adapted to manufacture fillers B3.

In the example illustrated in figure 9, five dispensing lines 112 can also be provided for which, from left to right, the following are respectively configured for feeding the second semifinished product adapted to manufacture bead cores Bl, the second semifinished product adapted to manufacture reinforcement elongated elements or "chafers" B5, the second semifinished product adapted to manufacture an elastomeric base B4, the second semifinished product adapted to manufacture a protective band or "breaker" B2, the second semifinished product adapted to manufacture fillers B3.

Preferably all of the above-listed dispensing lines are provided for, selectable as a function of the type of tyre to be built, or it is possible to dedicate the dispensing lines illustrated in figure 9 to different second semifinished products as a function of the type of tyre to be built or it is possible to substitute each time the dispensing lines as a function of the type of tyre to be built. Each dispensing line 112 dispenses the respective second semifinished product Bl-Bm directly towards the building drum 20, up to a second pointing zone 113. Several possible second pointing zones 113 of respective second semifinished products are schematically indicated in figure 1 and correspond to the second pointing zones of second semifinished products adapted to respectively manufacture the bead cores 5, the possible elastomeric base 9, the possible reinforcement elongated elements 11 or "chafers", the possible protective band 7 or "breaker" and the possible fillers 13.

The dispensing line/lines 112 and the respective second pointing zone/zones 113 are arranged in an upper half-space SS with respect to a radial plane R.2 of the building drum 20 parallel to the horizontal plane "0" (i.e. horizontally arranged).

When in the building area 101 provision is made for a plurality of dispensing lines 112, each second semifinished product Bl-Bm is dispensed towards a respective second pointing zone 113 this defining a plurality of second pointing zones 113 distributed along a same axial pointing section axially arranged along the building drum 20 in the upper half-space SS, preferably a top section of the building drum 20.

Preferably provision is made for a shuttle 114 which supports the at least one dispensing line 112, preferably a plurality of dispensing lines 112.

The shuttle 114 is movable along the rotation axis "X" or parallel to the rotation axis "X" of the building drum 20 in order to position a dispensing line being processed at the respective second pointing zone along the axial pointing section. Therefore, it is preferably provided to set the respective second pointing zone 113 along the axial pointing section before each action d), moving the shuttle 114.

Preferably at least one dispensing line 112, for example all of the dispensing lines except for the dispensing line configured for dispensing the second semifinished product adapted to manufacture bead cores Bl, are configured for dispensing the respective second semifinished product Bl-Bm associated with a service belt (not illustrated). In this case the dispensing line comprises means 115 for separating and collecting the service belt, for example transmission elements and collection reels. In the action d), dispensing the second semifinished product Bl-Bm towards the second pointing zone 113 comprises separating and collecting the service belt.

In the course of the building, it is preferable to execute the action c) relative to a first semifinished product simultaneously with the action d) relative to a second semifinished product, except for the action of winding the piece "C" around the building drum 20.

Preferably, during the building, the action c) and/or d) comprises comparing the diameter of the building drum 20 with a reference value of the component to be built and possibly modifying the diameter of the building drum 20 in order to reach the reference value.

The building area 101 also comprises a rolling pallet 116 preferably arranged in a lower half-space SI with respect to the radial plane R.2.

The rolling pallet 116 preferably comprises one or more movable rollers 116a in order to be abutted against the building drum 20 and pressing green tyre 1 being processed during or at the end of the building. The rollers 116a are for example thrust by pistons 116b against the building drum 20.

The rolling pallet 116 is preferably mounted on horizontal guides 117 and movable along the same in order to axially extended the rolling zone.

The building area 101 also comprises a grip ring 118 configured for axially removing a built green tyre 1 from the building drum 20.

The grip ring 118 is preferably mounted on an axial guide 119 so as to be coaxial with the building drum 20.

The grip ring 118 preferably comprises a plurality of suckers (not illustrated) or other grip systems, for example by vacuum application, configured for grasping, in grip position, the radially outer surface 2b of the green tyre, and subsequently axially remove it from the building drum 20.

The apparatus 100 also comprises a control unit 120 configured for executing a building cycle according to that described above and according to the method for building green tyres for bicycles. In particular the control unit has an interface through which it is possible to select the type of green tyre 1 and consequently select the respective building cycle.

For example the building cycle pursuant to the diagram of figure 10 is set, if a green tyre 1 is selected in its base version illustrated in figure 5A comprising in addition a protective band 7 or "breaker" which is extended circumferentially between two layers of the carcass ply 4 that are mutually superimposed in radial direction (figure 6A - dashed line) and two reinforcement elongated elements 11 or "chafers" applied on the carcass ply 4 respectively in proximity to a bead core 5, outside the bead, at the radially outer surface 2b of the tyre.

Such building cycle, with regard to the carcass ply 4, provides for carrying out the following actions:

I) unwinding the first semifinished product adapted to manufacture a first carcass ply Al,

II) centring the first semifinished product,

III) setting to size the first semifinished product,

IV) cutting the first semifinished product in order to form a piece "C",

V) pointing on the building drum 20 of the piece "C",

VI) joining the ends of the piece "C".

Such building cycle, with regard to the bead cores 5, provides for carrying out the following actions:

V) pointing on the building drum 20 of the second semifinished product adapted to manufacture bead cores Bl,

VII) building the bead cores on the carcass ply 4,

VIII) expanding the drum,

IX) cutting the second semifinished product adapted to manufacture bead cores Bl and joined to form the bead cores 5.

Such building cycle, with regard to the protective band 7, provides for carrying out the following actions:

V) pointing on the building drum 20 of the second semifinished product adapted to manufacture a protective band B2, VII) building the protective band 7 on the carcass ply 4,

IX) cutting the second semifinished product adapted to manufacture a protective band B2 and joined to form the protective band 7. Such building cycle, with regard to the reinforcement elongated elements 11, provides for carrying out the following actions:

X) turning up of the end flaps 4a

V) pointing on the building drum 20 of the second semifinished product adapted to manufacture the reinforcement elongated elements B5,

VII) building the reinforcement elongated elements 11 on the carcass ply 4,

IX) cutting the second semifinished product adapted to manufacture the reinforcement elongated elements B5 and joined to form the reinforcement elongated elements 11.

Such building cycle, with regard to the tread band 6, provides for carrying out the following actions:

I) unwinding the first semifinished product adapted to manufacture a tread band A5,

II) centring the first semifinished product,

III) setting to size of the first semifinished product,

IV) cutting the first semifinished product to form a piece "C",

XI) further verification of the length of the piece "C",

XII) movement of the respective support structure 105b carrying the piece "C" from the distal position to the proximal position to the first pointing zone 106,

V) pointing on the building drum 20 of the piece "C",

VII) building of the tread band 6 on the carcass ply 4,

VI) joining the ends of the piece "C",

XIII) rolling,

XIV) collapse of the building drum 20 (before the collapse is carried out of the building drum 20, the grip ring 118 is carried onto the building drum 20 in grip position), XV) discharging the green tyre 1 from the building drum 20.

In addition to that described above, provision is made for executing a series of controls.

A first control relates to the verification of the height of the first semifinished product adapted to manufacture the tread band 6.

Such control is for example executed through an encoder connected to levers for verifying the presence of the first semifinished product and its thickness.

A second control relates to the verification of the length of the tread band by two sensors operating on the respective feeding line so as to calculate the speed ratio between the application conveyor belt 105 and the building drum 20.

A third control relates to the verification of the application tension of the bead core 5 by load cells positioned in proximity to the respective dispensing line.

Claims

1. Method for building green tyres (1) for bicycles comprising: a) arranging a plurality of semifinished products (Al-An, Bl-Bm) divided into a first group and into a second group, wherein each group respectively comprises at least one first semifinished product (Al-An) and at least one second semifinished product (Bl-Bm), and wherein each first or second semifinished product (Al-An, Bl-Bm) is adapted to build a component of a green tyre (1) for bicycles, b) arranging a building drum (20) rotating around a rotation axis (X) parallel to a horizontal plane (0), c) building at least one component of said green tyre (1) for bicycles starting from said at least one first semifinished product (Al-An), comprising :

- feeding said at least one first semifinished product (Al-An) along a respective feeding line (103), cutting to size a piece thereof and thrustingly feeding said piece (C) by means of a respective motorised application conveyor belt (105) of said feeding line (103) which moves it towards said building drum (20) up to a respective first pointing zone (106) on said building drum (20),

- winding said piece (C) around said building drum (20), continuing to feed it thrustingly towards said respective first pointing zone (106), d) building at least one component of said green tyre for bicycles starting from said at least one second semifinished product, comprising:

- along a respective dispensing line (112), dispensing said at least one second semifinished product (Bl-Bm) directly towards said building drum (20) up to a second pointing zone (113) on said building drum (20),

- winding said at least one second semifinished product (Bl-Bm) around said building drum (20), continuing to dispense it towards said second pointing zone (113),

- cutting said second semifinished product (Bl-Bm) wound around said building drum (20), e) repeating the action c) and/or d) according to a predefined sequence as a function of the type of tyre to be built, up to completing the green tyre (1), f) axially removing said green tyre (1) from the building drum (20).

2. Method for building green tyres (1) for bicycles according to claim 1, wherein said at least one dispensing line (112) and the respective second pointing zone (113) are arranged in an upper half-space (SS) with respect to a radial plane (R.2) of the building drum (20) parallel to the horizontal plane (O) and wherein said at least one feeding line (103) and the respective first pointing zone (106) are arranged in one same lateral half-space (SL1) of the two lateral half-spaces (SL1, SL2) with respect to a radial plane (R.1) of the building drum (20) perpendicular to the horizontal plane (0), the other lateral half-space (SL2) being free for the access of an operator to the building drum (20).

3. Method for building green tyres (1) for bicycles according to claim 1 or 2, wherein the action c) comprises moving, at least in translation along a horizontal direction, a support structure (105b) of said application conveyor belt (105) from a distal position to a proximal position with respect to said first pointing zone (106) in order to move the piece (C) close to the building drum (20).

4. Method for building green tyres (1) for bicycles according to claim 3, wherein the action c) comprises adjusting a linear sliding speed of said application conveyor belt (105) with respect to the support structure (105b) and an angular speed of said building drum (20) in order to control the tension applied to the piece (C) during the winding of the piece (C) on the building drum (20).

5. Method for building green tyres (1) for bicycles according to one or more of the preceding claims, wherein the action c) comprises thrustingly feeding said first semifinished product (Al- An) along said feeding line (103) by means of a motorised preparation conveyor belt (108) that moves it towards a cutting zone configured for cutting to size said piece (C).

6. Method for building green tyres (1) for bicycles according to claim 5, wherein the action c) comprises translating a support structure (105b) of said application conveyor belt (105) from a proximal position to said preparation conveyor belt (108) to a proximal position with respect to said first pointing zone (106).

7. Method for building green tyres (1) for bicycles according to claim 6, wherein said first semifinished product (Al-An) is fed by means of said motorised preparation conveyor belt (108) while said motorised application conveyor belt (105) translates from the proximal position with respect to said preparation conveyor belt (108) to the proximal position with respect to said first pointing zone (106), bringing a piece (C) that has been previously separated from the first semifinished product (Al-An).

8. Method for building green tyres (1) for bicycles according to one or more of the preceding claims, wherein said first group comprises at least one first semifinished product adapted to manufacture a first carcass ply (Al) and a first semifinished product adapted to manufacture a tread band (A5), each first semifinished product (Al, A5) being fed along a respective feeding line.

9. Method for building green tyres (1) for bicycles according to claim 8, wherein said first group also comprises one or more from among: a first semifinished product adapted to manufacture a second carcass ply (A2); a first semifinished product adapted to manufacture strips for reinforcing the sidewalls (A7); a first semifinished product adapted to manufacture a liner (A3); a first semifinished product adapted to manufacture an enlarged protective band or "bead to bead" (A6); a first semifinished product adapted to manufacture elements for reinforcing the beads or "flippers" (A4); each first semifinished product (A2, A3, A4, A6, A7) being fed along a respective feeding line.

10. Method for building green tyres (1) for bicycles according to claim 8 or 9, wherein each first semifinished product (Al-An) is fed towards a respective first pointing zone (106), said first pointing zones (106) being distributed along a circumferential pointing section arranged laterally with respect to said building drum (20) in one (SL1) of the two lateral half-spaces (SL1, SL2) with respect to a radial plane (R.1) of the building drum (20) perpendicular to the horizontal plane (O).

11. Method for building green tyres (1) for bicycles according to one or more of the preceding claims, wherein said second group comprises at least one second semifinished product adapted to manufacture bead cores (Bl) fed along a respective feeding line.

12. Method for building green tyres (1) for bicycles according to claim 11, wherein said second group also comprises at least one second semifinished product (B2, Bm) associated with a service tape and wherein dispensing said second semifinished product (Bl-Bm) towards said second pointing zone (113) comprises separating and collecting said service tape.

13. Method for building green tyres (1) for bicycles according to claim 11, wherein said second group also comprises one or more from among: a second semifinished product adapted to manufacture reinforcement elongated elements or "chafers" (B5); a second semifinished product adapted to manufacture a protective band or "breaker" (B2); a second semifinished product adapted to manufacture an elastomeric base (B4); a second semifinished product adapted to manufacture fillers (B3).

14. Method for building green tyres (1) for bicycles according to claim 12 or 13, wherein each second semifinished product (Bl- Bm) is dispensed towards a respective second pointing zone (113), said second pointing zones (113) being arranged along a same axial pointing section axially arranged along said building drum (20).

15. Method for building green tyres (1) for bicycles according to claim 14, comprising, before each action d), setting the respective second pointing zone (113) along said axial pointing section.

16. Method for building green tyres (1) for bicycles according to one or more of the preceding claims, comprising executing the action c) except for winding said piece around said building drum (20), simultaneously with the action d).

17. Method for building green tyres (1) for bicycles according to one or more of the preceding claims, wherein said building drum (20) has variable diameter and wherein the action c) and/or the action d) comprises comparing the diameter of the building drum (20) with a reference value of the component to be built and possibly modifying the diameter of the building drum (20) in order to reach said reference value.

18. Method for building green tyres (1) for bicycles according to one or more of the preceding claims, wherein said building drum (20) is arranged with rotation axis (X) fixed.

19. Apparatus for building green tyres (1) for bicycles comprising: a building drum (20) rotating at a rotation axis (X) parallel to a horizontal plane (0), at least one feeding line (103) configured for feeding a first semifinished product (Al, An) constituting part of a first group of a plurality of semifinished products, a cutting device (104) operative along said at least one feeding line (103) and configured for cutting to size a piece (C) of said first semifinished product (Al-An), wherein said at least one feeding line (103) comprises a motorised application conveyor belt (105) configured for thrustingly feeding said piece (C) so as to move it towards said building drum (20) up to a respective first pointing zone (106), at least one dispensing line (112) configured for dispensing a second semifinished product (Bl-Bm) constituting part of a second group of said plurality of semifinished products directly towards said building drum (20) up to a second pointing zone (113), a grip ring (118) configured for axially removing a built green tyre (1) from the building drum (20).

20. Apparatus for building green tyres (1) for bicycles according to claim 19, wherein said at least one dispensing line (112) and the respective second pointing zone (113) are arranged in an upper half-space (SS) with respect to a radial plane (R.2) of the building drum (20) parallel to the horizontal plane (0) and wherein said at least one feeding line (103) and the respective first pointing zone (106) are arranged in one same lateral halfspace (SL1) of the two lateral half-spaces (SL1, SL2) with respect to a radial plane (R.1) of the building drum (20) perpendicular to the horizontal plane (0), the other lateral halfspace (SL2) being free for the access of an operator to the building drum (20).

21. Apparatus for building green tyres (1) for bicycles according to claim 19 or 20, wherein said motorised application conveyor belt (105) is slidably mounted on a support structure (105b) that is movable at least in translation along a horizontal direction between a distal position and a proximal position with respect to said first pointing zone (106).

22. Apparatus for building green tyres (1) for bicycles according to one or more of the claims from 19 to 21, wherein said at least one feeding line (103) comprises a motorised preparation conveyor belt (108) configured for thrustingly feeding the respective first semifinished product (Al-An) along said feeding line (103) towards said cutting device (104).

23. Apparatus for building green tyres (1) for bicycles according to claim 22, wherein said motorised application conveyor belt (105) is slidably mounted on a support structure (105b) that is movable at least in translation along a horizontal direction between a proximal position with respect to said preparation conveyor belt (108) and a proximal position with respect to said first pointing zone (106).

24. Apparatus for building green tyres (1) for bicycles according to one or more of the claims from 19 to 23, comprising a feeding line (103) configured for feeding a first semifinished product adapted to manufacture a first carcass ply (Al) and a feeding line (103) configured for feeding a first semifinished product adapted to manufacture a tread band (A5).

25. Apparatus for building green tyres (1) for bicycles according to claim 24, also comprising a feeding line (103) configured for feeding one from among: a first semifinished product adapted to manufacture a second carcass ply (A2); a first semifinished product adapted to manufacture strips for reinforcing the sidewalls (A7); a first semifinished product adapted to manufacture a liner (A3); a first semifinished product adapted to manufacture an enlarged protective band or "bead to bead" (A6); a first semifinished product adapted to manufacture elements for reinforcing the beads or "flippers" (A4).

26. Apparatus for building green tyres (1) for bicycles according to claim 24 or 25, comprising a plurality of first feeding lines (103) each configured for feeding a respective first semifinished product (Al-An) and a respective piece (C) towards a respective first pointing zone (106), said first pointing zones (106) being arranged along a same circumferential pointing section arranged laterally with respect to said building drum (20) in one (SL1) of the two lateral half-spaces (SL1, SL2) with respect to a radial plane (R.1) of the building drum (20) perpendicular to the horizontal plane (0).

27. Apparatus for building green tyres (1) for bicycles according to one or more of the claims from 19 to 26, comprising at least one dispensing line (112) configured for dispensing a second semifinished product adapted to manufacture bead cores (Bl).

28. Apparatus for building green tyres (1) for bicycles according to claim 27, also comprising at least one dispensing line (112) configured for dispensing a second semifinished product associated with a service tape and wherein said at least one dispensing line comprises means (115) for separating and collecting said service tape.

29. Apparatus for building green tyres (1) for bicycles according to claim 27, also comprising at least one dispensing line (112) configured for dispensing one from among: a second semifinished product adapted to manufacture reinforcement elongated elements or "chafers" (B5); a second semifinished product adapted to manufacture a protective band or "breaker" (B2); a second semifinished product adapted to manufacture an elastomeric base (B4); a second semifinished product adapted to manufacture fillers (B3).

30. Apparatus for building green tyres (1) for bicycles according to claim 28 or 29, comprising a plurality of dispensing lines (112) each configured for dispensing a respective second semifinished product (Bl-Bm) towards a respective second pointing zone (113), thus defining a plurality of second pointing zones (113) distributed along a same axial pointing section arranged axially along said building drum (20).

31. Apparatus for building green tyres (1) for bicycles according to claim 28 or 29, comprising a shuttle (114) which supports said at least one dispensing line (112) and which is movable along the rotation axis (X) of the building drum (20) in order to position a dispensing line (112) being processed at the respective second pointing zone (113) along an axial pointing section axially arranged along said building drum (20).

32. Apparatus for building green tyres (1) for bicycles according to one or more of the claims from 19 to 31, wherein said building drum (20) has variable diameter.