METHOD AND APPARATUS FOR THE MANUFACTURE OF ECOLOGICAL BICYCLE TIRES
Patent Information
- Authority / Receiving Office
- MX · MX
- Patent Type
- Patents
- Current Assignee / Owner
- PIRELLI TYRE SPA
- Filing Date
- 2025-06-12
- Publication Date
- 2026-05-19
Smart Images
Figure MX434528B0
Abstract
Description
[0001] APPARATUS AND METHOD FOR BUILDING GREEN TYRES FOR BICYCLES
[0002] The present invention relates to an apparatus and a method for building green tyres for bicycles.
[0003] The building of a tyre for bicycles normally provides that one or more carcass plies be applied according to a cylindrical configuration around an external surface of a building drum. A pair of bead cores are fit or applied, each around of the axially opposite end flaps of the carcass ply. The end flaps are then turned up around the respective bead cores. There is then the application of a tread band, typically manufactured in the form of a strip made of elastomeric material and 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.
[0004] At the end of the winding, the opposite ends of the tread band are slightly superimposed and mutually joined by a head-head joint.
[0005] 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, in fact, a step of mutual approaching of the bead cores is normally provided for shaping the carcass structure according to a toroidal configuration during coupling with a belt structure having a diameter greater than that of the bead cores.
[0006] 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 therein, as well as possibly to impart, on the tread band, a desired tread pattern.
[0007] By "insert" it is intended an elongated or strip element, preferably made of elastomeric material. Preferably said strip is cut to size. It is known that the strip can comprise one or more metallic, textile or hybrid cords, parallel to each other and arranged according to the longitudinal direction of said strip.
[0008] The term "semifinished product" will be used for defining both a composite element provided with the insert and with a service band, and just the insert, so as to include in a single definition both the inserts that require service bands and those that possibly do not require them.
[0009] With the expression "carcass structure" it is intended instead to define a set formed by or provided with at least one carcass ply having mutually parallel cords, incorporated in an elastomeric matrix; such expression therefore defines the carcass structure in any building step thereof, from the single carcass ply to a more advanced step in which further components are added to the single carcass ply, such as bead cores, inserts or further carcass plies.
[0010] The terms "pointing" and "point" will be used for identifying the step in which the front end of the insert (or of the semifinished product) is initially fixed to the or pressed on the carcass structure, in an initial step of the process of application and winding of the reinforcement insert. 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 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.
[0011] The term "automate" will be used for defining the execution of processes and movements by means of mechanical, electromechanical members governed by a control unit, for the completion of which it is not necessary to have the manual intervention of an operator (or only in a marginal / residual way). The terms "radial" and "axial" and the expressions "radially inner / outer" and "axially inner / outer" are used with reference to the rotation axes of the components, in particular to a primary rotation axis of the building drum or of the finished tyre.
[0012] The terms "circumferential" and "circumferentially" are instead used by referred to the annular extension of a component, in particular of the building drum or of rolling elements such as rollers or small rollers.
[0013] The expressions "low", "under", "lower" or "on the lower part", and "top", "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.
[0014] In the video clip https: / / youtu.be / e3sHyJKaFMo?t=879 (time counter from 14' 37" to 15' 50" - last viewing 17 / 12 / 2022) the sequential deposition of the carcass ply, of the bead cores, of the sidewall reinforcements, of the bead reinforcements and of the tread band is visible, for the purpose of building a tyre for bicycles on a building drum. Each of these components is made simultaneously with its deposition by a semifinished product in continuous strip form, coming from a respective feeding group that guides it up to the immediate vicinity of the point of application on the building drum, where an operator provides for the execution of the operations necessary for their application. The application of each component provides that a head end of the respective semifinished product is manually fixed on the deposition surface of the drum, after which the drum completes one or more revolutions around a rotation axis thereof in order to determine the circumferential winding of the semifinished product around the deposition surface. For several components, such as for example the carcass ply, sidewall reinforcements, bead reinforcements and tread band, the operator is required to act manually on the semifinished product and / or on the building drum during winding, in order to facilitate a correct distribution and application of the material.
[0015] For the sidewall reinforcements, the operator is required to manually guide the semifinished product for the purpose of the correct alignment and to manually control the tensioning thereof. At the end of the winding of each component, the rotation of the drum is stopped and the operator must manually cut the semifinished product and join the tail end of the component obtained on the head end already applied on the deposition surface.
[0016] DE102019131336 shows a building drum above which a trolley is situated, on which a plurality of semifinished products is situated that are wound in respective reels. In order to allow a correct movement of the inserts and the maintenance of their nominal size, the inserts are wound in a reel and conveyed in coupling with respective protective bands.
[0017] Each semifinished product extends between a feeding reel, in which the semifinished product is complete with insert and protective band, and a discard reel, on which only the protective band is rewound following the application of the insert to the carcass ply; the discard reel is motorised by means of an electric motor suitably sized so as to allow the advancement of the semifinished product and, above all, the rewinding of the protective band which obtains the separation between insert and protective band at the time of the application.
[0018] For such purpose, provision is made for presence of an applicator member placed in proximity to the forming drum and operatively interposed between the two feeding and discard reels.
[0019] The semifinished product is therefore "drawn in" in order to advance starting from the feeding reel towards the discard reel, passing by the applicator member, which is shaped so as to define a separation edge at which the semifinished product is pressed on the carcass ply (i.e. on the building drum).
[0020] In particular, the applicator member comprises a metallic spatula provided with a sliding sidewall that receives the semifinished product coming directly from the feeding reel and extended up to the separation edge, approached to the drum such that the insert is pressed on the carcass ply, being coupled thereto; the rotation of the building drum together with that of the motorised discard reel draws the protective band such that the semifinished product goes beyond the separation edge, with the insert that advances coupled with the carcass ply and the protective band in rewinding around the discard reel itself.
[0021] The operations of assembly of the components on the building drum, even if assisted by automatic or semi-automatic feeding systems for feeding the semifinished products, still 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 purpose of manufacturing the components on the building drum.
[0022] Such reduced automation can lead to a reduced precision and a poor repeatability of the process, as well as to a limited production capacity.
[0023] The Applicant has therefore proposed increasing the level of precision, repeatability and / or production capacity of the building processes for bicycle tyres, and has observed that the machines and methods normally employed in making tyres for motor vehicles, such as cars and / or motorcycles, which instead have a high level of automation, cannot be employed in making tyres for bicycles. The operations of building the tyres for bicycles in fact require the preparation and handling of extremely thin and delicate manufactured items. Many components, e.g. the liner, the carcass plies, and other textile reinforcement structures can have thicknesses between 0.1 mm and 1 mm, with width extensions that 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, e.g. smaller than 0.5 mm and with width greater than 120 mm. These size characteristics almost always lead to the use of semifinished products that result lacking a structural strength sufficient for allowing the correct handling thereof by the machines normally employed in the building of tyres for motorcycles or cars.
[0024] Due to the reduced size and weight both of the semifinished products and of the plies, therefore, most of the additional components is pointed and cut to size by a direct and manual intervention by the personnel, which clearly involves several critical points, both regarding the productivity and the safety for the personnel.
[0025] The Applicant has then observed that the apparatuses of the type described in DE102019131336, do not have a satisfactory application precision.
[0026] The Applicant has identified, as possible cause of such reduced precision, the presence of a semifinished product made to advance directly between the feeding reel and a static separation edge.
[0027] The semifinished product in fact reaches the applicator member directly from the feeding reel, which makes it difficult to compensate for possible lateral slipping of the material.
[0028] On such matter, the Applicant has in fact observed that the inserts applied at the end flaps of the carcass ply, already turned up around the respective bead cores, involve a high risk of lateral slipping due to the curving of the application surface.
[0029] In order to limit this slipping effect, it becomes important to optimise the size of the pressure exerted by the applicator member on the carcass ply.
[0030] The Applicant on the matter has observed that the very limited thicknesses at play, as stated on the order of tenths of a millimetre, make a reliable control of this parameter complex, if not impossible.
[0031] In the absence of such control, it is not rare that the applicator member exerts an excessive force on the semifinished product, risking to stretch it, or an insufficient force, facilitating the slipping thereof.
[0032] The Applicant has verified that solutions such as that described in DE102019131336 make necessary a repeated intervention of the personnel both during the pointing of the insert, hard to automate in light of the reduced exertable pressure, and during cutting, with simultaneous possibility of correcting the slipping.
[0033] The Applicant has therefore identified that such critical features are in open contrast with the current trend of the field, in which aspects like productivity and manufacturing quality are subjected to increasingly tight constraints.
[0034] The Applicant has therefore perceived that the maintenance of a correct position of the semifinished product along the advancement axis and up to the application zone plays a key role in limiting the risk of lateral slipping of the insert.
[0035] The Applicant has finally found that the use of an applicator device capable of releasing the application and guide function, so as to optimise both, simultaneously facilitates the automation of the process and the increase of the quality of the finished product.
[0036] In accordance with a first aspect, the invention relates to an apparatus for building green tyres for bicycles.
[0037] Preferably, provision is made for a building drum rotating around a primary rotation axis.
[0038] Preferably, provision is made for the presence of at least one feed line configured for dispensing at least one semifinished product towards a pointing section of the building drum.
[0039] Preferably, the semifinished product comprises an insert and a service band.
[0040] Preferably, said at least one feed line comprises an applicator device situated in radially outer position with respect to said building drum.
[0041] Preferably, the applicator device is configured for feeding said semifinished product along an advancement direction and for applying said insert on a carcass structure arranged on said building drum.
[0042] Preferably, the applicator device comprises a guide body and an applicator member.
[0043] Preferably, an outlet section of the guide body is situated, with reference to the advancement direction, in proximity to an application portion of the applicator member.
[0044] Preferably, the guide body is configured for maintaining the semifinished product in an alignment condition along said advancement direction opposing slip forces transverse to said advancement direction acting on said semifinished product.
[0045] Preferably, the applicator member is configured for receiving the semifinished product aligned by the guide body and for pressing said insert on said carcass structure along a radially inner direction so as to apply the insert on said carcass structure.
[0046] The Applicant deems that the use of an application device that uncouples the function of guide of the semifinished product from that of application of the insert allows optimising both actions, enabling the manufacturing of the manufactured item with increased quality. The possibility of guiding the semifinished product up to a zone close to the pointing section prevents the lateral slip forces imparted by the coupling between insert and carcass structure from leading to a certain deflection from the ideal deposition line. In addition, the lack of guide function by the applicator member allows reducing the risk of interferences between the member itself and the carcass structure, entirely to the benefit of the quality of the process and product.
[0047] In accordance with a second aspect, the invention refers to a method for building green tyres for bicycles.
[0048] Preferably, provision is made for arranging a building drum rotating around a primary rotation axis.
[0049] Preferably, provision is made for arranging a carcass structure around said building drum.
[0050] Provision is also preferably made for dispensing at least one semifinished product comprising an insert and a service band towards a pointing section of said building drum.
[0051] Preferably, provision is made for applying said insert on an extrados of said carcass structure at said pointing section of the building drum.
[0052] Preferably, provision is made for winding said insert around said carcass structure by rotating said building drum following said application.
[0053] Preferably, the step of applying the insert provides for guiding the semifinished product along a predetermined advancement direction and, simultaneously, opposing slip forces transverse to said advancement direction acting on said semifinished product. Preferably, such guiding and opposition actions are exerted up to a release zone close to said pointing section. Preferably, the semifinished product is fixed on said extrados of the carcass structure at said pointing zone by applying a pressure on said semifinished product.
[0054] Preferably, said pressure is exerted along a radial direction towards the interior with reference to said primary rotation axis. Preferably, said pressure is exerted by means of an applicator member situated in a pointing and application position.
[0055] The Applicant deems that the separation between the guiding and application / pointing functions of the insert allows optimising both actions, entirely to the benefit both of the productive capacity and of the quality of the finished product.
[0056] The possibility of guiding the semifinished product up to a zone close to the pointing section prevents lateral slip forces imparted by the coupling between insert and carcass structure from leading to a non-negligible deflection from the ideal deposition line.
[0057] In at least one of the aforesaid aspects, the invention comprises one or more of the following preferred characteristics that are described below.
[0058] Preferably, the outlet section of the guide body is situated, with respect to the application portion of the applicator member, at a distance measurable along the advancement direction comprised between 3 and 15 mm.
[0059] Advantageously, the reduced distance between the guide body and the applicator member renders the process of pointing easily automatable, considerably reducing the frequency of intervention of the personnel.
[0060] Preferably, the guide body comprises at least two lateral walls that are opposite and spaced from each other, situated on the sides of the semifinished product and defining a centring section of the semifinished product adapted to oppose said slip forces transverse to said advancement direction acting on said semifinished product.
[0061] It is noted that the presence of two lateral walls placed in proximity to the adjustment member, but separate therefrom, allows opposing, in an efficient manner, the lateral slipping of the material without negatively affecting the precision and the quality of application of the insert.
[0062] Preferably, the guide body of the applicator device comprises a perimetrically closed through cavity, extended along the advancement direction and, during use, crossed by said insert in sliding.
[0063] Advantageously, this reduces the freedom of movement of the semifinished product, both in lateral translation (or slipping) and in twisting.
[0064] Preferably, said through cavity is at least partly perimetrically delimited by said lateral walls.
[0065] Preferably, said through cavity has a section transverse to said advancement direction substantially counter-shaped with respect to a corresponding transverse section of the semifinished product.
[0066] Advantageously, this minimises the possibility of movement of the semifinished product with respect to the ideal advancement direction.
[0067] Preferably, said through cavity has a transverse section that is substantially rectangular.
[0068] Preferably, provision is made for an adjustment element configured for varying, transverse to the advancement direction, the relative position between said semifinished product and said guide body so as to adjust the position of the semifinished product within the through cavity.
[0069] This allows adjusting, preferably in real time, the position of the semifinished product in the cavity so as to allow that the only surface that is potentially sliding is that of the service band.
[0070] Preferably, the adjustment element is situated, with reference to said advancement direction, upstream of the guide body.
[0071] This allows limiting the distance between guide body and applicator member to a maximum.
[0072] Preferably, the semifinished product extends along the advancement direction and comprises two flat faces opposite and parallel to each other, said adjustment element being movable with respect to the guide body transverse to said flat faces along an adjusting direction in order to translate the semifinished product along said adjusting direction within the through cavity. Preferably, said two flat faces are orthogonal to two lateral edges, also substantially parallel to and opposite each other.
[0073] Preferably, the adjustment element comprises a small roller rotatable around a rotation axis small roller orthogonal to the advancement direction and parallel to said flat faces.
[0074] Preferably, the adjustment element comprises a small roller movable along said adjusting direction in order to contact one of said flat faces and adjust the position of the semifinished product within the through cavity.
[0075] Advantageously, this allows adjusting the relative position between semifinished product and guide body without generating sliding on the semifinished product.
[0076] Preferably, the adjustment element comprises a movement member connected to the guide body in order to translate it transverse to the advancement direction so as to vary the position of the guide body with respect to said semifinished product.
[0077] Preferably, the applicator member comprises an applicator roller rotatable around a rotation axis roller parallel to said primary rotation axis of the building drum.
[0078] Advantageously, the rolling contact between semifinished product and applicator member considerably reduces both the possible stretching of the material and the stresses to which it is subjected, also allowing the increasing of the application pressure.
[0079] In addition, the presence of a rolling element that is counterrotating with respect to the building drum allows that, also in the case of contact between the roller and a portion of the carcass structure, this does not lead to damage thereof.
[0080] Preferably, the applicator roller is selectively movable between a cutting position and a pointing and application position.
[0081] Preferably, in the cutting position the applicator roller is situated at a predetermined radial distance from said building drum such that a part of the insert tangent to the applicator roller itself is spaced from said building drum.
[0082] Preferably, in the pointing and application position, the applicator roller is radially approached to said building drum such that said part of the insert tangent to the applicator roller itself is maintained in contact with said carcass structure wound on the building drum.
[0083] Advantageously, this allows carrying out an automatic pointing of the insert, without preventing the operator the possibility to manually intervene during the cutting or other operations.
[0084] Preferably, the applicator device comprises an pneumatic actuator, more preferably linear, associated with said applicator roller in order to move it between the cutting position and the pointing and application position.
[0085] Advantageously, the compressibility of the air within the cylinder allows the actuator to operate as damper, analogously compensating for possible irregularities of the carcass structure. Preferably, said pneumatic actuator is configured for moving integrally with respect to each other the applicator member and the guide body.
[0086] This allows simplifying the movement of the components, preventing voltage jumps on the semifinished product. Preferably, the applicator roller has, with reference to said rotation axis roller, a radially outer circumferential surface (or peripheral surface) made of material that is elastically deformable by an elastomer with polyurethane base with high- density closed cells, e.g. of Vulkollan™.
[0087] Advantageously, this allows analogically compensating for possible irregularities of the carcass structure.
[0088] Preferably, said applicator roller has a radially outer circumferential cylindrical surface.
[0089] This allows preventing or minimising the risk of contact between the roller and the carcass structure, without however negatively impacting the alignment of the insert, due to the presence upstream of the guide body.
[0090] Preferably, said application portion of the applicator member is defined, at each instant of time, by a part of said radially outer circumferential surface of the applicator roller substantially tangent to said building drum.
[0091] Preferably, the applicator device comprises a recovery group of the service band configured for re-winding said service band that is separated from the insert.
[0092] Preferably, the recovery group of the service band is arranged downstream of the applicator member in order to re-wind said service band which, in the radially inner position of said applicator roller, is separated from the insert due to a driving action generated by the building drum placed in rotation around the proprio primary rotation axis.
[0093] Preferably, the apparatus comprises a control unit associated with said building drum and with said applicator device.
[0094] Preferably, the control unit is configured for imparting, to the applicator roller, a movement from the cutting position to the pointing and application position.
[0095] Preferably, the control unit is configured for driving an activation of the recovery group of the service band.
[0096] Preferably, the control unit is configured for driving a rotation of the building drum.
[0097] Preferably, said rotation of the building drum follows said activation of the recovery group of the service band.
[0098] The Applicant has thus detected that the activation of the recovery group of the service band before the activation of the rotation of the building drum allows the correct separation between insert and service band at the pointing section.
[0099] Preferably, the control unit is configured for maintaining the rotation of the building drum and said activation of the recovery group of the service band for a predetermined rotation angle of the building drum. The control unit is preferably configured for imparting, to the applicator roller, a movement from the pointing and application position to the cutting position.
[0100] Preferably, such movement is activated in proximity to the building drum's attainment of said predetermined rotation angle. Preferably, the control unit is configured for driving a stoppage of the rotation of the building drum upon reaching said predetermined rotation angle and, simultaneously, maintaining the activation of the recovery group of the service band advancing the semifinished product for a predetermined extrastroke along the advancement direction.
[0101] Preferably, the control unit is configured for driving a stoppage of the recovery group of the service band upon reaching said predetermined extra-stroke.
[0102] Advantageously, the extra-stroke of the recovery group of the service band allows creating an excess of material that facilitates the step of cutting the insert.
[0103] Preferably, the control unit is configured for driving the activation of the recovery group of the service band simultaneously with or before the rotation of said building drum. Advantageously, this allows the semifinished product to maintain the correct voltage before starting the building drum, obtaining the correct point of separation between service band and insert. Preferably, the winding of said insert around said carcass structure provides for maintaining said pressure on said semifinished product, along the radial direction towards the interior and with reference to said primary rotation axis, at said pointing section.
[0104] Preferably, provision is made for arranging an applicator device comprising a guide body and said applicator member. More preferably, said applicator member is arranged immediately downstream of the guide body along the advancement direction. Preferably, the guide body comprises a perimetrically closed through cavity, extended along the advancement direction. Preferably, provision is made for drawing in said semifinished product within said through cavity.
[0105] Preferably, provision is made for sliding in the semifinished product along the applicator member, upstream or simultaneously with the fixing of the insert on said extrados of the carcass structure.
[0106] Advantageously, the passage of the semifinished product in the cavity allows the insert to remain guided along the advancement direction up to the pointing section.
[0107] Preferably, provision is made for separating the service band from the insert immediately downstream or simultaneously with said application of the insert by the applicator member.
[0108] Preferably, provision is made for sliding in an external face of the service band along the applicator member, generating a rolling contact.
[0109] Preferably, the winding of said insert around said carcass structure provides for exerting a traction on the service band, said traction being oriented along said advancement direction and starting from a recovery zone of the service band operatively placed downstream of said applicator member. Preferably, provision is made for maintaining the rotation of the building drum and the dispensing of said semifinished product for a predetermined rotation angle of the building drum.
[0110] Preferably, provision is made for lifting the applicator member from the pointing and application position to a cutting position, radially outer with respect to said pointing and application position with reference to the primary rotation axis.
[0111] Preferably, provision is made for stopping the rotation of the building drum upon reaching said predetermined rotation angle and, simultaneously, maintaining the dispensing of said semifinished product for a predetermined extra-stroke along the advancement direction.
[0112] Preferably provision is made for stopping the dispensing of said semifinished product upon reaching said predetermined extrastroke, defining a free flap of said insert extended between a first end and a second end, situated respectively in proximity to said building drum and to said applicator member in the cutting position.
[0113] Preferably, provision is made for executing an first cut on the insert at said first end.
[0114] The extra-stroke allows generating an excess of semifinished product downstream of the applicator member, facilitating the successive cutting operations.
[0115] Preferably, provision is made for a step of executing a second cut on the insert at said second end.
[0116] Advantageously, this allows the operator to intervene on the apparatus only during cutting, allowing the automatic pointing of the insert.
[0117] Preferably, arranging said carcass structure comprises depositing at least one carcass ply circumferentially around a deposition surface of said building drum.
[0118] Preferably, provision is made for applying a pair of bead cores at a predetermined mutual axial distance around said at least one carcass ply and for turning up axially outer end flaps of said at least one first carcass ply around the bead cores.
[0119] Preferably, in addition, the application of the insert on an extrados of said carcass structure provides for maintaining said mutual axial distance of the bead cores substantially unchanged. Preferably, provision is made for depositing a tread band circumferentially around the deposition surface.
[0120] Preferably, the deposit of the tread band is executed after said application of the insert.
[0121] Preferably, the deposit of the tread band is executed by maintaining the mutual axial distance of the bead cores substantially unchanged.
[0122] Preferably, the semifinished product has a thickness smaller than 3 mm and said insert has a thickness smaller than 2 mm, more preferably smaller than 1 mm.
[0123] Preferably, the insert has a width, measured orthogonally to an advancement direction of said first insert, comprised between 5 and 60 mm, more preferably comprised between 7 and 60 mm. Further characteristics and advantages will be clearer in the detailed description of a preferred but not exclusive embodiment of an apparatus and of a method 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 as a mere non-limiting example, in which:
[0124] - figure 1 shows a side view of an apparatus for building green tyres for bicycles in accordance with the present invention, according to a first embodiment; - figure 2 shows an enlargement of a portion of the apparatus of figure 1;
[0125] - figure 2a shows a detail of the enlargement of figure 2;
[0126] - figures from 3 to 7 show the portion of the apparatus of figure 2 in different operating positions;
[0127] - figure 8 shows the schematic structure of a tyre for bicycles;
[0128] - figure 9 schematically shows the structure of a semifinished product used in the method according to the present invention.
[0129] With reference to the enclosed figures, reference number 1 indicates an apparatus for building tyres, in particular tyres for bicycles.
[0130] The present invention is aimed for the processing of tyres 100 for bicycles, of the type schematically exemplified in figure 8, for example for use on road, track, mountain bikes, e-bikes etc..
[0131] In the tyre 100, the following are identifiable: a radially inner surface 101a, substantially facing towards a geometric rotation axis of the tyre 100, and a radially outer surface 101b substantially facing away from the geometric rotation axis.
[0132] The tyre 100 for bicycles has a carcass structure 102 comprising at least one carcass ply 103 having mutually parallel cords, incorporated in an elastomeric matrix.
[0133] Axially opposite end flaps 103a of the carcass ply or plies 103 are engaged with respective bead cores 104, i.e. anchoring annular structures integrated in the zones normally identified with the name "beads", at which there is the mechanical engagement between the tyre 100 in use conditions and a respective a mounting rim. In radially outer position with respect to the carcass structure 102, a tread band 105 is applied that is made of elastomeric material.
[0134] Between the carcass structure 102 and the tread band 105, reinforcement inserts 106 are normally applied, in modes and configurations that differ as a function of the building scheme.
[0135] Such reinforcement inserts 106, which have different nature and / or function, can be used for reinforcing the beads (chafers), the sidewalls (sidewall reinforcement), for reinforcing the tread application zone (breakers, rubber bases) or on the contrary the intrados of the tyre (liner).
[0136] The inserts 106 have very limited dimensions, with thicknesses preferably smaller than 2 mm and, in most cases, smaller than one mm, comprised between 0.2 and 0.8 mm.
[0137] The width of the reinforcement inserts 106 is preferably comprised between 5 and 60 mm, preferably comprised between 7 and 50 mm.
[0138] It is also known that, depending on the type, the inserts 106 can be continuously applied and cut after the application or cut to size, in a step preceding application.
[0139] It is noted that, unlike what occurs in the tyres typically intended for use on motor vehicles, such reinforcement inserts 106 do not have any significant effect on the structural strength, geometric stability and / or dynamic behaviour of the tyre 100 itself; in the tyres intended for use on vehicles such as automobiles and motorcycles / scooters, such structural function is exerted by the so-called belt reinforcement layers (or belt layer), normally absent in the tyres for bicycles. Preferably, in addition, on the radially outer surface 101b of the tyre 100 for bicycles, carcass ply 103 portions directly exposed towards the outside environment are identifiable between the axially outer edges of the tread band 105 and the bead cores 104. The tyre 100 for bicycles in fact typically lacks sidewalls, i.e. layers elastomeric material applied laterally to the outside of the carcass structure 102, each extended between one of the beads and the respective axially outer edge of the tread band.
[0140] The building of the tyre 100 described above therefore occurs with the aid of an apparatus 1 configured for applying the single components on a building drum 2 so as to attain a predetermined building scheme.
[0141] The building drum 2 preferably has substantially cylindrical shape and therefore comprises an external surface 2a, or extrados, extended around a primary rotation axis "A" thereof.
[0142] Preferably, the building drum 2 is provided with a rotation shaft (not illustrated) coaxial with the primary rotation axis "A" and integral with the drum itself in order to rotate it.
[0143] Provision is made for the presence of a feeding group (not illustrated) for feeding one or more carcass plies 103, configured for applying the carcass ply or plies 103 on the building drum 2 so as to define a carcass structure 102.
[0144] Preferably, the apparatus 1 also comprises a positioning member (not illustrated) of a pair of bead cores 104 configured for dispensing the bead cores and winding them around a first carcass ply 103 at a predetermined mutual axial distance. It is noted that, preferably, the bead cores are dispensed in the form of a threadlike insert of polymer material which is wound in a plurality of revolutions around the building drum 2 so as to define a bundle of filaments defining the single bead core 104.
[0145] On the matter, preferably the building drum 2 is also provided with or associated with a turning up member configured for turning up axially outer end flaps 103a of said at least one first carcass ply 103 around the bead cores 104.
[0146] The apparatus 1 comprises at least one feed line 3 configured for dispensing at least one semifinished product 108 towards a pointing section 2b of said building drum 2.
[0147] Preferably, the semifinished product 108 is wound in a reel 108a on a rotatable first spool 3a which allows the unwinding thereof. Preferably, it is noted that the semifinished product comprises an insert 106 and a service band 107 that are coupled together. The insert 106 has the size characteristics discussed above.
[0148] The service band 107 has belt-like shape and is coupled to the insert 106 with the function of size control and protection. Preferably, the service band 107 and the insert 106 are longitudinally coupled.
[0149] The insert 106 is in fact preferably made of elastomeric material which, given the reduced product dimensions, is subjected to shrinkage and deformations that can compromise the quality of the tyre. The presence of the service band limits these drawbacks to a maximum, allowing the insert 106 to be applied on the carcass structure 102.
[0150] Preferably, the service band 107 is made of polythene.
[0151] It is noted that depending on the type of insert 106 applied, the feed line 3 can be configured for dispensing the semifinished product 108 on a single (first) carcass ply 103 wound on the building drum 2 or on a structure defined by one or more that are already turned up. In accordance with that already defined, for the sake of simplicity hereinbelow, reference will be generically made to a "carcass structure 102", including both cases with this term.
[0152] Preferably, the feed line 3 comprises an applicator device 4 situated in radially outer position with respect to said building drum 2 in order to feed said semifinished product 108 along an advancement direction "B" and applying said insert 106 on the carcass structure 102 arranged on the building drum 2.
[0153] It is noted that, the semifinished product 108 extends along the advancement direction "B" and comprises two flat faces 108a that are opposite and parallel to each other.
[0154] Preferably, the semifinished product 108 has a section transverse to said advancement direction "B" with quadrangular shape, defined by the two flat faces 108a and by two lateral edges 108b, also substantially parallel to and opposite each other. The lateral edges 108b are preferably orthogonal to the flat faces 108a.
[0155] In the preferred embodiment, the applicator device 4 is situated above the building drum 2, with reference to a horizontal support plane (i.e. the ground).
[0156] More preferably, the building drum 2 has a top portion 2c defined around a top thereof.
[0157] The applicator device 4 is preferably situated on top of said top portion 2c.
[0158] In more detail, with reference to a vertical section plane passing through the primary rotation axis "A", the building drum 2 is divided into a front half-part 2d, operator-accessible, and a rear half-part 2e.
[0159] Preferably, the applicator device 4 is situated in a position proximal to the front half-part 2d with respect to the group for feeding the carcass plies 103.
[0160] Advantageously, in such a manner, the applicator device 4 and the pointing section 2b of the building drum 2 remain accessible for an operator from the front half-part 2d of the building drum 2 itself, facilitating manual operations if necessary.
[0161] Preferably, the applicator device 4 comprises a guide body 5 and an applicator member 6.
[0162] The guide body 5 is configured for maintaining the semifinished product 108 in an alignment condition along said advancement direction "B" opposing slip forces transverse to said advancement direction "B" acting on said semifinished product 108.
[0163] The applicator member 6 is instead configured for receiving the semifinished product 108 correctly aligned by the guide body 5 and for pressing said insert 106 on said carcass structure 102 along a radial direction towards the interior so as to apply it.
[0164] Advantageously, the use of an application device that uncouples the function of guiding the semifinished product from that of application of the insert allows optimising both actions, increasing the quality of manufacturing of the manufactured item.
[0165] Preferably, the guide body 5 has an outlet section 5a which is preferably situated, with reference to the advancement direction "B", in proximity to an application portion 6a of the applicator member 6.
[0166] In the preferred embodiment, the outlet section 5a of the guide body 5 is situated, with respect to the application portion 6a of the applicator member 6, at a distance measurable along the advancement direction "B" comprised between 3 and 15 mm.
[0167] The Applicant deems that the lack of guide function by the applicator member 6 allows reducing the risk of interferences between the member itself and the carcass structure 102, entirely to the benefit of the quality of the process and product.
[0168] In addition, the reduced distance between the guide body 5 and the applicator member 6 renders the pointing process easily automatable, considerably reducing the intervention frequency of the personnel.
[0169] Preferably, the guide body 5 comprises at least two lateral walls 5b that are opposite and spaced from each other, situated on the sides of the semifinished product 108.
[0170] The two lateral walls 5b preferably orientation substantially vertical, and they are parallel to each other and situated at a distance close to the width of the semifinished product 108.
[0171] The lateral walls 5b therefore define a centring section of the semifinished product 108 adapted to oppose the slip forces transverse to said advancement direction "B" acting on said semifinished product 108.
[0172] It is noted that, preferably, a middle line axis of the centring section corresponds to a median axis of the semifinished product 108 moving along an ideal advancement line.
[0173] In the preferred embodiment, the guide body 5 of the applicator device 4 comprises a perimetrically closed through cavity 7, extended along the advancement direction "B" and, during use, crossed by the semifinished product 108 in sliding.
[0174] In other words, the through cavity 7 is defined by a duct peripherally delimited by one or more walls, which extends along the advancement direction "B" between an inlet section 5c of the semifinished product 108 and said outlet section 5a of the semifinished product 108.
[0175] It is noted that, preferably, the through cavity 7 is at least partly delimited perimetrically by the lateral walls 5b.
[0176] Advantageously, this reduces the freedom of movement of the semifinished product 108, both in lateral translation (or slipping) and in twisting.
[0177] Indeed, the presence of the lateral walls 5b opposes the lateral slipping of the material, while the presence of abutments, also above and below of the semifinished product, opposes the twisting thereof.
[0178] On the matter, preferably the through cavity 7 has a section transverse to the advancement direction "B", substantially counter-shaped with respect to a corresponding transverse section of the semifinished product 108.
[0179] Preferably, it is noted that the semifinished product 108 has a quadrangular, preferably rectangular transverse section; analogously, also the through cavity 7 has a transverse section thus shaped.
[0180] Advantageously, this minimises the possibility for moving the semifinished product 108 with respect to the ideal advancement line.
[0181] In the preferred embodiment, the through cavity 7 has a transverse section with rectangular shape defined by:
[0182] - a long horizontal side, comprised between 10 and 60 mm, preferably between 7 and 51 mm;
[0183] - a short vertical side, comprised between 0.5 and 3 mm, preferably comprised between 0.5 and 2.5 mm.
[0184] In the preferred embodiment, the guide body 5 is defined by a block of plastic or polymer material 8 having a reduced friction coefficient and crossed, along the advancement direction "B", by said through cavity 7.
[0185] Preferably, the applicator member 6 comprises an applicator roller 9 rotatable around a rotation axis roller "C" parallel to said primary rotation axis "A" of the building drum 2.
[0186] In such a manner, the rolling contact between semifinished product 108 and applicator member 6 allows increasing the application pressure, allowing avoiding damage of the carcass structure 102 also in case of accidental contact with the applicator roller 9.
[0187] Preferably, with reference to said rotation axis roller "C", the applicator roller 9 has a radially outer circumferential surface made of elastically deformable material, by an elastomer with polyurethane base with high-density closed cells, e.g. in Vulkollan™.
[0188] It is noted that, in the preferred embodiment, the applicator roller 9 has a radially outer circumferential surface with cylindrical shape.
[0189] More precisely, the radially outer circumferential surface of the applicator roller 9 substantially lacks shoulders, notches or grooves that locally modify the diameter of the applicator roller 9; in other words, said radially outer circumferential surface is substantially smooth.
[0190] This allows preventing or minimising the risk of contact between the applicator roller 9 and the carcass structure 102, without however negatively impacting the correct alignment of the insert 106 due to the presence, immediately upstream, of the guide body 5. It is noted that the application portion 6a of the applicator member 6 is defined, at each instant of time, by a part of the radially outer circumferential surface of the applicator roller 9 substantially tangent to said building drum 2, i.e. tangent to the carcass structure 102.
[0191] Preferably, the applicator roller 9 is selectively movable between a cutting position and a pointing and application position.
[0192] In the cutting position, the applicator roller 9 is preferably situated at a predetermined radial distance from said building drum 2 in a manner such that a part of the insert 106 tangent to the applicator roller 9 itself is spaced from said building drum 2.
[0193] In the pointing and application position, the applicator roller 9 is radially approached to said building drum 2 in a manner such that the part of the insert 106 tangent to the applicator roller 9 itself is maintained in contact with said carcass structure 102 wound on the building drum 2.
[0194] In other words, the distance between the primary rotation axis "A" of the building drum 2 and the rotation axis roller "C" of the applicator roller 9 is greater in the cutting position than in the pointing and application position.
[0195] In more detail, in the pointing and application position the distance between the primary rotation axis "A" of the building drum 2 and the rotation axis roller "C" of the applicator roller 9 is substantially corresponding to the sum between the radii of the building drum 2 and of the applicator roller 9, except for a small increasing variation dictated by the thickness of the carcass structure 102 and of the semifinished product 108.
[0196] On the contrary, in the cutting position the distance between the primary rotation axis "A" and the rotation axis roller "C", it is significantly greater than said sum between the radii of the building drum 2 and of the applicator roller 9.
[0197] Preferably, the applicator device 4 comprises an actuator 10, preferably linear, associated with said applicator roller 9 in order to move it between the cutting position and the pointing and application position.
[0198] Preferably, the actuator 10 is of pneumatic type.
[0199] Advantageously, the compressibility of the air within the cylinder allows the actuator to operate as damper, analogically compensating for possible irregularities of the carcass structure. Preferably, in addition, the actuator 10 is configured for moving the applicator member 6 and the guide body 5 integrally with respect to each other, simplifying the movement of the components, preventing voltage jumps on the semifinished product.
[0200] In the preferred embodiment, the feed line 3 comprises a first frame 11 and a second frame 12.
[0201] The first frame 11 is associated with the first spool 3a and a system of pulleys which guides the semifinished product up to the applicator device 4.
[0202] The second frame 12 is associated with the applicator device 4; in particular, the applicator roller 9 and the guide body 5 are coupled to the second frame 12 and are moved integrally therewith.
[0203] Preferably, therefore, the actuator 10 is operatively interposed between the first frame 11 and the second frame 12 in order to move the second frame 12 with respect to the first frame 11.
[0204] In the preferred embodiment, the second frame 12 is rotatably constrained to the first frame 11; more precisely, the second frame 12 is pivoted to the first frame 11 so as to vary the tilt thereof with respect to the first frame 11, by rotating with respect to a pin axis "D" that is substantially horizontal and parallel to said primary rotation axis "A" of the building drum 2. Said actuator 10 comprises a pneumatic cylinder pivoted between the first frame 11 and the second frame 12 at a predetermined distance from the pin axis "D", such that a linear movement thereof corresponds with a tilt of the second frame 12.
[0205] In accordance with that illustrated, the actuator 10 is movable between a contracted position and an extended position, which respectively correspond to the cutting position and the pointing and application position of the applicator roller 9.
[0206] Preferably, the applicator device 4 comprises an adjustment element 13 configured for varying, transverse to the advancement direction "B", the relative position between said semifinished product 108 and said guide body 5 so as to adjust the position of the semifinished product 108 within the cavity 7. More preferably, the adjustment element 13 is movable with respect to the guide body 5 along an adjusting direction "E" transverse to the flat faces 108a of the semifinished product 108.
[0207] In other words, the adjustment element 13 is preferably configured for selectively varying the distance between a flat face 108a of the semifinished product 108 and the wall of the through cavity 7 facing thereto.
[0208] This allows adjusting, preferably in real time, the position of the semifinished product 108 in the through cavity so as to allow that the only surface potentially sliding is that of the service band 107.
[0209] In other words, the adjustment element 13 is selectively drivable for modifying the relative position between guide body 5 and semifinished product 108 such that the flat face 108a defined by the service band 107 is closer to the corresponding wall of the through cavity 7 with respect to the flat face 108a defined by the insert 106.
[0210] Preferably, the adjustment element 13 is situated, with reference to said advancement direction "B", upstream of the guide body 5.
[0211] Due to this, it is possible to limit the distance between guide body 5 and applicator member 6 to a maximum.
[0212] In the preferred embodiment, the adjustment element 13 comprises a small roller 13a rotatable around a rotation axis small roller "F" orthogonal to the advancement direction "B" and parallel to said flat faces 108a.
[0213] More preferably, the small roller 13a is movable along said adjusting direction "E" in order to contact one of said flat faces 108a and adjust the position of the semifinished product 108 within the through cavity 7.
[0214] Alternatively, the adjustment element 13 could comprise a movement member (not illustrated) connected to the guide body in order to translate it transverse to the advancement direction "B" so as to vary the position of the guide body 5 with respect to said semifinished product 108.
[0215] Preferably, in addition, the applicator device 4 comprises a recovery group 14 of the service band 107 configured for rewinding said service band 107 which, during use, is separated from the insert 106. Preferably, the recovery group 14 of the service band 107 is arranged operatively downstream of the applicator member 6, so as to rewind the service band 107 which, in the radially inner position of said applicator roller 9, is separated from the insert
[0216] 106 due to a driving action generated by the building drum 2 placed in rotation around the primary rotation axis "A" thereof. The recovery group 14 of the service band 107 therefore comprises a rotatable second spool 14a actuated by a motor (not illustrated), preferably an electric motor, still more preferably a brushless motor.
[0217] The apparatus 1 also comprises a control unit 15 associated with said building drum 2 and with said applicator device 6.
[0218] Preferably, once arranged, the carcass structure 102 on the building drum 2, the control unit 15 is configured for imparting, to the applicator roller 9, a movement from the cutting position to the pointing and application position.
[0219] At this point, the control unit 15 drives an activation of the recovery group 14 of the service band 107 and a rotation of the building drum 2.
[0220] Preferably, the control unit 15 is configured for driving the activation of the recovery group 14 of the service band 107 simultaneously with or before the rotation of said building drum 2.
[0221] Advantageously, this allows the semifinished product 108 to maintain the correct voltage before starting the building drum 2, obtaining the correct point of separation between service band
[0222] 107 and insert 106.
[0223] In the preferred embodiment, the control unit 15 is configured for activating the motor of the recovery group 14 of the service band 107 before the start of the building drum 2, in a manner such that the reduced traction produced by the recovery group 14 of the service band 107 is sufficient to maintain the semifinished product 108 under voltage without being able to move it along the advancement direction "B", direction along which it can be moved with the aid of the movement imparted to the building drum 2.
[0224] The control unit 15 is therefore configured for maintaining the rotation of the building drum 2 and the activation of the recovery group 14 of the service band 107 for a predetermined rotation angle of the building drum 2.
[0225] Preferably, said predetermined rotation angle is comprised between 350 and 370°, more preferably about 360°.
[0226] During the rotation, preferably, the control unit 15 is configured for imparting, to the applicator roller 9, a movement from the pointing and application position to the cutting position.
[0227] A stoppage of the rotation of the building drum 2 is therefore driven, upon reaching said predetermined rotation angle.
[0228] Simultaneously, the control unit 15 is configured for maintaining the activation of the recovery group 14 of the service band 107, thus advancing the semifinished product 108 for a predetermined extra-stroke along the advancement direction "B".
[0229] At this point, the control unit 15 drives a stoppage of the recovery group 14 of the service band 107 upon reaching said predetermined extra-stroke.
[0230] Advantageously, the extra-stroke of the recovery group 14 of the service band 107 allows creating an excess of material which facilitates the step of cutting the insert 106. During use, the apparatus 1 as described above allows implementing a method for building tyres for bicycles according to the present invention.
[0231] It is noted that in the description of the method, the same reference numbers that have been used in the description of the apparatus up to now will also be used.
[0232] In any case, it is indicated that all of the characteristics of the apparatus, even if not explicitly identified or used in the following description of the method, are to be considered applicable thereto.
[0233] The method provides for arranging the building drum 2 rotating around the primary rotation axis "A" around which a carcass structure 102 was previously arranged.
[0234] The arrangement of the carcass structure 102 provides for depositing at least one first carcass ply 103 circumferentially around a deposition surface of the building drum.
[0235] The semifinished product 108 is therefore dispensed towards the pointing section 2b of the building drum 2.
[0236] At this point, provision is made for the application of the insert 106 on the extrados of the carcass structure 102, at the pointing section 2b.
[0237] The insert is therefore wound around the carcass structure 102; this is carried out by rotating the building drum 2 following the application of the semifinished product 108.
[0238] On the matter, preferably the step of applying the insert 106 provides for guiding the semifinished product 108 and then fixing the insert 106 on the extrados of the carcass structure 102.
[0239] In particular, the semifinished product 108 is preferably guided along the advancement direction "B" and, simultaneously, provision is made for opposing the slip forces transverse to said advancement direction "B" acting on the semifinished product 108.
[0240] Such opposing action is preferably carried out by means of the guide body 5 described above.
[0241] It is noted that the guiding and opposing actions continue up to a release zone close to said pointing section 2b; preferably, the release zone corresponds with the outlet section 5a of the guide body 5 described above.
[0242] Preferably, therefore, the insert 106 is fixed on said extrados of the carcass structure 102, at said pointing section 2b, by applying a pressure on said semifinished product 108.
[0243] The pressure is applied along a direction which, with reference to said primary rotation axis "A", is radial towards the interior. Preferably, the pressure is exerted by means of the applicator member 6 situated in the pointing and application position.
[0244] The Applicant deems that the separation between the functions of guiding and application / pointing of the insert allows optimising both the actions, entirely to the benefit both of the productive capacity and of the quality of the finished product.
[0245] The possibility of guiding the semifinished product 108 up to a zone close to the pointing section 2b prevents the lateral slip forces imparted by the coupling between insert 106 and carcass structure 102 from leading to a non-negligible deflection from the ideal deposition line.
[0246] Preferably, in addition, the winding of said insert 106 around the carcass structure 102 provides for maintaining said pressure on said semifinished product 108, along the radial direction towards the interior and with reference to said primary rotation axis "A", at said pointing section 2b.
[0247] Preferably, such pressure is exerted for a predetermined rotation angle of the building drum 2, which in the preferred embodiment is comprised between 350 and 370°, preferably about 360°.
[0248] In order to arrange the semifinished product 108 for the application, the method provides for drawing in said semifinished product 108 within said through cavity 7 of the guide body 5.
[0249] In other words, the method provides for crossing the through cavity 7 by moving a free end of the semifinished product from the inlet section 5c to the outlet section 5a of the guide body 5. Provision is also made for sliding in the semifinished product 108 itself along the applicator member 6, upstream or simultaneously with the fixing of the insert 106 on said extrados of the carcass structure 102.
[0250] It is also noted that the method provides for separating the service band 107 from the insert 106 following the guiding step, hence preferably downstream of the release zone.
[0251] Preferably, the separation between the service band 107 and the insert 106 occurs immediately downstream or simultaneously with the application of the insert 106 by the applicator member 6.
[0252] It is noted that, preferably, the sliding of the semifinished product 108 along the applicator member 6 provides for sliding in an external face of the service band 107 along the applicator member 6 generating a rolling contact. It is noted that such external face corresponds with the flat face 108a defined by the service band 107 described above.
[0253] Preferably, the winding of the insert 106 around the carcass structure 102 provides for exerting a traction "T", along said advancement direction "B", on the service band 107 starting from a recovery zone of the service band 107 operatively placed downstream of said applicator member 6.
[0254] Preferably, such recovery zone of the service band 107 corresponds with the recovery group 14 of the service band 107. Advantageously, the exercise of the traction "T" on the service band 107 simultaneous with the pressure generated by the applicator member 6 facilitates the separation between service band 107 and insert 106, entirely to the benefit of the process precision.
[0255] Preferably, the method also provides for lifting the applicator member 6 from the pointing and application position to the cutting position (i.e. terminating the exercise of the pressure in radial direction towards the interior) in proximity to attaining the predetermined rotation angle, stopping the rotation of the building drum 2 upon reaching said predetermined rotation angle.
[0256] It is noted that, preferably, the method provides for maintaining the dispensing of said semifinished product 108 for a predetermined extra-stroke along the advancement direction "B" simultaneously with the stoppage of the building drum 2.
[0257] Provision is in fact made for stopping the dispensing of said semifinished product 108 only upon reaching said predetermined extra -stroke.
[0258] The extra-stroke allows generating an excess of semifinished product downstream of the applicator member, facilitating the successive cutting operations.
[0259] In such a manner, in fact, a free flap 109 of the insert 106 is defined, extended between a first end and a second end, respectively situated in proximity to said building drum 2 and said applicator member 6 in the cutting position.
[0260] The method therefore provides for executing a first cut on the insert 106 at said first end.
[0261] At this point, the insert has the free flap 109 hanging, starting from the applicator member 6, allowing the operator (or a suitable cutting device) to easily execute a second cut on the insert 106 at said second end.
[0262] Advantageously, this allows the operator to operate on the apparatus only during cutting, allowing the automatic pointing of the insert.
[0263] During the building, provision is also made for the application of a pair of bead cores 104 at a predetermined mutual axial distance around said at least one carcass ply 103.
[0264] The axially outer end flaps 103a of said at least one first carcass ply 103 are therefore turned up around the bead cores 104.
[0265] In the embodiments in which the insert 106 is applied on the carcass structure 102 following the turning up of the end flaps 103a, such application preferably provides for maintaining said mutual axial distance of the bead cores 104 substantially unchanged.
[0266] The building method finally provides for depositing a tread band 105 circumferentially around the deposition surface, in which said deposit of the tread band is executed:
[0267] - following said application of the insert 106 and
[0268] - maintaining the mutual axial distance of the bead cores 104 substantially unchanged.
[0269] Such characteristic is a particular feature of the method for building a bicycle tyre, since it is no longer common practice to proceed in such a manner for tyres of another kind.
[0270] 5
Claims
CLAIMS1. Apparatus for building green tyres (100) for bicycles comprising:- a building drum (2) rotating around a primary rotation axis (A),- at least one feed line (3) configured for dispensing at least one semifinished product (108) comprising an insert (106) and a service band (107) towards a pointing section (2b) of said building drum (2); wherein said at least one feed line (3) comprises an applicator device (4) situated in radially outer position with respect to said building drum (2) in order to feed said semifinished product (108) along an advancement direction (B) and apply said insert (106) on a carcass structure (102) arranged on said building drum (2); wherein said applicator device (4) comprises a guide body (5) and an applicator member (6), where an outlet section (5a) of the guide body (5) is situated, with reference to the advancement direction (B), in proximity to an application portion (6a) of the applicator member (6), wherein:- the guide body (5) is configured for maintaining the semifinished product (108) in an alignment condition along said advancement direction (B), opposing slip forces transverse to said advancement direction (B) acting on said semifinished product (108);- the applicator member (6) is configured for receiving the aligned semifinished product (108) from the guide body (5) and for pressing said insert (106) on said carcass structure (102) along a radially inner direction so as toapply the insert (106) on said carcass structure (102).
2. Apparatus according to claim 1, wherein the outlet section (5a) of the guide body (5) is situated, with respect to the application portion (6a) of the applicator member (6), at a distance measurable along the advancement direction (B) comprised between 3 and 15 mm.
3. Apparatus according to any one of the preceding claims, wherein the guide body (5) comprises at least two lateral walls (5b) that are opposite and spaced from each other in order to be situated on the sides of the semifinished product (108) and defining a centring section of the semifinished product (108) adapted to oppose said slip forces transverse to said advancement direction (B) acting on said semifinished product.
4. Apparatus according to any one of the preceding claims, wherein the guide body (5) of the applicator device (4) comprises a perimetrically closed through cavity (7), extended along the advancement direction (B) and, during use, crossed by said insert (106) in sliding.
5. Apparatus according to claim 4, wherein said through cavity (7) has a transverse section which is transverse to said advancement direction (B) and is substantially counter-shaped with respect to a corresponding transverse section of the semifinished product (108).
6. Apparatus according to any one of the preceding claims,comprising an adjustment element (13) configured for varying, transverse to the advancement direction (B), the relative position between said semifinished product (108) and said guide body (5) so as to adjust the position of the semifinished product (108) within the through cavity (7).
7. Apparatus according to claim 6, wherein the adjustment element (13) is situated, with reference to said advancement direction (B), upstream of the guide body (5).
8. Apparatus according to claim 6 or 7, wherein the semifinished product (108) extends along the advancement direction (B) and comprises two flat faces (108a) opposite and parallel to each other; said adjustment element (13) being movable with respect to the guide body (5) transverse to said flat faces (108) along a adjusting direction (E) in order to translate the semifinished product (108) along said adjusting direction within the through cavity (7).
9. Apparatus according to any one of the preceding claims, wherein the applicator member (6) comprises an applicator roller (9) rotatable around a roller rotation axis (C) parallel to said primary rotation axis (A) of the building drum (2).
10. Apparatus according to claim 9, wherein the applicator roller (9) is selectively movable between:- a cutting position, wherein the applicator roller (9) is situated at a predetermined radial distance from said building drum (2) such that one part of the insert (106) tangent to the applicatorroller (9) itself is spaced from said building drum (2);- a pointing and application position, wherein the applicator roller (9) is radially approached to said building drum (2) in a manner such that said part of the insert (106) tangent to the applicator roller (9) itself is maintained in contact with said carcass structure (102) wound on the building drum (2).
11. Apparatus according to claim 10, wherein the applicator device (4) comprises a linear pneumatic actuator (10) associated with said applicator roller (9) in order to move it between the cutting position and the pointing and application position.
12. Apparatus according to claim 11, wherein said actuator (10) is configured for moving, integrally with respect to each other, the applicator member (6) and the guide body (5).
13. Apparatus according to any one of the claims from 10 to 12, wherein the applicator roller (9) has a radially outer circumferential surface, with reference to said roller rotation axis, made of an elastomer with polyurethane base with high- density closed cells.
14. Apparatus according to claims 2 and 13, wherein said application portion (6a) of the applicator member (6) is defined, at each instant of time, by a part of said radially outer circumferential surface of the applicator roller (9) that is substantially tangent to said building drum (2).
15. Apparatus according to any one of the preceding claims,wherein the applicator device (4) comprises a recovery group (14) for recovering the service band (107) configured for rewinding said service band (107).
16. Apparatus according to claim 15, wherein said recovery group (14) for recovering the service band (107) is arranged downstream of the applicator member (6) in order to re-wind said service band (107) which, in the radially inner position of said applicator roller (9), is separated from the insert (106) due to a driving action generated by the building drum (2) placed in rotation around the primary rotation axis (A) thereof.
17. Apparatus according to claim 15 or 16, comprising a control unit (15) associated with said building drum (2) and with said applicator device (4) and configured for:- imparting, to the applicator roller (9), a movement from the cutting position to the pointing and application position;- driving an activation of the recovery group (14) for recovering the service band (107);- driving a rotation of the building drum (2);- maintaining the rotation of the building drum (2) and said activation of the recovery group (14) for recovering the service band for a predetermined rotation angle of the building drum (2);- imparting, to the applicator roller (9), a movement from the pointing and application position to the cutting position;- driving a stoppage of the rotation of the building drum (2) upon reaching said predetermined rotation angle and, simultaneously, maintaining the activation of the recovery group (14) forrecovering the service band (107) by advancing the semifinished product (108) for a predetermined extra-stroke along the advancement direction (B);- driving a stoppage of the recovery group (14) for recovering the service band (107) upon reaching said predetermined extrastroke.
18. Method for building green tyres (100) for bicycles comprising:- arranging a building drum (2) rotating around a primary rotation axis (A),- arranging a carcass structure (102) around said building drum (2);- dispensing at least one semifinished product (108) comprising an insert (106) and a service band (107) towards a pointing section (2b) of said building drum (2);- applying said insert (106) on an extrados of said carcass structure (102) at said pointing section (2b) of the building drum (2);- winding said insert (106) around said carcass structure (102) by rotating said building drum (2) following said application; wherein said step of applying the insert (106) provides for:- guiding the semifinished product (108) along a predetermined advancement direction (B) and, simultaneously, opposing slip forces transverse to said advancement direction (B) acting on said semifinished product (108), up to a release zone proximal to said pointing section (2b);- fixing the insert (106) on said extrados of the carcassstructure (102) at said pointing section (2b) by applying a pressure on said semifinished product (108) along a radial direction towards the interior with reference to said primary rotation axis (A); said pressure being exerted by means of an applicator member (6) situated in a pointing and application position.
19. Method according to claim 18, comprising:- arranging an applicator device (4) comprising a guide body (5) and said applicator member (6), wherein an outlet section (5a) of the guide body (5) is situated, with respect to an application portion (6a) of the applicator member (6), at a distance measurable along the advancement direction (B) comprised between 3 and 15 mm.
20. Method according to claim 19, wherein the guide body (5) comprises a perimetrically closed through cavity (7), extended along the advancement direction (B); said method comprising:- drawing in said semifinished product (108) within said through cavity (7);- sliding the semifinished product along the applicator member (6), upstream of or simultaneously with the fixing of the insert (106) on said extrados of the carcass structure (102).
21. Method according to any one of the claims from 18 to 20, wherein provision is made for:- sliding an external face of the service band (107) along the applicator member (6), generating a rolling contact;- separating the service band (107) from the insert (106)immediately downstream of or simultaneously with said application of the insert by the applicator member (6).
22. Method according to any one of the claims from 18 to 21, wherein the winding of said insert (106) around said carcass structure (102) provides for exerting a traction (T) on the service band (107), said traction being oriented along said advancement direction (B) and starting from a recovery zone of the service band operatively placed downstream of said applicator member (6).
23. Method according to any one of the claims from 18 to 22, comprising:- maintaining the rotation of the building drum (2) and the dispensing of said semifinished product (108) for a predetermined rotation angle of the building drum (2);- lifting the applicator member (6) from the pointing and application position to a cutting position, radially outer with respect to said pointing and application position, with reference to the primary rotation axis (A);- stopping the rotation of the building drum (2) upon reaching said predetermined rotation angle and, simultaneously, maintaining the dispensing of said semifinished product (108) for a predetermined extra-stroke along the advancement direction (B);- stopping the dispensing of said semifinished product (108) upon reaching said predetermined extra-stroke, defining a free flap (109) of said insert (106) extended between a first end and a second end, respectively situated in proximity to said buildingdrum (2) and to said applicator member (6) in the cutting position;- executing a first cut on the insert (106) at said first end.
24. Method according to claim 23, comprising a step of executing a second cut on the insert (106) at said second end.
25. Method according to any one of the preceding claims, wherein said semifinished product (108) has a thickness lower than 3 mm and said insert has a thickness smaller than 2 mm.
26. Process according to any one of the preceding claims, wherein said insert (106) has a width, measured orthogonally to an advancement direction (B) of said first insert, comprised between 5 and 60 mm.