Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/38—Textile inserts, e.g. cord or canvas layers, for tyres; Treatment of inserts prior to building the tyre
  • B29D30/44—Stretching or treating the layers before application on the drum
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/08—Building tyres
  • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
  • B29D30/28—Rolling-down or pressing-down the layers in the building process
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/08—Building tyres
  • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
  • B29D30/30—Applying the layers; Guiding or stretching the layers during application
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/08—Building tyres
  • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
  • B29D30/30—Applying the layers; Guiding or stretching the layers during application
  • B29D30/3007—Applying the layers; Guiding or stretching the layers during application by feeding a sheet perpendicular to the drum axis and joining the ends to form an annular element
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/38—Textile inserts, e.g. cord or canvas layers, for tyres; Treatment of inserts prior to building the tyre
  • B29D30/44—Stretching or treating the layers before application on the drum
  • B29D2030/4406—Adjusting the positions of the layers
  • B29D2030/4418—Adjusting the positions of the layers laterally, e.g. sideways

Definitions

• the present invention relates to an apparatus and a method for building green tyres for bicycles.
• the opposite ends of the tread band are slightly superimposed and mutually joined by a head-head joint.
• 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.
• 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.
• 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.
• insert it is intended an elongated or strip element, preferably made of elastomeric material.
• strip is cut to size.
• 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.
• 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.
• 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.
• elastomeric material it is intended a composition comprising at least one elastomeric polymer and at least one reinforcement filler.
• 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.
• annular 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.
• 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.
• 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.
• the operator is required to manually guide the semifinished product for the purpose of the correct alignment and to manually control the tensioning thereof.
• 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.
• 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.
• 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.
• 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).
• 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.
• 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.
• the components made of elastomeric material 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• the invention relates to an apparatus for building green tyres for bicycles.
• the semifinished product comprises an insert and a service band.
• said at least one feed line comprises an applicator device situated in radially outer position with respect to said building drum.
• 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.
• the applicator device comprises a guide body and an applicator member.
• 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.
• 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.
• 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.
• 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.
• 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.
• the invention refers to a method for building green tyres for bicycles.
• 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.
• such guiding and opposition actions are exerted up to a release zone close to said pointing section.
• the semifinished product is fixed on said extrados of the carcass structure at said pointing zone by applying a pressure on said semifinished product.
• said pressure is exerted along a radial direction towards the interior with reference to said primary rotation axis.
• said pressure is exerted by means of an applicator member situated in a pointing and application position.
• 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.
• the invention comprises one or more of the following preferred characteristics that are described below.
• 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.
• 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.
• 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.
• 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.
• this reduces the freedom of movement of the semifinished product, both in lateral translation (or slipping) and in twisting.
• said through cavity is at least partly perimetrically delimited by said lateral walls.
• 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.
• said through cavity has a transverse section that is substantially rectangular.
• 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.
• the adjustment element is situated, with reference to said advancement direction, upstream of the guide body.
• 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.
• said two flat faces are orthogonal to two lateral edges, also substantially parallel to and opposite each other.
• 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.
• 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.
• this allows adjusting the relative position between semifinished product and guide body without generating sliding on the semifinished product.
• 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.
• the applicator member comprises an applicator roller rotatable around a rotation axis roller parallel to said primary rotation axis of the building drum.
• 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.
• the applicator roller is selectively movable between a cutting position and a pointing and application 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.
• 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.
• 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.
• 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.
• the compressibility of the air within the cylinder allows the actuator to operate as damper, analogously compensating for possible irregularities of the carcass structure.
• said pneumatic actuator is configured for moving integrally with respect to each other the applicator member and the guide body.
• 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 VulkollanTM.
• this allows analogically compensating for possible irregularities of the carcass structure.
• said applicator roller has a radially outer circumferential cylindrical surface.
• 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.
• the applicator device comprises a recovery group of the service band configured for re-winding said service band that is separated from the insert.
• 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.
• the apparatus comprises a control unit associated with said building drum and with said applicator device.
• control unit is configured for imparting, to the applicator roller, a movement from the cutting position to the pointing and application position.
• control unit is configured for driving an activation of the recovery group of the service band.
• control unit is configured for driving a rotation of the building drum.
• said rotation of the building drum follows said activation of the recovery group of the service band.
• 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.
• 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.
• 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.
• control unit is configured for driving a stoppage of the recovery group of the service band upon reaching said predetermined extra-stroke.
• 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.
• 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.
• 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.
• 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.
• 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.
• the guide body comprises a perimetrically closed through cavity, extended along the advancement direction.
• the passage of the semifinished product in the cavity allows the insert to remain guided along the advancement direction up to the pointing section.
• 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.
• 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.
• the extra-stroke allows generating an excess of semifinished product downstream of the applicator member, facilitating the successive cutting operations.
• this allows the operator to intervene on the apparatus only during cutting, allowing the automatic pointing of the insert.
• arranging said carcass structure comprises depositing at least one carcass ply circumferentially around a deposition surface of said building drum.
• 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.
• the deposit of the tread band is executed after said application of the insert.
• the deposit of the tread band is executed by maintaining the mutual axial distance of the bead cores substantially unchanged.
• 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.
• 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.
• - 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;
• figure 2a shows a detail of the enlargement of figure 2;
• FIG. 8 shows the schematic structure of a tyre for bicycles
• FIG. 9 schematically shows the structure of a semifinished product used in the method according to the present invention.
• reference number 1 indicates an apparatus for building tyres, in particular tyres for bicycles.
• 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..
• a radially inner surface 101a substantially facing towards a geometric rotation axis of the tyre 100
• a radially outer surface 101b substantially facing away from the geometric rotation axis.
• 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.
• 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.
• 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.
• a tread band 105 is applied that is made of elastomeric material.
• reinforcement inserts 106 are normally applied, in modes and configurations that differ as a function of the building scheme.
• 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).
• 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.
• the width of the reinforcement inserts 106 is preferably comprised between 5 and 60 mm, preferably comprised between 7 and 50 mm.
• the inserts 106 can be continuously applied and cut after the application or cut to size, in a step preceding application.
• 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.
• belt reinforcement layers or belt layer
• 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.
• 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.
• 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.
• 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.
• a rotation shaft (not illustrated) coaxial with the primary rotation axis "A" and integral with the drum itself in order to rotate it.
• 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.
• 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.
• 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.
• 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.
• the semifinished product 108 is wound in a reel 108a on a rotatable first spool 3a which allows the unwinding thereof.
• 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.
• the service band 107 has belt-like shape and is coupled to the insert 106 with the function of size control and protection.
• the service band 107 and the insert 106 are longitudinally coupled.
• 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.
• the service band 107 is made of polythene.
• 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.
• 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.
• 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.
• the semifinished product 108 extends along the advancement direction "B" and comprises two flat faces 108a that are opposite and parallel to each other.
• 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.
• the applicator device 4 is situated above the building drum 2, with reference to a horizontal support plane (i.e. the ground).
• the building drum 2 has a top portion 2c defined around a top thereof.
• the applicator device 4 is preferably situated on top of said top portion 2c.
• the building drum 2 is divided into a front half-part 2d, operator-accessible, and a rear half-part 2e.
• 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.
• 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.
• the applicator device 4 comprises a guide body 5 and an applicator member 6.
• 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 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• a middle line axis of the centring section corresponds to a median axis of the semifinished product 108 moving along an ideal advancement line.
• 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.
• 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.
• the through cavity 7 is at least partly delimited perimetrically by the lateral walls 5b.
• this reduces the freedom of movement of the semifinished product 108, both in lateral translation (or slipping) and in twisting.
• 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.
• 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.
• the semifinished product 108 has a quadrangular, preferably rectangular transverse section; analogously, also the through cavity 7 has a transverse section thus shaped.
• the through cavity 7 has a transverse section with rectangular shape defined by:
• - a short vertical side, comprised between 0.5 and 3 mm, preferably comprised between 0.5 and 2.5 mm.
• 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.
• 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.
• 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.
• 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 VulkollanTM.
• the applicator roller 9 has a radially outer circumferential surface with cylindrical shape.
• 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.
• 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.
• the applicator roller 9 is selectively movable between a cutting position and a pointing and application position.
• the applicator roller 9 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.
• 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.
• 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.
• the actuator 10 is of pneumatic type.
• the feed line 3 comprises a first frame 11 and a second frame 12.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• the adjustment element 13 is situated, with reference to said advancement direction "B", upstream of the guide body 5.
• 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.
• 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.
• 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.
• 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.
• 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
• 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.
• the apparatus 1 also comprises a control unit 15 associated with said building drum 2 and with said applicator device 6.
• 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.
• control unit 15 drives an activation of the recovery group 14 of the service band 107 and a rotation of the building drum 2.
• 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.
• 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
• 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.
• 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.
• said predetermined rotation angle is comprised between 350 and 370°, more preferably about 360°.
• control unit 15 is configured for imparting, to the applicator roller 9, a movement from the pointing and application position to the cutting position.
• a stoppage of the rotation of the building drum 2 is therefore driven, upon reaching said predetermined rotation angle.
• 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".
• control unit 15 drives a stoppage of the recovery group 14 of the service band 107 upon reaching said predetermined extra-stroke.
• 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.
• the apparatus 1 as described above allows implementing a method for building tyres for bicycles according to the present invention.
• 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.
• 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.
• the semifinished product 108 is therefore dispensed towards the pointing section 2b of the building drum 2.
• 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.
• 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.
• 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.
• Such opposing action is preferably carried out by means of the guide body 5 described above.
• 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.
• 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.
• the pressure is applied along a direction which, with reference to said primary rotation axis "A", is radial towards the interior.
• the pressure is exerted by means of the applicator member 6 situated in the pointing and application position.
• 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.
• 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.
• 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°.
• the method provides for drawing in said semifinished product 108 within said through cavity 7 of the guide body 5.
• 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.
• the method provides for separating the service band 107 from the insert 106 following the guiding step, hence preferably downstream of the release zone.
• 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.
• 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.
• 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.
• such recovery zone of the service band 107 corresponds with the recovery group 14 of the service band 107.
• 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.
• 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.
• the extra-stroke allows generating an excess of semifinished product downstream of the applicator member, facilitating the successive cutting operations.
• 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.
• the method therefore provides for executing a first cut on the insert 106 at said first end.
• 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.
• this allows the operator to operate on the apparatus only during cutting, allowing the automatic pointing of the insert.
• the axially outer end flaps 103a of said at least one first carcass ply 103 are therefore turned up around the bead cores 104.
• such application preferably provides for maintaining said mutual axial distance of the bead cores 104 substantially unchanged.
• 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.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Tyre Moulding (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=85556630

Family Applications (1)

Country Status (5)

Family Cites Families (7)

• 2022
  • 2022-12-28 IT IT102022000026925A patent/IT202200026925A1/it unknown
• 2023
  • 2023-12-20 WO PCT/IB2023/062978 patent/WO2024141866A1/en not_active Ceased
  • 2023-12-20 CN CN202380087798.5A patent/CN120530016A/zh active Pending
  • 2023-12-20 EP EP23843999.6A patent/EP4642631A1/de active Pending
• 2025
  • 2025-06-12 MX MX2025006913A patent/MX2025006913A/es unknown

Also Published As

Similar Documents

Legal Events