Apparatus for manufacturing bead wires for pneumatic tires comprising a head for switching between cutting and crimping tools

The installation for manufacturing a bead wire intended to reinforce a pneumatic tire, said installation comprising a receiving table which is adapted to receive a braided torus which comprises a braid wire which extends longitudinally from a first end section to a second end section, a cutting tool, a crimping tool adapted to crimp a sleeve around said first and second end sections, and a configuration unit which is adapted automatically to switch the installation from a cutting configuration in which the receiving table cooperates with the cutting tool so as to position the braided torus and the first and second end sections so that said first and second end sections are sectioned by the cutting tool to a crimping configuration in which the receiving table cooperates with the crimping tool.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of PCT Patent Application No. PCT/FR2019/053137 filed on 18 Dec. 2019, entitled “APPARATUS FOR MANUFACTURING BEAD WIRES FOR PNEUMATIC TIRES COMPRISING A HEAD FOR SWITCHING BETWEEN CUTTING AND CRIMPING TOOLS”, and French Patent Application No. 20190000951, filed on 31 Jan. 2019, entitled “APPARATUS FOR MANUFACTURING BEAD WIRES FOR PNEUMATIC TIRES COMPRISING A HEAD FOR SWITCHING BETWEEN CUTTING AND CRIMPING TOOLS” and French Patent Application No. 20180074244, filed on Dec. 27, 2018, entitled “APPARATUS FOR MANUFACTURING BEAD WIRES FOR PNEUMATIC TIRES COMPRISING A HEAD FOR SWITCHING BETWEEN CUTTING AND CRIMPING TOOLS”.

BACKGROUND

The present disclosure concerns the field of the manufacture of reinforcing bead wires that are intended to reinforce tires, in particular pneumatic tires, in order to retain said tires on a rim.

In a manner known in itself, a bead wire takes the form of an annular rigid material, generally metal, element that may consist of a strand comprising a plurality of interlaced braid wires.

It is therefore known, during the manufacture of a bead wire, to provide an operation of braiding during which a braid wire is wound in helicoidal turns around a core that is closed on itself in a ring so as to obtain a braided torus, followed by a joining operation during which the ends of said braid wire are fixed to one another, for example by means of a crimped sleeve, in order to produce the cohesion of the braided torus in the form of an annular element that will constitute the bead wire.

To this end, it is necessary to adjust the length of the ends of the braid wires by means of a cutting operation preceding the joining operation and then to engage the sleeve to be crimped on said ends.

These operations are sometimes difficult, which can make it difficult to reproduce them from one bead wire to another.

Moreover, it sometimes happens that the sleeve is incorrectly placed on the ends of the braid wire, which leads to rejection of the bead wire, and thus to a waste of raw material and energy.

2. Related Art

In an attempt to alleviate these drawbacks, there has been proposed, for example by the document JP-2007-160640, using tubular sleeves of very specific shape, including an internal central abutment that separates two end housings, together with positioning jaws that are also very specific comprising chamfered mouths deemed to facilitate the insertion of the end sections of the wire in said end housings of the sleeve.

This kind of solution, which can undoubtedly increase the reliability of crimping, nevertheless requires precise positioning of the sleeve in the positioning jaws, followed by careful manual insertion of each of the wire end sections in the corresponding housing of the sleeve, and finally, when all the elements have been pre-assembled, triggering crimping.

A method of this kind is therefore time-consuming and tedious, and what is more costly, and this all the more so in that the specific shape of the sleeves complicates the production of said sleeves.

SUMMARY OF THE INVENTION

The objects assigned to the disclosure therefore aim to remedy the aforementioned disadvantages and to propose a new installation for manufacturing bead wires that enables bead wires to be manufactured rapidly, at relatively low cost, and reliably.

The objects assigned to the disclosure are achieved by means of an installation for manufacturing a bead wire intended to reinforce a tire, in particular a pneumatic tire, said installation including:a receiving table that is adapted to receive a braided torus that includes at least one wire, termed “braid wire”, that extends longitudinally from a first end section to a second end section and that is interlaced in helicoidal turns around and along a generatrix line that forms a ring around a principal axis that corresponds to the central axis of said braided torus,a cutting tool adapted to section the first end section and the second end section in order to adjust the length of said first and second end sections,a crimping tool adapted to crimp a sleeve around said first end section and said second end section in order to join and to fix said first and second end sections to one another,
said installation including a configuration unit that is adapted to cause said installation to pass automatically from a first working configuration, termed “cutting configuration”, in which the receiving table cooperates with the cutting tool in such a manner as to position the braided torus and the first and second end sections so that said first and second end sections are sectioned by the cutting tool, to a second working configuration, termed “crimping configuration”, distinct from the first working configuration, in which the receiving table cooperates with the crimping tool in such a manner as to position the braided torus and the first and second end sections so that the crimping tool joins said first and second end sections by means of the sleeve.

The configuration unit advantageously enables automatic chaining of the cutting and crimping operations and precise and reproducible execution of said operations in a very short time.

It is therefore in particular possible to carry out in the same installation all the operations necessary for sleeving the bead wire, and this with great accuracy, since it is possible to retain the same frame of reference tied to the installation to position the braided torus and the cutting and crimping tools automatically with respect to one another.

Moreover, as will emerge hereinafter, the disclosure enables the provision of a kinematic chain for reconfiguring the manufacturing installation that is particularly favorable to the compactness and the efficacy of said installation.

DETAILED DESCRIPTION OF THE ENABLING EMBODIMENTS

The present disclosure concerns an installation1for manufacturing a bead wire9intended to reinforce a tire, in particular a pneumatic tire.

By way of example, these bead wires9intended to retain such pneumatic tires on a rim may be adapted to equip pneumatic tires of which the dimensions, here more particularly the diameter of the rim to which the diameter of the bead wire9corresponds, are between 13 inches and 24 inches inclusive. The disclosure is of course applicable to the manufacture of bead wires9intended for pneumatic tires for private vehicles, in particular with the aforementioned dimensions, but also for the manufacture of bead wires9intended for pneumatic tires for heavy goods vehicles or for civil engineering machines.

The installation includes a frame100.

For convenience of description, it will be considered that this frame100geometrically defines a frame of reference termed a “fixed frame of reference” comprising a preferably horizontal reference plane (X, Y) as well as a preferably vertical reference axis Z that is normal to the reference plane (X, Y).

“Abscissa axis” will designate the axis X, horizontal here, of the reference plane (X, Y) and “ordinate axis” the axis Y, here horizontal, that with the abscissa axis X defines the reference plane (X, Y) and that forms with the abscissa axis X and the vertical reference axis Z an orthonormal trihedron.

The installation1includes a receiving table2that is adapted to receive a braided torus3which, as can be seen inFIG.5in particular, includes at least one wire4, termed a “braid wire”, that extends longitudinally from a first end section5to a second end section6and that is interlaced in helicoidal turns7around and along a generatrix line L8that forms a ring around a principal axis that corresponds to the central axis Z3of said braided torus3.

The braid wire4is preferably a metal, for example steel, wire, possibly coated with a protective layer. Alternatively, without departing from the scope of the disclosure, said braid wire4could be made of any appropriate material having a sufficiently high Young's modulus (modulus of elasticity) and in particular an appropriate polymer material, or an appropriate mixture of polymer materials, or a metal and polymer composite material.

The braid wire could preferably have a section diameter between 1.20 mm and 3.5 mm inclusive, for example chosen from 1.30 mm, 1.55 mm, 1.75 mm, 2.00 mm and 3.00 mm.

The braid wire4could be shaped during a preceding braiding step in which the helicoidal turns7are shaped to obtain the braided torus3. The cutting, respectively crimping, operations in accordance with the disclosure will take place after this braiding operation.

The braid wire4advantageously extends continuously, that is to say in one piece, from the first end section5that precedes the helicoidal turns7to the second end section6that follows on from the helicoidal turns7, and said braid wire4performs a plurality of complete turns in azimuth about the central axis Z3, each completed turn having the effect of adding one unitary section of said braid wire4to the overall section of the braided torus3, as can be seen in particular in the detail partial section illustrated inFIG.17.

In practice the generatrix line L8that is represented in dashed line inFIGS.1,5,17and18could preferably consist of a core8that is closed on itself in a ring, preferably with a circular shape, around the principal axis Z3.

Said core8advantageously forms a braiding support around and along which the braid wire4is wound in helicoidal turns7, as mentioned above.

Said core8may be a single-strand core, that is to say formed of a single monolithic core wire, or alternatively a multi-strand core, that is to say formed of a plurality of interlaced core wires.

The core8or the core wires could be made of any appropriate material that is sufficiently rigid and has a tensile strength above a predetermined threshold.

The core8or the core wires are preferably metal, for example steel, wires.

Alternatively, without departing from the scope of the disclosure, another material could nevertheless be used, for example an appropriate polymer, or an appropriate mixture of polymers, or a metal-polymer composite material.

The receiving table2will preferably include guide members10,11such as rollers10and/or centring rods11enabling the braided torus3to be positioned on and guided along a predetermined path on said receiving table2. For convenience of description this path could be deemed to be the same as the generatrix line L8and the plane corresponding thereto that contains said generatrix line L8could be termed the “guide plane”.

The installation1also includes a cutting tool20adapted to section the first end section5and the second end section6in order to adjust the length of said first and second end sections5,6as illustrated inFIGS.11A and12A.

The cutting tool20will enable the end sections5,6to have a predetermined residual length suitable for the subsequent fitting of a sleeve14.

More preferably, following the braiding operation and before the cutting operation, the end sections5,6, seen in projection in the reference plane (X, Y), initially cross at a crossover point13and the effect of the cutting tool20is to shorten the first and second end sections5,6on either side of said crossover point13in order to interrupt each end section5,6before it reaches said crossover point, as can be seen inFIG.11A.

The sleeve14could therefore then form a bridge between the first and second end sections5,6substantially where the crossover point13was located so that said end sections5,6are finally arranged in longitudinal alignment with one another without overlapping longitudinally inside the sleeve14. This facilitates the crimping operation and improves the compactness of the sleeved joint.

The cutting tool20preferably includes a cutter21.

As can be seen inFIGS.1,11A and19, said cutter21may preferably include a first set of blades22for cutting the first end section5and a second set of blades23for cutting the second end section6.

The cutting tool20will of course include a preferably automatic actuator mechanism for activating the closure of the cutter21in order to cut the end sections5,6.

As illustrated inFIG.2, this mechanism will preferably include a motorized actuator member24such as an actuator cylinder24.

Said actuator cylinder24could for example be coupled to a cam25that cooperates with an actuator roller26carried by a cutting lever27which drives a set of blades22,23to close them against the action of a return spring28.

In this instance, the cam25could be mounted on the frame100to rotate about a cam axis Y25parallel to the ordinate axis Y with the actuator cylinder24mounted to pivot on that same frame100.

It will be noted that this cam, roller, cutting lever and return spring mechanism could where appropriate be duplicated for each set of blades22,23so that each of said sets of cutters could be actuated independently of the other.

In fact, in accordance with a particularly preferred feature that may constitute a disclosure in its own right, the cutter21has a differential action, the second set of blades23being to this end adapted to act after the first set of blades22has finished cutting the first end section5.

In other words, the cutting tool20is preferably adapted to cut the end sections5,6one after the other and not simultaneously.

To this end, there could be provided a pair of cams25offset axially, here along the ordinate axis Y, and angularly shifted relative to one another to actuate successively two cutting levers27each associated with one of the sets of blades22,23and each carrying a roller26engaged by one of said two cams25. Each of said cutting levers27will preferably be independently returned by its own return spring28.

This kind of cutter21comprising two sets of blades22,23on the ordinate axis Y on either side of the crossover point13and two corresponding cutting levers27is illustrated inFIG.19.

Thus having a time difference between the two cutting operations advantageously makes it possible, at each moment of the cutting operation, to concentrate the cutting force on only one end section5,6at a time, and consequently on only one braid wire4section.

This reduces the cutting force necessary. The cutting operation therefore requires less power, which advantageously enables reduction of the size of the cutting tool20and the actuator mechanism and limitation of wear of the cutter21.

The installation1also includes a crimping tool30adapted to crimp a sleeve14around the first end section5and the second end section6in order to join and to fix to one another said first and second end sections5,6.

Crimping on a sleeve14advantageously enables a robust joining of the end section5,6to be obtained simply, rapidly and with low consumption of energy, and more particularly joining of said end sections5,6without welding. This joint guarantees the cohesion of the braided torus3by definitively preventing the helicoidal turns7from unwinding or loosening.

The crimping tool30preferably includes a crimper31that is adapted to receive a sleeve preform12and then to press and to close by plastic deformation said sleeve preform12into the form of a sleeve14around the first and second end sections5,6.

Said sleeve preform12is preferably slit over all its length so that, as can be seen inFIG.16, said sleeve preform has a U-shaped concave curved cross section that comprises a rounded bottom12B and two flared lateral branches12C,12D.

The sleeve preform12therefore preferably has along all its length an opening the width W12of which is equal to or greater than the greatest diameter of the first wire end section5and the second wire end section6as shown diagrammatically inFIG.16so that the crimper31can apply the sleeve preform12to said wire end sections5,6by offering it up laterally, transversely to the longitudinal direction of said wire end sections5,6.

The sleeve preform12therefore as it were forms a slit sleeve that the crimper31will be able to close around and to clamp onto the end sections5,6of wire4by bending the lateral branches12C,12D against the perimeter of the section of said wire4in an angular sector of said section of the wire4that is situated in the half-plane diametrically opposite, relative to the center of the section of the wire4, the half-plane that contains the angular sector of the wire4against which the bottom12B of the sleeve preform12comes to be applied.

This kind of lateral, transverse approach is advantageously easy to implement and easy to automate, in particular because it dispenses with the need to thread the sleeve14and more particularly the sleeve preform12longitudinally onto each of the end sections5,6.

Moreover, the dimensions of the sleeve preform12and more particularly the cumulative length of the bottom12B and of the lateral branches12C,12D are advantageously chosen so that the sleeve14that results from the plastic bending of the sleeve preform12on itself grips inside it a single section of a wire4, that is to say so that the sleeve14envelops only one section of a wire4and is therefore coaxial with each of the unitary end sections5,6of said wire4.

In particular, in the case of a braided torus3that includes in the same torus cross section a plurality of unitary sections of the braid wire4each corresponding to one helicoidal turn7, then the dimensions of the sleeve preform12and more particularly the cumulative length of the bottom12B and the lateral branches12C,12D of said sleeve preform12, that is to say the arc length that said sleeve preform12is able to cover around the longitudinal direction of the braid wire4when said sleeve preform has been bent into its final shape as the sleeve14, therefore preferably correspond to a fraction, typically 65% to 100%, preferably 70% to 99%, or even 75% to 95%, of the perimeter of a single unitary section of the braid wire4, so that the sleeve14finally contains only one unitary section of braid wire4, the other unitary sections of the braid wire4in the same cross section of the braided torus3then being outside the sleeve14, as can be seen in particular inFIG.5.

In other words, the dimensions of the sleeve14will preferably be such as not to envelop all of the sections of the braided torus3, that is to say not to envelop all the turns7of the braid wire4, but only the unitary section that corresponds to the joint between the first and second end sections5,6.

This therefore and advantageously avoids creating an extra thickness of material on the bead wire9and more particularly on the radial external surface of the bead wire9, which makes it possible for said bead wire9not to have an abrasive character for rubber-based plies that constitute the casing of the pneumatic tire, in particular the carcass ply.

It will also be noted that, once the sleeve preform12has been closed to form a sleeve14over the end sections5,6, and more particularly a unitary section of the braid wire4corresponding to the section of said end sections5,6, the lateral branches12C,12D preferably do not overlap and preferably do not touch edge-to-edge, in other words the sleeve14covers less than 100% of the circumference of the section of the wire4. This therefore avoids creating any unnecessary increased thicknesses of material.

By way of illustration, the front width of the preferably metallic strip constituting the sleeve preform12, that is to say the cumulative length of the bottom12B and the lateral branches12C,12D, considered in a cross section of the sleeve preform12perpendicular to the longitudinal direction of said sleeve preform12, will preferably be between 4 mm and 7 mm inclusive in order typically to cover, as mentioned above, between 70% and 99% of the circumference of a (unitary) section of wire4.

As can be seen inFIGS.15and16in particular, the crimper31may include a plurality of jaws32,33,34comprising a bottom jaw32adapted to receive the bottom12B of the sleeve preform12, preferably in a rounded housing35, and a first lateral jaw33and a second lateral jaw34.

The first lateral jaw33and the second lateral jaw34are respectively adapted to interengage with the first lateral branch12C and with the second lateral branch12D of the sleeve preform12and to be moved toward one another transversely to the mid-line of the wire4, so as to bend one toward the other, by plastic deformation, said first lateral branch12C and said second lateral branch12D of the sleeve preform12, in order by closing up to envelop said sleeve preform12on the section of said wire4and thus to trap the end sections5,6inside the sleeve14.

The lateral jaws33,34could have any shape and any kinematic chain allowing accentuation of the curvature, here of the concavity, of the sleeve preform12by plastic deformation against the wire4to obtain the finished sleeve14.

In order to retain the sleeve preform12inside the crimper31until said crimper31is engaged on the wire4the lateral jaws33,34could be spring-loaded toward one another by means of one or more suspension springs36and have non-return rims37,38adapted to cooperate with the sleeve preform12by clipping action, as illustrated inFIG.16.

The free edges of the lateral branches12C,12D of the sleeve preform12will preferably rest in a stable manner against said anti-return rims37,38, which will prevent said sleeve preform12falling out.

Of course, during the crimping operation, there will first be effected a closure of the crimper31by forced movement toward one another of the lateral jaws33,34to bring about the crimping of the sleeve14and then, thereafter, once the sleeve14has actually been crimped onto the wire4, opening of the crimper31by moving apart the lateral jaws33,34by simple elastic return effect or by a forced motorized manoeuvre, in order to release the end sections5,6now joined by said sleeve14.

The forced movements of the lateral jaws33,34, in particular the closing movements, could be effected, where appropriate against the suspension spring36, by any appropriate driving member, such as an actuator cylinder24or an electric motor.

In particular, in an analogous manner to what has been described for the cutter21, the crimper31could be actuated by an actuator mechanism including a cam325rotated by a motorized actuator member24such as an actuator cylinder24, which cam325cooperates with an actuator roller326carried by a crimping lever327that acts on the jaw33,34concerned against a return spring328to close the crimper31.

It will be noted that, in accordance with a preferred feature that may constitute a disclosure in its own right, the cutting tool20and the crimping tool30may share a common actuator mechanism and in particular the same actuator cylinder24, which further improves the compactness of the installation1.

In this regard, the cam325that controls the closing of the crimper31could advantageously be mounted on the same rotation axis Y25as the cam25that commands the closing of the cutter20, as can be seen inFIGS.2and4. The two cams25,325could even and preferably be constrained to rotate with one another on said rotation axis Y25.

In accordance with the disclosure, the installation1includes a configuration unit40that is adapted to cause said installation1to go automatically from a first working configuration, termed “cutting configuration” C20, corresponding toFIGS.2,11A and11B, in which the receiving table2cooperates with the cutting tool20in such a manner as to position the braided torus3and the first and second end sections5,6so that said first and second end sections5,6are sectioned by the cutting tool20, to a second working configuration, termed “crimping configuration” C30, distinct from the first working configuration C20, which corresponds toFIGS.1,4,13A and13B, and in which the receiving table2cooperates with the crimping tool30in such a manner as to position the braided torus3and the first and second end sections5,6so that the crimping tool30joins said first and second end sections5,6by means of the sleeve14.

The configuration unit40, preferably controlled by an electronic control system43that preferably also controls the actuation of the cutting tool20and the crimping tool30, advantageously allows automatically chaining of the cutting operation and then the crimping operation on each braided torus3, with no loss of the machine's reference point. The installation1is therefore able to carry out these operations in an autonomous manner, precisely, rapidly and perfectly reproducibly from one braided torus3to another.

The configuration unit40will in particular be capable of managing both the movements to position the receiving table2and therefore to position the braided torus3relative to the frame100and movements of the cutting tool20and then the crimping tool30relative to that same frame100. The configuration unit will therefore allow fine and reproducible positioning of the receiving table2and therefore of the braided torus3relative to the cutting tool20and the crimping tool30, in a tightly controlled frame of reference tied to the frame100.

The configuration unit40will more particularly be adapted, in the cutting configuration C20, to move the braided torus3and more particularly the angular sector of said braided torus that contains the crossover point13of the first and second end sections5,6to face the cutting tool20so that the first and second end sections5,6are positioned in the cutter21and the two sets of blades22,23are therefore located on either side of the crossover point13of said end sections5,6.

Likewise, the configuration unit40will be adapted, in the crimping configuration C30, to effect thereafter the necessary transfers relative to the frame100, to move the braided torus3and more particularly the first and second end sections5,6shortened by the cutting operation to face the crimping tool30in such a manner as to engage said end sections5,6between the jaws32,33,34of the crimper31in the sleeve preform12present in said crimper31.

As indicated above, the installation includes a frame100with which is associated a frame of reference termed “fixed frame of reference” (X, Y, Z).

In absolute terms, distributing the cutting tool20and the crimping tool30on the frame could be envisaged so as respectively to define a cutting location and a crimping location distinct from the cutting location to cause the configuration unit40automatically to move the braided torus3from one location to the other.

However, as can be seen inFIGS.3and12B, the configuration unit40preferably includes a switching head41that carries both the cutting tool20and the crimping tool30and that is adapted to be able to position alternately, by a first movement M41termed “switching movement” effected relative to the frame100, said cutting tool20, for the cutting configuration C20, and respectively said crimping tool30, for the crimping configuration C30, facing a same predetermined common working location42in the fixed frame of reference (X, Y, Z) of the installation1.

For the braided torus3the cutting location and the crimping location are therefore identical and correspond to the single working location42at which, thanks to the switching movement41, the cutting tool20and then the crimping tool30are successively present.

The use of a switching head41in particular allows significant reduction of the overall size of the installation1and the cycle time necessary to go from the cutting configuration C20to the crimping configuration30(then, conversely, returning from the crimping configuration30to the cutting configuration C20).

Moreover, as will emerge hereinafter, this kind of switching head41allows the change of configuration to be effected by means of a combination of simple and well-controlled movements, of moderate amplitude and inertia that can be guided with precision, thereby limiting the sources of errors linked to mechanical clearances, and preserving common referencing in the fixed frame of reference of the frame100. This improves the installation in terms of precision, reliability and compactness.

As can be seen inFIG.3, the switching movement M41is preferably effected by pivoting the switching head41about a pivot axis Y41that is parallel to the reference plane (X, Y), here horizontal, of the frame100.

More particularly, said pivot axis41will be parallel to the ordinate axis Y and preferably situated below the plane of the receiving table2.

The use of a pivoting switching head41advantageously allows the switching movement41to be performed in a relatively small space and in a particularly simple manner.

The switching movement M41will preferably correspond to a quarter-turn.

End of travel stops could of course be used to index the two positions that respectively correspond to the cutting configuration C20and to the crimping configuration C30.

The switching head41could advantageously have a substantially L-shaped arrangement, one of the branches of the L carrying the cutting tool20and the other branch carrying the crimping tool30.

This orthogonal disposition of the tools20,30will be perfectly suitable for a quarter-turn switching movement M41and will moreover allow downward disengagement of the crimper31, under the plane of the braided torus3and under the receiving table2, to facilitate supplying said crimper30with a new sleeve preform12, in concurrent time between two crimping operations effected on two successive braided toruses3.

The switching movement M41could be produced by any appropriate driving member, for example by a switching cylinder44, as illustrated inFIGS.2to4. Said switching cylinder44will preferably be distinct from the actuator cylinder24for actuating the closure of the cutter21, respectively the crimper31.

The rod of said switching cylinder44could preferably be articulated by means of a crank pin45on a portion of the switching head41that forms a crank with respect to the pivot axis Y41.

In accordance with a preferred feature that may constitute a disclosure in its own right, the installation1may include a shared actuator mechanism24,25,325, here driven by the same actuator cylinder24, said actuator mechanism being adapted selectively to control, according to whether the installation1is in the cutting configuration C20or to the contrary in the crimping configuration C30, either to actuate the cutting tool20, here the cutter21, to close it or, respectively, to actuate the crimping tool30, here the crimper30, to close it.

A single actuator mechanism could therefore advantageously be used for each of these cutting and then crimping operations.

The switching movement M41of the switching head41will advantageously allow not only appropriate positioning of the tool20,30facing the braided torus3and of the end sections5,6but consequently also selectively to associate said tool20,30with the actuator mechanism.

In this regard, the rotation axis Y25of the cams, common to the cam25for closing the cutter21and to the cam325for closing the crimper31, will preferably coincide with the pivot axis Y41of the switching head.

The position of said rotation axis Y25of the cams will therefore be invariant during the switching movement M41so that the same actuator cylinder24could be used to drive the various cams25,325forming the same subassembly of cams25,325, constrained to rotate together.

The cutting lever27and the crimping lever327and their respective rollers26,326will be arranged on the switching head41in such a manner that they can be presented alternately facing the cams25,325according to the chosen configuration C20, C30.

In the cutting configuration C20the rotary movement of the subassembly of cams25,325driven by the actuator cylinder24will therefore be transmitted to the roller26associated with the cutter21via the cam25to close the cutter but will have no effect on the crimper31because the corresponding cam325turns idly without being able to interfere with the roller326associated with the crimper31.

Conversely, in the crimping configuration C30the rotary movement of the subassembly of cams25,325driven by the actuator cylinder24will be transmitted to the roller326associated with the crimper31via the cam325but will have no effect on the cutter21.

The installation1therefore has optimized and particularly compact kinematics.

The configuration unit40preferably includes a carriage46that carries the receiving table2and is mounted to be mobile in a second movement, termed “engagement/disengagement movement” M46, distinct from the switching movement M41, which alternately allows i/ to bring the braided torus3to the common working location42to enable the interaction between the braided torus3and the cutting tool20in the cutting configuration C20, respectively the interaction between the braided torus3and the crimping tool30in the crimping configuration C30, and ii/ to move the braided torus3away from said common working location42when the switching head41has to effect the switching movement M41.

The receiving table2is therefore advantageously retractable in order to free up the space necessary for the switching movement M41and thus to prevent the receiving table2and the braided torus3from interfering with the switching head41when the latter pivots.

The carriage46and the switching head will to this end follow distinct trajectories, allowing their respective to-and-fro movements M41, M46during phases of reconfiguring the installation1.

One could therefore go easily from one configuration C20to the other configuration30, and vice versa, by a combination of separate and coordinated movements M41, M46that are relatively simple, easy to guide and able to be effected within a compact volume.

The engagement/disengagement movement M46is preferably a movement in translation parallel to the reference plane (X, Y) of the frame100and more preferably parallel to the abscissa axis X.

The carriage therefore and preferably moves transversely to the reference axis Z and therefore transversely to the axis Z3of the braided torus3, which preferably allows the braided torus to move toward the working location42by a centrifugal advance movement M46_F and to move away from it by a centrifugal withdrawal movement M46_R.

Here again, this horizontal translation movement M46would be able to be guided in a precise and reliable manner.

Of course, the configuration unit40could to this end be provided with all the appropriate guiding and driving members controlled by the control system43.

The switching head41is preferably disposed inside the perimeter of the braided torus3.

When the braided torus3is in place on the receiving table2, and the configuration is either the cutting configuration C20or the crimping configuration C30, or in any intermediate transition configuration, the switching head41is therefore and advantageously contained in a cylindrical envelope that is centered on the central axis Z3and delimited radially by the radially internal face of the braided torus3.

This kind of arrangement advantageously favours the compactness of the installation1.

This kind of arrangement further favours access of the cutter21and of the crimper31to the end sections5,6by radially inward, substantially horizontal, approach in the plane of the braided torus3.

This kind of arrangement moreover allows other members of the installation1, notably members for driving the carriage46or members for driving spreader members (as described in detail hereinafter) to be disposed outside the perimeter of the braided torus3. All the space available within the installation1can therefore and advantageously be used.

Moreover, the configuration unit40preferably includes spreader members51,52,53,54adapted to engage the first and second end sections5,6in order to cause said first and second end sections5,6to project relative to the body3A of the braided torus formed by the helicoidal turns7, thereby forming a passage between said end sections5,6and the body3A of the braided torus3, in such a manner as to render said first and second end sections5,6accessible to the cutting tool20, respectively to the crimping tool30.

Causing the end sections5,6to project advantageously allows said end sections5,6to be moved away from the surface of the body3A of the braided torus formed by the superposed helicoidal turns7and more particularly to lift said end sections5,6from the surface of said body3A of the braided torus against which said end sections5,6initially rest, and this sufficiently to allow the cutting tool20and the crimping tool30to distinguish the end sections5,6from the rest of the braided torus3and thus to act exclusively on said end sections5,6.

The bending of the end sections5,6caused by the action of the spreader members51,52,53,54will preferably be strictly elastic in that the stresses generated by this action in the braid wire4will not exceed the yield strength at 0.2% extension, usually denoted “Rp0.2”, of the material constituting the braid wire4, and in such a manner as not to cause permanent deformation of the end sections5,6and thus to allow elastic return of said end sections5,6and of the sleeve14against the body3A of the braided torus after the crimping operation, as can be seen inFIG.5.

It will also be noted that causing the end sections5,6to project simultaneously is advantageously effected in such a manner that the first end section5and the second end section6cross at a crossover point13that is therefore offset at a distance from the body of the braided torus3A because of the elastic flexing of the end sections5,6because of the action of the spreader members.

More preferably, the end sections5,6will preferably be bent by the spreader members51,52,53,54so as to project toward the interior of the torus3, that is to say toward the central axis Z3, so that, in a projection plane normal to the central axis Z3and/or in the reference plane (X, Y), the crossover point13that results from causing them to project will be radially nearer said central axis Z3than the radially internal surface of the body of the braided torus3A formed by the helicoidal turns7is.

This choice notably allows the sleeve14thereafter to be disposed on the radially internal face of the braided torus3, as can be seen in particular inFIG.5, which prevents the sleeve14in operation causing premature wear by abrasion of the reinforcement plies of the pneumatic tire and more particularly of the carcass ply of said pneumatic tire.

In practice, the cutting operation and then the crimping operation must be effected in an angular sector considered in azimuth around the central axis Z3and more globally around the vertical reference axis Z that contains the crossover point13and that is preferably substantially or even exactly centered on the crossover point13.

The working location42common to the cutting tool20and to the crimping tool30, the switching movement M41of the switching head41, and the trajectory of the carriage46allowing the receiving table2to perform its movements of engagement M46_F and of disengagement M46_R, will therefore be defined in such a manner as to position the crossover point13of the end sections5,6inside said working location42and more particularly in such a manner as successively to position the crossover point13inside the cutter21(FIG.11A) and then inside the crimper31(FIG.13A).

The spreader members51,52,53,54preferably include retaining fingers53,54on the carriage46so as to be able to retain the first and second end sections5,6in position projecting relative to the body3A of the braided torus3both in the working configurations C20, C30and during the engagement/disengagement movements M46.

A projecting configuration of the end sections5,6could therefore advantageously be defined that could be substantially preserved and therefore used as a reference both for the cutting operation and for the subsequent crimping operation.

It will be noted that the installation1preferably includes two sets of spreader members.

A first set of spreader members51,52includes paddles51,52, that allow the end sections5,6initially to project relative to the body3A of the braided torus3(FIGS.7A,7B) and said end sections5,6to continue to project while the receiving table2effects an azimuth rotation movement R2about the reference axis Z (or, which is substantially equivalent, about the central axis Z3), in order to orient the braided torus3in azimuth relative to the working location42.

This rotation movement R2in azimuth will more particularly allow a reference to be taken by detecting the passage of one of the projecting end sections5,6by a reference point O60associated with the frame100by means of an appropriate sensor60, such as an optical sensor60the beam of which materializes the reference point O60, as illustrated inFIG.8A.

The paddles51,52will obviously be such that each of them is able to slide between the body of the braided torus3and the end section5,6that is assigned to them in order to capture said end section5,6(FIGS.7A,7B) and to be able to guide the sliding of said end section5,6on said paddles51,52during the rotation R2in azimuth without allowing said end section5,6to escape (FIGS.8A,8B).

The paddles51,52will preferably be on the carriage46and mounted to be mobile in translation relative to the receiving table2parallel to the reference plane (X, Y) and more preferably parallel to the abscissa axis X so as to be able to engage the first and second end sections5,6by centripetal lateral approach.

The retaining fingers53,54will preferably form a second set of spreader members that will be substituted for the paddles51,52in order to hold the end sections5,6in a position projecting relative to the body of the braided torus3by providing for said end sections5,6supports that are closer to the crossover point13than the supports provided by the paddles51,52were and that advantageously remain during and after the cutting operation, as far as the crimping operation.

The retaining fingers53,54will advantageously further occupy a smaller space than the paddles51,52, which will facilitate access of the cutting tool20and then the crimping30to the first and second end sections5,6.

The retaining fingers will preferably be mobile with at least one component of movement parallel to the vertical axis Z and therefore preferably substantially parallel to the central axis Z3of the braided torus3, which will allow said retaining fingers53,54to cross the plane of the torus and to engage the end sections5,6by being inserted, by a movement of axial penetration, into the space between the paddles51,52, between the body3A of the braided torus and the crossover point13, such that said space has been opened up by the paddles51,52as is illustrated inFIGS.9A and9B.

Once each of the retaining fingers53,54has engaged its respective end section5,6, the paddles51,52, which are advantageously retractable, will preferably be withdrawn automatically, here in centrifugal translation relative to the central axis Z3, by a retraction movement parallel to the abscissa axis X.

The retaining fingers will preferably be carried by arms55,56that could preferably be mounted to rotate in yaw about yaw axes parallel to the vertical axis Z so as to be able, after the engagement of the retaining fingers53,54in contact with the end sections5,6, to deploy the retaining fingers53,54through an angular opening in yaw, as illustrated inFIG.10A.

This movement of deployment in yaw moves the retaining fingers53,54away from one another and each is moved away from the crossover point13, whilst remaining in contact with and sliding along their respective end section5,6so as to rise along said end section toward the portion of the wire4that attaches said end section5,6to the braided torus3.

In so doing, the retaining fingers53,54, whilst maintaining, or even accentuating, the bending of said end sections5,6and therefore the projecting nature of the latter, advantageously clear a free space in an angular sector of the torus3that contains the crossover point13, which allows and favours the access of the cutting tool20and then the crimping tool30to the end sections5,6in the vicinity of said crossover point13.

As can be seen inFIG.17, the braided torus3extends axially between a first imaginary plane, termed “first base plane” P1, transverse to the central axis Z3and tangential to a first face of said braided torus3, and a second imaginary plane, termed “second base plane” P2, transverse to the central axis Z3and tangential to a second face of the braided torus3axially opposite the first face relative to the generatrix line L8of the braided torus.

For convenience of geometrical description, the first and second base planes P1, P2could be considered normal to the central axis Z3.

In accordance with a preferred feature that may constitute a disclosure in its own right, applicable to any installation for sleeving a braided torus3, the receiving table2, where applicable the cutting tool20if it is integrated into the installation, and the crimping tool30are arranged in such a manner as to place the sleeve14systematically on the radial internal face of the braided torus3, oriented toward the central axis Z3, in a space that is strictly confined axially between the first base plane P1and the second base plane P2, and radially contained inside the generatrix line L8of the braided torus3, that is to say situated at a radial distance from the central axis Z3less than the radius R8of said generatrix line L8, as can be seen inFIGS.5,17and18.

In this regard, following the braiding operation, on the one hand the end sections5,6initially cross at a crossover point13situated inside the perimeter of the braided torus3, on the same side as the radially internal face of said braided torus, and on the other hand the cutting operation is effected from the interior of the braided torus, in an angular sector of the torus that contains said crossover point13and that is preferably centered on said crossover point so as to shorten the first and second end sections on either side of said crossover point13in order to interrupt each end section5,6before it reaches said crossover point, and then the sleeve14is finally placed in this same angular sector to form a bridge between the first and second end sections substantially at the location where the crossover point13was located.

It will be noted that a feature of this kind relating to the positioning of the sleeve14on the radially internal surface of the braided torus3is applicable to any installation for manufacturing bead wires9including at least one receiving table2and one crimping tool30or more globally applicable to any crimping installation using a crimping tool30enabling a sleeve14to be crimped to join said two end sections5,6of a wire4closed on itself inside a braided torus3in order to provide the cohesion of said braided torus3.

In all cases, by placing the sleeve14exclusively on the radially internal face of the braided torus, without said sleeve overshooting or projecting axially from the flanks of the braided torus or projecting radially outwards on the radially external face of the braided torus, and more particularly projecting radially outwards on the external equatorial line of said braided torus, it is advantageously certain that, once the bead wire9has been integrated into the pneumatic tire, the sleeve14does not injure or damage by abrasion the structural and reinforcement elements of the casing of said pneumatic tire, such as the carcass ply of said tire.

This therefore improves the quality and the robustness of said pneumatic tire.

Of course, placing the sleeve14on the braided torus3by inward radial approach is facilitated by placing the cutting tool20and the crimping tool30inside the perimeter delimited by the braided torus3as indicated hereinabove and more particularly by providing a pivoting switching head41that is situated inside said braided torus3and that moves the cutter and crimper21,31of said tools20,30open and facing the radially internal face of said braided torus3, in a horizontal plane (X, Y) substantially or even exactly normal to the central axis Z3of the braided torus3.

By way of illustration, the length of the sleeve14could be between 15 mm and 50 mm inclusive, preferably between 20 mm and 40 mm inclusive, and for example between 22 mm and 30 mm inclusive.

The crimping tool30comprising, as stated above, a crimper31that is adapted to receive a sleeve preform12that is split over all its length and that has a U-shaped concave curved cross section comprising a rounded bottom12B and two flared lateral branches12C,12D, said crimper31is preferably adapted to form the sleeve14by pressing the bottom12B of the sleeve preform12against the cross section of the first and second end sections5,6placed to project from the body of the braided torus3, preferably by centrifugal radial approach relative to the central axis Z3of the braided torus, and thereafter by bending in plastic deformation, by means of a first lateral jaw33and a second lateral jaw34, the lateral branches12C,12D of said sleeve preform12around said cross section, through the passage created by the spreader members53,54between the body3A of the braided torus3and said first and second end sections5,6, so as to envelop said cross section, as illustrated in dashed line inFIG.16.

It is therefore advantageously possible to attach the end sections5,6without affecting the rest of the braided torus3by incorporating in the sleeve14a single unitary section of the braid wire4without creating an extra thickness of material that would occupy all the circumference of the section of the braided torus3and more globally of the bead wire9, and that could thus be potentially prejudicial to the service life or to the performance of the pneumatic tire.

Moreover, when the installation1is in the cutting configuration C20, the crimper31is preferably in a reloading position, here substantially vertical and with the jaw at the bottom as illustrated inFIGS.2and15, in which reloading position a reloading tool (schematically shown inFIG.20) comes to place a new sleeve preform12in said crimper31.

To this end the lateral jaws33,34are preferably each provided with an anti-return retaining rim37,38and associated with an elastic suspension member36, such as a spring36, in such a manner as to be able to cooperate clipping fashion with the lateral branches12C,12D of said sleeve preform12and thereby to prevent said sleeve preform12falling out of the crimper31on going from the cutting configuration C20to the crimping configuration C30and more particularly during the pivoting movement M41of the switching head41.

The crimper31can therefore advantageously be reloaded in concurrent time and in a small space, in particular if the choice is made to produce the sleeve preform12on demand, on each crimping cycle, by bending a continuous metal strip into a U shape and cutting it to the length of the required sleeve.

In accordance with a preferred feature that may constitute a disclosure in its own right, the receiving table2has relative to the reference plane (X, Y) of the frame100an inclination, termed “compensation inclination”, at a non-zero pitch angle A2the value of which corresponds to the helix angle A7of the helicoidal turns7of the braided torus3, as can be seen inFIG.18, so that said receiving table2offers up the first and second end sections5,6facing the cutting tool20and then facing the crimping tool30in an orientation that is parallel to the reference plane (X, Y) of the frame.

In practice the pitch angle A2corresponds to the angle at which the plane guiding the receiving table2, and containing the generatrix line L8, is inclined relative to the reference plane (X, Y), here horizontal, of the frame100.

The pitch angle A2will preferably have the same absolute value as the helix angle A7and the opposite sign to the latter, so as to compensate the inclination of the braid wire4created relative to the generatrix line L8by said helix angle A7.

Thus it would advantageously be possible to align perfectly, here horizontally, the end sections5,6with the respective slots of the cutter21and the crimper31into which said end sections5,6have to be introduced, which will in particular prevent incorrect insertion of one of the end sections5,6in either the cutting tool20or the crimping tool30or accidental ejection of the sleeve preform12out of the crimper31during said insertion of the end sections5,6.

Thus there will be provided as intended a very precise sequential cutting operation, one end section after the other, followed by homogeneous crimping of the sleeve14. This will therefore improve the quality and the reliability of the production of bead wires9.

Of course, the disclosure also concerns a method employing one and/or the other of the steps described above.

Referring to the figures, said method may in particular comprise the following sequence of steps or a part of that sequence of steps, advantageously controlled automatically by the control system43.

A braided torus3being placed on the receiving table2, the paddles51,52are advanced to cause the end sections5,6to project (FIGS.7A,7B).

The receiving table2then causes the braided sleeve3and its projecting end sections5,6to turn, here in rotation in azimuth in the clockwise direction, by means of a roller/pinch roller motorized assembly10, until the passage of one of said end sections6past the reference point O60defined relative to the frame100by the sensor60is detected (FIG.8A).

Once this referencing has been done, and therefore once the presence and the orientation in azimuth of the braided torus3relative to the frame100are known, the receiving table2adjusts the orientation in azimuth of said braided torus3by a rotation about the vertical axis, which preferably is substantially coincident with the central axis Z3of said braided torus3, within the pitch angle A2. As a result, the receiving table2places the angular sector of the braided torus3containing the crossover point13of the end sections5,6angularly facing the working location42(FIG.8A).

The switching head41is placed so as to present the cutter21facing the working location42, and to be more precise in that working location42.

The retaining fingers53,54are then engaged in contact with the end sections5,6(FIGS.9A,9B), the paddles51,52retracted, and then the retaining fingers deployed (FIGS.10A,10B).

The carriage46then moves the braided torus3toward the working location42and the cutting tool20by a movement in translation transverse to the reference axis Z, in such a manner as to place the two projecting end sections5,6in the cutter21, the crossover point13being located between the two sets of blades22,23(FIGS.2,11A,11B).

The actuator cylinder24then pivots the cams25in order to actuate successively the levers27each associated with a set of blades22,23so as to sequentially section one end section5and then the other one6, thus clearing a void between said end sections5,6where the crossover point13was located before cutting (FIG.11A).

The carriage46then manoeuvres the receiving table2and the braided torus3to retract them, the shortened end sections of which braided torus are still projecting, held by the retaining fingers53,54, in order to extract said end sections5,6from the cutter21and to allow the switching cylinder44to pivot the switching head41, here in the clockwise direction inFIGS.3and4, to move the cutter21away and to substitute the crimper31for the latter at the working location42(FIGS.3,4,12A,12B).

The carriage46then moves the receiving table2and the braided torus3forward again, the shortened projecting end sections5,6of which braided torus are then held by the retaining fingers53,54, until returning to the working location42that it had previously quit, so as to insert the end sections5,6between the jaws of the crimper31, in the hollow space of the sleeve preform12(FIGS.13A,13B).

The actuator cylinder24then pivots the cam325in order to activate the lever327that drives the movement toward one another of the crimping jaws33,34in order to close the sleeve preform12plastically onto the end sections5,6, thus filling in by a bridge the void previously left by the cutting tool20(FIGS.13A,13B,14).

One the sleeve14has been crimped, there may follow a step of checking the presence of said sleeve, for example by means of an optical sensor, while the end sections5,6are still held at a distance from the body3A of the braided torus3by the retaining fingers53,54(FIG.14).

Finally, the retaining fingers53,54are withdrawn so as to free the end sections5,6attached by the sleeve14, which therefore return to being pressed against the radially internal face of the braided torus3by simple elastic return (FIG.5). This produces a finished bead wire9.

The switching head41pivots in the opposite direction (here anticlockwise with reference toFIGS.2to4) so as to come to replace the cutter21at the working location42and simultaneously to allow the loading of a new sleeve preform12into the crimper31.

The control system43associated with the systems driving the various movements will advantageously allow automatic chaining of those various steps and in particular chaining at the same working location42of the cutting operation and then the crimping operation.

Of course, the disclosure is in no way limited to only the variant embodiments described above, the person skilled in the art being in particular in a position freely to isolate or to combine with one another the aforementioned features or to substitute equivalents for them.