WO2020120918A1

WO2020120918A1 - Device and method for laying a reinforcing ply on a tyre-building drum with cutting on-the-fly

Info

Publication number: WO2020120918A1
Application number: PCT/FR2019/053055
Authority: WO
Inventors: Olivier CAREO; Jean-Pierre PAISSEREAU; Manuel VALLEJO CRIADO
Original assignee: Compagnie Generale Des Etablissements Michelin
Priority date: 2018-12-14
Filing date: 2019-12-13
Publication date: 2020-06-18

Abstract

The present invention relates to a tyre building device (1) which comprises a synchronizing unit (30) designed to automatically synchronize a cutting movement (M10) for cutting a continuous strip with a winding movement (M20) for winding the said continuous strip (3) onto a drum (20), so as to drive the cutting tool (10) in movement across the entire width (W3) of the continuous strip (3) so as to detach a reinforcing ply (4) from the continuous strip (3) while the forward front (4F) of the said reinforcing ply (4), formed by the forward front of the continuous strip (3), is engaged on the drum (20) and the continuous strip (3) is being driven with the said reinforcing ply (4) at a non-zero speed in the direction of winding (S20) so as to accompany the on-going winding movement (M20).

Description

DEVICE AND METHOD FOR LAYING REINFORCEMENT SHEET ON A DRUM FOR MANUFACTURING PNEUMATIC BANDAGE WITH CUT-OFF

The present invention relates to the general field of manufacture of tires, in particular pneumatic tires.

It is known to reinforce the pneumatic tires by means of reinforcing plies containing reinforcing threads which are embedded in a layer of rubber and arranged parallel to each other at a predetermined angle, called "ply angle", by relative to the longitudinal direction of the reinforcing ply.

The laying of such plies, which can in particular be superimposed so as to cross the reinforcing threads from one layer to another, is generally carried out on a drum, on which the reinforcing ply concerned is wound. and closing said reinforcement ply on itself by operating a junction of the front and rear ends of said reinforcement ply.

In order to exactly cover the circumference of the drum, and to allow the ends of the reinforcement ply to be butted together without play or overlap, said reinforcement ply must be cut and laid very precisely.

In addition, when the cutting operation is carried out manually, it durably mobilizes the operator, who must remain present in front of the station during the entire laying cycle.

Furthermore, the cutting path must imperatively follow the interstitial space between two successive reinforcing wires, without cutting said wires.

[0007] Thus, when the ply angle is small, the length of the cutting path is large, which requires the operator to adopt a non-ergonomic posture to travel with his tool cutting the entirety of said cutting path.

The objects assigned to the invention therefore aim to remedy the above-mentioned drawbacks and to propose a device for manufacturing a bandage which makes it possible to reduce the cycle time and the manual work load necessary for laying a sheet of reinforcement, while ensuring a precise adjustment of the length of said reinforcement ply. The objects assigned to the invention are achieved by means of a tire manufacturing device, in particular pneumatic tire, said device comprising: a supply system arranged to supply said manufacturing device with a strip called "strip" continuous "routed in a longitudinal direction,

- A cutting tool which is mounted movable in a cutting direction transverse to the longitudinal direction, so as to be able to operate a movement called "cutting movement" which makes it possible to cut said continuous strip across its width and thus to detach from the strip continues a reinforcement ply which extends, in the longitudinal direction, from a front front to a rear front,

- a drum, which is arranged to be able to be driven in rotation in a direction known as “winding direction” which makes it possible to wind the reinforcing ply around the circumference of said drum, in a movement known as “winding movement”,

said manufacturing device being characterized in that it comprises a synchronization unit arranged to automatically synchronize the cutting movement with the winding movement, so as to drive the cutting tool in displacement over the entire width of the continuous strip in order to detach the reinforcement ply from the continuous strip by generating the rear edge of said reinforcement ply, while the front front of said reinforcement ply is engaged on the drum and the continuous strip is entrained with said reinforcement ply at a non-zero speed in the winding direction to accompany the winding movement in progress of said reinforcing ply on the drum.

Advantageously, the device according to the invention makes it possible to automate at least in part the operations of laying the reinforcement ply by automatically carrying out a cut on the fly making it possible to completely detach said reinforcement ply from the continuous strip, then even as said reinforcing ply executes its winding movement on the drum, without the need to interrupt or even reverse the direction of rotation of the drum, and more particularly without the need to stop the running of the continuous strip during the cutting operation. If necessary, the running of the continuous strip will be interrupted only before the cutting operation, just the time necessary for the cutting tool to engage the continuous strip. Commitment cutting tool can be done for example by piercing, at the starting point of the cutting path, the thickness of the continuous strip using a portion of said cutting tool forming a sharp blade.

By simultaneously performing the cut to length and the winding of the reinforcing ply, one can advantageously reduce the corresponding cycle time, and free the operator for other tasks.

In addition, the cutting operation can thus be carried out by means of a space-saving structure, simple to control by the synchronization unit, which makes it possible to obtain a relatively compact work station.

Other objects, characteristics and advantages of the invention will appear in more detail on reading the description which follows, as well as with the aid of the appended drawings, provided purely by way of non-limiting illustration, among which :

Figures IA and IB illustrate, in schematic views respectively from above and from the side, the engagement of the tip of a continuous strip on a drum and the start of the winding operation within a device according to the invention.

Figures 2A and 2B illustrate, in schematic views respectively from above and from the side, the start of the cutting operation, at the moment when the cutting tool enters the continuous strip which is being wound up. on the drum.

Figures 3A and 3B illustrate, in schematic views respectively from above and from the side, the joint pursuit of synchronized cutting and winding operations.

Figures 4A and 4B illustrate, in schematic views respectively from above and from the side, the completion of the cutting operation, when the cutting tool is extracted from the continuous strip by the edge opposite to the edge by which it entered said continuous strip.

Figures 5A and 5B illustrate, in schematic views respectively from above and from the side, the end of the winding operation of the reinforcing ply which has just been detached from the continuous strip by the operation of cutting, and butting the front edges and rear of said reinforcement ply to close the latter on itself around the drum.

6 shows, in a detailed perspective view, an example of a cutting tool blade engaging the edge of the continuous strip in accordance with the step illustrated in Figures 2 A and 2B.

The present invention relates to a device 1 for manufacturing a tire, and more particularly a pneumatic tire.

The present invention is particularly suitable for the manufacture of pneumatic tires which are intended for heavy goods vehicles, typically whose Total Authorized Weight (“GVW”) is greater than 3.5 tonnes, or intended for civil engineering machinery, and which therefore have large dimensions and high masses.

It is however perfectly adaptable to the manufacture of pneumatic tires for passenger vehicles, two-wheelers, etc.

The manufacturing device 1, hereinafter "device" 1, firstly comprises a supply system 2, which is arranged to supply said manufacturing device with a strip called "continuous strip" 3, routed according to a longitudinal direction L3, as can be seen in particular in FIG. 1 A.

Said strip 3 is said to be “continuous” in that it is presented in one piece, in the longitudinal direction L3, over a relatively large length, which is much greater than the unit length of the reinforcement plies 4 that it is desired to take from said continuous strip 3 by cutting said continuous strip 3 into successive sections.

More particularly, it will thus be possible to continuously supply a length of continuous strip 3 greater than several times the unit length of the reinforcement ply 4 desired, for example equal to or greater than 10 times, equal to or greater than 50 times, by example substantially equal to 100 times the unit length of the reinforcement ply 4.

The supply system 2 may for example include an unwinding station capable of accommodating an input coil 7 which initially contains the continuous strip 3, which will be unwound as and when the needs for reinforcing ply 4. As shown in particular in Figure 6, the continuous strip 3 is preferably made of a plurality of reinforcing son 5, preferably metallic, which are arranged parallel to each other and oriented at an angle A5 predetermined non-zero, called "ply angle" A5, relative to the longitudinal direction L3, and which are embedded in a layer of rubber 6, preferably based on unvulcanized rubber.

Preferably, the ply angle A5 will be strictly between 10 degrees and 80 degrees, and more preferably between 15 degrees and 70 degrees, for example between 16 degrees and 65 degrees.

Said reinforcing son 5 may be multi-strand, that is to say each consisting of several filaments assembled by braiding, or preferably single-strand, that is to say each consisting of a single filament in one piece, preferably metallic.

The device 1 also includes a cutting tool 10 which is mounted movable in a cutting direction L10 transverse to the longitudinal direction L3, so as to be able to operate a movement called "cutting movement" M10 which makes it possible to cut the strip continues 3 in the width W3 of said continuous strip, and which thus makes it possible to detach from the continuous strip 3 a reinforcement ply 4 which extends, in the longitudinal direction L3, from a front edge 4F to a rear edge 4R .

The cutting tool 10 may preferably be formed by a blade 12, the cutting edge of which cuts the continuous strip 3, and more particularly the layer of rubber 6, as illustrated in particular in FIG. 6.

As shown in Figure 6, said blade 12 may have a puncture tip 13 which allows the cutting tool 10 to engage the continuous strip 3 by perforating said continuous strip, in the direction of the thickness of said strip, at the starting point of the cutting plot.

Alternatively, the cutting tool 10 could be formed for example by a laser beam, a pressurized water jet which may or may not be charged with abrasive particles, or any other suitable cutting means.

Said cutting tool 10 can be guided in translation along the cutting direction L10, for example by means of a guide rail 11. The device 1 also includes a drum 20, which is arranged to be able to be rotated in a direction called "winding direction" S20 which allows to wind the reinforcing ply 4, and therefore more generally the corresponding portion of the continuous strip 3, on the circumference of said drum 20, in a movement called "winding movement" M20.

The drum 20 advantageously has a form of revolution around its central axis Z20 of rotation. Said drum 20 could for example form a right cylinder with a circular base or, optionally, as a variant, a toric core, the shape of which corresponds substantially to that of the tire to be obtained.

Note that the longitudinal direction L3 of the portion of the continuous strip 3 engaged on the drum 20 is preferably oriented perpendicular to the central axis Z20 of the drum 20, and more particularly is preferably contained in a plane which is normal to the central axis Z20 of the drum, and even more preferably coincides with the equatorial circumference of said drum 20. It is thus possible to easily and precisely wind the reinforcement ply 4 on itself.

According to the invention, the device 1 comprises a synchronization unit 30 which is arranged to automatically synchronize the cutting movement M10 with the winding movement M20, so as to drive the cutting tool 10 moving over any the width W3 of the continuous strip 3 in order to detach the reinforcement ply 4 from the continuous strip 3 by generating the rear edge 4R of said reinforcement ply 4, while the front 4F before of said reinforcement ply is engaged on the drum 20 and the continuous strip 3 is driven, with said reinforcement ply 4, at a non-zero speed in the winding direction S20 to accompany the winding movement M20 in progress of said reinforcement ply 4 on the drum 20 .

For convenience of description, we can assimilate in the figures the cutting movements M10, respectively of winding M20, and the speeds at which these movements are executed M10, M20.

Advantageously, the device 1 therefore makes it possible to carry out on the fly a cut of the continuous strip 3, which has the effect of completely detaching the reinforcement ply 4 from said continuous strip 3, even though said continuous strip 3 continues its winding movement M20, and the reinforcing ply 4 is engaged with the drum 20.

Advantageously, the invention in particular avoids having to stop the advance of the continuous strip 3, and therefore the winding operation on the drum 20, during the cutting operation. In particular, as soon as the cutting tool 10 has started its engagement with the continuous strip 3, the cutting can be carried out entirely and thus detach the reinforcing ply 4 without it being necessary to stop the winding movement M20 , or to stop the cutting movement M10, or even more so to reverse the direction S20 of the winding movement (to start the continuous web 3 back) or the direction of the cutting movement M10 (to turn back with the cutting tool 10).

This advantageously avoids having to interrupt and then resume the cutting action on the same cutting path, intended to generate a single rear edge 4R. This continuity of movement makes it possible not only to reduce the time necessary for the cutting operation, but also to limit the inertial phenomena which would be likely to affect the moving parts, in particular the drum 20 and the cutting tool 10. thus obtains a precise and clean cut, without jerks.

It will be noted that, in a manner known per se, the reinforcing ply 4, and more generally the continuous strip 3, may come into engagement on the circumferential surface of the drum 20 by simple adhesion, due to the natural ability ( called "sticky") of the rubber 6 to adhere to said surface of the drum 20.

It will also be noted that, preferably, the winding movement M20 corresponds here, especially when the continuous strip 3 is present at the cutting tool 10, to a translational movement of the continuous strip 3 according to the longitudinal direction L3.

It will also be noted that, as long as the cutting tool 10 has not completed its cutting operation, that is to say as long as the reinforcing ply 4 is not completely detached from the rest of the continuous strip 3 from which said reinforcement ply 4 comes, the continuous strip 3 is driven integrally with the reinforcement ply 4, according to the same winding movement M20, at the same speed (not zero) as said reinforcement ply 4 . Advantageously, the invention makes it possible to execute, simultaneously with the winding movement M20, a cutting movement M10 in a cutting direction L10 which intersects the longitudinal direction L3 in which the continuous strip 3 runs past the location of the cutting tool 10, so that the resulting line produced by the cutting tool 10 on the continuous strip 3, and which therefore corresponds to the line of the rear edge 4R of the reinforcement ply 4 being separated from the continuous strip 3 corresponds, vectorially, to the combination of these two movement components M10, M20, namely the winding movement component M20 and the cutting movement component M10.

In order to cut the continuous strip across its width W3, the cutting movement M10 is executed from the leading edge, here the left edge 3 A in the figures, of the continuous strip 3, at which the cutting tool 10 engages said continuous strip 3, as illustrated in FIG. 2A, up to the trailing edge, here the right edge 3B in the figures, of said continuous strip 3, by which said cutting tool 10 is extracted from said continuous strip 3 once the rear edge 4R has been created, as illustrated in FIG. 4A.

The cutting tool 10 may for example engage the continuous strip 3 by lateral approach, so as to transversely penetrate said continuous strip 3, from the outside of said continuous strip 3, by one of the side edges of said continuous strip, forming the leading edge 3 A, in a transverse engagement movement which is oriented in the width direction W3 of the continuous strip 3, and more preferably which coincides with the cutting direction L10 of the cutting movement M10.

Advantageously, the execution of such a transverse engagement movement can be carried out without interrupting the winding movement M20.

The cutting movement M10 can then also advantageously correspond to the simple pursuit of said engagement movement.

According to another possibility of implementation, the cutting tool 10 can engage the continuous strip 3 by initially perforating said continuous strip 3 at the edge of attack 3A according to a so-called "plunging" engagement movement. M13 which is oriented in the thickness direction of the continuous strip 3, preferably in a direction normal to the surface of the continuous strip 3, as illustrated in FIG. 6. To this end, the cutting tool 10 will include a puncture tip 13 which is initially driven into the continuous strip 3, near the edge 3 A. The said puncture tip 13 goes in widening and has a sufficiently wide base, having regard to the amplitude of the plunging engagement movement M13 and the proximity of the point of penetration with respect to the leading edge 3 A, to section said leading edge 3A during the execution of said plunging engagement movement M13. In this way, it will then suffice to carry out the transverse cutting movement M10 to the trailing edge 3B to completely detach the reinforcement ply 4 from the continuous strip.

It will be noted that, to simplify the structure of the cutting tool 10 and guarantee the precision of the cutting operation, it will be preferable to temporarily stop the winding movement M20 the time necessary for the execution of the movement of plunging engagement Ml 3. We will then resume said winding movement M20 when the cutting movement M10 begins, after perforation of the continuous strip 3, which is synchronized with said winding movement M20, and which is oriented in a secant direction to the direction of the plunging engagement movement M13.

Whatever the way in which the cutting tool 10 engages the continuous strip 3 at the leading edge 3 A, the cutting movement M10 is preferably continuous, that is to say without interruption , and monotonous, that is to say without reversing the direction of said cutting movement M10, from the leading edge 3A to the trailing edge 3B.

It is advantageously the same for the winding movement M20, which, during the cutting movement M10, continues continuously and monotonously, without interruption, that is to say without being stopped the rotation of the drum 20, nor inversion, that is to say without modifying the direction of rotation S20 of the drum 20.

We can thus achieve a regular cut, in a direction well controlled by the synchronization unit 30.

The synchronization unit 30 will preferably be an electronic unit, preferably programmable.

Preferably, said synchronization unit 30 will make it possible to adjust, as a function of the continuous strip 3 to be treated and therefore of the orientation of the desired cutting course, a synchronization ratio K30 between the speed of the winding movement M20 and the speed of the cutting movement M10:

M10 = K30 * M20

Preferably, the drum 20 will be driven in rotation by a drum motor, preferably an electric motor, placed under the dependence of the synchronization unit 30 and making it possible to generate the winding movement M20.

According to one possible embodiment, the cutting movement M10 could be generated, indirectly, by the drum motor, using for example a disengageable transmission mechanism which connects the drum motor to the cutting tool 10, and which can be alternately engaged and disengaged by the synchronization unit 30. The transmission ratio of said transmission mechanism, when the latter is engaged, would then correspond to the abovementioned synchronization ratio K30.

However, preferably, the cutting tool 10 will have, to generate the cutting movement M10, its own drive motor, called "cutting motor", separate from the drum motor. Here again, it will preferably be an electric motor, which will simplify the control by the synchronization unit 30, here an electronic synchronization unit 30, as well as the adjustment of the synchronization ratio K30.

Preferably, the cutting tool 10 is guided in rectilinear translation in a cutting direction L10 which is perpendicular to the longitudinal direction L3 of the continuous strip 3.

Such an orthogonal arrangement of the cutting direction L10 with respect to the longitudinal winding direction L3, and therefore the orthogonal arrangement of the components of cutting movement M10 and winding M20, which here each correspond to a component of displacement in rectilinear translation, makes it possible to enslave in a simple manner the cutting movement M10 with respect to the winding movement M20, since the resulting direction of the cutting line with respect to the continuous strip 3 is oriented, at an oblique angle to the longitudinal direction L3, at an angle whose tangent is then equal to the value of the synchronization ratio K30. In addition, such an orthogonal arrangement is invariant by plane symmetry along a sagittal plane perpendicular to the continuous strip 3 and containing the longitudinal direction L3, sagittal plane which is here normal to the axis of rotation Z20 of the drum 20.

Therefore, one can, in absolute terms, choose to cut the continuous strip 3 from its left edge 3 A to its right edge 3B, or vice versa, from its right edge 3B to its left edge 3A , which in particular makes it possible to adapt the device 1 to the orientation of the reinforcing wires 5, whether said reinforcing wires 5 are oriented to the left relative to the longitudinal direction L3 or, on the contrary, to the right. The device 1 is therefore particularly versatile.

Of course, if the cutting tool 10 is formed by a blade 12, the edge of said blade 12 will be oriented accordingly.

In particular said blade 12 may advantageously be double-edged, so that it can operate indifferently in both directions.

Similarly, the perforation tip 13 of said blade 12 may have a double edge, so as to be able to perforate the continuous strip 3 indifferently near the left edge 3 A or the right edge 3B, before the blade 12 does not continue its cutting movement M10 towards, and (at least) up to, the opposite edge 3B, 3A.

Note also that the cutting tool 10 is preferably arranged just upstream of the drum 20, between the input coil 7 which unwinds the continuous strip 3 and the drum 20 on which the reinforcing ply 4 is used , so that the reinforcement ply 4 is effectively used as soon as it is detached from the continuous strip 3.

This avoids altering the properties of said reinforcing ply 4, in particular the adhesive properties ("sticky") of the eraser 6.

The device 1 thus contributes to reducing material losses in order to avoid any waste.

The device 1 is also advantageously arranged so as to allow the junction of the front front 4L with the rear front 4R.

The reinforcing ply 4 can thus be closed in a ring on itself, for example to form a crown ply constituting a part of the frame of a pneumatic tire, and more particularly a pneumatic tire with radial carcass.

Preferably, the length of the reinforcement ply 4 between the front front 4F and the rear front 4R therefore corresponds to the circumference of the drum 20, so as to allow said front and rear fronts 4F, 4R to operate junction by abutment on themselves at the end of the winding movement M20 of the reinforcing ply 4 on the drum 20, as illustrated in FIGS. 5A and 5B.

Advantageously, by choosing a length of reinforcement ply 4 equal to the developed of the perimeter of the drum 20, taking account where appropriate of the thickness of said reinforcement ply 4, it is avoided to create at the junction between the front 4F and rear 4R fronts of the reinforcement ply 4 an additional thickness which would be linked to an overlap of said fronts 4F, 4R, and more particularly to an overlap of the reinforcement wires 5 located in the immediate vicinity of said fronts 4F, 4R, or on the contrary to allow a vacuum to remain at said junction between said fronts 4F, 4R.

Preferably, as already mentioned above, the continuous strip 3, and therefore the reinforcement ply 4 which results therefrom, is reinforced by a network of reinforcing threads 5 which are arranged parallel to each other and oriented at a non-zero predetermined angle A5, and preferably strictly between 15 degrees and 70 degrees, called the "ply angle" A5, relative to the longitudinal direction L3.

Preferably, the cutting tool 10 can then be controlled so as to engage in an intermediate space 8 comprised between two successive reinforcing wires 5, as can be seen in FIGS. 3A and 6.

In such a case, the synchronization unit 30 preferably defines a synchronization ratio K30, between the cutting movement M10 and the winding movement M20, which corresponds to the ply angle A5, so that the rear edge 4R of the reinforcing ply generated by the cutting tool 10 extends parallel to the reinforcing wires 5 which delimit the intermediate space 8.

Preferably, we will thus have:

K30 = M10 / M20 = tan (A5) The choice of a synchronization ratio K30 defined by the value of the ply angle A5 advantageously makes it possible to ensure that the relative movement of the cutting tool 10 relative to the continuous strip 3 takes place well oblique in a direction parallel to that of the reinforcing wires 5.

Preferably, the device 1, and more particularly the feed system 2, comprises a conveyor 40 which is arranged to support a portion of the continuous strip 3 called "tip" 41, 42 which forms an acute angle between on the one hand the front front 4F of the continuous strip 3, intended to form the front front 4F of the reinforcing ply 4 to be wound, and on the other hand the edge 3 A of said continuous strip 3 by which the action begins of the cutting tool 10.

Note that, for convenience of description, we can assimilate the front edge of the continuous strip 3 with the front edge 4F of the reinforcement ply 4 and thus in particular use the same reference 4F to designate these elements in the figures .

In order to ensure its grip on the continuous strip 3, the conveyor 40 may be provided with any suitable gripper, for example a vacuum gripper, or even, preferably, a magnetic gripper with magnet or with electro magnet.

The shape, size and orientation of the gripper may be subject to variations without departing from the scope of the invention.

For example, the gripper of the carrier 40 may include, as illustrated schematically in Figures IA, 4 A and 5 A, a bar, preferably a magnetic bar, having a flat sole which comes in bearing against the point 41, 42 of the continuous strip 3. Said sole may possibly be oriented substantially along the angle of the ply A5, and therefore substantially parallel to the edges 4F, 4R of the reinforcing ply 4.

Preferably, the synchronization unit 30 is arranged to control the conveyor 40 so that said conveyor 40 first supports and accompanies a first tip 41 of the continuous strip 3, which corresponds to the front edge 4F d a first reinforcement ply 4, up to the drum 20, and places said first tip 41 in engagement with said drum 20. Thus, a first function of the conveyor 40 is therefore, before the cutting operation, to bring the point 41 of the continuous strip 3 to the drum 20, and to anchor said continuous strip 3 on said drum 20 by the tip 41, in order to engage said continuous strip 3 by its front edge 4F on the drum 20, for the winding operation.

Note that the transfer of the tip 41 of the continuous strip 3 of the conveyor 40 to the drum 20 can be carried out by simple contact pressure, using the natural adhesion (or "sticky") of the rubber 6 on the drum 20.

The synchronization unit 30 is also arranged to control the conveyor 40 in such a way that, after having placed and anchored the first tip 41 on the drum 20, said conveyor 40 then ensures, during the winding operation of the first reinforcement ply 4 and during the cutting operation making it possible to detach said first reinforcement ply 4 from the continuous strip 3, and as illustrated in FIGS. 2 A, 3 A and 4A, support and support of said continuous strip 3 coming into engagement on said continuous strip 3 at the location of a future second tip 42, which corresponds to the tip of a second reinforcing ply which comes after the first reinforcing ply 4 , and by accompanying the displacement of the continuous strip 3 induced by the winding movement M20 during the first reinforcement ply 4, and this in order to stabilize said continuous strip 3 at the level of the second tip 42 during the operation of cut that allows dice stain the first reinforcement ply 4 of said continuous strip 3.

Advantageously, the carrier 40, and more particularly the sole thereof, can thus play the role of anvil which supports the continuous strip 3 against the forces exerted on said continuous strip 3 by the tool. cutting 10, and in particular which supports the continuous strip 3 during the penetration of the perforation tip 13 of the blade 12 at the start of the cutting sequence of the rear edge 4R.

In any event, the transporter 40 is therefore preferably designed to go back and forth by first progressing forward, to deposit a first tip 41 on the drum 20, corresponding to the front edge of the continuous strip 3 (FIGS. 1A and 1B), then release said first tip 41, then go back along the continuous strip 3 to grip said continuous strip 3 at a second future tip 42 corresponding to a sheet next reinforcement (Figure 2A, 2B), in order to then start again towards the front, in the winding direction S20, and following the winding movement M20, to accompany said continuous strip 3 up to the location of the cutting tool 10 (FIGS. 2A, 2B), support the continuous strip 3 during the entire cutting operation on the fly (FIGS. 3A, 3B, 4A, 4B), then, subsequently, convey the new second tip 42 after cutting to the drum 20 during the next laying cycle, etc.

Of course, the synchronization unit 30 will allow the movements of the conveyor 40 to be synchronized with the winding movement M20, and therefore with the cutting movement M10.

It will be noted that, preferably, the conveyor 40 can be controlled by the synchronization unit 30 in such a way that, after the cutting operation, said conveyor 40 operates the continuous strip 3, and more particularly the second tip 42, towards the rear, that is to say operates a movement away from the drum 20, in the direction opposite to the winding direction S20, so as to separate the continuous strip 3 from the drum 20 and thus clear access to said drum 20 for the end of the winding operation of the reinforcement ply 4 during installation, as illustrated in FIGS. 5A and 5B.

This clearance facilitates the subsequent installation on the same drum 20 of other constituent elements of the bandage which are superimposed on the reinforcement ply 4 thus wound, and / or any intervention by the operator, or even removing the bandage from the drum 20 after the assembly of said bandage, or the assembly of the sub-assembly of said bandage which it is desired to make on the drum 20, is completed.

Furthermore, the conveyor 40 can optionally be used to exert on the continuous strip 3, against the winding movement M20, a tensile retention force which makes it possible to adjust the longitudinal tension of the ply of reinforcement 4 during the winding operation. In this way, it facilitates or even automates the adaptation of the length of said reinforcement ply 4 to the circumference of the drum 20, in order to obtain a perfect joining of the edges 4F, 4R of said reinforcement ply 4.

Furthermore, provision may be made, as illustrated in Figures IB, 2B, 3B, 4B, a pressure roller 43, which is elastically prestressed against the drum 20, for example by means of a return spring , and mounted counter-rotating with respect to said drum 20, in order to guide the reinforcement ply 4 and to apply said regularly and efficiently reinforcement ply 4, thus sandwiched between the drum 20 and the pressure roller 43, against the surface of said drum 20.

Preferably, the device 1 comprises an optical detector (not shown) which allows the synchronization unit 30 to define, with respect to a reference point which is associated with the continuous strip 3, which is in progress winding on the drum 20, an attack position at which the cutting tool 10 engages the continuous strip 3 to generate the rear edge 4R of said reinforcing ply 4.

For example, the benchmark may be materialized by a paint mark made on the continuous strip 3.

In such a case, the optical detector, such as a camera or a photosensitive cell, will be able to distinguish by contrast the color of the paint mark from the background formed by the material constituting the continuous strip 3, typically the eraser. 6.

Said optical detector can then be placed above or below the continuous strip 3, upstream and at a known distance from the location of the cutting tool 10 along the longitudinal direction L3, typically between the input coil 7 and said cutting device 10.

The paint mark may, for example, form a line which spatially coincides with the interstitial space 8 between two successive reinforcing wires 5, at the location of the continuous strip 3 where it is desired to make the cut.

According to another example of possible implementation, the reference point may correspond to the front edge 4L of the reinforcement ply 4, when said front edge 4L passes through a predetermined position, such as a given azimuthal position around the axis of rotation Z20 of the drum 20.

In such a case, the optical detector may for example form a jump sensor, capable of detecting the change in the rate of reflection of a light beam, such as a laser beam, pointed at the surface of the drum 20 at the azimuthal position chosen, when the front edge of the 4L sheet crosses, due to the winding rotation, the azimuthal position of said light beam, and the reflecting surface passes from the bare surface from the drum 20, not covered by the reinforcement ply 4, to a surface covered by said reinforcement ply 4.

Alternatively, the optical detector may create, between a transmitter and a receiver or between a transmitter and a reflector which cooperates with said transmitter, a light beam which crosses the path of the continuous strip 3 upstream of the drum 20, here between the input coil 7 and the drum 20, so that when said continuous strip 3 is conveyed to the drum 20 by the conveyor 40, the point 41 corresponding to the front edge 4F of said continuous strip 3 comes to cut said beam, which allows the detection of said front edge 4F.

It will be noted that a reference point based on the detection of the front edge 4F of the continuous strip 3 is advantageously more precise and less sensitive to possible pollution than a reference point based on a paint mark.

However, regardless of the nature of the benchmark used, the optical sensor can of course be positioned and calibrated according to the configuration of the device 1 and / or the characteristics of the continuous strip 3 to be treated (width W3 , tablecloth angle A5, etc.)

Of course, the invention also relates as such to a process incorporating all or part of the characteristics described above.

In particular, the invention relates to a method of manufacturing a tire, in particular a pneumatic tire, during which a continuous strip 3 is conveyed in a longitudinal direction F3, a front edge 4F of said continuous strip is engaged on a drum 20 and said drum is rotated in a direction called "winding direction" S20 so as to wind said continuous strip 3 around the circumference of said drum, in a movement called "winding movement" M20, and during from which one cuts off said continuous strip 3 by means of a cutting tool 10 which is displaced over the entire width W3 of said continuous strip, according to a cutting movement M10 which is oriented transversely to the longitudinal direction F3 and which makes it possible to detach from the continuous strip 3 a reinforcing ply 4 which extends, in the longitudinal direction F3, from the front front 4F of the continuous strip to a rear front 4R generated by the cutting movement. According to this method, the cutting movement M10 is automatically synchronized with the winding movement M20 so as to be able to detach on the fly the reinforcement ply 4 from the rest of the continuous strip 3, while said reinforcement ply 4 is engaged on the drum 20 and driven, with the continuous strip 3, by a non-zero speed of movement in the winding direction S20.

As indicated above, in accordance with the synchronization implemented, the cutting tool 10 describes the continuous strip 3 right through, from one edge 3A to the other edge 3B, in one and same direction along the cutting direction L10, while the drum 20, and therefore the continuous strip 3 engaged on said drum 20, are driven by a continuous winding movement M20, of non-zero speed and constant direction.

Said method may also include one, the other, or any combination, and in particular all, of the successive steps illustrated by FIGS. IA, IB to 5 A, 5B, and detailed above.

In particular, after placing the tip 41 of the continuous strip 3 on the drum 20 and starting the winding of said continuous strip 3 on said drum 20, it will be possible to temporarily interrupt the winding movement M20, and therefore stop the continuous strip 3, the time to perforate said continuous strip 3 by means of the perforating tip 13 of the cutting tool 10, then jointly resume the winding movement M20 and the cutting movement M10 to detach the sheet of reinforcement 4 of the rest of the continuous strip 3 by generating the rear edge 4R.

Particularly preferably, the cutting operation is carried out on a continuous strip 3 containing reinforcing threads 5, and by choosing a synchronization ratio K30 such that it prevents cutting of said reinforcing threads 5, and more particularly a sectioning of any one of said reinforcing wires 5, so as not to degrade the performance of said continuous strip 3.

After the cutting operation, the tail 44 of the reinforcement ply 4, carrying the rear edge 4R, is in turn placed and wound on the drum 20 following the tip 41.

In doing so, the method thus comprises, following the cutting step which makes it possible to detach the reinforcement ply 4 from the rest of the continuous strip 3, a step of joining the during which the rear front 4R is joined with the front front 4F so as to close on itself the reinforcement ply 4 placed on the drum 20, as can be seen in FIG. 5B.

The reinforcing ply 4 will thus form an annular structure whose diameter is defined by the drum 20.

Of course, the invention is in no way limited to the variant embodiments described in the foregoing, the person skilled in the art being in particular able to isolate or freely combine one or the other. of the above characteristics, or substitute an equivalent.

Claims

1. Device (1) for manufacturing tires, in particular pneumatic tires, said device (1) comprising:

a supply system (2) arranged to supply said manufacturing device with a strip (3), called "continuous strip" (3), conveyed in a longitudinal direction (L3),

- a cutting tool (10) which is mounted movable in a cutting direction (L10) transverse to the longitudinal direction (L3), so as to be able to operate a movement called "cutting movement" (M10) which makes it possible to cut said continuous strip (3) across its width (W3) and thus detach from the continuous strip (3) a reinforcing ply (4) which extends, in the longitudinal direction (L3), from a front edge (4F) up '' at a rear edge (4R),

- a drum (20), which is arranged to be able to be driven in rotation in a direction called "winding direction" (S20) which makes it possible to wind the reinforcement ply (4) around the circumference of said drum, according to a movement called "winding movement" (M20),

said manufacturing device being characterized in that it comprises a synchronization unit (30) arranged to automatically synchronize the cutting movement (M10) with the winding movement (M20), so as to drive the cutting tool ( 10) moving over the entire width (W3) of the continuous strip (3) in order to detach the reinforcement ply (4) from the continuous strip (3) by generating the rear edge (4R) of said reinforcement ply, while that the front edge (4F) of said reinforcement ply (4) is engaged on the drum (20) and that the continuous strip (3) is driven with said reinforcement ply (4) at a non-zero speed in the direction winding (S20) to accompany the winding movement (M20) in progress of said reinforcing ply (4) on the drum (20).

2. Device according to claim 1 characterized in that it is configured so that the length of the reinforcing ply (4) between the front front (4F) and the rear front (4R) corresponds to the circumference of the drum (20), so as to allow said front and rear edges (4F, 4R) to operate a butt-joint on themselves at the end of the winding movement (M20) of the reinforcement ply (4) on the drum (20).

3. Device according to claim 1 or 2 characterized in that the continuous strip (3), and therefore the reinforcing ply (4) which results therefrom, is reinforced by a network of reinforcing threads (5) which are arranged parallel to each other and oriented at a predetermined non-zero angle (A5), preferably strictly between 15 degrees and 70 degrees, called the "tablecloth angle" (A5), relative to the longitudinal direction (L3), in that the 'cutting tool (10) is controlled so as to engage in an intermediate space (8) between two successive reinforcing wires (5), and in that the synchronization unit (30) defines a synchronization ratio (K30) between the cutting movement (M10) and the winding movement (M20) which corresponds to said ply angle (A5), so that the rear edge (4R) of the reinforcing ply generated by the cutting tool cut (10) extends parallel to the reinforcing son (5) which delimit said intermediate space (8).

4. Device according to any one of the preceding claims, characterized in that the cutting tool (10) is guided in rectilinear translation in a cutting direction (L10) which is perpendicular to the longitudinal direction (L3) of the continuous strip (3).

5. Device according to any one of the preceding claims, characterized in that it comprises a conveyor (40) arranged to support a portion of the continuous strip (3) called the "tip" (41, 42) which forms an acute angle understood between on the one hand the front edge (4F) of the continuous strip (3), intended to form the front edge (4F) of the reinforcement ply to be wound, and on the other hand the edge (3A) of said continuous strip (3) by which the action of the cutting tool (10) begins, and in that the synchronization unit (30) is arranged to drive said conveyor (40) in such a way that said conveyor (40) supports and first accompanies a first point (41) of the continuous strip (3), which corresponds to the front edge (4F) of a first reinforcement ply (4), up to the drum (20), and places said first point (41) engaged on said drum (20), then that said conveyor (40) then ensures, during the winding operation of said first reinforcement ply (4 ) and during the cutting operation making it possible to detach said first reinforcement ply (4) from said continuous strip (3), a support and an accompaniment of said continuous strip (3) by engaging on said continuous strip (3) at the location of a future second point (42), which corresponds to the point d '' a second reinforcement ply which comes after the first reinforcement ply (4), and accompanying the displacement of the continuous strip (3) induced by the winding movement (M20) during the first ply of reinforcement (4), in order to stabilize said continuous strip (3) at the second point (42) during the cutting operation which makes it possible to detach the first reinforcement ply (4) from said continuous strip (3) .

6. Device according to any one of the preceding claims, characterized in that it comprises an optical detector allowing the synchronization unit (30) to define, with respect to a reference point associated with the continuous strip (3) which is being wound on the drum (20), such as for example a reference point materialized by a paint mark made on the continuous strip (3) or even a reference point corresponding to the front edge (4F) of the reinforcing ply when said front edge (4F) passes through a predetermined position, such as a given azimuthal position around the axis of rotation (Z20) of the drum, an attack position at which the tool cut (10) engages the continuous strip (3) to generate the rear edge (4R) of said reinforcement ply.

7. A method of manufacturing a tire, in particular a pneumatic tire, during which a continuous strip (3) is conveyed in a longitudinal direction (L3), a front edge (4F) of said continuous strip is engaged on a drum (20) and driving said drum in rotation in a direction called "winding direction" (S20) so as to wind said continuous strip (3) on the circumference of said drum (20), in a movement called "winding movement »(M20), and during which said continuous strip is cut (3) by means of a cutting tool (10) which is displaced over the entire width (W3) of said continuous strip, according to a cutting movement (M10 ) which is oriented transversely to the longitudinal direction (L3) and which makes it possible to detach from the continuous strip a reinforcing ply (4) which extends, in the longitudinal direction, from the front edge (4F) of the continuous strip up to '' to a rear edge (4R) generated by the movement cutting (M10), said method being characterized in that the cutting movement (M10) is automatically synchronized with the winding movement (M20) so as to be able to detach on the fly the reinforcement ply (4) from the rest of the continuous strip (3), while said reinforcing ply (4) is engaged on the drum (20) and animated, with the continuous strip (3), of a non-zero speed of movement in the direction d winding (S20).