EP1802407B1 - Method and device for winding up a strip - Google Patents

Description

The subject of the invention is a coil winding method and installation of a strip and applies in particular to the winding of a steel strip after hot rolling according to the preambles of claims 1 and 14, described, for example, in the document US-A-3,587,274 .

At the exit of a hot strip train, the steel strip is generally transported on a roller table, to one or more winders located at a distance downstream of the roller table, generally below the roller table. this.

Upstream of the winder, the band is driven by a clamping device followed by guide means which direct the band towards a rotating mandrel on which the band, driven by friction, winds in superimposed turns.

For the winding of a new band, the head thereof is applied to the outer face of the rotating mandrel to be dragged downstream, and then guided by a curved bending plate so as to bending while remaining applied on the mandrel, along a gradually increasing angular sector, which increases the frictional drag effect. After a turn, the head of the band passes below the inner face thereof to form a second turn and so on. To maintain the tension required for winding, the strip is retained upstream by a device usually comprising a baffle roller and a nip roll rotated at a slightly lower angular velocity than the mandrel, the band being able to be stretched along a tangent winding theoretical plane, upstream to the deflector roll, along a generatrix thereof and downstream to the coil during winding. Usually, the mandrel is retractable to decrease in diameter to allow removal of the spool when the spool has reached the desired diameter.

The document US Patent 2,918,226 for example, describes a winding installation of this type comprising, downstream of a baffle roll placed at the exit of a roller table, a rotary mandrel arranged inside a pit and associated with two sets winding each having a roll of application of the band on the face external cylindrical mandrel and a curved bending plate for guiding the band during winding. In the layout of the document US Patent 2,918,226 , the assembly is placed on a support frame pivotally mounted about an axis parallel to that of the mandrel and actuated by a jack, so as to move between a remote position and a service position for which the bending plate is substantially parallel to the outer face of the mandrel. On the other hand, the application roller is itself mounted on an auxiliary frame hinged to the support frame of the bending plate and pushed towards the mandrel by a spring so as to exert an elastic force of application of the strip on the mandrel, in a thrust direction passing through a generatrix bearing the outer face of the mandrel and the axis thereof.

In addition, the application roller can be rotated about its axis in opposite directions of the mandrel, in order to apply, on the outer face of the strip, an additional force of friction drive which is added to the main driving force applied by the mandrel on the inner face of the band.

At the beginning of the winding, the head of the strip comes to bear on the bending plate placed downstream of the application roll and is guided in the annular space between the bending plate and the outer face of the mandrel to 'wrap on it. After a rotation of one turn, the head of the band can pass below it so as to form a second turn, the application roller, driven by a spring, being able to deviate slightly.

In a more advanced embodiment described in the document US Patent 3,587,274 , an additional roll is mounted, upstream of the application roller and the mandrel, on a frame hinged about an axis, to exert a pre-bending torque on the band.

Until now, such devices were satisfactory because they were used for winding steel strips of fairly thin thickness, for example between 2 and 12 mm.

For such thicknesses, in fact, the strip bends easily and can be guided in the annular space formed between the mandrel and the bending plate, to apply on the cylindrical face of the mandrel to be driven by friction.

However, it is now envisaged to use devices of this type for winding hot strips having thicknesses of greater and greater, which can be, for example, up to 25 mm. In addition, it may be necessary to wind products of high elastic limit, for example of the order of 370 MPa at the temperature of use.

However, it has appeared that, for fairly large thicknesses, the usual arrangement of the type represented on the figure 1 would not allow sufficient bending of the band, especially at the beginning of its winding.

At this moment, in fact, the band is applied only on a small angular sector of the mandrel, and the main driving force exerted by the mandrel on the inner face of the band depends essentially on the pressure exerted by the roller. applying the strip to the mandrel.

However, in the previous provisions disclosed by the documents cited above, this thrust force, exerted by a spring system or an elastic stop, would be insufficient to allow the winding of a relatively thick and rigid hot strip.

The object of the invention is to solve such problems by means of a new arrangement making it possible in particular to considerably increase the downstream drive energy transmitted to the strip by friction and, thus, the bending energy , which makes it possible to wind plates of relatively thick thickness which can go, for example, up to 25 mm.

The subject of the invention is therefore generally a coil winding installation of a strip product traveling in a longitudinal direction, comprising a winding mandrel driven in rotation about an axis orthogonal to the direction of travel and having a cylindrical outer face, means for guiding the strip, along a tangential running plane, upstream to a deflector roll and, downstream, to the mandrel, means for applying the strip , on an inner face, on the outer face of the mandrel along a bearing generatrix and a bending plate having a curved web-guiding face along the outer face of the mandrel, said applying means having an application roller rotating about an axis parallel to that of the mandrel, and a means for urging said roll towards the mandrel in a thrust plane passing substantially through the axes of the mandrel and the application roller, the latter being rotated about its axis in the opposite direction of the mandrel and at a corresponding tangential speed, for the application of a force driving downstream on each of the two faces, respectively internal and external of the strip.

In accordance with the invention, the application roller is rotatably mounted on a mobile support frame on which at least one hydraulic cylinder bearing is supported in an opposite direction on a fixed part so as to exert an adjustable clamping force of the strip between the mandrel and the application roller, and an additional roller is rotatably mounted on said movable support frame of the application roll, upstream of the latter in the winding direction, and is rotated around its axis in opposite direction and at a tangential speed corresponding to that of the mandrel, said additional roller being slightly spaced from the plane of travel between the baffle roller and the mandrel, a distance corresponding to a predictable bending effect of the strip upstream of the application roller, given its rigidity.

Preferably, the plane of travel between the deflector roll and the mandrel is tangential to the latter along a generator placed a little upstream of the thrust plane of the application roller towards the mandrel.

According to another particularly advantageous feature of the invention, the diameter and the position of the axis of the additional roller on the frame are determined so that, taking into account the bending of the strip between the baffle roller and the mandrel, the strip comes to bear on its external face on said additional roll.

In a preferred embodiment, the additional roll is placed as close as possible upstream of the application roll and its diameter is between 0.5 and one time the diameter of the application roll.

The invention also covers a method of winding a roll of a web product according to claim 14.

In particular, the diameter and the position on the frame of the additional roll are determined so that, taking into account the bending of the band between the baffle roll and the mandrel, the outer face of the band comes into contact with the additional roll for spacing. the outer face of the application roller with respect to the outer face of the strip at the thrust plane, greater than a quarter of the thickness of the strip.

To maintain the band applied on the outer face of the mandrel, after passing through a first winding assembly successively comprising an additional roller, an application roller and a bending plate, the installation comprises at least a second winding assembly. having a second application roll bearing on the outer face of the strip immediately downstream of the exit end of the first bending plate and a second cylindrical bending plate having an inlet end immediately downstream of the second Application roller and an exit end.

In a preferred embodiment, the installation comprises three winding assemblies arranged successively around the mandrel in the winding direction, respectively a first assembly covering an angular sector of the mandrel of about one quadrant between a first application roll. and the exit end of a first bending plate, a second assembly covering a sector of about one quadrant between a second application roll and the exit end of a second bending plate, and a third set covering an angular sector of at least one quadrant between a third application roll and a third bending plate extending to an exit end positioned as close as possible to the inner face of the band, upstream of the first Application roller.

However, according to another particularly advantageous arrangement, the installation comprises four successive winding sets, respectively, three sets each covering an angular sector of at most one quadrant between an application roll and the exit end of a bending plate, and a fourth assembly having at least a fourth application roll disposed immediately downstream of the exit end of the third bending plate.

• La figure 1 est une vue d'ensemble d'un dispositif d'enroulement selon l'invention, à la sortie d'une table à rouleaux.
• La figure 2 est un schéma de principe du système d'entraînement et de cintrage de la bande.
• La figure 3 et la figure 4 montrent deux étapes successives de cintrage de la tête de la bande.
• La figure 5 est une vue d'ensemble d'une variante du dispositif d'enroulement.

The invention also covers other advantageous arrangements which will appear in the following description of certain particular embodiments, given by way of example and shown in the accompanying drawings.

• The figure 1 is an overview of a winding device according to the invention, at the exit of a roller table.
• The figure 2 is a schematic diagram of the drive and bending system of the belt.
• The figure 3 and the figure 4 show two successive stages of bending the head of the band.
• The figure 5 is an overview of a variant of the winding device.

On the figure 1 , the whole of a winding device of the type described, for example, in the document US-A-2,918,226 mentioned above and therefore having a winding mandrel 2 placed in a pit F at the exit of a roller table T on which a metal strip 1 driven by a pinch-deflector device comprising a deflection roller D on which the strip passes is deflected downwardly towards the mandrel 2 by winding thereon to be frictionally driven, and a nip roll R which is rotated at a speed a little less than that of the mandrel, in order to hold the band 1 which can thus be energized so as to wind in tight turns on the mandrel 2.

Also known, the band 1 is applied on the mandrel 2 by a roller 3 exerting a thrust force in a radial plane Q passing through the axes 21 of the mandrel 2 and 31 of the roller 3. This roller 3 is, other part, followed by a bending plate 4 having a curved face substantially parallel to the outer face 20 of the mandrel 2 and spaced therefrom by a distance at least equal to the thickness of the strip.

In this way, the band 1 which is clamped between the application roller 3 and the mandrel 2 is frictionally driven in the annular space between the bending plate and the mandrel 2 and gradually winds up around it .

The application roller 3 and the associated bending plate 4 form a winding assembly E carried by a support frame 6 pivotally mounted about an axis 60 so as to be able to move under the action of a jack 62, between the winding position shown on the figure 1 and a spaced apart position for removal of the coiled coil.

In the layout of the document US Patent 2,918,226 , the mandrel is associated with two winding assemblies each carried by a pivoting frame.

As will be seen below, the arrangements according to the invention make it possible to reduce the angular sector covered by the bending plate and thus to place around the mandrel at least three winding assemblies in the manner shown in FIG. figure 1 .

As indicated above, the winding device of the document US Patent 2,918,226 is provided for winding a strip of relatively small thickness which can thus be stretched along the theoretical plane of travel (P) tangent, upstream, to a generatrix of the deflector roll D and, downstream, to a generator 22 of the mandrel 2.

The invention, on the contrary, is provided for winding a hot strip of greater thickness, up to 25 mm and, therefore, more rigid. It is then more advantageous, as shown by figure 2 , that the generator 23 through which the plane of thrust Q is slightly offset downstream relative to the generator 22 corresponding to the theoretical direction of travel of the strip, so that it is subjected to a torque preclining before being clamped on the mandrel by the application roller.

Moreover, in the layout of the document US Patent 2,918,226 , the application roller is carried by an auxiliary frame rotatably mounted on the main support frame of the bending plate and is simply pushed towards the mandrel by a spring bearing on the same frame.

In the invention, on the contrary, the application roller 3 is rotatably mounted directly on the support frame 6 of the bending plate 4 and the assembly is pushed towards the mandrel by the actuating jack 62 bearing in a direction, on the foundation block by a fixed hinge 63 and in the other direction on the frame 6 by a hinge 64.

This jack 62 is provided as above, to control the displacement of the support frame 6 between the winding position shown in FIG. figure 1 and a separated position of removal of the coil. However, because the application roller 3 is rotatably mounted directly on the frame 6, the jack 62 can itself constitute a means for adjusting the thrust force F ₃ exerted by the application roller 3 on the mandrel 2 along the bearing generatrix 23. The band 1 thus clamped between the mandrel 2 and the application roller 3 is then subjected to two opposite forces, the thrust force F ₃ applied by the roller 3 to the outer face 12 of the strip and the reaction force F ₂ exerted by the mandrel 2 on the inner face 11.

This thrust force exerted, according to the invention, by the actuator (s) 62 of the chassis 6 can be much greater than in the previous provisions because it is balanced by the reaction of the mandrel and simply depends on the thrust capacity of the or cylinders 62 and the strength of the frame 6 and the joints 63, 64. In addition, the use of one or more jacks allows easy control of the force exerted by hydraulic means allowing, in particular, to limit the applied pressure.

As shown in figure 1 at the exit of the roller table T, the metal strip 1 is deflected by the deflection roll D which is associated with the nip roll R and thus driven downstream, that is to say to the right on the figure 1 , at a certain speed of movement which depends on the rotational speed of the rollers R, D.

The strip is then directed by a guide chute which will be described later, towards the mandrel 2 placed in the pit F, substantially following a theoretical plane P tangent, upstream, to a generatrix of the deflector roll D and, in downstream, to a generatrix 22 of the mandrel 2. The head 13 of the band then engages between the mandrel 2 and the application roller 3 which is rotated in the direction of travel, then it comes into contact with the plate curved bending 4.

If f ₂ and f _{3 are} the coefficients of friction of the strip, respectively on the mandrel 2 and the application roll 3, the strip is subjected to a forward feed force equal to F ₂ f ₂ + F ₃ f ₃ , F ₃ being the radial thrust force of the roller 3 exerted by the jack 62 and F ₂ the opposite reaction force of the mandrel 2.

When the head 13 of the strip comes into contact with the bending plate 4, in the position shown in FIG. figure 3 it is subjected to a deflection force F ₄ which tends to bring it down along the outer face 20 of the mandrel 2.

As a result, the bending plate 4 opposes to the advancement of the band a resisting force F ₄ f ₄ , f ₄ being the coefficient of friction of the head 13 of the band on the plate 4.

To allow the bending and winding of the strip, it is therefore necessary that the forward force applied by the mandrel and the application roller on both sides of the strip is greater than the resistant force. opposite by the bending plate and so we have the relationship $${\mathrm{F}}_{}$$$${\mathrm{}}_{\mathrm{4}}<figure-callout\; id="4"\; label="\; f"\; filenames="imgf0002.png"\; state="\{\{state\}\}">\; </figure-callout>{\mathrm{f}}_{}{\mathrm{}}_{\mathrm{4}}\mathrm{\le }{\mathrm{<figure-callout\; id="2"\; label="F"\; filenames="imgf0002.png"\; state="\{\{state\}\}">F</figure-callout>}}_{\mathrm{2}}<figure-callout\; id="2"\; label="\; f"\; filenames="imgf0002.png"\; state="\{\{state\}\}">\; </figure-callout>{\mathrm{f}}_{}{\mathrm{}}_{\mathrm{2}}\mathrm{+}{\mathrm{<figure-callout\; id="3"\; label="F"\; filenames="imgf0002.png"\; state="\{\{state\}\}">F</figure-callout>}}_{\mathrm{3}}<figure-callout\; id="3"\; label="\; f"\; filenames="imgf0002.png"\; state="\{\{state\}\}">\; </figure-callout>{\mathrm{f}}_{}{\mathrm{}}_{\mathrm{3}}$$

However, the thrust effect exerted by the head 13 of the band 1 on the bending plate 4 carried by the support frame 6 tends to pivot this frame 6 about its axis 60 away from the mandrel 2 with the application roller 3 which, according to the invention is rotatably mounted directly on the frame 6. As a result, the outer face 30 of the roller 3 deviates from the outer face 12 of the strip 1 by a distance (d ) and that the roll 3 is no longer applied to the band, the driving effect F ₃ f ₃ being, therefore, eliminated.

Conversely, the bending effect exerted by the curved plate 4 on the head 13 of the band tends to maintain the inner face 11 thereof applied to the outer face 20 of the mandrel 2 under an application force F ₂ and, at the same time, to increase the angular sector of application on which this effort is distributed. As a result, the strip 1 is subjected, by the mandrel, to a driving force F ' ₂ f' ₂ .

However, this driving force which results solely from the bending of the band may be insufficient to overcome the resistant force applied by the bending plate 4 on the head 13 of the band.

Therefore, according to another essential feature of the invention, the support frame 6 carries an additional roller 5 which is rotatably mounted about its axis 51 upstream, in the direction of travel, the application roller 3 and which is dimensioned and positioned so that, taking into account the bending effect of the band at the level of the bearing generator 23, the external face 12 of the latter bears on the external face 50 of this additional roller 5 which therefore exerts a thrust force F ₅ . This additional roller 5 is rotated about its axis 51 at a tangential speed corresponding to that of the mandrel 2, so as to be able to exert on the outer face 12 of the belt 1 a downward drive force F ₅ f ₅ which, in the case of a spacing of the application roller 3, may be added or substituted for the driving force thereof.

With this additional roller 5, the relationship reflecting the resistance opposed by the bending plate 4 to the advancement of the strip 1 can therefore be written: $${\mathrm{<figure-callout\; id="4"\; label="F"\; filenames="imgf0002.png"\; state="\{\{state\}\}">F</figure-callout>}}_{\mathrm{4}}<figure-callout\; id="4"\; label="\; f"\; filenames="imgf0002.png"\; state="\{\{state\}\}">\; </figure-callout>{\mathrm{f}}_{}{\mathrm{}}_{\mathrm{4}}\mathrm{\le }{\mathrm{F\; \text{'}}}_{\mathrm{2}}{\mathrm{f\text{'}}}_{\mathrm{2}}\mathrm{+}{\mathrm{<figure-callout\; id="5"\; label="F"\; filenames="imgf0002.png"\; state="\{\{state\}\}">F</figure-callout>}}_5<figure-callout\; id="5"\; label="\; f"\; filenames="imgf0002.png"\; state="\{\{state\}\}">\; </figure-callout>{\mathrm{f}}_{}{\mathrm{}}_5+{\mathrm{<figure-callout\; id="3"\; label="F"\; filenames="imgf0002.png"\; state="\{\{state\}\}">F</figure-callout>}}_{\mathrm{3}}<figure-callout\; id="3"\; label="\; f"\; filenames="imgf0002.png"\; state="\{\{state\}\}">\; </figure-callout>{\mathrm{f}}_{}{\mathrm{}}_{\mathrm{3}}$$

In this relation, the thrust forces F ₃ , F ₅ exerted respectively by the application roll 3 and the additional roll 5 depend on the bending effect of the band and may be zero but substituting one for the other.

Thanks to the additional effect of driving exerted by the additional roller 5, the advancement of the band can continue by determining the bending of its head 13 which is deflected to the outer face 20 of the mandrel 2, in the position shown on the figure 4 . The rotation effect towards the outside of the support frame 6 decreases and the application roll 3 gradually returns to contact with the outer face 12 of the band 1 which can then be driven simultaneously by the two rollers 3 and 5 and the mandrel 2.

Advantageously, at the exit of the bending plate 4, the head of the band can be supported by a second application roller itself followed by a second bending plate, so as to maintain the band applied to the bending plate 4. outer face 20 of the mandrel 2 as its winding.

As a result, the angular sector of application of the inner face 11 of the strip on the mandrel increases gradually and the driving effect of the mandrel becomes predominant. The tension exerted on the strip may therefore increase and, depending on the rigidity of the strip, the outer face 12 thereof may deviate from the outer face 50 of the additional roll 5, to come into the position shown on the drawing. figure 2 .

The path followed by the strip 1 upstream of the mandrel 2 and, in particular, the variation of its spacing relative to the theoretical plane of movement P, as shown schematically on the Figures 2, 3, 4 , may advantageously be provided by simulation taking into account the diameter of the mandrel, the thickness of the strip and its mechanical characteristics, in particular its rigidity and its elastic limit. With this representation, it is possible to determine the predictable bending effect of the band at the level of the bearing generator 23, in particular at the moment when the head 13 comes into contact with the bending plate 6 and deducing the dimensions and the positioning of the additional roll 5 so that the band comes to bear on the outer face 50 thereof, when the driving effect of the application roll 3 decreases and then vanishes due to the spacing of the support frame 6.

In general, the additional roll 5 will be placed as close as possible to the application roll 3, upstream thereof, its diameter possibly being between, for example, 0.5 and one-fold the diameter of the roll. application 3.

In principle, the diameter and the position on the frame 6 of the additional roll 5 will be determined so that, given the predictable bending effect of the band between the deflector roll D and the mandrel 2, the outer face 12 of the strip comes into contact with the additional roller 5 for a spacing d of the outer face 30 of the application roller 3 relative to the outer face 12 of the strip greater than one quarter of the thickness e of the strip at the thrust plane Q.

It therefore appears that the assembly, according to the invention, of the application roll 3 and of an additional roll 5 on the same frame 6 and the use, as a pushing means, of one or more hydraulic cylinders 62, allows hydraulically adjusting the thrust force by adapting it to the bending resistance of the strip so that the sum of the frictional drive forces, respectively, on the inner face 11 of the strip 1 by the mandrel 2 and on its outer face 12, either by the application roller 3, or by the additional roller 5, or by the two rollers, determines a longitudinal thrust capable of causing sufficient bending of the strip for its winding on the mandrel and the take supported by it.

Moreover, to keep the strip in contact with the mandrel until complete winding of a turn, it is known to have several winding assemblies distributed around the mandrel.

For example, in the arrangement described by the document US Patent 2,918,226 , the winding mandrel is associated with two winding assemblies each comprising an application roll and a bending plate which extends over a large angular sector, close to half a turn. Such an arrangement is provided, indeed, for a relatively thin strip which can be guided in a reduced space between the bending plate and the mandrel.

The invention, on the contrary, is provided for strips of fairly high thickness, up to 25 mm, and the interval i between the bending plate 4 and the outer face 20 of the mandrel is therefore relatively large. It follows, moreover, that one thus increases the angular sector of application of the internal face 11 of the strip on the mandrel at the moment when the head of the strip comes into contact with the bending plate 4 and begins to bend.

However, the angular sector covered by the bending plate 4 downstream of the application roller 3 can advantageously be reduced so that the head 13 of the strip is supported by a second application roll as soon as it returns to the contact of the outer face 20 of the mandrel 2.

As a result, it is advantageous, as shown on the figure 1 arranging around the mandrel 2, three successive winding assemblies, respectively a first set E1, a second set E2 and a third set E3.

The first winding assembly E1 therefore comprises successively, in the winding direction, the additional roll 5, a first application roller 3 and a first bending plate 4, the assembly being mounted at the end of the support frame 6 which essentially comprises two arms 61 integral in rotation and pivoting about a shaft 60 under the action of at least one hydraulic cylinder 62 having an articulated element, about an axis 63, on a fixed frame or, directly, on the foundation block M and a second articulated element, about an axis 64, on the arms 61 of the frame 6, for example at the level of the nip roll 3. The two arms 61 of the frame 6 are extended, beyond the axis 64 by a bent portion 65 facing the mandrel 2 and carrying, at its end, the bending plate 4.

This bending plate 4 has a cylindrical internal face 40, generatrices parallel to the axis O of the mandrel, with an upstream end 41 which extends substantially to the nip roll 3 in the dihedron opening between the outer face 30 of the latter and the outer face 20 of the mandrel 2.

The second winding assembly E2 comprises a second application roll 3b and a second bending plate 4b mounted on a frame 6b pivoting about a fixed axis 63b under the action of a jack 62b.

Similarly, the third winding assembly E3 comprises a nip roll 3c and a bending plate 4c mounted on a frame 6c whose pivoting can be controlled by a jack 62c.

At the end of the winding of a coil, the three winding assemblies E1, E2, E3 can be separated from the coil by the jacks 62, 62b, 62c to allow to lower it, for example on a carriage G placed below the mandrel 2 and having two rows of spaced rollers on which can be deposited the wound coil.

The cylinders 62, 62b, 62c then bring the chassis 6, 6b, 6c back into the winding position shown in FIG. figure 1 .

The arrangements which have just been described make it possible to adapt to the strength of the strip, not only the application pressures of the rollers and the mandrel on the two faces, respectively external 12 and internal 11 of the strip 1, but also the pairs rotational forces applied by the drive motors, respectively on the additional roller 5, the application roller 3 and the mandrel 2, which makes it possible to develop the driving power required, not only to overcome the drag resistance. which results from the friction of the band on the bending plate 4 but also to provide the energy required for bending. Consequently, by adjusting the application pressures and the torques applied by the motors, it is possible, by virtue of the invention, to bend the strip sufficiently so that the inner face 11 of the latter is applied to the outer face. mandrel 2 from the radial plane Q passing through the axes of the mandrel 2 and the application roller 3, the other two pinch rollers 3b and 3c being themselves centered in radial planes passing through the axis O of the mandrel and the support generator.

Moreover, the bending plate 4c associated with the third wrapping roll 3c can be extended so that the three winding assemblies cover in total an angular sector of the upper mandrel with three quadrants, the downstream end 42c of the third plate 4c forming a wedge which engages in the dihedron opening between the outer face 20 of the mandrel and the plane P scroll tangent thereto.

In the example shown on the figure 1 , the guide chute 7 consists of two sets of plates, respectively lower 71 and upper 72. The lower assembly 71 comprises a series of plates aligned along the plane P of travel of the band tangent upstream to the deflection roller D and, downstream, to the mandrel 2. Advantageously, the last guide plate 71a is formed directly on the frame 6c of the third winding assembly E3.

The upper guide 72 may advantageously consist of a first plate 72a having a nose which engages in the plane of travel between the two pinch rollers D, R and a second plate 72b which, advantageously, is carried by the frame 6 of the first winding assembly E1 and directed tangentially to the additional roller 5.

Due to the perfect bending of the band obtained, even for a rather strong thickness, thanks to the additional roll 5, it is possible to further reduce the length of the bending plates and to bring the application rollers closer together in order to produce a device with four winding assemblies, as shown on the figure 5 . In this case, in fact, each of the winding assemblies E1, E2, E3 covers at most one quadrant and it is possible to place a fourth assembly in the sector remaining between the outlet 42c of the third bending plate 4c and the plane P scrolling the tape. This fourth assembly E4 comprises at least one application roller 3d mounted on a frame 6d which may comprise a curvilinear face-shaped portion 4d which engages in the dihedron opening between the outer face 20 of the mandrel 2 and the scrolling plane P.

The pivoting of the frames 6, 6b 6c, 6d of the four assemblies is controlled by jacks 62, 62b, 62c, 62d. The fixed axis 60c of the body of the third cylinder 6c is brought closer to the vertical plane passing through the axis of the mandrel in order to leave room for the pivoting jack 62d of the frame 6d of the fourth winding assembly E4. In this case, the two cylinders 62c and 62d may be substantially parallel.

Of course, the invention is not limited to the details of the embodiments which have just been described but covers all the variants using, for example, equivalent means.

In particular, the provisions of the figures 1 and 5 have been given as an indication but the excellent bending achieved through the provisions of the invention could allow other arrangements.

Claims (17)

1. Plant for winding into a coil a band-type product (1) running along a longitudinal direction, including a winding chuck (2) driven into rotation around an axis orthogonal to the running direction and having a cylindrical external face (20), means (7) for guiding the band (1), along a tangent running plane (P), upstream to a deflecting roll (D) and downstream to the chuck (2), means (3) for the application of the band (1), by an internal face (11), on the chuck (2) along a back-up generatrix (23) and a bending plate (4) having a curved face (41) for guiding the band (1) along the external face (20) of the chuck (2), said means of application including an application roll (3) revolving around an axis (31) parallel to the axis of the chuck, and a means (62) for pushing said roll (3) towards the chuck (2) along a pushing plane (Q) running substantially through the axes (21) of the chuck (2) and (31) of the application roll (3), the application roll being driven into rotation around its axis (31) in a reverse direction relative to the direction of rotation of the chuck (2), and at a corresponding tangential velocity, for applying a driving downstream force on each of the two faces, respectively internal (11) and external (12) of the band (1), characterised in that the application roll (3) is mounted rotatably directly on a mobile supporting chassis (6) whereon rests at least one hydraulic jack (62) comprising the means for pushing the application roll (3) towards the chuck (2), and resting, in an opposite direction, on a fixed portion, in order to exert an adjustable pinching force on the band (1) between the chuck and the application roll (3), in that an additional roll (5) is mounted rotatably upstream of the application roll (3) on said mobile chassis (6), and is driven into rotation around its axis (31) in a reverse direction relative to the chuck (2) and at a tangential velocity corresponding to the velocity of the chuck, and in that said additional roll (5) is slightly spaced apart from the running plane (P) between the deflecting roll (D) and the chuck (2) by a distance corresponding to a predictable bending effect of the band (1) upstream of the application roll (3), taking its rigidity into account.
2. Winding plant according to claim 1, characterised in that the running plane (P) between the deflecting roll (D) and the chuck (2) is tangent to the chuck along a generatrix (22) slightly offset upstream, in the running direction, of the pushing plane (Q) of the application roll (3), towards the chuck (2).
3. Winding plant according to one of claims 1 and 2, characterised in that the diameter and the position of the axis (51) of the additional roll (5) on the chassis (6) are determined such that, taking into account the bending of the band (1) between the deflecting roll (D) and the chuck (2), the band (1) comes to rest by its external face (12) on said additional roll (5).
4. Winding plant according to one of the preceding claims, characterised in that the external face (50) of the additional roll (5) is spaced apart outwardly relative to the running plane (P), between the deflecting roll (D) and the chuck (2), by a distance corresponding to the bending of the band upstream of the chuck (2), taking its thickness and its rigidity into account.
5. Plant according to one of the preceding claims, characterised in that the diameter of the additional roll (5) ranges between 0.5 and 1 times the diameter of the application roll (3).
6. Plant according to one of the preceding claims, characterised in that the axis (51) of the additional roll (5) is spaced apart upstream of the axis (31) of the application roll (3) by a distance slightly greater than the sum of the radii of the application roll (3) and of the additional roll (5).
7. Plant according to one of the preceding claims, characterised in that the supporting chassis (6) is mounted rotatably around a fixed axis (60).
8. Plant according to one of the preceding claims, characterised in that it includes at least two winding assemblies arranged successively around the chuck (2) in the winding direction, respectively, a first assembly (E1) including successively an additional roll (5), a first application roll (3) and a first bending plate (4) extending, between an inlet end, immediately downstream of the application roll (3) and an outlet end, and at least one second assembly (E2) including a second application roll (3b) resting on the external face (12) of the band (1) immediately downstream of the outlet end of the first bending plate (4) and a second cylindrical bending plate (46) having an inlet end, situated immediately downstream of the second application roll (3b), and an outlet end.
9. Plant according to claim 8, characterised in that it includes three winding assemblies arranged successively around the chuck (2) in the winding direction, respectively a first assembly (E1) covering an angular sector of the chuck of approximately one quadrant between a first application roll (3) and the outlet end of a first bending plate (4), a second assembly (E2) covering a sector of approximately one quadrant between a second application roll (3b) and the outlet end of a second bending plate (4b), and a third assembly (E3) covering an angular sector of approximately one quadrant between a third application roll (3c) and a third bending plate (4c) extending to an outlet end situated as close as possible to the internal face (11) of the band (1), upstream of the first application roll (3).
10. Plant according to claim 8, characterised in that it includes four successive winding assemblies, respectively, three assemblies (E1, E2, E3) each covering one angular sector of at most one quadrant between an application roll (3, 3b, 3c) and the outlet end of a bending plate (4, 4b, 4c), and a fourth assembly (E4) including at least one fourth pinch roll (3d) arranged immediately downstream of the outlet end of the third bending plate (4c).
11. Plant according to claim 10, characterised in that the fourth winding assembly (E4) includes a fourth bending plate (4d) in the form of a wedge extending as close as possible to the back-up generatrix (21) of the running plane (P) on the chuck, in the dihedron between the internal face (11) of the band and the external face (20) of the chuck (2).
12. Plant according to one of claims 8 to 11, characterised in that each winding assembly (E1, E2, E3) is mounted on a chassis (6, 6a, 6b, 6c) hinged around a fixed axis (60, 60b, 60c, 60d) and pivoting between a winding position and a spaced-apart position for removing a wound coil.
13. Plant according to claim 12, characterised in that it includes, upstream of the chuck (2), a guiding chute (7) including at least two plates converging towards the space between the pinch roll and the chuck, respectively an upper plate (72b) carried by the chassis (6) of the first winding assembly (E1) and a lower plate (71a) carried by the chassis (6c) of the last winding assembly (E3).
14. Method for winding into a coil a band-type product (1) running along a longitudinal direction and wound around a chuck (2) driven into rotation around an axis (21) orthogonal to the running direction, by means of at least one winding assembly (E) including an application roll (3) mounted on a supporting chassis (6) and driven into rotation around an axis (31) parallel to the axis of the chuck (2) and in reverse direction relative to said chuck, means (62) for pushing the application roll (3) towards the chuck (2) along a pushing plane (Q), and a bending plate (4) provided on the chassis (6) downstream of the application roll (3) and having a curved internal face (41) for guiding the band (1) along the external face (20) of the chuck (2),
    characterised in that the pushing force (F3) applied by the application roll (3) to the chuck (2) is exerted by at least one hydraulic jack (62) resting on the chassis (6) towards the chuck (2) and, in the opposite direction, on a fixed portion (M), and in that, if the driving roll (3) is spaced apart to the outside, the band (1) comes to rest, by its external face (12), on an additional roll (5) mounted rotatably on the supporting chassis (6), upstream of the driving roll (3) and driven into rotation around an axis (51) parallel to the axis of the chuck (2) in order to exert on the band (1) a driving downstream force which is added to or replaces the driving force exerted by the application roll (3).
15. Method according to claim 14, characterised in that the diameter and the position on the chassis (6) of the additional roll (5) are determined such that, taking into account the bending of the band (1) between the holding device (R) and the chuck (2), the external face (12) of the band (1) comes into contact with the additional roll (5) for a spacing of the external face (50) of the roll (5) relative to the external face (12) of the band (1) at the pushing plane (Q) greater than a quarter of the thickness (e) of the band (1).
16. Method according to one of claims 14 and 15, characterised in that the pushing force exerted by the thrust jack (62) on the supporting chassis (6) and the rotational torques applied to the chuck (2) and the rolls (3, 5) are adjusted, relative to the bending resistance of the band (1), such that the driving downstream force exerted by friction on the external face (12) of the band (1) by at least one of the two application (3) and additional (5) rolls, carried by said chassis (6), and the force exerted by the chuck on the internal face (11) of the band (1) are capable of causing sufficient bending of the band (1) for winding the band around the chuck (2).
17. Method according to claim 14, characterised in that the rotational torques applied to the chuck (2) and the application roll (3) and/or the additional roll (5) make it possible to provide a driving downstream power capable, on the one hand, of overcoming the drag resistance opposed by the bending plate and, on the other hand, of providing the energy necessary for bending the band.

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