Patent Publication Number: US-10773483-B2

Title: Magazine for embossing rollers and embossing device comprising the magazine

Description:
FIELD OF THE INVENTION 
     The present invention relates to improvements to the field of machines for processing web material, for example, and especially, a multi-ply cellulose material. More in particular, the invention relates to improvements to embossing machines or devices, especially for tissue paper, and to the parts or components thereof. 
     BACKGROUND ART 
     In the production of cellulose ply material, for example rolls of toilet paper, rolls of kitchen towels, paper handkerchiefs, paper napkins and the like, a cellulose ply is usually embossed, by passing it through an embossing nip formed by a pair of steel rollers or by a pair constituted by a roller made of steel or other relatively rigid material and a roller coated with a yielding material like rubber. The steel roller has protuberances entering the elastically yielding coating of the pressure roller. The pressure between the embossing roller and the pressure roller causes the permanent deformation of the web of cellulose material which passes through the embossing nip between the embossing roller and the pressure roller. Two or more plies, at least one of which, or some of which, or all are embossed, are then bonded together in order to for a multi-ply web material. The web material may be wound in order to form rolls, or it may be cut and folded to form napkins, handkerchiefs and the like. 
     Each ply can in turn be composed of one or more layers of cellulose material. 
     The embossing pattern has both decorative and functional purposes. From a functional viewpoint, the embossing creates limited areas, onto which glue is applied for bonding together multiple plies forming the web material. A further purpose of embossing is to increase the overall thickness of the web material, to increase the softness and the absorption capacity thereof, as well as to increase other functions thereof known to those skilled in the art. 
     Generally speaking, an embossing device is a device performing an embossing processing on at least one ply and, in case, bonding two or more plies together by means of lamination, for example using glue applied on at least one of the plies, preferably on the top surfaces of at least some embossing protuberances formed on one or more plies. 
     In order to satisfy the needs of the modern tissue paper processing lines, it is necessary to replace the embossing rollers of the embossing device, with the purpose of both changing the pattern of the web material, and modifying the technical and functional features thereof, for example to switch from manufacturing of toilet paper to manufacturing of kitchen towels and vice versa. In fact, since embossing has not only aesthetical purposes but also, in some cases, functional purposes, embossing patterns suitable for manufacturing of toilet paper are not always suitable for manufacturing kitchen towels, and vice versa. Also consistency, grammage and content of the cellulose plies may differ depending on the type of articles to be produced, and different embossing patterns may be required for different products. 
     Embossing units or devices have been studied, having particular solutions for making the roller replacement simpler and quicker. 
     WO-A-2015/150452 discloses examples of embossing or embossing-laminating devices, provided with a magazine for interchangeable embossing rollers. In this way, it is possible to replace the embossing roller(s) mounted in the embossing device with other embossing rollers stored in the magazine. A specific handling member is provided to this end, transferring embossing rollers from the magazine to the supports for the embossing rollers, with which the embossing device is equipped, and vice versa. In some embodiments disclosed in WO-A-2015/150452 a magazine for embossing rollers is provided, comprising a carriage provided with a plurality of embossing roller support seats adjacent to one another according to an alignment direction, and a guide system for guiding the carriage in a handling direction parallel to the alignment direction of the support seats. 
     This magazine is particularly useful for making the embossing device more efficient and versatile, allowing the embossing rollers to be replaced quickly. 
     However, there is still a need for further improvements of embossing roller magazines, and embossing devices comprising said magazines, in order to make the replacement of the embossing rollers easier, more effective and quicker, further increasing the performance of the embossing device. 
     SUMMARY OF THE INVENTION 
     According to one aspect, a magazine for embossing rollers is disclosed, comprising a plurality of support seats for embossing rollers, adjacent to one another according to an alignment direction. A guide system is also provided, for guiding the seats in a handling direction. The movement according to the handling direction allows selectively to move each seat to a given station, for instance to a station where an embossing roller may be taken from said seat and inserted into an embossing device, or where an embossing roller taken from an embossing device may be arranged into the magazine seat. Moreover, or alternatively, the station may be a station where the seats can be extracted from the magazine and inserted therein, in order to extract single rollers from the magazine or to insert them therein. The seats may be provided with mutual connecting members so as to be connected to, and released from, one another. In some embodiments, the mutual connecting members are so configured as to allow mutually to connect and release the seats by means of a fastening and releasing movement according to an insertion and extraction direction, not parallel to the handling direction. This may be essentially achieved by means of a shaped-coupling, for instance by means of shaped profiles provided on the seats that mutually couple and mutually release through the movement of one seat with respect to the other. 
     According to a further aspect, an embossing device is disclosed comprising: 
     at least one embossing roller provided with embossing protuberances; 
     at least one pressure roller defining, with the embossing roller, an embossing nip; 
     a magazine for embossing rollers as defined above. 
     Advantageously, the magazine for embossing rollers may be integrated in a bearing structure of the embossing device. The bearing structure may also, directly or indirectly, support a handling member configured and arranged to extract single rollers from the magazine and to transfer them to an operative position, for instance in operative seats provided in the bearing structure, as well as to remove single embossing rollers from an operative position and transfer them to the magazine. 
     Thanks to a magazine and an embossing device of the type described above, a significant operational flexibility of the embossing device can be achieved. The magazine may allow the extraction and the insertion of single embossing rollers, while the embossing unit is operating. In this way, it is possible to use a high number of embossing rollers in combination with the same embossing device, thus achieving high operational flexibility. Moreover, the embossing rollers may be replaced on the embossing device simply and quickly, thus increasing, with respect to known solutions, the number of embossing rollers that can be alternatively used on the same embossing device, reducing the maintenance times as much as possible and, thus, the downtimes and the consequent production losses. 
     Thanks to the magazine and the systems for extracting the embossing rollers therefrom, it is also possible to clean, repair and, in general, maintain the embossing rollers combined with the embossing device, while this latter is operating. 
     According to a further aspect, a method is provided for managing an embossing device, wherein the embossing device comprises: a bearing structure; at least one embossing roller provided with embossing protuberances; at least one pressure roller defining, with the embossing roller, an embossing nip; a magazine for embossing rollers integrated in the bearing structure; a handling member movably arranged on the bearing structure in order to transfer single embossing rollers from an operative position to the magazine seats, and vice versa. The method may advantageously comprise the following steps:
         feeding at least one ply of web material through the embossing nip and embossing the ply of web material by means of the embossing roller and the pressure roller;   extracting one or more embossing rollers from, and/or inserting them into, the magazine while the ply of web material is embossed.       

     Further advantageous features and embodiments of the magazine and the embossing device incorporating are set forth in the attached claims, which form an integral part of the present description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood by following the description and the accompanying drawing, which shows non-limiting practical embodiments of the invention. More particularly, in the drawing: 
         FIG. 1  is a side view of an embossing device, where a magazine according to the invention may be inserted; 
         FIGS. 1A, 1B  are enlargements of details indicated with IA and IB in  FIG. 1 ; 
         FIG. 2  shows a step of a cycle for replacing an embossing roller in the embossing device of  FIG. 1 ; 
         FIG. 3  is a plan view of the magazine with a roller arranged on one of the seats of a carriage arranged inside the magazine; 
         FIG. 3A  shows a cross-section according to III A -III A  of  FIG. 3 ; 
         FIG. 4  is a plan view similar to that of  FIG. 3 , in a step of extracting a section of the support carriage for the rollers; 
         FIG. 5  shows an enlargement of the detail indicated with V in  FIG. 2 ; 
         FIGS. 5A, 5B  are cross-sections according to V A -V A  and V B -V B  of  FIG. 5 ; 
         FIG. 6  is an enlargement of the detail indicated with VI in  FIG. 3 ; 
         FIG. 7  is a front view according to VII-VII of  FIG. 3 ; 
         FIGS. 8 and 9  are cross sections according to VIII-VIII and IX-IX of  FIG. 6 ; 
         FIGS. 10 and 11  show cross-sections according to X-X and XI-XI of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIGS. 1, 1A, 1B, and 2  show an embodiment of an embossing device where a magazine for embossing rollers according to the present invention may be incorporated. The embossing device described herein comprises two embossing rollers and two pressure rollers, as well as a gluing unit, in order to produce glued multi-layer web material. However, it should be understood that the novel features of the magazine for embossing rollers described below may be advantageously used also in embossing devices of different type, for example in embossing devices without a gluing unit, or in embossing devices equipped with only one embossing roller and one pressure roller, or in embossing devices with more than two pairs of embossing rollers and pressure rollers cooperating together. 
       FIGS. 1 and 2  show a schematic side view of the embossing device. More in particular,  FIG. 1  shows an embossing device  200  during a step of production of a web material N. The web material N may be obtained by bonding two continuous plies V 1 , V 2 . In  FIGS. 1 , P 1  and P 2  indicate, as a whole, two paths of the plies V 1  and V 2 . In other embodiments, the number of plies of the web material N may be greater than two, and more than two feeding paths may be provided for the plies. 
     Each ply V 1 , V 2  may be formed by one or more layers, sheets or components put over one another and, in case, bonded to one another, for example by means of a ply-bonding unit or an embossing unit arranged upstream of the embossing device  200 . 
     In the illustrated embodiment, the embossing device  200  has a bearing structure indicated as a whole with number  201 . The bearing structure may comprise two side flanks  203  and a base structure  205 . 
     In some embodiments, a first embossing roller  207  and a second embossing roller  209  may be arranged between the two flanks  203  of the bearing structure  201 . The first embossing roller  207  may be provided with embossing protuberances  207 P, as shown in the enlarged detail of  FIG. 1A , while the second embossing roller  209  may be provided with embossing protuberances  209 P, as shown in the enlargement of  FIG. 1B . 
     The first embossing roller  207  may co-act with a first pressure roller  211 . In some embodiments, the pressure roller  211  may be coated with an outer layer  211 A made of a yielding material, preferably a resiliently yielding material, for example rubber. The second embossing roller  209  may co-act with a second pressure roller  213 . In some embodiments, also the pressure roller  213  may be coated with an outer layer  213 A made of a yielding material, especially a resiliently yielding material. 
       207 X,  209 X,  211 X and  213 X indicate the rotation axes of the two embossing rollers  207 ,  209  and of the two pressure rollers  211 ,  213 , respectively. These axes are substantially parallel to one another. 
     Between the first embossing roller  207  and the first pressure roller  211  a first embossing nip  215  is formed, through which the first ply V 1  passes for being embossed by means of the protuberances  207 P of the first embossing roller  207 . If the pressure roller  211  is provided with an outer yielding coating  211 A, the protuberances  207 P are pressed against the first pressure roller  211  and enter into the yielding coating  211 A, thus deforming the ply V 1  permanently. 
     Between the second embossing roller  209  and the second pressure roller  213  a second embossing nip  217  is formed, through which the second ply V 2  passes. The second ply V 2  is embossed analogously to the first ply V 1 , due to the effect of the protuberances  209 P of the second embossing roller  209  that are pressed against the second embossing roller  213 . If this second embossing roller is provided with an elastically yielding coating  213 A, the embossing protuberances  209 P penetrate the yielding coating and cause permanent deformation of the ply V 2 . 
     The two pressure rollers  211 ,  213  may be supported by means of arms or other members, that allow a movement thereof towards or away the respective embossing rollers  207 ,  209 , for the purposes that will be explained below. Actuators (not shown), for example cylinder-piston actuators, may be used to press the pressure roller  211  against the first embossing roller  207  and the second pressure roller  213  against the second embossing roller  209 . 
     In some embodiments, the two embossing rollers  207 ,  209  may be configured to operate in a tip-to-tip way, i.e. with the protuberances  207 P,  209 P arranged opposite to one another in order to press the plies of web material against one another in the nip  219  formed between the two embossing rollers  207 ,  209 . 
     In other embodiments, the embossing device  200  may comprise a laminating roller  221 , pressed against the embossing roller  209  and forming a lamination nip  223  therewith. In this way, the two plies V 1  and V 2  may be laminated between the second embossing roller  209  and the laminating roller  221 . In the nip  219 , the embossing rollers  207 ,  209  are slightly spaced from each other, so that the two plies V 1 , V 2  do not touch each other. In this case, the embossing device may generate a material embossed according to the so-called nested technique, with embossing protuberances of the ply V 2  nested between embossing protuberances of the ply V 1 , and vice versa. 
     In some embodiments, the embossing device  200  may be configured to operate in the tip-to-tip mode and in the nested mode, alternatively. To this end, the embossing rollers may be, for example, movable angularly around their axes and/or parallel to their axes, and the laminating roller may be alternatively moved between an active position and an inactive position. 
     The embossing device  200  may comprise a glue dispenser  225 . The glue dispenser  225  may comprise a glue source  227 , a first screened roller or anilox roller  229 , which picks up glue from the glue source  227 , and a second plate roller or applying roller  231 , which receives glue from the screened roller  229  and distributes glue on portions of the embossed ply V 2  adhering to the second embossing roller  209 . Generally, glue is applied at at least some front surfaces of the embossing protuberances  209 P, with which the embossing roller  209  is provided, on the portions of ply embossed by means of the embossing protuberances  209 P. 
     In some embodiments, the glue dispenser  225  is mounted on a slide or carriage  233  movable according to the double arrow f 233 , for example along guides  235  carried by an element of the fixed structure  201 . The movement according to the double arrow f 233  may be controlled by means of a suitable actuator, for example a cylinder-piston actuator, an electric motor, or any other suitable actuator, not shown. 
     In some embodiments, one or more uprights  237  are associated with the carriage  233 , which extend substantially vertically and onto which guides may be provided for the movement of a slide  239  according to the double arrow  2239  along the upright(s)  237 . In some embodiments, two uprights  237  may be provided, arranged near the flanks  203 . A respective slide  239  may be arranged on each upright. In the drawing, only one upright and one slide are shown, and it shall be understood that the second upright and the second slide are behind the upright and the slide shown in the drawing. 
     A suitable actuator (not shown) may be provided to control the upward and downward movement of the slide  239  or of each slide  239  according to the double arrow f 239 . For example, to this end a threaded bar may be provided, actuated by means of a motor, for instance an electric or a hydraulic motor. A nut screw carried by the slide may mesh the threaded bar. In other embodiments, a mechanism may be provided, comprising a toothed belt or other continuous flexible member, driven around pulleys, at least one of which is motorized. The slide  239  may be fastened to a branch of the continuous flexible member, so that the movement of the belt causes the movement of the slide in vertical direction. In further embodiments, the vertical movement of the slide  239  or of each slide  239  may be provided by means of a rack-and-pinion mechanism, for example by arranging a fixed rack on the upright  237  and a motorized pinion on the slide. If two uprights and two slides are provided, the lifting and lowering mechanisms may be double, for the two slides and suitably coordinated and electronically synchronized, in order to simultaneously lifting and lowering the two slides  239 . 
     In advantageous embodiments, each slide  239  carries a respective handling member  241  for moving the embossing rollers in order to replace the embossing roller  207  and/or  209  mounted in the embossing device  200  with other embossing rollers housed in a magazine described below. In case two or more slides  239  are provided, the set of handling members  241  forms a handling device for moving the embossing rollers. 
     As it will be clearly apparent from the description below of an embossing roller replacing cycle, the handling device  241  is provided with a composite movement, for example advantageously according to a horizontal direction and a vertical direction. This allows to move the embossing roller away from the respective pressure roller and/or from the other embossing roller, up to a position where the embossing roller may be transferred to the magazine by means of a downward translation movement. 
     The movement of the carriage  233  according to double arrow f 233  causes the horizontal movement also of the upright (2)  237 , as it is visible by comparing  FIGS. 1 and 2  showing two possible positions of the carriage  233 . Consequently, also the slide(s)  239  and the handling device  241  may horizontally translate together with the carriage  233 . 
     Moreover, as described above, the slide(s)  239  may be movable for example between a lower position and an upper position. 
     The slide(s)  239 , and consequently the handling device  241 , are therefore provided with a movement according to two translation axes orthogonal to each other, respectively a horizontal axis and a vertical axis, in order to move the embossing rollers so as to replace them, according to a cycle described below. 
     A magazine  245  for a plurality of interchangeable embossing rollers may be associated with the base structure  205 , wherein each roller may replace one or the other of the two embossing rollers  207 ,  209 , which in the arrangement of  FIG. 1  are mounted between the flanks  203  of the bearing structure  201 . 
     In the illustrated embodiment, the magazine  245  is contained inside the base structure  205 . In some embodiments, the magazine  245  may comprise a carriage  247  provided with a translation movement according to a movement direction indicated by the double arrow f 247 , in order to allow to select one or the other of the replacement interchangeable embossing rollers contained in the magazine  245 . As will be clearly apparent from the description below, the movement direction according to the double arrow f 247  allows to position an embossing roller, i.e. a seat of the carriage, in a station  21  ( FIG. 4 ) for extracting the rollers from and inserting them into the magazine. In this way, single rollers can be extracted from the magazine, and inserted therein, also while the embossing device  200  is operating. 
     In the illustrated embodiment, the magazine  245  comprises five for embossing roller support seats, the seats being indicated with  249 A,  249 B,  249 C,  249 D and  249 E. In the configuration of  FIG. 1 , the magazine  245  contains four embossing rollers  251 ,  253 ,  255  and  257  housed respectively in the support seats  249 A,  249 B,  249 D and  249 E. In the condition of  FIG. 1 , the intermediate seat  249 C is empty and is arranged in a central position, approximately below the gluing roller  231 . 
     As shown in  FIG. 1 , in this embodiment the base structure  205  has, in the direction f 247 , a larger dimension than the length of the carriage, so that the carriage can move inside the base stricture  205  in order to bring one or the other of the seats  249 A- 249 E in correspondence of a passage  261  that may be formed in the upper part of the base structure  205  by moving the carriage  233  away from the embossing rollers  207 ,  209 . The embossing rollers are transferred to and from the magazine  245  through the passage  261 , as explained below. 
     The embossing rollers  207 ,  209  that are in the machine, in a working position, may be integrally contained between the flanks  203 . The embossing rollers  207 ,  209  may be advantageously held and driven into rotation by means of centers (not shown) mounted on the flanks  203 . In other embodiments, the embossing rollers may be supported by known openable supports in order to extract the embossing roller from and to insert it in the embossing device. Examples of embodiments of the centers and the openable supports are described in WO2015/150452, the content whereof is integrally incorporated in the present description. 
     Generally, the handling device  241  is configured to engage any one of the embossing rollers  207  or  209 ,  251 - 257  and to move them as described below, in order to replace one or the other of the embossing rollers  207 ,  209 , or both them, that are in the machine, with one or the other of the embossing rollers  251 - 257  that are in the magazine  245 . 
     In  FIG. 1  the embossing device  200  is shown in operational condition, with the first ply V 1  and the second ply V 2  moving forward according to the arrows f 1  and f 2  towards the embossing rollers in order to be separately embossed between the pairs of rollers  207 ,  211  and  209 ,  213 . The embossed plies are glued and laminated between the embossing roller  209  and the laminating roller  221 , and consequently form a multi-ply web material N moving forwards according to arrow fN towards a downward station, for example a rewinding station, not shown. The pressure roller  213  is pressed against the embossing roller  209 , while the pressure roller  211  is pressed against the embossing roller  207  and the laminating roller  221  is pressed against the embossing roller  209  in order to couple the plies V 1 , V 2  together. 
     When one or both the embossing rollers  207 ,  209  shall be replaced with other embossing rollers arranged in the magazine  245 , first of all feeding of the plies V 1 , V 2  is interrupted and the movement of the various rollers of the embossing device  200  is stopped. The carriage  233  may be moved away from the embossing rollers  207 ,  209  and from the pressure rollers  211 ,  213 .  FIG. 2  shows the step wherein the carriage  233  has been moved away from the pair of flanks  203  and from the embossing rollers  207 ,  209 , thus leaving a passage  271  above the empty seat  249 C of the magazine  245 . 
     In the following step, the handling device  241  may be lifted from the lower position, inside the base structure  205  or in the space thereof, where it remains housed during the normal operation of the embossing device  200 . The handling device  241  is lifted up to a position where the support elements  241 A are approximately at the same height of the collars or annular projections  265  of the upper embossing roller  209 . For a detailed description of the following operations, reference shall be made to what has been disclosed in WO-A-2015/150452. 
     In other embodiments, the handling member  241  and the moving systems thereof may be configured such that the handling member may remain outside the magazine when this latter is closed and the embossing device  200  is operating. In this way, the interior of the magazine as well as the rollers contained therein are better protected against penetration of cellulose fibers or other debris generated by processing of the plies V 1 , V 2  of web material. 
     In order to increase flexibility and performances of the magazine  245 , a novel structure is provided for the carriage  247  carrying the seats  249 A- 249 E and shown only schematically in  FIGS. 1 and 2 . The details of the magazine  245  will be described below with reference to  FIGS. 3-11 . 
     Generally speaking, the carriage  247  of the magazine  245  may be subdivided into single sections, which can be connected to one another, and released from one another. A position of the magazine  245  forms a station for extracting and inserting single sections of the carriage  247 , each of which has at least one seat for a respective embossing roller. In this way, it is possible to extract single sections of the carriage  247  from the magazine in a position for loading and unloading the embossing rollers. In this position it is possible, for instance by means of a bridge crane, to remove the embossing roller arranged in the seat extracted from the magazine and replace it with another one. All these operations may be performed while inside the magazine there is still a number of sections of the carriage suitable to allow both the operation of the embossing unit, and the replacement of the mounted and working embossing rollers with the rollers arranged in the seats of the sections of the carriage that are still inside the magazine. More in particular, the carriage sections may be extracted and inserted again while the embosser is regularly operating with the embossing rollers mounted in the embosser. Therefore, the embosser works independently of the operations performed on the replacement rollers inside or outside the magazine. The only step where the magazine and the embosser cooperate is the step of replacing one or both the embossing rollers. 
     More in particular, according to some embodiments, the carriage  247  comprises a plurality of sections  1 , each of which comprises members defining at least one seat  249  for an embossing roller. The seat may be formed by two opposite pairs of support surfaces, each pair defining a cradle for supporting the respective roller R arranged on the section  1  of the carriage  247 . In the illustrated embodiment, each roller R is provided with support bearings C, which remain connected to the rotation journal P of the roller and are therefore removed from the embossing device  200  together with the roller R. In the illustrated embodiment, each seat  249  is configured to support the respective bearing C of the roller R. 
     The two pairs of support surfaces forming the seats  249  are fastened to profiles  250  or other structural elements, connected by means of bars  2 . In the example illustrated in the attached drawing, the two profiles of each carriage section  1  are connected to each other by means of two bars  2 , but it should be understood that in other embodiments a different number of connecting bars  2  may be provided, for instance also just one suitably shaped bar, or three or more substantially parallel bars  2 . 
     In  FIGS. 3-11  only one embossing roller R is shown, that can be any one of the embossing rollers  207 ,  209 ,  251 - 257 . The carriage  247  also comprises an auxiliary section  3 , connected to one of the farthest sections  1  of the series of sections  1  connected together. 
     The carriage  247  is arranged in a translation space  7  for the carriage  247 , defined between two longitudinal parallel guides  5 , see in particular  FIGS. 3 and 4 . In the illustrated embodiment, each longitudinal guide  5  is provided with a rack  9  engaging a respective pinion  11 . The two pinions  11  are coaxial and keyed on a shaft  13 , that can be driven into rotation by means of a motor  15  controlling the movement in the handling direction f 247  of the carriage  247 . The motor  15  and the shaft  13 , with the respective supports, may be mounted on the auxiliary section  3  of the carriage  247 . 
     In other embodiments, different mechanisms can be used for moving the carriage  247  in the handling direction f 247 , for example belt systems, threaded bar systems or other systems. 
     Each of the longitudinal guides  5  has a gap  17  (see in particular  FIG. 5 ) in an intermediate position along the longitudinal extension thereof, for example, but without limitation, at approximately the middle thereof. The gap  17  define an extraction and insertion station for extracting and inserting the sections  1  forming part of the carriage  247 . Two longitudinal guide portions  19 A,  19 B are inserted in the gaps  17 ; the guide portions are so configured as to engage, each time, one of the sections  1  that are moved in an insertion and extraction direction F as described below. The extraction and insertion station is schematically indicated with  21  ( FIG. 4 ). The longitudinal guide portions  19 A,  19 B are connected to each other by means of bars  20 , see in particular  FIGS. 8 and 9 . In the illustrated example, three bars  20  are provided, but in other embodiments a different number of bars  20  may be provided, for example one, two, four or more bars  20 . 
     Each section  1  of the carriage  247  comprises engagement elements  23  for engaging with the longitudinal guides  5 . In the illustrated embodiment, the longitudinal guides  5  have a C-shaped profile  5 C (see  FIGS. 3, 3A ) and the engagement elements  23  comprise wheels that are inserted in the profiles  5 C. Each section  1  advantageously comprises a plurality of wheels for each guide  5 . In other embodiments, the engagement elements  23  may be differently configured, for example in the form of shoes engaging with prismatic longitudinal guides  5 . 
     The longitudinal guide portions  19 A,  19 B have such a shape as to be engaged by the same engagement elements  23 , see for example  FIGS. 10 and 11 . For example, the longitudinal guide portions  19 A,  19 B may have a C-shaped profile equal or substantially equal to the profile  5 C of the longitudinal guides  5 . 
     In other embodiments, the engagement elements  23  and the guides  19 A,  19 B may be made in a different way. For example, the guides  19 A,  19 B may be dovetailed, or may have any other suitable shape, and the engagement elements  23  may be shoes sliding engaging with the guides. 
     When the longitudinal guide portions  19 A,  19 B are inserted in the gaps  17  of the longitudinal guides  5 , they form with these latter two continuous longitudinal guides, so that the various sections  1  of the carriage  247  may translate along the whole length of the translation space  7  of the carriage  247 . To this end, the longitudinal guide portions  19 A,  19 B have C-shaped profile segments, indicated again with  5 C and forming a C-shaped continuous profile when the longitudinal guide portions  19 A,  19 B are aligned with the longitudinal guides  5 . 
     The sections  1  can be connected to one another and to the auxiliary section  3  by means of a fast coupling and releasing system. The sections  1  and  3  preferably have connecting members that can be coupled to one another by means of a simple mutual movement of the sections  1 ,  3  in the insertion and extraction direction F ( FIGS. 3, 4 ). The insertion and extraction direction F is substantially orthogonal to the handling direction f 247  of the carriage  247  in the space  7  of the magazine. 
     In the illustrated embodiment, each section  1  has, at both the sides thereof, i.e. adjacent to both the guides  5 , two appendices  25 ,  27 , each of which defines a groove extending in the insertion and extraction direction F of the sections  1  of the carriage  247 . The grooves defined by the two appendices  25 ,  27  face opposite: the groove formed by the appendix  25  is opened downwards, while the groove formed by the appendix  27  is opened upwards. In this way, two appendices  25 ,  27  may be mutually coupled and released by means of a simple movement according to the direction F. 
     With this arrangement, it is possible to insert each section  1  into, and to extract it from, the translation space  7  with a movement according to the arrow F, which movement causes the automatic coupling of the section  1  to, or the automatic releasing thereof from, the adjacent sections. Each section  1  of the carriage  247  may be extracted from the magazine  245  independently of the two sections  1  adjacent thereto, and may be inserted again or replaced with another section  1  in the same position. 
     In order to insert and extract each section  1  in a simple way, the section arranged in the extraction station  21  remains advantageously engaged with the two longitudinal guide portions  19 A,  19 B by means of the engagement members  23 ; see  FIGS. 10 and 11 . By inserting the engagement elements  23  of the section  1  arranged in the extraction station  21  in the longitudinal guide portions  19 A,  19 B, the section  1  is engaged to the guide portions  19 A,  19 B. The longitudinal guide portions  19 A,  19 B are, thus, extracted in the insertion and extraction direction F together with the section  1 . 
     In some embodiments, each longitudinal guide portion  19 A,  19 B may be associated with engaging members for engaging with a transverse guide system  29  extending parallel to the insertion and extraction direction F. The transverse guide system  29  may comprise one or more tracks, channels or other longitudinal guide elements, parallel to one another, with which shoes, wheels or other engagement members engage, which are fastened to the two longitudinal guide portions  19 A,  19 B. 
     For example, two parallel tracks may be provided, with which shoes or wheels co-act, which are in turn fastened to the two longitudinal guide portions  19 A,  19 B. Alternatively, the guide system may comprise a roller conveyor fixed to the ground, co-acting with engagement members for engaging with the roller conveyor and that are integral with the longitudinal guide portions  19 A,  19 B. 
     In the illustrated embodiment, a more complex transverse guide system  29  is provided, comprising a pair of outer tracks  31 A,  31 B and a pair of inner tracks  33 A,  33 B, arranged between the outer tracks  31 A,  31 B and parallel thereto (see in particular  FIGS. 8 and 9 ). Shaped wheels  37 A,  37 B, carried by the longitudinal guide portion  19 B, may engage with the outer tracks  31 A,  31 B. Shoes  39 A,  39 B, integral to the longitudinal guide portion  19 A, may engage with the inner tracks  33 A,  33 B (see also  FIGS. 5, 5A, 5B ). 
     As shown in  FIGS. 5, 5A, 5B , the shoes  39 A,  39 B may be staggered with respect to each other in the extraction direction F, in order to ensure better support and better reaction forces. 
     A motor  41 , driving a pinion  43 , is fastened to the longitudinal guide portion  19 A. The pinion  43  meshes with a rack  45 , which may be integral with the transverse guide system  29 . In the illustrated example, the rack  45  is adjacent and parallel to the track  33 B. In this way, the rotation of the motor  41  causes the translation of the section  1 , which is aligned with the extraction station  21 , in the extraction direction F. 
     With the described arrangement, the carriage  247  may operate as described below in order to replace embossing rollers arranged in the magazine  245 . The carriage  247  is translated, by means of the motor  15 , according to arrow f 247  until the section  1  to be extracted has achieved the extraction station  21 . The movement is along the longitudinal guides  5 , whose intermediate gap  17  has been closed by means of the guide portions  19 A,  19 B temporarily aligned with the longitudinal guides  5  and connected to each other by means of the bars  20 . When the section  1 , that shall be extracted for example in order to remove and replace the embossing roller R arranged in the seat  249 , is position in the extraction station  21 , the motor  41  is actuated. This moves the selected section  1  along the transverse guide system  29 . The shoes  39 A,  39 B give suitable reaction forces for guiding the movement under the thrust of the pinion  43  co-acting with the rack  45 . The section  1  is temporarily connected, by means of the engagement elements  23 , to the two longitudinal guide portions  19 A,  19 B, which substantially form a slide together with the bars  20  and with the engagement members (shoes  39 A,  39 B, shaped wheels  37 A,  37 B) for engaging with the transverse guide system  29 . In this way, the section  1  and the longitudinal guide portions  19 A,  19 B, connected to each other by means of the bars  29 , move as a single slide in the direction F. The section  1 , with the embossing roller R supported in the respective seat  249 , is supported by means of the shoes  33 A,  33 B and the wheels  31 A,  31 B along the transverse guide system  29 . The extraction movement according to the arrow F automatically causes the release of the section  1  fastened to the longitudinal guide portions  19 A,  19 B from the two adjacent sections  1 , thanks to the shape of the mutual connecting members  25 ,  27 . 
     Once the section  1  of the carriage  247  has been brought outside the translation space  7  between the two longitudinal guides  5 , it is outside the space of the embossing device where the magazine  245  is incorporated. In this position, the embossing roller R arranged on the extracted section  1  can be removed and replaced with another embossing roller. In this step, handling of the embossing rollers may be performed in a known manner, for example by means of a bridge crane, or by means of a ground handling system. 
     Once the embossing roller R has been replaced, the section  1  may be inserted again in the translation space  7 , with an operation opposite to that described for the extraction thereof, bringing the longitudinal guide portions  19 A,  19 B aligned again with the longitudinal guides  5 . This restores the continuity of the longitudinal guides and allows the translation of the carriage  247  according to arrow f 247 , in order to bring a different section  1  to the extraction station, if necessary. 
     With such a configured magazine and carriage  247  it is possible to replace, for example during the operation of the embosser, one or more embossing rollers of the magazine  245  with other embossing rollers, in a simple and fast way. 
     The magazine  245  may be provided with closing systems, for example a side wall and/or an upper wall, in order to protect the embossing rollers contained therein, especially against dust and cellulose fibers that could fall from the plies V 1 , V 2  processed by the embossing device  200 . The closing systems may be opened when it is necessary to extract a section  1  of the carriage  247  from the magazine  245 , or to insert it in the magazine. 
     Whilst in the embodiments described above the single sections  1  of the carriage  247  can be mutually connected and released by a simple movement according to the insertion and extraction direction F, thanks to the grooves  25 ,  27  in other embodiments it is possible to connect the sections  1  to one another and to the auxiliary sections  3  by means of different mechanical members, with fastening and releasing actuators, if necessary. For example, coupling members may be provided, which connect to one another in order to join the sections  1  and which disconnect from one another by means of a suitable actuator. The actuator may be for example arranged in fixed position in the station  21 , or a respective actuator may be provided on each section  1  and, if necessary, on the auxiliary section  3 .