Abstract:
Drive device for unwinding a reel of foil in an unwinding module of a stamping machine, having an inactive position, and an active position in engagement with the reel, and comprising: a belt, having an inactive configuration, and an active configuration for contacting a portion of the reel and driven by a driver of the module so as to unwind the reel, rollers, maintaining the belt in the inactive and the active configuration, a translatable roller, which engages the belt and compensates for variations in length when the belt moves from the inactive to the active configuration, and a biasing arrangement, attached to the roller and thereby keeping the belt tensioned in both the inactive and the active configuration, and the biasing arrangement is actuated and disengaged from the belt, to move the belt from the inactive to the active configuration and vice versa.

Description:
[0001]    The present invention relates to a drive device for rotatively driving a reel of stamping foil. The invention refers to an unwinding module for stamping foil, equipped with at least one such drive device. The invention relates to a stamping machine for the manufacture of packaging comprising at least one such drive device. The invention also relates to a stamping machine for the manufacture of packaging provided with an unwinding module equipped with at least one such drive device. 
         [0002]    In the area of the manufacture of packaging, for example that destined for the luxury industry, a converting machine by stamping applies patterns onto a sheet element by means of pressure. The patterns, for example usually metallized texts and/or decorations, are obtained by means of a shape to be stamped or a plate. The patterns originate from portions of a film derived from one or more stamping foils. 
         [0003]    In the stamping machine, the sheet elements are taken off a stack located upstream, gripped by a conveyor and brought one after the other into a stamping platen press carrying the plate. The plate is mounted on the top fixed beam of the press. A stamping counterpart corresponding to the plate is mounted on the bottom mobile platen of the press. In the case of hot stamping, known as “hot foil stamping”, the plate is heated. The metallized stamping foils are driven between the running plane of the sheet elements and the top beam. 
         [0004]    In a vertically upward movement, the bottom movable platen will press the stamping foil against each sheet element between the plate and its counterpart in order to deposit portions of film there. Once the film has been deposited, the bottom platen goes down again and the stamped sheet element is then released by the gripper bar onto a stack in a delivery in order to leave space for the new sheet element following. 
         [0005]    In the same space of time, the stamping foil is displaced so that a new surface of the film is matched to the plate. The transport of the foils requires intermittent means for unwinding and advancing generally provided by rolls against which the foils are nipped by the pressing rollers. The motorized drive of these rolls allows for the intermittent advancing of these foils. 
         [0006]    The majority of patterns deposited on the packaging can be realized from stamping foils with a small web width, generally not exceeding 30 cm. However, it is sometimes necessary to use stamping foils with a larger web width, typically in the order of between 50 cm and 70 cm. A set of narrower foils disposed side by side where the overall accumulated web width reaches this order of size can also be used. 
         [0007]    The reels of stamping foils are stocked in an unwinding module. In this module, the foils are driven in order to be unwound there. The module serves for supporting the reels and for supplying the machine with the foil or foils. In numerous stamping machines, the module is like a cabinet located at the rear outside said machines. The module has a bearing structure in which are arranged one or more reel carriers, each one of which supports at least one reel. There are two systems for unwinding the stamping foil. 
       PRIOR ART 
       [0008]    Document EP-1&#39;588&#39;968 describes one of the two systems, having a drive device for reels which are mounted so as to be freely rotatable on their respective reel carrier. The device comprises a belt which manages the advancing and braking function of the unwinding of the reel and therefore the supply of stamping foil to the machine. Rotational synchronization is ensured thanks to the friction of the belt both against a drive axle and against the reel. The belt of the device is tensioned by a spring. 
         [0009]    However, when the operator puts the device into the active position on a reel, the belt automatically makes the reel turn. This phenomenon leads to reject of stamping foil. 
         [0010]    A second disadvantage observed is the difficulty of putting several devices into the active position on one wide reel. Once a first device is placed into position on a larger width reel, this latter is blocked by the drive axle as the reel and the drive axle are coupled by the tensioned belt. When the operator has to put a second device into position on the same reel, the belt of the second device tries to turn this reel which is already blocked by the first device. The operator thus has to press very strongly and with a great deal of effort to put the second device on the reel. The forcing makes it difficult to place this second device in position and the foil is very greatly crumpled on the surface of the reel. 
         [0011]    Yet another disadvantage is a shortcoming in the operating area. As the reel is unwound, it has less inertia but turns more quickly. Without disregarding the inertia of the hub, the power required is greater than for the full reel, in the case of a reel with a larger width. On account of the spring principle, the tension of the belt decreases and results in this belt sliding over its surface, at the end of the reel. In this case, it is necessary to reduce the rate in order to compensate for this phenomenon. 
       SUMMARY OF THE INVENTION 
       [0012]    A principal aim of the present invention is to refine a drive device for unwinding a reel of foil in an unwinding module in a stamping machine. A second aim is to make a drive device simpler and to reduce the time taken to put it into an active position. A third aim is to resolve the technical problems mentioned for the prior art document. A fourth aim is to provide an unwinding module incorporating one or more drive devices for one or more reels. A fifth aim is to incorporate a device in a stamping machine. Yet another aim is that of realizing a stamping machine with an unwinding module. 
         [0013]    The invention relates to a drive device for unwinding a reel of foil for an unwinding module for a stamping machine, this drive device comprising:
       a belt, able to move from an inactive configuration to an active configuration in contact with a portion of a peripheral circumferential surface of the reel and with drive means of the module so as to unwind the reel,   a series of rollers, maintaining the belt in the inactive configuration and in the active configuration,   a translatable roller, compensating for variations in length when the belt moves from the inactive configuration to the active configuration and   biasing means, attached to the movable roller and keeping the belt tensioned in the inactive configuration and in the active configuration.       
 
         [0018]    In accordance with one aspect of the present invention, the device is characterized in that the biasing means are means able to be disengaged and to be actuated in order to move the belt from the inactive configuration to the active configuration and vice versa. 
         [0019]    In other words, the biasing means are no longer passive. The device provides two functions. On the one hand, it couples the drive means and the reel thanks to the tensioned belt. On the other hand, the tension of the belt is controlled throughout the unwinding of the reel. 
         [0020]    The biasing means maintain the belt at a constant tension when following the unwinding of the reel, thus suppressing the shortcoming in the operating area. Furthermore, the tension of the belt can be adapted as a function of the necessary power, the quality of the hub and the quality of the unwinding of the foil. 
         [0021]    At the moment when the device is put into the active position and the belt is put into the active configuration, the coupling between the reel and the drive shaft is removed by the operator. Prior to being put into the active position and into its inactive configuration, the belt is slack or weakly tensioned. 
         [0022]    The disengageable and actuatable means only ensure the belt is tensioned once the device has been put into the active position. By way of the disengageable and actuatable means, the belt is tensioned at the last moment of being put into the active position. A slack or weakly tensioned belt during take-up of the active position neither makes the reel turn to no purpose, nor does it make it block the reel. Taking up the position becomes much more ergonomic. 
         [0023]    The foil is defined, by way of non-restricting example, as being a metallized foil, for example aluminized, gilded, colored or other types also. 
         [0024]    In another aspect of the invention, an unwinding module for a stamping machine is characterized in that this unwinding module is equipped with at least one drive device for the reel of stamping foil, having one or more of the technical features described below and claimed. 
         [0025]    According to another aspect of the invention, a machine for stamping patterns on a sheet element is characterized in that this machine comprises at least one device having one or more of the technical features described below and claimed. 
         [0026]    According to yet another aspect of the invention, a machine for stamping patterns on a sheet element is characterized in that this machine is provided with an unwinding module having one or more of the technical features described below and claimed. 
         [0027]    The sheet element is defined, by way of non-restricting example, as being in a material such as paper, flat cardboard, corrugated cardboard, laminated corrugated cardboard, flexible plastic, for example polyethylene (PE), terephtalate polyethylene (PET), bioriented polypropylene (BOPP), or other polymers, or also other materials. 
         [0028]    The front is defined in relation to the front face of the machine, from the side of the control desk of the machine, known as the “operator&#39;s side”. The rear is defined in relation to the rear face of the machine on the side opposite the control desk of the machine, known as “opposite the operator&#39;s side”. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    The invention will be well understood and its various advantages and different characteristics will emerge better by way of the following description of the non-restricting exemplified embodiment, with reference to the accompanying schematic drawings, in which: 
           [0030]      FIG. 1  shows a synoptic side view of a stamping machine provided with an unwinding module; 
           [0031]      FIG. 2  shows a rear view in perspective of the unwinding module of  FIG. 1  comprising drive devices according to the invention; 
           [0032]      FIG. 3  shows a side view of a drive device in inactive position; 
           [0033]      FIG. 4  shows a side view of the drive device in  FIG. 3  in active position and 
           [0034]      FIG. 5  shows a side view of a blocking switch of the drive device. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0035]    As illustrated in  FIG. 1 , a hot foil stamping machine, in the present case a gilding machine  1 , comprises, in sequence, different stations  2 ,  3 ,  4 ,  6  and  7  which are placed side by side and are interdependent. From upstream to downstream the machine  1  comprises an infeed station  2 , a feed table  3 , a stamping station  4 , a station for supplying and recovering foil  6  and a delivery station  7 . 
         [0036]    The sheet elements, in the present case cardboard sheets  8 , having to be covered with gilded patterns, are placed into the machine  1  in the infeed station  2  in the form of a stack  9 . The sheets  8  are removed one by one from the top of the stack  9  and are placed in shingle stream on the feed table  3 . At the end of the shingle stream, the front sheet is positioned precisely. Each sheet is then gripped and conveyed individually from the output of the feed table  3  through the machine  1  as far as up to the delivery station  7  by a conveyor. 
         [0037]    The conveyor is generally constituted by a gripping member, in this case a series of grippers, each being mounted on a transverse gripper bar  11  which is movable longitudinally. The gripper bars  11  are attached to two endless gripper bar chains  12 , disposed laterally on each side of the machine  1 , and drive the sheets to be covered  8  in the longitudinal direction (arrow L). The gripper bar  11  grips the sheet to be covered  8  and the gripper bar chains  11  brings it into the successive stations  4 ,  6  and  7  in a rated running. 
         [0038]    The gripper bar chains  12  is set in motion, runs through a loop and stops periodically in a rated running such that during conveying, each gripper bar  11  with its sheet  8  is moved from an upstream station to the adjacent downstream station. The position of the stops of the gripper bars  11  is constant. 
         [0039]    The function of the stamping station  4  is to deposit on each sheet  8 , by hot foil stamping, metalized film, in this case gilded film, derived from a stamping foil  13 . In the case of the gilding, the foil  13  is formed with a layer of gold laminated on a plastic support foil. The stamping operation is carried out with a platen stamping press  14 , between a top beam  16  which is static and a bottom platen  17  which is mounted so as to be movable following a vertical alternating movement stroke. 
         [0040]    Stamping tools (not visible) are associated with each of the platens  16  and  17 . The plate is mounted on the bottom face of the top beam  16  and the stamping counterpart corresponding to the plate is mounted on the top face of the bottom platen  17 . The plate is heated for hot foil gilding. 
         [0041]    The sheet covered with gilded patterns  18  is automatically released by the gripper bar  11  at the delivery station  7 . The sheets covered with gilded patterns are then removed in a stack  19  from the machine  1 . 
         [0042]    The station for supplying and recovering foil  6  is placed downstream of the stamping station  4  and is responsible both for supplying the machine with stamping foil  13  and for removing this used foil  21  once it has been utilized. The stamping foil  13  is stored in a wound form in a rotatably mounted supplying reel  22 . In a similar manner, after passing through the stamping press  14 , the used foil  21  is wound around a rotatably mounted recovery reel  23 . 
         [0043]    Between its storage point and its recovery point, the foil  13  is driven to move by a drive system which makes it run. The running path starts with the supplying reel  22 , passes especially through the stamping press  14  and ends by the recovery reel  23 . The drive system comprises a tension shaft and its pressing roller  24 , positioned downstream of the path and driven at an overspeed to pull the foil  13 . The drive system comprises a series of diverting bars  26  set up along the path to guide the movement of the stamping foil  13  and of the used foil  21 . 
         [0044]    In the majority of cases, the stamping of patterns onto the sheet  8  requires the simultaneous use of several reels  22  (not shown in the figures). The sheet  8  has to be covered with patterns at numerous different places according to a particular position as a function of the desired decoration for the final packaging. The operator thus establishes a layout for the sheet  8 . 
         [0045]    It is preferable from a cost view, therefore, to use several reels  22  with smaller widths rather than to use one single reel  22  with a large width. The loss of surface on used foil  21  which is not stamped and laminated with gold and located in the recovery reel  23  is less important with several reels  22  with smaller widths than with one single reel  22  with a large width. The reels  22  with the smaller widths have to be positioned precisely as a function of the layout. 
         [0046]    The supplying reel or reels  22  are placed and unwound at the station supplying and recovering foil  6  and more particularly thanks to an unwinding module  27 . The module  27  is like a cabinet and is located outside the machine  1 , so that an operator has ergonomic access to the machine  1  and can easily load new supplying reels  22 . The module  27  is installed at the rear of the machine  1 , on the side opposite the control desk of the machine  1 , known as “opposite the operator&#39;s side”. The foil  13  enters into the machine  1  by one of its rear faces. 
         [0047]    One or more supplementary reels  22  are placed in storage in the module  27  so that the operator is able to prepare the later stamping job which is going to follow the stamping job currently being produced. 
         [0048]    The module  27  comprises a frame  28 , with a base  29 , four feet  31  and two vertical side walls  32  which are parallel with one another (see  FIG. 2 ). Several levels  33 , in this case three levels, disposed one above the other, are arranged in the module  27 . Each level  33  is provided in order to support at least one reel  22  and to supply the machine  1  by unwinding this reel or reels  22 . 
         [0049]    Each reel  22  is maintained on a reel support  34 . The reel support  34  comprises two vertical flanks  36  maintaining the sides of the reel  22  and a maintaining axle  37  whilst allowing the reel  22  to rotate freely (see  FIGS. 2 to 4 ). 
         [0050]    Each level  33  of the module  27  comprises a crossbar  38  like a spacer which is substantially horizontal between the two walls  32 . The crossbar  38  is positioned substantially at the middle of the module  27 . At least one reel support  34  carrying one reel  22  is placed on the crossbar  38  and is fastened thereto. 
         [0051]    The reel support  34  and its associated reel  22  are mounted to slide along the crossbar  38  so as to be positioned by the operator in a precise manner as a function of the layout established for the sheet  8 . To do this, a bottom part of the two flanks  36  of the reel support  34  has a fastener with a concave form in a slot. The fastener complements the square profile of the crossbar  38 . The two flanks  36 , and thus the reel support  34 , are perpendicular to the crossbar  38 . The holding axle  37  for the reel  22  is parallel to the crossbar  38 . A lug  39  locks the reel support  34  on the crossbar  38 . When leaving the reel  22 , the foil  13  is held by a foil return  40  and then enters the machine  1  by the rear. 
         [0052]    The reel  22  is unwound thanks to a drive device  41  which is mounted in the module  27 . Each reel  22  is rotatively driven and unwound by one or more devices  41 , this number being a function of the width of the reel  22 . The device or devices  41  can move from an inactive position, without entering into contact and therefore without driving the reel  22  ( FIG. 3 ), to an active position in engagement with the reel  22  ( FIG. 4 ), and vice versa. 
         [0053]    Given that each level  33  is provided to support at least one reel  22 , each level  33  is equipped with at least one device  41 . Devices  41  can be placed stored in the inactive position (shown for example in  FIG. 2  on the left-hand side, against the side wall  32 ). 
         [0054]    The device  41  is positioned above the reel  22  that it has to drive. The device  41  comprises a structure  42  with two lateral flanges. The structure  42  has a bottom cutout allowing the reel to be unwound  22  to pass through. 
         [0055]    Each level  33  of the module  27  comprises a rod  43  like a horizontal spacer between the two walls  32 . The rod  43  is positioned substantially toward the front of the module  27 . The rod  43  is parallel to and is located above the crossbar  38 . At least one device  41  is attached to the rod  43 . 
         [0056]    The device  41  is mounted to slide along the rod  43 , so as to be positioned and locked by the operator in a precise manner as a function of the position of the reel  22  and so as to be able to drive it. 
         [0057]    To do this, a front part of the structure  42  preferably has an attaching member  44 . The attaching member  44  has a rounded concave form. The attaching member  44  complements the round profile of the rod  43  and locks the device  41  on the rod whilst allowing for tilting. The structure  42 , and therefore the device  41  are perpendicular to the rod  43 . 
         [0058]    The device  41  moves from the inactive position to the active position by pivoting toward the back and toward the bottom with respect to the rod  43  (arrow Pa in  FIG. 3 ). Conversely, the device  41  moves from the active position to the inactive position by pivoting toward the front and toward the top with respect to the rod  43  (arrow Pi in  FIG. 4 ). 
         [0059]    The device  41  comprises an endless drive belt  46 . The belt  46  is maintained by the structure  42  along a path defined by a set of eight rollers. When the device  41  is in the inactive position, the belt  46  is located in an inactive configuration. When the device  41  is in the active position, the belt  46  is in an active configuration. 
         [0060]    The belt  46  is driven along its run thanks to drive means which are present at the module  27 . The drive means are an advance shaft or rotatory drive axle  47 . When the device  41  is in the inactive position, the belt  46  is not driven ( FIG. 3 ). When the device  41  is in the active position, the belt  46  comes into contact with and is driven by friction against the drive shaft  47  ( FIG. 4 ). 
         [0061]    Each level  33  of the module  27  comprises a drive axle  47 . The drive axle  47  is positioned substantially toward the front of the module  27 , between the crossbar  38  and the rod  43 . The drive axle  47  is parallel to the crossbar  38  and to the rod  43 . The drive axle  47  is located between the crossbar  38  and the rod  43 . The structure  42 , and thus the device  41  are perpendicular to the drive shaft  47 . 
         [0062]    The drive axle  47  is divided into two axle segments (not visible in the figures), each of the two segments being rotatively driven by a different motor and its associated belt  48 . Each level  33  of the module  27  thus comprises two motors  48 . These two axle segments  47  allow at least two devices  41  present on the same level  33  of the module  27  to be driven at different speeds. The speed of the motors  48  is controlled as a function of the layout of the sheet  8 . 
         [0063]    The device  41  comprises eight rollers pivotally mounted on the structure  42 . A rear bottom roller  49  and a central bottom roller  51  allow the belt  46  to be guided and to be maintained in contact with a portion of a peripheral circumferential surface of the reel  22 . In the active position, the device  41  rests on the reel  22  by means of the belt  46 . The device  41  tilts (arrow Pa) relative to the rod  43  throughout the unwinding of the reel  22 . 
         [0064]    The central bottom roller  51  and a front bottom roller  52  allow the belt  46  to be guided and maintained in contact with a portion of a peripheral circumferential surface of the drive shaft  47 . 
         [0065]    In its inactive configuration, the belt  46  has a substantially rectilinear path between the rear bottom roller  49  and the central bottom roller  51  and between this same central bottom roller  51  and the front bottom roller  52  ( FIG. 3 ). 
         [0066]    In the active configuration of the belt  46 , the unwinding of the reel  22  is synchronized with the rotation of the drive shaft  47 . In this way the belt  46  has a curved path between the rear bottom roller  49  and the central bottom roller  51  when hugging the portion of the peripheral circumferential surface of the reel  22 . In the active configuration, the belt  46  has a curved path between the central bottom roller  51  and the front bottom roller  52  hugging the portion of the peripheral circumferential surface of the drive shaft  47  ( FIG. 4 ). 
         [0067]    The belt  46  follows a path guided and maintained by four other top rollers  53 . A mobile roller  54  ends the path of the belt  46 , forming a variable length loop with two of the top rollers  53 . The mobile roller  54  is pivotally mounted on a mobile slider  56 . The slider  56  slides in a slot  57 . The slot is arranged between the front and the rear of the structure  42 . The slider  56 , associated with the mobile roller  54 , serves to compensate for variations in length of the path of the belt  46  when the latter moves from the inactive configuration with a substantially rectilinear path to the active configuration with a curved path. 
         [0068]    When the path is rectilinear and therefore short, the slider  56  is in the forward position such that a distance between two of the top rollers  53  and the mobile roller  54  is large (di in  FIG. 3 ), the length of the belt  46  remaining constant. When the path is curved and therefore extended, the slider  56  is in the rearward position such that the distance between two of the top rollers  53  and the mobile roller  54  is short (da in  FIG. 4 ), the length of the belt  46  remaining constant. 
         [0069]    The device  41  comprises biasing means, attached to the slider  56  and therefore to the mobile roller  54 . The biasing means maintains the belt  46  tensioned in the inactive configuration and in the active configuration. In the active configuration, the biasing means allow the belt  46  to fit the shape of the portion of the peripheral circumferential surface and therefore with the reducing diameter of the reel  22  as this latter unwinds. 
         [0070]    According to the invention, the biasing means are means which are able to be actuated and disengaged in order to make the belt  46  move from the inactive configuration to the active configuration and vice versa. The biasing means are preferably in the form of a cylinder  58 , for example a pneumatic cylinder. The cylinder  58  is oriented substantially from the front toward the rear, parallel to the slot  57 . The cylinder  58  is attached to the structure  42  above the slot  57 . 
         [0071]    The free end of the piston rod  59  of the cylinder  58  is attached to the front part of the slider  56 . When the device  41  passes Pa to the active position, the piston rod  59  of the cylinder  58  is simultaneously retracted from the rear to the front (arrow Sa in  FIG. 3 ), the slider  56  passes from the rear to the front, which makes the belt  46  move to the active configuration. In reverse, when the device  41  passes Pi to the inactive position, the piston rod  59  of the cylinder  58  is simultaneously extended from the front to the rear (arrow Si in  FIG. 4 ), the slider  56  passes from the front to the rear, which makes the belt  46  move to the inactive configuration. 
         [0072]    Each level  33  of the module  27  comprises a ramp  61  like a horizontal spacer between the two walls  32 . The ramp  61  is positioned substantially toward the rear of the module  27 . The ramp  61  is parallel to the drive axle  47 , the crossbar  38  and the rod  43 . The ramp  61  is located substantially at the same height as the drive axle  47 . At least one device  41  is joined to the ramp  61 . The structure  42 , and thus the device  41  are perpendicular to the ramp  61 . 
         [0073]    The device  41  is joined to the ramp  61  both in its raised inactive and in its lowered active position. To do this, the device  41  preferably comprises joining means  62  (see  FIG. 5 ). 
         [0074]    In a favorable manner, the joining means includes an arm  63 . The arm  63  projects toward the rear of the structure  42  of the device  41 . A front end of the arm  63  is maintained to the structure  42  of the device  41  whilst allowing pivoting. The arm  63  is able to pivot between a low angle in the raised inactive position and a high angle in the lowered active position. 
         [0075]    A rear end of the arm  63  has a rounded concave form, like a hook. This shape matches the round profile of the ramp  61 , which allows the arm  63  to remain joined to the ramp  61  whatever the tilted position of the device  41 . Thanks to such joining, the arm  63  is mounted to slide on the rod  43 , so as to be positioned and joined by the operator in a precise manner, by following the position of the device  41  on the rod  43 . 
         [0076]    The joining means  62  advantageously includes a gripping member  64 . The gripping member  64  is provided at the rear end of the arm  63 . The gripping member  64 , in this case, is a tightening handle turned by the operator. The handle  64  makes a screw move so as to be able to join the device  41  and to maintain it on the ramp  61 . 
         [0077]    The joining means  62  favorably comprises an actuator  66  which is connected to the biasing means, i.e. in this case to the cylinder  58 . The actuator  66  is in the form of a tappet and is mechanically connected to the handle  64 . The actuator  66  acts on two valves  67  which are pneumatically connected to the cylinder  58  by means of a pneumatic control valve (not visible in the figures). 
         [0078]    First of all, the operator places the reel  22  of metallized foil  13  with the reel support  34  on the crossbar  38 , as a function of the layout of the sheet  8 . Then, the operator moves the device  41  on the rod  43  and positions it so that the belt  46  is centered relative to the width of the reel  22 . If the web width of the metallized foil  13  is large, and therefore if the width of the reel  22  is large, the operator shifts the first device  41  and adds a second device  41  by the side of the first one. 
         [0079]    The operator then lowers the device  41 , making the structure  42  tilt relative to the rod  43  and making the arm  63  pivot relative to the structure  42  such that the belt  46  moves into engagement with the drive axle  47  and with the reel  22 . 
         [0080]    Thanks to the disengaged biasing means with pneumatic cylinder  58 , the operator does not have to force the belt  46  to move it from its inactive configuration to its active configuration. The biasing means  58  being disengaged, the slider  56  and the mobile roller  54  move easily. 
         [0081]    The operator then makes the handle  64  turn in one direction, simultaneously he joins the device  41  to the ramp  61 , and he actuates the cylinder  58  by making it engage. The belt  46  is tensioned against the reel  22  to be unwound. 
         [0082]    When the operator makes the handle  64  turn in the opposite direction, he disjoins the device  41  from the ramp  61  and he disengages the cylinder  58 . The tension of the belt  46  can relax. The operator can then carry out the reverse operations to those described above for the device  41 . 
         [0083]    Each level  33  of the module  27  preferably comprises a compressed air distribution channel in the form of a pipe  68 . The pipe  68  is positioned substantially in the middle of the module  27  and above the device  41 . The pipe  68  is parallel to the drive axle  47 , the crossbar  38 , the rod  43  and the ramp  61 . The pipe  68  is connected to the pneumatic cylinder  58  of the device  41 , via the pneumatic control valve. 
         [0084]    The pipe  68  supplies one or more devices  41  of the level  33 . The devices  41  can be positioned easily and rapidly, then connected, or even disconnected, then stored at the side, without creating the least problem. 
         [0085]    The present invention is not limited to the embodiments described and illustrated. Numerous modifications can be realized without in any way departing from the framework defined by the scope of the set of claims. 
         [0086]    In another alternative, the biasing means  58  can be replaced by an electrically-actuated linear motor. 
         [0087]    In another category of machines, the device or devices  41  can be incorporated in the station for supplying and recovering foil  6 .