Patent Publication Number: US-6699354-B2

Title: Method and a device for gluing together flat materials

Description:
FIELD OF THE INVENTION 
     The invention is in the field of processing of flat materials, in particular blanks and/or webs, of preferably textile materials, and relates to a method for gluing together such materials lying over one another. Furthermore the invention relates to devices for gluing together textile materials. 
     BACKGROUND OF THE INVENTION 
     The gluing together of flat materials, in particular of material blanks and/or material webs is effected usually on so-called laminating machines using the application of heat and pressure. The flat materials to be glued together, lying over one another, between two belt faces facing one another of belt conveyors arranged over one another, are transported along heating elements. At the same time the belts of the belt conveyor, which are directed towards one another, with the flat materials lying therebetween slide along the heating elements. Usually behind a heating station provided with the heating elements there is arranged a cooling station with cooling elements which cool the materials heated up for gluing together. 
     If such pressure sensitive materials, for example so-called distance weavings are glued together, at the same time only a slight pressure may be exerted onto these materials. The gluing is effected then essentially only by way of the effect of heat. If such pressure-sensitive materials are to be glued together on laminating machines, then alone it is not sufficient to bring the heating and/or cooling elements allocated to the belt conveyors lying over one another to such a distance that the belt faces, directed towards one another, of the belt conveyors lying over one another have a distance corresponding to the total thickness of the materials to be glued together. Alone the weight which the sagging upper belt face of the upper belt conveyor exerts onto the upper side of the materials to be glued leads to a pressure loading which has a negative effect on pressure-sensitive materials. Such pressure-sensitive materials may be pressed so much together and thus compacted by the weight of the sagging upper belt face that in particular on account of the heat acting on the materials with the gluing, the compacting is irreversible, thus permanent. 
     Proceeding from this it is the object of the invention to provide a method and device with which also pressure-sensitive flat materials may be glued together without problem, in particular without permanent deformations (compacting). 
     SUMMARY OF THE INVENTION 
     In the method according to the invention for gluing together flat materials lying over one another, the materials between belt faces directed to one another of belt conveyors arranged over one another are led past heating elements and in particular also cooling elements. The belt face at least of an upper belt conyeyor, said belt face being allocated to the upper side of the materials, is held up without contact. 
     By way of the fact that at least the upper belt face, allocated to the upper side of the materials, of at least one upper belt conveyor (of the heating and/or cooling station) is held up without contact, a sagging of the upper belt face is alleviated. The weight force of the upper belt face may by way of this no longer rest on the flat materials to be glued together. By way of this a pressing-together of pressure-sensitive materials on gluing is effectively avoided, so that also no permanent deformations may arise. 
     According to a preferred further embodiment of the method the upper-lying upper belt face is not only held up without contact but also lifted up without contact. By way of this an initial sagging of the upper belt face is first alleviated and subsequently the upper belt face is held without sagging. 
     The contactless holding-up and where appropriate lifting of the upper belt face may be effected in a different manner. Preferably this is effected magnetically or pneumatically by way of a vacuum. It is also conceivable to hold up and where appropriate lift up the upper belt face magnetically as well as pneumatically. The lifting-up of the upper belt face may be effected magnetically as well as pneumatically, whilst the upper belt face is held up only magnetically or only pneumatically. 
     According to a preferred embodiment of the method the upper belt face is lifted up until below the heating elements and/or cooling elements. This is effected preferably in a manner such that the upper belt face bears below the lower side of the heating and/or cooling elements and here is held, and specifically without a gap, by which means there is guaranteed a good thermal conduction of the heating and cooling energy. The lower sides of the heating and/or cooling elements at the same time serve for the lift limitation on lifting up the upper belt face of the upper lying belt conveyor and define the course of the held-up upper belt face below the heating and/or cooling elements. 
     The device according to the invention for gluing together flat materials lying over one another comprises belt conveyors arranged over one another as well as heating and/or cooling elements. Between belt faces, facing one another, of the belt conveyor the materials are transportable past the heating and/or cooling elements. To the heating and cooling elements which are allocated to the belt face, facing the upper side of the materials, of the upper belt conveyor, there are allocated means for holding up the upper belt face. 
     Accordingly the (upper) belt face, of the upper-lying belt conveyor, which comes into contact with the upper side of the materials to be joined, is provided with means which hold up the upper belt face at least without contact. These means are in turn allocated to the heating and/or cooling elements, wherein they may be an integral part of the heating and/or cooling elements. It is however also conceivable alternatively or additionally to arrange the means neighboring the heating and/or cooling elements. In each case the means hold the upper belt face without contact on or below the heating and/or cooling elements. The means at the same time ensure a bearing of the upper belt face on the heating and/or cooling elements, by which means a good energy transmission to the upper transport belt and from there to the flat materials to be glued is ensured and simultaneously a sagging of the belt face of the belt conveyor concerned which loads the upper side of the flat materials is alleviated. 
     According to one possible embodiment of the invention the means are designed as suction air producers or suction means. With this it is preferably the case of suction bores, suction nozzles and/or narrow suction slots. In particular suction bores are provided which open in flat grooves on the lower sides of the heating and/or cooling elements. By way of this a contactless lifting up of the upper belt face over preferably the whole width is possible, by which means reliably and with low air or pressure losses a vacuum may be maintained for the reliable contactless holding-up of the upper belt face. 
     In one advantageous embodiment of the invention the suction bores or nozzles are connected to a vacuum channel. With this preferably the suction nozzles or likewise and the vacuum channels are integrated in the respective heating and/or cooling element. Usefully (but without this limiting the invention), to each heating and/or cooling element there is allocated an elongate groove as well as a suction air channel. The suction nozzles produce a vacuum in the respective groove in the base wallings of the heating and/or cooling elements allocated to the upper belt conveyor. By way of this the upper belt face is held over a large surface below the lower side of the upper cooling and/or heating elements that serves for the delivery of energy. 
     An alternative means for the contactless holding and where appropriate lifting of the upper belt face is formed by way of magnets, preferably permanent magnets. Above all permanent magnets have the advantage that they are self-sufficient, by which means the upper belt face may be held up without the expense of energy. 
     With the use of magnets at least the conveyor belt of each upper belt conveyor is designed such that it may be attracted by the magnets. For this in the conveyor belt there may be incorporated or interlaced metallic particles or metallic threads. In this manner the conveyor belt concerned may simply be made magnetically effective, wherein the conveyor belt otherwise must be formed of non-conductive and thus magnetically non-effective materials. 
     The magnets are preferably arranged outside the heating and/or cooling magnets, preferably between neighboring heating and/or cooling elements. This arrangement is made such that the lower sides of the magnets lie roughly in a plane formed by the base surfaces of the heating elements and/or cooling elements. Preferably the lower sides of the magnets are arranged slightly over the plane spanned by the base wallings of the heating and/or cooling elements. By way of this the magnets do not obtain a direct contact with the conveyor belt, which means always between the magnet and the conveyor belt there exists a thin air gap. By way of this it is ensured that the belt face, of the corresponding belt conveyor, which is allocated to the flat materials to be glued always bears below the heating and/or cooling elements. By way of this a favorable energy transition from the heating and/or cooling elements to the belt face of the conveyor belt is ensured, wherein the air gap between the belt face of the conveyor belt and the magnet acts in an insulating manner so that the energy delivered by the heating and/or cooling elements is effectively conducted to the flat materials to be glued and not to the magnets which by way of this in the region of the heating zone do not significantly heat up and on account of this could lose their effectiveness. 
     A further device according to the invention for gluing together flat materials lying over one another comprises belt conveyors arranged over one another, as well as heating and/or cooling elements. Between belt faces, facing one another, of the belt conveyor, the materials are transportable past the heating and/or cooling elements. The upper heating and/or cooling elements allocated to the or to each upper belt conveyor are movable up and down by way of a lift means. 
     Accordingly the heating and/or cooling elements, preferably the heating and/or cooling elements arranged over the flat materials to be glued together, may be moved up and down by way of a lifting means. By way of the lifting means the heating and/or cooling elements may be moved up and down simply and exactly in an infinite manner for setting and maintaining an exact gap or conveyor gap between belt faces, facing one another, of the conveyor belts of the belt conveyors arranged over one another for transporting through the flat materials to be glued together. 
     Preferably all heating elements of the heating zone which are arranged over the flat materials to be glued together are arranged on a frame and by way of this may be commonly moved up and down by the lifting means. Likewise a frame is allocated to all upper-lying cooling elements of the cooling zone so that also these may be commonly moved up and down by way of a (separate) lever drive allocated to them. The common adjusting of all heating elements on the one hand and all cooling elements on the other hand ensures a simple and uniform adaptation of all heating and/or cooling elements to the thicknesses of the sheet formation to be glued in each case. 
     To the frame for holding all heating elements on the one hand and all cooling elements on the other hand there are allocated guide members, preferably upright lift columns. By way of this a uniform and tilt-free up and down movement of the frames and thus all heating elements or cooling elements allocated to them is ensured. According to a preferred embodiment of the invention to each frame there are allocated four lift columns that preferably are allocated to the corners of the rectangular, square frame. In this case the lift means allocated to each frame comprises four toggle levers, wherein in each case one toggle lever serves for the up and downward movement of a lift column. The four toggle levers of the frame for all heating elements or of the frame for all cooling elements can preferably be actuated commonly, and specifically synchronously. By way of this all four guide columns for adjusting the heating elements or cooling elements are moved up and down uniformly and together, by which means all heating elements or cooling elements over their whole length are adjustable up and down uniformly by the same height amount. 
     For the synchronization of the toggle levers below the lift columns of the frame of the heating elements or of the cooling elements there serve push rods that in each case connect two toggle levers. Four toggle levers are then allocated to two push rods. These two push rods are in turn connected to one another so that all four toggle levers are mechanically coupled to one another and can be actuated to the same extent via a single drive, in particular a lift means such as for example a pressure means cylinder. It is also conceivable to mechanically connect to one another two toggle levers which are not connected to one another, by way of push rods by another coupling member, in particular a coupling rod, so that on actuation of one toggle lever the other toggle lever is co-moved. The coupling may also be effected hydraulically or pneumatically. 
     The described lifting means, in particular the drive of this ensures with a simple construction a reliable uniform up and down movement of all heating elements or cooling elements. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiment examples of the invention are hereinafter explained in more detail by way of the drawings. In these there are shown: 
     FIG. 1 a schematic side view of a device according to a first embodiment example of the invention, 
     FIG. 2 an enlarged cross section through a heating profile, 
     FIG. 3 a longitudinal section through the heating profile of FIG. 2, 
     FIG. 4 a detail of a device according to a second embodiment example of the invention, specifically a cross section through several heating profiles arranged next to one another with magnets arranged therebetween, and 
     FIG. 5 a horizontal section V—V through the device of FIG. 1 with a view of the lifting means. 
    
    
     DESCRIPTION OF A PREFERRED EMBODIMENT 
     The device that is shown completely in FIG. 1 serves for gluing together flat materials. The materials to be glued to one another are laid over one another and may be formed of webs and/or blanks. Preferably the device serves for gluing together flat textile parts, such as e.g. upper materials and inlays that are not shown in the figures. At least one of the textile pieces to be glued in each case is provided with an adhesive coating which is activated by heat. The gluing is accordingly effected by impinging the textile pieces to be glued with heat and at least a slight pressure. 
     The device shown here has at its disposal a heating station  10 , whereupon in the working direction  11  of the device there follows a line pressure means  12  and therebehind a cooling station  13 . The glued, flat textile pieces behind the cooling station  13  are led away out of the device by way of a delivery conveyor  14  to for example a stacking means. 
     In the device there are arranged two belt conveyors  15  and  16  lying over one another. Each belt conveyor  15  and  16  comprises a revolvingly drivable (endless) conveyor belt  17  and  18  respectively. The conveyor belt  17 ,  18  of each belt conveyor is led over various deflection drums  19  and support rollers  20 . At least one deflection drum  19  of each belt conveyor  15  and  16  is drivable. Belt faces  21  and  22  of the conveyor belt  17  of the upper belt conveyor  15  and of the conveyor belt  18  of the lower belt conveyor  16 , said belt faces facing one another, with the device shown here have a straight-lined horizontal course. The belt faces  20  and  21  run at a distance parallel to one another, by which means between the (upper) belt face  21  at the lower side of the upper belt conveyor  15  and the (lower) belt face  22  at the upper side of the lower belt conveyor  16  there is formed a conveyor gap  23  with a constant thickness over the whole length of the belt conveyor  15  and  16 . The flat textile pieces to be glued together are transported through the device through the conveyor gap  23  between the belt faces  21  and  22 . 
     To the upper-lying outer side, that is to say to the side of the upper belt face  21  which faces the space enclosed by the revolving conveyor belt  17  there are allocated heating elements in the region of the heating station  10 . With this it is the case of elongate heating profiles  24  which are arranged at a slight distance next to one another in the working direction  11 . With regard to their direction of longitudinal extension the elongate heating profiles  24  are aligned transversely to the working direction. Planar, horizontal base wallings  25  of all equally formed heating profiles at the same time lie in a common horizontal plane. Below the base wallings  25  of the heating profiles  24  allocated to the upper belt conveyor  15  there bears the upper belt face  21  with the upper outer side. 
     To the lower belt face  22  there are also allocated heating profiles that are arranged and formed exactly as the heating profiles  24  that are allocated to the upper belt face  21 . The heating profiles  24  of the lower belt conveyor  16  with their base wallings likewise located in a horizontal plane bear from below on the outer side of the lower belt face  22 . The allocated heating profiles  24  at opposite outer sides of the belt faces  21  and  22  limiting the conveyor gap  23  support the belt faces  21  and  22  of the conveyor belt  15  and  16  in the heating station  10  so that by way of the heating profiles  24  the conveyor gap  23  along the working direction is held at a predetermined width which is the same everywhere. 
     The line pressure means  12  consists of opposite pressure rollers  26  and  27  which as with the heating profiles are allocated to the outer sides of the belt faces  21  and  22  of the conveyor belts  17  and  18 , said outer sides facing away from the conveyor gap  23 . The pressure rollers  26  and  27  have a distance to one another which is such that also in the region of the line printing means  11  the inner sides, facing one another, of the belt faces  21  and  22 , keep the conveyor gap  23  at a width which corresponds to the width of the conveyor gap  23  in the region of the heating station. The line pressure station  12  may be designed such as is known from DE 42 15 028 C2. In this case the upper print roller  26  comprises an elastic casing to which are allocated support rollers  28 . The line pressure means  12  may where appropriate however also be formed of only two pressure rollers  26  and  7  with essentially rigid casings. 
     The cooling station  13  following the line pressure means  12  is basically designed as the heating station  10 . Here to opposite outer sides of the belt faces  21  and  22  there are allocated cooling profiles  29  which are formed and arranged as the heating profiles. Thus the belt faces  21  and  22  also run along the base wallings  30 , lying in parallel planes, of the cooling profiles. With this the cooling profiles  29  in the region of the cooling station  13  hold the belt faces  21  and  22  at a uniform, predetermined distance so that also here the conveyor gap  23  over its whole length has essentially the same width which preferably corresponds to the width of the conveyor gap  23  in the heating station  10  and the line pressure station  12 . In the shown embodiment example the cooling station  13  differs from the heating station further in that the number of heating profiles  24  in the heating station  10  is larger than the number of cooling profiles  29  of the cooling station  13 . Just the same the number of heating profiles  24  and of the cooling profiles  29  may however be equally large or more cooling profiles  29  than heating profiles  24  may be present. Inasmuch as this is concerned the invention is not limited to the shown embodiment example. 
     The upper belt conveyor  15  and the heating profiles  24  as well as the cooling profiles  29  allocated to the outer side of the belt face, but also the pressure rollers  26  and the support rollers  28  of the line pressure means  12  are commonly held in a frame  31  which in FIG. 1 is represented only by way of indication. By way of this the relative arrangement of the heating profiles  24  and of the cooling profiles  29  to the conveyor belt  17  of the upper belt conveyor  15  is fixed. The same applies to the upper part of the line pressure means  12 . In each of the four corner regions of the rectangular frame  31  there is fastened a perpendicular lift column  32 . The part of the device lying above the conveyor gap is thus held on four equally formed lift columns  32 . Each lift column  32  in two guides  33  distanced from one another is mounted upwardly and downwardly movable in a frame housing shown only schematically in FIG.  1 . The guides  33 , arranged at a distance above one another, of each lift column  32  lie at different sides of the conveyor gap  23 . All four lift columns  32  are movable up and down in the guides  33  simultaneously by way of a lever drive  35 , by which means the frame  35  with the upper belt conveyor  15 , the upper part of the line printing means  12  and the heating profiles  24  and cooling profiles  29  lying above the conveyor gap  29  are movable up and down as a unit. By way of this the width of the conveyor gap  23  may be changed in that by way of the up and down movement of the upper belt face  21  at the height-adjustable upper part of the device with respect to the stationary lower belt face  22  the distance between the belt faces  21  and  22  are uniformly and continuously changed. For this the lower part of the device with the lower belt conveyor  16 , the lower part of the line printing means  12  and the heating profiles  24  and cooling profiles  29  allocated to the outer side of the lower belt face  22  are mounted on the frame housing  34  of the device in a stationary manner, specifically unchangeable with respect to height. 
     The lift means  35  comprises four toggle levers  36 , wherein in each case one toggle lever  32  is allocated to a lower end  37  of each lift column  32 . Each of the equally formed toggle levers  36  has at its disposal two equally long lever arms  38  and  39  that are connected to ends facing one another, in a link point  40 . A free end  41  of the upper lever arm  38  is linkedly connected to the lower end  37  of the respective lift column  32 . A free end  42  of the lower lever arm  39  is pivotably fastened about a fixed bearing point  43  on the frame housing of the device (FIG.  1 ). 
     Two toggle levers  36  lying on each side of the device are at the link points  40  connected to one another by way of a push rod  46  (FIG.  1  and  5 ). By way of this the two toggle levers  36  on each side of the device can synchronously be actuated. Furthermore two opposite toggle levers  26  at two different sides of the device at the free ends  42 , allocated to the bearing points  39 , of the lower lever arms  39 , are connected to one another by a coupling rod  44 , an specifically in an unrotatable manner (FIG.  5 ). Likewise in the shown embodiment example in each case two toggle levers  36  lying opposite one another on different sides of the device are coupled to one another at the link points  40  by connection rods  45  (FIG.  5 ). The coupling rods  44 , connection rods  45  and the push rods  46  connect the four toggle levers  36  to one unit, and specifically in a manner such that a single actuation in the region of a toggle lever  36  is sufficient in order to simultaneously and synchronously move all toggle levers  36 . By way of this the lift means  35  is in the position of moving up and down all four lift columns  32  synchronously and by in each case an equal amount, by which means the upper part of the device, specifically the upper belt conveyor  15 , the upper part of the line printing means  12  and the heating profiles  24  as well as cooling pofile  29  allocated to the upper belt conveyer  15  are uniformly movable up and down with respect to the stationary lower belt conveyor  16 , for the symmetrical changing of the width of the conveyor gap  23  between the inner sides, facing one another, of the two parallel belt faces  21  and  22 . 
     The single drive for adjusting the lift means  35 , that is to say for the uniform actuation of all four toggle levers  36  is in the shown embodiment example designed as a pressure means cylinder  47 . Alternatively there may also be provided a spindle drive, a rack drive or likewise. A movable piston rod  48  of the pressure means cylinder  47  is linkedly joined to a free end  49  of a tilt lever  50  that is connected in a rotationally fixed manner to one end of a coupling rod  44 . On the coupling rod  44  free ends  42  of the lower lever arms  38  of two opposite toggle levers  36  are unrotatably fastened (FIG.  5 ). By way of actuation of the pressure means cylinder  47  the tilt lever  50  is pivoted and by way of this the coupling rod  44  is rotated. By way of this the lever arms  38  and  39  of the two toggle levers  36  is pivoted on that side of the lift means  35  that is allocated to the pressure means cylinder  47 . By way of the connection of these two toggle levers  36  with the remaining two toggle levers  36  by way of the push rods  46 , the lever arms  38  and  39  of these two toggle levers  36  are pivoted in opposite directions to the same extent and by way of this all four lift columns  32  are simultaneously moved up and down by the lift means  35 . 
     To the heating profiles  24  and cooling profiles  29  lying above the upper belt face  21  there are allocated means for the contactless holding-up of the upper belt face  21  of the conveyor belt  17  of the upper belt conveyor  15 . 
     With the means shown in the FIGS. 1 to  3  it is the case of suction means. The suction means in the shown embodiment example comprise suction nozzles  51  (or also suction bores). The suction nozzles  51  in each case arranged in a row are open towards to base walling  25  of the heating profiles  24  and the base walling  30  of the cooling profiles  29 . Open ends of the suction nozzles  51  facing the inside of the respective heating profile  24  or cooling profile  29  open into an elongate, cylindrical vacuum channel  53 . At the opposite open ends of each vacuum channel  53  there are arranged air supply tubings or tubes that are not shown in the figures. By way of this the vacuum channels  53  are connected to the producer of the vacuum. Preferably each heating profile  24  and each cooling profile  29  is provided with a vacuum channel  53 , wherein the vacuum channels  53  of all heating profiles  24  on the one hand and all cooling profiles  29  on the other hand are connected to the same vacuum supply tubings or the same vacuum supply tubes, and specifically in the manner of a parallel connection. By way of this it is ensured that in all vacuum channels  53  there may set in the same vacuum. 
     The suction nozzles  51  in the base wallings  25  of the heating profiles  24  and the base wallings  30  of the cooling profiles  29 , said suction nozzles following one another in a middle row at preferably uniform distances, impinge a flat groove  54  in the middle of the lower side  25  of the respective base walling  25  and  30  respectively. The groove  54  by way of this forms a relatively large suction surface for suctioning a strip-shaped region of the outer side of the upper belt face  21  of the upper belt conveyor  15 . The groove  54  is in its length designed such that it extends almost over the whole width of the upper belt face  21  of the conveyor belt  17  (FIG.  3 ), but at a small distance in front of the side edges  55  of the upper belt face  21  so that from the lower side  52  of the respective heating profile  24  or cooling profile  29  the groove  54  impinged with suctioning air is completely covered by the upper belt face  21  and by way of this no air may flow out through the groove  54 , by which means the force with which the upper belt face  21  of the conveyor belt  17  is suctioned below the heating profiles  24  or the cooling profiles  29  could be reduced or lifted. 
     Each heating profile  52  on opposite sides of the vacuum channel  52  has at its disposal heating channels  56 . The heating channels  56  are designed in the usual manner, and specifically in the same manner as the vacuum channels  53 . Thus the vacuum channels  53  in the heating profiles  24  may be formed of a middle heating channel of usual heating profiles. In the same manner the cooling profiles  29  on opposite sides of the vacuum channel  53  have at their disposal cooling channels which are not shown in the figures and which are designed exactly as the vacuum channels  53 . 
     By way of the fact that to each heating profile  24  and to each cooling profile  29  there is allocated a vacuum channel  53  with suction nozzles  51  and a groove  54  for increasing the suction surface of the upper belt face  21  of the upper belt conveyor  15 , the upper belt face  21  at each heating profile  24  or each cooling profile  29  is held in a strip-shaped region, and specifically without contact by way of vacuum. The upper belt face  21  thus continuously bears on the lower side  52  of the heating profiles  24  and the cooling profiles  29 . By way of this not only is a sagging, caused by gravity, of the upper belt face  21  alleviated and a conveyor gap  23  formed which over the whole working direction  11  has a uniform width, but much more the large-surfaced bearing of the upper belt face  21  below the heating profiles  24  and the cooling profiles  29  leads to the fact that no air gap is present between the lower sides  52  of the heating profiles  24  and cooling profiles  29  and the outer side of the upper belt face  21 . By way of this a direct and effective energy transition from the heating profiles  24  or the cooling profiles  29  to the upper belt face  21  of the upper belt conveyor  15  is ensured, so that the heating and cooling energy from the heating profiles  24  and the cooling profiles  29  directly above the upper belt face  21  may be delivered to the flat textile formations to be glued together. 
     Preferably also a contactless, pneumatic lifting of the upper belt face  21  is effected by the vacuum produced below the heating profiles  24  and where appropriate also cooling profiles  29 . The sagging upper belt face  21  is then by way of the vacuum lifted until below the lower sides  52  of the heating profiles  24  and the cooling profiles  29  which limit the lift path of the originally sagging upper belt face  21 . After the upper belt face  21  has been lifted without contact by way of vacuum, it is held on the lower sides  52  of the heating profiles  24  and of the cooling profiles  29 , and specifically at least for so long as pressure-sensitive materials, in particular flat textile objects, are to be glued together. By way of the upper belt face  2  held below the heating profiles  24  and the cooling profiles  29 , the force weight of this does not load the materials to be glued, in particular textile sheet formations. These may be transported through the conveyor gap  23  between the belt faces  21  and  22  of the revolvingly driven conveyor belts  17  and  18  in the working direction  11 , wherein only a slight pressure that may be set and metered in a directed manner is exerted onto the materials to be glued. The pressure is roughly equally large along the whole conveyor gap  23 . In the cooling station  13  the pressure may be greater or less than in the heating station  10  or in the line printing means  12 . Where appropriate it may also be sufficient only in the region of the heating station  10  to hold the upper belt face  21  below the heating profiles  24 , thus only during the gluing together of pressure-sensitive materials not to let the weight of the upper belt face  21  rest on the surface of this since in the cooling station  13  by way of the cooling, the materials are no longer so pressure-sensitive. 
     It is also possible to support the lifting of the sagging upper belt face  21  in that for this, by way of the lift means  35  the upper belt conveyor  15  with the heating profiles  24  and the cooling profiles  29  is traversed downwards and a reduction of the conveyor gap  23  between the belt face  21  and  22  effected by way of this at least partly reduces the sagging of the upper belt face  21  by way of the bearing of the upper belt face  21  on the lower belt face  22 . Then only by way of vacuum in a contactless manner, only a small part of the sagging of the upper belt face  21  needs to be lifted. This manner of proceeding is particularly suitable with those devices with which the sagging of the upper belt face  21  in the middle is so large that that it alone on account of the vacuum would no longer be suctionable below the heating profiles  24  or the cooling profiles  29 . After the traversing together of the belt faces  21  and  22  and the contactless suctioning and lifting of the lower belt face  21  below the heating profiles  24  and the cooling profiles  29  then by way of the lift means  35  the upper belt conveyor  15 , the heating profiles  24  and the cooling profiles  29  are again traversed upwards, and specifically so far until the belt faces  21  and  22  have such a distance which corresponds to the desired width of the conveyor gap  23 . 
     FIG. 4 shows an alternative formation of the device. With this the heating profiles  57  shown in FIG. 4 are designed in a manner known per se. However between the heating profiles  57  lying next to one another at a small distance there are arranged magnets  58 . Preferably in the intermediate space between two neighboring heating profiles  57  there is located an elongate magnet  58  which only partly fills out this intermediate space and which extends roughly over the whole length of the conveyor belt  17 . With the magnet  58  it is preferably the case of a permanent magnet. 
     The planar, horizontally running lower sides  59  of all magnets  58  are located in the plane formed by the undersides  60  of the upper belt face  21  when this is pulled up and is held below the heating profiles  57 . Where appropriate the magnets  58  may also be arranged somewhat higher so that between the outer side of the upper belt face  21  of the conveyor belt  17  and the lower side  59  of the magnets  58  there remains a small insulating gap. 
     So that the conveyor belt, and specifically the upper belt face  21  of this may be held by the magnet  58  without contact below the heating profiles  47  and where appropriate lifted, the conveyor belt  17  is either formed of a material reacting with the magnet  58  or is made magnetically conductive, and specifically by way of embedding metallic particles and/or thin metallic wires in otherwise anti-magnetic material of the conveyor belt  17 . The particles or wires consist of such material that is attracted by the magnets  58 . 
     In the previously described manner a holding and where appropriate lifting of the upper belt face  21  in the region of the cooling station  13  may also be effected. Then between the cooling profiles not shown in FIG. 4 there are likewise arranged magnets  58 . 
     Alternatively it is also conceivable to design the heating profiles  57  or the cooling profiles themselves as permanent magnets or electromagnets or to arrange the magnets in the hollow heating profiles  57  or cooling profiles, and specifically at those locations at which the base walling of the heating profiles or the cooling profiles are relatively thin. 
     Furthermore it is possible to hold the upper belt face  21  below the heating profiles  57 ,  24  and/or cooling profiles  29  without contact pneumatically as well as magnetically. Such a combination of different physically acting means is particularly suitable for the contactless lifting of the upper belt face  21  for alleviating the sagging. By way of the use of vacuum and magnet force a particularly strong and effective lifting of the upper belt face  21  is ensured. For the later contactless holding of the upper belt face  21  below the heating profiles  24 ,  57  and cooling profiles  29  the magnets  58  alone may be sufficient (or also only the vacuum means). For holding then the vacuum supply for producing a suction pressure may be set out of operation. 
     Numerous other embodiments may be envisaged, without departing from the spirit and scope of the invention.