DE19642831A1 - Device for automatic application of protective film onto freshly lacquered passenger car body components - Google Patents

Abstract

At least one roller stand (20) is for a spare roll in which the front end of the protective film is held. The pulled-off film is cut at right angles by a cutter. A freely programmable industrial and tenter robot (35) has at least five degrees of freedom for the movement of each different-sized surface part. Each rectangular tenter (37) has suction strips on two opposite longitudinal sides for holding the section of film. Another freely programmable industrial and perforating robot (50) has an operating arm on which is a heatable toothed disc for perforating tear-lines in a piece of film held tight by the tenter. A gantry (65) spanning the vehicle bodywork (1) is movable longitudinally and is in the form of an elastic sliding bar movable vertically.

Description

The invention relates to a method and an apparatus for Application of self-adhesive protective film on bodies for the dispatch of vehicles.

In the series production of many car manufacturers, the driving witnesses are prepared for dispatch in such a way that they do not Damage, especially that the painting due to storage and weather conditions are not affected. Be for the transfer of customers by train or even ship transport necessary, so you have the vehicles with wax protection layer covered, which is removed before customer delivery had to become. The residue-free removal of the protective wax was not just a labor-intensive job, it was stressful also people and the environment because of the solutions used tel. That is why the body has recently been adopted due to self-adhesive foils during transport protect, but only the weather and abla tears, essentially horizontally lying upper has protected areas of the body. Because this Degree of protection not only very effective, but also relative expensive, you have it not only as protection during the trans portes, but also as protection during vehicle assembly seen and accordingly the protective film before final assembly of the vehicle, d. H. immediately after painting the diamonds series applied.

The protective film should be free of wrinkles and bubbles be brought in because of wrinkles or blisters after a certain storage time can form a microclimate, which ever  by paint type and color u. U. can lead to visible traces. In order to be able to apply the protective films carefully, the Foil cuts previously held by four people Vehicle brought, aligned and to the associated surface kitchen areas are created. Despite the high personnel costs not always wrinkles or blisters when applying the Avoid protective film. When subsequently cutting the Areas for additional parts were often damaged Painting, so that extensive rework was necessary. With the previous manual application of the protective film one is proceeded as follows: First, at least two People matched in size to a surface area tes rectangular piece of protective film from a supply roll le peeled and cut off, making a total of four People had to be taken over. This piece of protective film was de by the four people hands-free with the self-adhesive Side stretched down freely, so over the body spent there, in a horizontal position on the associated waiter surface area lowered, more or less Wrinkle-free and bubble-free and by swiping with a soft, slippery object, e.g. B. a stiffened Piece of felt pressed on. To be grubbed in the area of the taped over gaps body parts such as fenders or doors Cut the protective film manually with a knife and cut the Cutting edges pressed on by hand. To the protective film in the Be rich in accessories such as roof trims, sunroof covers, Radiator attachment figure, windscreen washer nozzles, antennas, windscreen Cut out frames or the like and cut them out for assembly you have a flat strip-like template the body is positioned correctly and this with the applying protective film also taped over, so that to the Areas to be cut free not only in a small area distance to the body surface was kept, but through the template also a cutting and guiding edge for a knife is formed along which the film conforms to the contour can be separated. Working with a sharp-edged Knife close to the painted body surface  has to paint in the hectic, despite ongoing practice damage and led to extensive rework.

This state of the art corresponds at least to manufacturing practice at least with the applicant; after the United States for environmental protection reasons which no longer allow protective growths in vehicle dispatch, are probably other vehicle manufacturers at one similar film protection system for their vehicles during the Shipping passed. A printed publication however, the applicant is not aware of this.

Based on this state of the art, it is the task of the He finding, the application process or the corresponding method direction to improve that the monotonous handar replaced by mechanization, the quality of the appli cation with regard to freedom from bubbles and wrinkles protective film and avoid damage to the paintwork sert and personnel costs can also be saved.

This task is invented with regard to the application method according to the entirety of the features of claim 1 and with respect to the device solved by that of claim 16.

Then the mechanization of the film application to the Body a certain rectangular piece of protective film from a supply roll using a robot-guided Tensioning frame, preferably with suction legs, on the non-adhesive tendency page recorded, deducted from the supply roll and ded cut. Before applying the foil cut to the checks In the freely unclamped state, tear lines in the Be rich of attachments with a heated mechanically along Defined contour lines guided serrated from their perforated non-adhesive film side. Only then will it prepared, wrinkle-free protection in the stenter foil from the handling robot on the associated surface The kitchen area is lowered to the correct position, created bubble-free and with pressed on a scraper. This way you will be successive  sive taped over all surface areas. In the area of attachments len become protective film parts along the perforated tear lines deducted and the areas are cut out so that they can be assembled.

In an expedient embodiment of the invention, the first loosely applied foils all pressed together. In the area the protective film is cut through and the Cut edges in the gap area with a rotating brush pressed.

Further expedient embodiments of the invention can Subclaims are taken; otherwise the invention based on an exemplary embodiment shown in the drawing les explained below; show:

Fig. 1 shows the lay-out of a production line for automated, standard gluing of passenger cars in plan view,

Fig. 2 shows an enlarged detail of the basic working stations of the production line 1 is also shown in FIG., In plan view,

Fig. 3 and 4 are side view (FIG. 3) and top view (Fig. 4) to a device for demand-supply holding and peeling of protective film from a supply roll,

Fig. 5 is a detail view of a squeegee from the Einrich processing of Fig. 3 and 4 for holding the film vorauslau fenden end, facing the direction of the normal un tenliegende, saugwirksame side of the squeegee,

Fig. 6 is a robot-guided tensioning frame for the automated handling of a cut from the supply Folienzu section,

Fig. 7 is a cross-sectional showing through the leading-side suction bar of the clamping frame of FIG. 6 taken along section line VII-VII, additional gripper elements,

Fig. 8, the suction of the chute for holding the leading end film tail in registered opposition to the leading end of the suction clamping frame according to Fig. 6,

Fig. 9 is a longitudinal view of the station for the gluing of the Da ches in the stage where the stretched held ready in the clamping frame from the film sheet hanging Perforati is processed onsroboter,

Fig. 10 is a stretched in a tenter frame with different cut Folienzu retracted therein Perforati onslinien,

FIGS. 11 and 12 are two different side views of a Tan-the perforating tool are placed simultaneously with the two äquidi stante perforation in the stretched bereitge maintained protective film can

Fig. 13 is a double tool for perforating double or mono- perforation,

Fig. 14 is a perspective view of a displaceable body lie cross portal with a vertically movable foil blade for pressing the applied Schutzfo,

Fig. 15 shows a cross section through the coating bar of the portal shown in FIG. 14 taken along section line XV-XV and

Fig. 16 is a side view of a robot-guided double tool for measuring the position and for freeing joints as well as pressing the edges of the protective film.

Before the automated gluing of the Ka body is dealt with in detail, let us first invent Process according to the invention for film application with reference described in more detail on the drawings.

The self-adhesive protective film 23 provided in supply rolls 21 is automatically applied to certain, preferably the horizontal surfaces of car bodies 1 in the customary notchback version. In principle, it is possible to apply the protective film to the fully assembled vehicle or to the body at any other time during the final assembly of the vehicle. However, since the protective film applied already provides a certain amount of protection of the paint against assembly-related damage during assembly, the protective film is appliated on the freshly painted bodies 1 according to the exemplary embodiment shown, which then run into the final assembly with the protective film. It is also advantageous to glue the side surfaces of doors, preferably the front doors that are used particularly frequently during assembly, and in particular the driver's door. Regardless of whether the protective film is applied before, during or after assembly, the film must be recessed in places of accessories in order to be installed.

For automated film application, a measured piece of film 44 is pulled from the film supply by a robot-guided stenter 37 and taken over into the stenter without creases and under a certain internal stress. In this stretched film blank, which can be handled almost like a rigid work piece thanks to the stenter frame, perforation lines are placed in the film blank before the film application with a robot-guided perforation tool. Only then is the film cut provided with the perforation lines lowered by the stenter robot in the correct position on the associated surface area of the body and pressed onto it without creases or bubbles.

In detail, the following process steps are provided: The leading end of the protective film 23 , starting from the supply roll 21 , is fixed and provided in such a way defined and wrinkle-free that the film end 26 is at least partially accessible on the non-adhesive side 24. During the peeling off, the protective film 23 is continuously treated antistatically in a freely stretched span, so that the film cuts can later also be applied to the surface of the body without problems up to the edge. The mentioned end of the protective film on the supply side is taken over on its non-adhesive side by the tenter frame side, guided by the tenter frame robot in the pulling direction a, first suction strip 38 and loosening the film from the preparation holder.

Now a size-matched, rectangular piece of a protective film is pulled off the supply roll 21 and stretched out as long as the film pull-off piece still adheres to the supply. A trailing, second squeegee 39 of the clamping frame 37 is placed on the non-adhesive side of the protective film stretched out and also holds the film there by switched vacuum. As a result, the removed film deduction piece is clamped in the clamping frame and, at the same time, a new supply-side film end is held in place again at the readiness holding device. By means of suitable constructive measures when unwinding the protective film, it is ensured, in spite of different adhesion of the film layers of the winding to one another and despite un different winding diameters, that the protective film is removed from the supply roll with constant tension. A transverse knife cuts off the removed piece of film, which is already held in the clamping frame, from the supply.

The tenter frame robot 35 holds the now freely movable film blank 44 in a work-related manner and defines the position of the perforation robot 50 which, in the freely stretched film from the non-adhesive film side, has the required tear lines 45 , 45 ', 45 ''by means of a heated toothed washer 55 or egg nes perforated heated, crown-like perforation stamp.

The film blank pretreated in this way is now aligned from the stenter frame robot 35 to the associated surface section 3 , 4 , 5 of the body 1 provided in a defined position, lowered onto it and applied to it in the stretched-out and perforated state. When the film is applied to the curved surface of the body, the tension of the film cut held on the edge is increased. So that it does not tear at the perforation lines, the edge clamping is reduced to a lower value in this transfer phase, so that the film edge can slide out of the edge clamping with low tensile stress in the film blank. The protective film is then pressed on by means of a slidable and elastic scraper strip 67 . Advantageously, all areas to be protected are loosely covered with protective film and then all film sections are pressed on in a uniform process.

In the area of glued joints 6 , the film can be severed by means of a ro-guided knife, the cut edges being pressed on with a rotating brush 87 . The protective film parts in the area of attachments, which are disruptive during the subsequent assembly, are pulled off along the perforated tear lines, preferably manually.

With regard to a simple and residue-free removal of the protective film after use, that is to say when the vehicle is delivered to the customer, the adhesive property of the adhesive side 25 of the protective film is deliberately reduced compared to normal pressure-sensitive adhesive strips of packaging technology. However, to ensure that the protective film does not come loose during driving - test drives and short transfer runs are also carried out in a film-glued state - the edges of the protective film lying in the direction of travel are separately secured by a transversely extending adhesive strip with higher adhesion. After complete application of the protective film, these security strips are applied in one of the downstream manual work stations 17 . It is in the cases in which the foil cut on the longitudinal edges of the protective film must be secured with a safety strip on the body - z. B. when gluing doors - also conceivable to merge this security strip immediately with the protective film on the reel stand and to handle and appli this film composite together.

After a standard film coating from Fahr car bodies very much protective film is used, it is expedient, an automatic role change in the roles stands for the protective film and the supply rolls sized so d. H. so much protective film in each case roll of advice that a supply roll for the need a complete work shift is sufficient.

The production line shown in FIG. 1 10 for auto mated, standard gluing of passenger cars has a plurality of transport moderately linked workstations 12 to 17, through which the are conveyed adherend, position on the conveying carriage 11 defines fixed bodies 1 cyclically. In the individual workstations 12 , 13 , 14 and 16 according to FIG. 2 with work to be carried out automatically, the bodies are set in a defined position indirectly via the conveyor slides and fixing devices provided in the stations within a certain tolerance range. In between there are workstations with manual work in which a defined position fixation is not necessary. The individual workstations are spaced apart by the length of a bodywork plus freedom of movement and security.

The notchback body contains several horizontal surfaces, namely bonnet 3 with adjoining parts of the fenders, boot lid 4 also with adjoining fender flanges and the roof 5 . The protective film 23 to be applied thereon is stored in supply rolls 21 of different widths R, which are held in appropriate roll stands 20 , 20 ', 20 ''for processing. In the horizontally gela stored supply roll 21 , the non-adhesive side 24 faces outwards. After a deflection of the protective film pulled off the supply roll over a small, movably mounted deflection roller - dancer roller 22 - the protective film is guided to a suction line 27 , on which the film end 26 on the non-adhesive side - with the adhesive side 25 facing downward - is held.

The protective film is more or less for different reasons niger heavily charged, which is an automated process Processing and foil application disrupt. Therefore the protection fo lie treated antistatically when pulled off the supply roll. This can be done across the entire width of the film grounded contact rod from the non-adhesive side good electrically conductive material happen. To be stronger too quickly remove electrical charges from the protective film can, ionized air can be blown onto the protective film the one that compensates for the charge on the film.

Experience has shown that the individual layers within the winding assembly of the supply roll adhere more firmly to one another in the inner winding layers than in the outer winding layers. This leads to an increase in the withdrawal voltage as the supply roll becomes smaller. On the other hand, however, the protective film should be taken over into the tenter frame with a constant film tension. To compensate for any interference, the aforementioned dancer roller 22 is provided, which is mounted on a rocker 31 with respect to the supply roll 21 and can be moved radially and can be pressed onto the circumference of the supply roll by means of a pressure cylinder 32 with an adjustable force. In addition, the dancer roller 22 can be braked by means of a brake, not shown, with an adjustable braking torque. Such a brake can, for. B. can be accommodated as an axially loaded multi-disc brake or as a Ko brake brake inside the dancer roller. Due to the adjustable force with which the dancer roller is pressed onto the supply roll and due to the moment with which it is braked, a constant high pull-off force can be achieved regardless of changes in the diameter and the layer adhesion of the supply roll and thus a constant transfer voltage in the protective film is ensured. This can create good conditions for a constant application result of the protective film.

The size of the supply rolls are advantageously based on the need for a complete working shift, so that only one roll change is required per shift. In addition, a device for an automatic role lenwechsel is provided, which is designed such that when the last piece of film from the old supply roll is used, the new supply roll held in readiness is automatically put into use and its leading film end is placed on the suction bar 27 . Such Rollewechseleinrich device is not shown in the illustrated embodiment. It should therefore only be mentioned that instead of the fixed individual storage of a supply roll 21 on both sides in the roll stand, a centrally mounted rocker is provided, at the ends of which a supply roll is rotatably held. Of these two supply rolls, one is positioned in the position of use - as shown in the example - while the other supply roll is kept ready by the swing arm length. Furthermore, in the device for an automated transfer of the film end to the suction bar 27, a bracket which is also oscillating with the rocker is provided and which extends with a rod across the roll width. To prepare for an automatic roll change, the end of the film with the adhesive side of the protective film is applied manually to this rod. When changing roles this bracket is then pivoted from below to the suction bar 27 , which takes over the fo lienende of the new supply roll.

Depending on the production numbers per shift and the cycle time at Foil appliqués are supply rolls that work for one enough layer, so heavy that it is no longer on its surface outer circumference may be stored or handled because the Fo Otherwise there are pressure marks and the winding flat spots are preserved would interfere with proper processing would. Rather, film rolls of this weight or Diameter class - the film width is not decisive here influence - always in the center with special dishes recorded and stored in separate racks. To the rolls must be delivered with a metal mandrel be from the manufacture of the wrap to consumption the role remains with her and after consumption to the manufacturer must be returned.

The roll stands mentioned are arranged in the two gluing stations 12 and 13 for the bonnet and boot lid or for the roof. For each surface section 3 , 4 , 5 to be glued, a stenter robot 35 , 35 ', 35 ''is also provided, which has the usual six axes of movement and is freely programmable. The roller stand 20 and stenter robot 35 for the hood 3 on the one hand and the reel stand 20 'and stenter robot 35 ' for the boot lid 4 on the other are arranged in the same workstation 12 . For the film application to the roof 5 , a separate work station 13 is provided. In each adhesive work station 12 and 13 there is also a freely programmable, preferably six-axis perforation robot 50 or 50 '. To be precise, these are arranged above the body 1 for reasons of space in such a way that the working space of the perforation robot comes to lie approximately centrally in the work station. The perforation robot can be attached to the ceiling structure of the hall or hanging from a portal or it can be mounted on the side of a vertical mounting surface - wall-mounted - for example on the wall of the hall, on a pylon rising from the hall floor or on one the console or the wall of the hall.

On the roll stands, the leading end 26 of the protective film 23 is defined by the suction strip 27 and is held and provided in such a way that the end of the film on the non-adhesive side 24 is at least regionally accessible. The stator-side squeegee is perforated on its underside 28 and can be vacuum-struck with suction or ventilated so that the adhesive effect of the squeegee can be canceled if necessary and in a timely manner. The limiting edge of the suction strip pointing in the pulling direction a of the film is contoured in a crenellated manner, the projections 29 also being perforated on the underside for effective suction. As a result, the protective film can be held securely up to the end of the film 26 ; nevertheless, the immediate end of the film is accessible on the upper side in the area between the projections 29 .

Furthermore, egg ne device 30 for right-angled cutting of peeled protective film is provided in the immediate vicinity of the suction bar 27 . This cutting device consists essentially of a transverse to the film Füh guide bar, in which a knife mechanically guided and - z. B. is by means of a pneumatic cylinder over a cable - ben ben. A one-off transverse movement of the knife in the guide bar safely removes a piece of film that has been removed from the advice on the suction bar. With regard to knife wear - the protective film must be cut with a small cutting force, ie without the risk of wrinkles - a simple and quick knife change must be ensured by appropriate structural design. An automatisable knife change or a knife with a longer service life due to better knife material and / or due to ver sliding blade with increased wear reserve (sliding long blade or rotatable circular knife) could be advantageous.

The stenter robots 35 , 35 ', 35 ''carry on their Arbeitsar men 36 , 36 ', 36 '' each a to the size of the surface area 3 , 4 , 5 matched, rectangular Spannrah men 37 , the two opposite Has suction strips 38 , 39 arranged on the long sides for holding a film blank 44 , specifically a leading suction strip 38 and a trailing suction strip 39 . The individual suction strips can be switched on or vented via separate vacuum lines 46 or 46 '.

The leading in the pulling direction a squeegee 38 of the clamping frame is contoured on the long side pointing away from the inside of the frame - matching the crenellated contour of the upright squeegee 27 - also crenellated. Namely, the projections 40 of the tenter frame squeegee 38 can be immersed between the gaps of the standard suction bar 27 until they come into contact with the protective film 23 . On the leading suction bar 38 le diglich the end faces 41 of the projections are perforated for suction and can be subjected to negative pressure. When the film is taken over, the end faces of these frame-side projections between the projections of the stand-side squeegee 27 are lowered and brought into contact with the accessible areas of the film 26 , whereby the film end held ready is taken over by the tenter 37 .

The projections 29 of the upright suction bar 27 are narrower (width b) than the projections 40 of the stenter suction bar 38 , which are formed with a width B. The narrow projections only need to hold the film end in a wrinkle-free manner, whereas the wide projections 40 of the stenter suction line have to transfer the high pull-off forces of the self-adhesive protective film from the supply roll. To increase the pneumatic holding force of the clamping frame suction strips, the holes in the holding surfaces on the contact side are countersunk over a large area. It must be taken into account here that the film can only be pulled off the roll of advice 21 before with great effort due to the self-adhesion. In order to be able to hold the film end when pulling it away from the tensioning frame suction strip 38 , this is provided with pivotable gripping means 43 for additionally holding the protective film. The flap-like gripping means are - driven by pivot cylinder 49 - pivotable about a pivot axis 48 and can be preloaded on the unpressurized end face 41 of the projections 40 .

To take a film blank 44 from the roll stand 20 , the clamping frame 37 is placed transversely to the protective film 23 , that is to say vertically in the case of game, with the leading suction strip 38 on the protective film or the suction strip 27 on the stand side, that the end faces 41 of the frame-side projections 40 between Dip the gaps on the stand-side squeegee and place it on the non-adhesive side 24 of the film. Now the leading squeegee is subjected to vacuum and the gripping means are closed so that they lay on the adhesive side 25 of the recorded film end. The ständersei term suction bar 27 is now ventilated so that the film end is free. By moving the leading squeegee 38 of the tenter frame away from the stand 20 by means of the tenter frame robot 35 , a measured length of film is pulled off the roller 21 , the tenter frame being pivoted towards the horizontal at the same time, so that towards the end of the Pulling and swiveling movement also places the trailing suction bar of the tenter on the film. In this state, the second frame-side suction bar 39 and the stator-side suction bar 27 are located close to one another. Both adjacent suction strips are - as long as the film is still under the tension of pulling off - applied with vacuum and then the cutting device 30 is actuated, so that a film blank 44 is stretched out in the stenter 37 and taken over by the stenter. During the film cut through the film on both sides of the cut-off device 30 is held securely by suction strips 38 and 27 , so that there is no risk of wrinkling due to the force of the moving film separating knife. After cutting off, a new film end 26 is available in a position-defined and wrinkle-free manner on the stand-side suction bar 27 for a new takeover case.

In practical operation, it can never be entirely ruled out that the stenter robot 36 collides with the bulky stenter 37 somewhere, especially during the setup phase of the robot or when any maintenance work is carried out in the system. Smaller collisions are usually survived by the robot and essentially also by the stenter, but the stenter can warp due to a small collision. In order to be able to compensate for such slight deformations, the suction strips 38 and 39 are adjustably held on the stenter. They are adjustable with respect to each other and to the target plane of the stenter and must be adjustable for at least two spatial directions for this purpose. In addition, the flat sides of the two suction strips, which are decisive for the film position, must be able to be adjusted in alignment with one another; it must also be possible to adjust the circumferential position to a certain extent. This type of multiple adjustability of the tenter suction is not shown in the drawings. Should major damage occur to the stenter frame - regardless of the type or cause - the entire stenter frame must be replaced quickly so that there are no lengthy production interruptions. All mechanical connections between the clamping frame and the robot arm and all lines must therefore be able to be quickly disconnected and closed again. Of course, for such damage or repair, a proper stenter with all accessories must be kept ready in the access area of the stenter robot.

So that the mechanical tension in the film is not too great and the risk of a film tear along the perforation lines is avoided at the end of the transfer phase of the film cutting from the stenter to the - curved - body surface, the film edge is slid out of the hand holder of the film. This is realized in the suction strips 38 and 39 by a stepped reduction in the adhesive negative pressure. In fact, the suction chambers of the squeegees are only partially ventilated via a by-pass line that can be controlled in a timely manner, but remain connected to the vacuum source, so that outside air is sniffed in and a vacuum value with reduced adhesive effect is set in the squeegee. By appropriate dimensioning of the by-pass cross-section, the adhesive effect in the transfer phase of the film can be influenced in such a way that the film edge slides down from the squeegee while the film is still tolerable.

The approximately centrally of and above the body arranged in the Beklebestationen 12 and 13 with their working space Perforati ons robots 50, 50 'carry at their working arm 51, a perfora tion tool, with the tear lines 45, 45', 45 '' in the part of the Tenter frame robot to be held stretched film piece 44 to be perforated. For this purpose, the perforation tool has at least one circular, freely rotatably mounted, toothed toothed disk 55 made of metal, preferably of a corrosion-resistant steel, with a thickness of about 1 to 2 mm. The toothed disk protrudes only with its toothed outer circumference between thermally insulated skids 56 which slide along it when the protective foil 44 is perforated and limit the depth of penetration T of the toothed disk into the protective film. In the rest of the area, the toothed disk is surrounded by a small axial play of heat-conducting and heated material of the perforation tool, so that thermal energy can be transferred into the toothed disk via these zones. In the area lying behind the toothed disk, a heating device 57 in the form of a heating cartridge for controlled temperature-precise heating of the toothed disk is arranged in the perforation tool. For example, the toothed disk should be heated to a constant temperature in the range from 120 to 180 ° C. with a temperature fluctuation of ± 2 degrees. The optimal height of the toothed washer temperature depends on the film - material, film thickness - and on the speed of operation and must be empirically optimized on a case-by-case basis. In the exemplary embodiment according to FIGS. 10 and 11, the perforation tool is designed as a tandem tool with two serrated disks arranged parallel to one another. This means that two equidistant perforation lines 45 , 45 'can be placed in the protective film at the same time.

Fig. 13 shows a multi-tool as a perforation tool with a mono-perforation 53 and with a tandem-Per forationswerkzeug 52nd The tools 52 and 53 can be brought alternatively and optionally into the operative position, so that either a single perforation line 45 '' or two equidistantly running perforation lines 45 , 45 'can be placed in the protective film. The mono-perforation tool 53 can be advanced by means of a lifting cylinder in front of the tandem tool 52 , so that it is effective sam in this position indicated by dash-dotted lines. The tandem tool 52 is operative in the retracted position shown in full lines.

It is even advisable already in the tandem-perforation tool according to FIGS. 11 and 12, one of the two serrated discs along the lines of Fig. 13 between two Endposi functions to store displaceable, wherein the same position in an end position both sprockets and its skids and in the other end position the toothed wheels are offset in height. In the setting with identical toothed wheels, two equidistant perforation lines can be drawn, whereas in the case of height-adjusted toothed wheels only the exposed toothed wheel is effective; In this setting, mono perforation lines can be laid. The advantage of a perforation tool designed in this way is not only reduced construction costs, but above all in a compact design, which is particularly important when perforating the film cut out within a stenter frame.

So that the distance between the perforation lines can be set on the part of the tandem perforation tool, it is expedient if the holder of at least one of the two toothed disks 55 can be fixed in the tandem tool at different spacing positions from the other toothed disk. This can e.g. B. happen by shims or by screwing using the use of elongated holes.

Due to frequent and not insignificant temperature swans of the heated perforation tool - heating at Ar start of work, cooling down during work breaks - exists the risk of screw connections on this tool becoming loose and this leads to interference. Therefore the screw connections either stable in temperature in the area of the perforation tool executed and secured against thermal loosening or the workpiece division and the screw connections - as far as this is constructively possible - in one area be shifted, in which a heating of the perforation stuff does not occur.

In order to be able to continue working quickly in the event of any damage to a perforation tool, the connections of the tool 52 to the robot arm 51 are simple and are optimized with regard to rapid detachability and assembly. The same also applies to the line connections to the tools, which are designed as plug connections. Of course, at least one intact perforation tool must be readily available for each perforation robot.

Since the Perforationsroboter 50, but also the cutting-open executes rotations 80 spatially complicated movements and strong arm and hand, are leading to the robot tools lines highly stressed. In order to minimize the risk of a line defect, it is expedient to provide rotary joints for the individual lines at the articulation points, the axes of which are parallel or concentric to the respective axes of the robot arm.

For reliable perforation of the film, it depends on the formation of the toothed circumference of the toothed disk 55 of the perforation tool. Namely, several teeth 58 of about 3 to 8 mm circumferential extent are attached to the circumference of the toothed disk, which are spaced apart from one another by deeply cut tooth gaps 59 . The tooth gaps spring back behind the skids 56 of the tool. As a result, only the teeth 58 are perforated in the protective film. At the front and rear ends of each tooth 58 of the toothed disk, a pointed mandrel 60 of at least about 2 mm radial extension is formed and the tooth back between the two teeth of a tooth is provided with a blade-like sharpening 61 . The width Z of the tooth gaps 59 on the circumference of the toothed disk at the height of the skids is approximately 1 to 3 mm. This measure determines the length of the remaining cross-sections in the perforated film. This measure must also be optimized on a case by trial basis. On the one hand, the residual cross sections remaining after perforation must not be too small so that the perforated film can still be processed safely, ie continue to perforate and also be handled safely. On the other hand, the remaining cross sections should be small enough so that the pieces of film to be removed due to assembly along the perforation lines can also be torn off in a reliable manner without the remaining film detaching or tearing when torn off.

For perforating self-contained contour lines of small dimensions, e.g. B. small circles, rectangles or the like can also kro nenike shaped, also heatable perforation stamp can be used. The spiked ring is expediently shaped Lich Lich as the toothed disk 55th The serrated rim is surrounded at least on the outside by a stop ring that remains cold, which is set back by a certain amount compared to the tips of the serrations and limits the depth of immersion of the serrated rim in the film, thus determining the degree of perforation. Applications for such smaller, self-contained contour lines are cutouts for smaller accessories such as antennas, wash water nozzles, door handles, company emblems or the like.
In the subsequent to the gluing stations 12 and 13 as well as an interposed empty station 15 at the pressing station 14 , the perforated and loose but wrinkle-free protective film pieces applied to the body are pressed together on the surface parts, which improves their adhesion. For this purpose, a portal 65 is provided in the pressure station 14 in the longitudinal direction to the vehicle body on a floor guide 76 which is displaceable and provided with a corresponding drive, which spans the vehicle body. Within the opening of the portal, an elastic and slidable screed 67 extends horizontally across the entire width of the vehicle, the shape of which is roughly adapted to the cross-sectional contour of the surface parts to be covered. To adjust the contour, the scraper bar is composed of a straight, central bar section 68 and of two lateral bar sections 69 and 69 'arranged in a mirror-image inclination. The scraper bar 67 is in a vertical guide 66 tilt-proof - right against left - up and down movable, while maintaining its set inclination to the longitudinal axis of the vehicle (see Fig. 15). The portal is also equipped with a lifting drive for the scraper, with which the scraper can be raised and carefully lowered onto the body. In the lowered state on the body, the scraper bar loosely rests on the vehicle body at any height with a defined force and thus presses the foils onto the body. This pressing force results from gravity due to the dead weight of the molding and any additional weights placed in the vertical guide. The scraper bar can easily follow the longitudinal contour of the body as the portal travels along the body.

In the illustrated embodiment, the supporting part of the scraper bar is formed by an angle profile 70 , to which a rigid felt strip of approximately 15 mm in thickness and approximately 20 cm in width is screwed. A plastic strip 74 made of a fiber-reinforced elastic plastic is interposed between the angle profile 70 and the felt strip 73 to stiffen the felt, the exposed side of the plastic strip being toothed by a large number of closely adjacent incisions 75 and thus reduced in its resilience at the exposed edge is. In addition, the scraper bar can also twist more easily as a result of this, making it easier to adapt to different body-side contours.

To press the protective film, the portal 65 begins at the front position indicated by the dot-dash line in FIG. 2. There the scraper bar is lowered on the front of the body and the gantry travels in the longitudinal direction to the rear with a weighted scraper bar lying loosely on the body over the fixed body and thus presses on the loosely applied protective film. When the end of the bonnet has been reached, the portal raises the moldings to the roof level and carefully lowers them again at the beginning of the roof; pressing continues on the roof membrane. At the transition from the roof to the boot lid, the scraper bar is carefully moved again and the pressing process continues there as well. Towards the end of the boot lid, the scraper bar is raised completely and the portal moves back to the starting position indicated by dash-dotted lines when the scraper bar is raised and waits for the next body with the scraper bar raised.

Following the pressing station 14 , a Aufschneidestati on 16 is provided, in which taped joints 6 can be cut out automatically to movable parts of the body. In this station, another freely programmable industrial robot - slicing robot 80 - with six degrees of freedom is arranged for the robot arm 81 and a further, seventh movement axis for moving the slicing robot along the floor guide 89 . Not only because of the measuring task, but also because of the front and rear of the body Liche, taped joints 6 , where the film has to be cut open, the slicing robot is equipped with the aforementioned travel axis 89 Ver.

A double tool 82/83 which can be pivoted into different working positions is attached to the working arm 81 . When the bodies are transferred from station to station, the actual position of the bodies differs despite a mechanical fixation of the conveyor slides on the side and longitudinal stops on the station side within a tolerance range that is inadmissibly large for the free cutting of the joints. Certain intrinsic tolerances of the body itself are superimposed on these positional tolerances of the bodywork, which are in themselves considerably smaller than the positional tolerances, but are not completely negligible when gaps are cut free. Therefore, before the joints of the bodywork are cut free, their exact actual position in relation to the slicing robot must be determined at a few bodywork points at the front and rear. This measuring the actual position of the joints can he follow by a stationary three-dimensional measuring system.

In the illustrated embodiment, this actual position-He determination of the joints 6 also by the slicing robot 80 itself, which works here as a measuring robot. The effective in the egg nen pivot position of the dual tool part is accordingly designed as a measuring tool 82 with which the exact actual position of the body 1 or the joints 6 can be detected in relation to the slicing robot. The effective in the other pivoting position of the two-tool tool part is designed as a cutting and pressing tool 83 , which has a knife 84 for severing the protective film in the joint area and a rotating brush 87 for pressing the cut edges. The rotating brush 87 can be driven by an electric motor 88 via a speed-reducing bevel gear.

The knife 84 is suspended transversely to the cutting and moving direction by means of a leaf spring 85 , so that it may follow the positional deviations of the joint from the robot-side predetermined guide path. So that, on the other hand, the knife cannot deviate to the side to an unacceptable extent, the range of motion is restricted by a pair of stop arms 86 spanning the knife on both sides, the range of motion being able to be predetermined by adjusting screws 92 . When the knife is inserted into the joint, however, a clear position of the knife must be ensured and the freedom of movement must be eliminated. Therefore, the stop arms, which can be pivoted about a pivot axis 91, can be moved together by means of a small pneumatic cylinder 90 , which acts on the opposite lever arms via a spreading wedge, and the knife can be clamped between them in a defined position, which happens temporarily during the insertion of the knife into a joint.

Also in connection with the cutting tool 83, it should be mentioned that with a view to efficient work, a quick change of the knives 84 must be possible because these are subject to wear due to the large lengths of film to be cut. Measures to increase the tool life are also expediently used here, such as better knife material, hard coating of the cutting edge or higher wear reserve, for example by using rotatable circular knives. For the sake of completeness in connection with this robot tool it should be mentioned again that it must be replaced quickly in the event of damage and that all connections of a mechanical, electrical or fluidic type must be designed accordingly. The measuring tool 82 alone should also be able to be quickly replaced within the double tool 82/83.

It can easily with the described system body different vehicle types in the production mix  Protective films are stuck on if there is little in the stations Compatible additional equipment can be provided. And it has to at least one self-employed in the first workstation en Type recognition installed, one with the bodies drives carried data carrier and the body type from it determined. For example, this can be done by attaching to the body en carried barcode label and by a barcode reader in the entrance area of the workstation. Other In formation carriers are generally suitable for this. This In formation can be done by clocking the bodies of work station to workstation step by step through the work line be clocked through. In a suitable way, the Robot control of each workstation in the Body type located in the station. Furthermore a program selection must be treated in the robot controls different body types are available the one that can be changed quickly and automatically.

To make the production line more flexible with regard to a production mix, the width of the clamping frames 37 , 37 'and 37 ''need not necessarily be changeable; in this respect, they can be designed for the widest body type. In the case of narrower bodies, the protective film then extends a little more into the side wall, which is harmless. If one wants to avoid this, the suction lines should be equipped with switchable chambers in the edge area when using different width foils for different width bodies, so that the vacuum can be effective at different widths. In order to be able to use different lengths of surface parts with the same stenter, the rear squeegee of the stenter can expediently be moved into different positions by means of actuating cylinders, so that different frame lengths can be set.

In saloon sedans, three surface parts are usually to be protected, namely bonnet 3 , roof 5 and boot lid 4 , which can differ in width and or length for different body types. In the case of combi sedans, the roof is significantly longer, so that this extension can only be achieved with difficulty by extending the stenter frame. However, since the trunk lid is no longer required for Combi limousines, it is also a good idea to combine the production of Combi limousines with the longer roof of Combi limousines with two film sections - starting from the back to the front - with overlap and the Tension frame for roof and trunk lid to be used for the usual notchback sedans.

Claims (45)

1. A method for applying self-adhesive protective film ( 23 ) to surface areas ( 3 , 4 , 5 ) of car bodies ( 1 ), the protective film ( 23 ) being provided in the form of at least one supply roll ( 21 ) whose roll width ( R) is matched in each case to a side length of the surface parts ( 3 , 4 , 5 ) to be protected, with the following process steps:

• - From the supply roll ( 21 ) by a robot-guided ( 35 , 35 ', 35 '') clamping frame ( 37 ) a measured piece of film ( 44 ) is removed and wrinkle-free and under internal tension in the clamping frame ( 37 ) and cut off from the supply ,
• - In this film blank ( 44 ) stretched out in the clamping frame ( 37 ), perforation lines ( 45 , 45 ', 45 '') are drawn with a robot-guided ( 50 , 50 ') perforation tool ( 52 ) before the film application,
• - Only then is the perforated film blank ( 44 ) lowered by the stenter robot ( 35 , 35 ', 35 '') in the correct position on the associated surface section ( 3 , 4 , 5 ) of the body ( 1 ) and pressed onto it without creases or bubbles.

2. The method according to claim 1, characterized by the commonality of the following features

• a) position-defined and wrinkle-free holding and staging the leading, from the supply roll ( 21 ) the end ( 26 ) of the protective film ( 23 ) such that the film nende ( 26 ) on the non-adhesive side (24) is at least be accessible ,
• b) taking over the provided end ( 26 ) of the protective film ( 23 ) on its non-adhesive side (24) by means of a first suction strip ( 38 ) guided mechanically in the pulling direction (a) and detaching the film from the provision holder,
• c) pulling off a rectangular piece ( 44 ) of protective film which is matched to the size of a surface section ( 3 , 4 , 5 ) from the supply roll ( 21 ) and unclamping the piece of film removal piece ( 44 ) while still adhering to the stock,
• d) placing a at a certain distance from the first suction bar ( 38 ) and with it a clamping frame ( 37 ) forming the second suction bar ( 39 ) on the non-adhesive side te ( 24 ) of the stretched protective film ( 23 ) and thereby tensioning the removed Foil take-off piece ( 44 ) in the clamping frame ( 37 ) with subsequent acceptance of the new stock-side film end ( 26 ) at the staging holder and cutting off the pulled-off film piece ( 44 ) from the supply,
• e) Perforation of tear lines ( 45 , 45 ', 45 '') in the area of the later position of attachments by means of a heated serrated washer ( 55 ) guided mechanically along defined contour lines into the freely stretched piece of film ( 44 ) from the non-adhesive side of the film ( 24 ) ago,
• f) Aligning and lowering the perforated film blank ( 44 ) in the clamping frame ( 37 ) and the assigned surface area ( 3 , 4 , 5 ) of the vehicle body ( 1 ) provided in a defined position and applying the film cut ( 44 ) to it,
• g) subsequently pressing on the protective film ( 44 ) by means of a slidable and elastic scraper strip ( 67 ),
• h) cutting through the protective film in the area of taped joints ( 6 ) and pressing the cut edges with a rotating brush ( 87 ),
• i) Pulling off protective film parts in the area of additional parts along the perforated tear lines ( 45 , 45 ', 45 '') and recessing the remaining protective film on a daily basis and disposing of these film parts.

3. The method according to claim 1 or 2, characterized in that the protective film ( 23 ) on freshly painted vehicle body rien ( 1 ) is applied, which then enter the final assembly. 4. The method according to claim 1 or 2, characterized in that the removed protective film ( 23 ) treated antistatically before further processing, ie is freed of any static charge. 5. The method according to claim 1 or 2, characterized in that regardless of any changes in diameter of the supply roll ( 21 ) or fluctuations in adhesion of the protective film ( 23 ) in the supply roll before the protective film ( 23 ) from the supply roll ( 21 ) is removed with a constant tension. 6. The method according to claim 1 or 2, characterized in that the position-defined and wrinkle-free holding and providing the leading, from the supply roll ( 21 ) outgoing end ( 26 ) of the protective film ( 23 ) on its non-adhesive side (24) by means of a can be switched on and off, along a holding suction bar ( 27 ) effective negative pressure, at least in some areas a detectable edge strip of protective film is left over the holding suction bar ( 27 ). 7. The method according to claim 1 or 2, characterized in that the clamping frame ( 37 , 37 ', 37 '') for unclamping and handling the film blank ( 44 ) by a freely programmable industrial robot ( 35 , 35 ', 35 '') with at least five degrees of freedom of movement. 8. The method according to claim 1 or 2, characterized in that the removal of the protective film ( 23 ) from the stationary held NEN supply roll ( 21 ) by the robot-guided stenter ( 37 , 37 ', 37 ''), namely by moving the first away in parallel Suction strip ( 38 ) from the supply roll ( 21 ) and the stel supply bracket. 9. The method according to claim 1 or 2, characterized in that cutting off the removed piece of film ( 44 ) from the supply by means of a guided ( 30 ), transverse knife. 10. The method according to claim 1 or 2, characterized in that the perforation of the tear lines ( 45 , 45 ', 45 '') in the freely held piece of film ( 44 ) by a freely programmable industrial robot ( 50 , 50 ') with at least five degrees of freedom of movement occurs. 11. The method according to claim 1 or 2, characterized in that when applying a in the clamping frame ( 37 , 37 ', 37 '') held film blank ( 44 ) on the associated surface section ( 3 , 4 , 5 ) the holding force with which Tensioning frame ( 37 , 37 ', 37 '') holding the film blank ( 44 ) is reduced in such a way that the held edges of the film blank ( 44 ) slide out of the edge clamping under the curvature-increasing tension of the film cut ( 44 ) when applied. 12. The method according to claim 1 or 2, characterized in that in repetition of steps a) to f) with respect to the other surface parts to be coated ( 3 , 4 , 5 ) next all surface parts to be glued ( 3 , 4 , 5th ) of the body ( 1 ) with protective film ( 44 ) are stuck in a defined position and that the pressing of the protective films ( 44 ) only afterwards by means of a stretch over the entire vehicle width of the elastic scraper strip ( 67 ) uniformly for all over glued surface parts ( 3 , 4 , 5 ). 13. The method according to claim 1 or 2, characterized in that the bodywork of notchback sedans, the protective film for the hood ( 3 ) and for the trunk lid ( 4 ) are applied simultaneously and staggered for film application on the roof ( 5 ). 14. The method according to claim 1 or 2, characterized in that protective film is not only applied to substantially horizontally extending surface portions ( 3 , 4 , 5 ) of the body ( 1 ), but also on the side surfaces of doors. 15. The method according to claim 12, characterized in that the elastic scraper strip ( 67 ) relative to the body ( 1 ) under approximately constant pressing force in the longitudinal direction over the body ( 1 ) is slid away. 16. The method according to claim 1 or 2, characterized in that the severing of the protective film in the area pasted Fu gene ( 6 ) and pressing the cut edges by a freely programmable industrial robot ( 80 ) with at least five degrees of freedom of movement. 17. The method according to claim 16, characterized in that before cutting the protective film in the area of taped joints ( 6 ) and pressing the cut edges, the actual position of the joints ( 6 ) of the body ( 1 ) within the Ar beitsraumes of the industrial robot ( 80 ) measured and the relative position of the joints ( 6 ) to the industrial robot ( 80 ) is fed into the robot controller. 18. The method according to claim 1 or 2, characterized in that in the area of the fenders and doors protruding cut sections are left on the body ( 1 ). 19. The method according to claim 1 or 2, characterized in that the protective film parts in the area of accessories along the perforated tear lines ( 45 , 45 ', 45 '') are manually removed from the Ka rosseries ( 1 ). 20. Device for the automated, serial application of self-adhesive protective film ( 23 ) on substantially horizontally extending surface sections ( 3 , 4 , 5 ) of freshly painted car bodies ( 1 ) which are still free of attachments, in particular for carrying out the method according to claim 1,

• - With at least one roll stand ( 20 , 20 ', 20 '') for a supply roll ( 21 ), in which the leading end ( 26 ) of the protective film ( 23 ) is defined and wrinkle-free in such a way that the film end ( 26 ) is accessible at least in some areas on the non-adhesive side (24) and with a device ( 30 ) for right-angled cutting of the removed protective film ( 44 ),
• - further with a freely programmable industrial robot - stenter frame robot ( 35 , 35 ', 35 '') - with at least five degrees of freedom of movement for each surface section ( 3 , 4 , 5 ) of different sizes, from which stenter robot ( 35 , 35 ', 35 '') each on his working arm ( 36 , 36 ', 36 '') a rectangular clamping frame ( 37 ) matched to the size of the surface part to be glued ( 3 , 4 , 5 ) with on two opposite longitudinal sides arranged sow slats ( 38 , 39 ) for holding a film blank ( 44 ),
• - further with another freely programmable industrial robot - perforation robot ( 50 , 50 ') - with at least five degrees of freedom of movement, on the working arm ( 51 ) of which a heatable ( 57 ) toothed disk ( 55 ) for perforating tear-off lines ( 45 , 45 ', 45 '') is arranged in a piece of film ( 44 ) held open on the part of the clamping frame robot ( 35 , 35 ', 35 ''),
• - further comprising a longitudinally slidable to the vehicle body (1), the vehicle body (1) spanning the portal (65) in which an over the entire vehicle width extending adapted in shape to the over-adhesive surface parts, resilient, slidable brushing bar ( 67 ) is movably guided in the vertical direction ( 66 ), which can be pressed onto the vehicle body ( 1 ) with a certain force.

21. The apparatus according to claim 20, characterized by a further freely programmable industrial robot - on cutting robot ( 80 ) - with at least five degrees of freedom of movement, on the working arm ( 81 ) a cutting and pressing tool ( 83 ) is attached, which has a knife ( 84 ) for severing the protective film ( 44 ) in the area of taped joints ( 6 ) and a rotating brush ( 87 ) for pressing the cut edges. 22. The apparatus according to claim 20, characterized in that the cutting and pressing tool ( 83 ) can be pivoted into different working positions and is combined with a further tool, namely a measuring tool ( 82 ), which in one pivoting position is combined with the measuring tool ( 82 ) Effective of the dual tool for the actual position detection of the exact relative position of the joints ( 6 ) of the body ( 1 ) to be cut inside the working space of the cutting robot ( 80 ) and in the other swivel position with the cutting and pressing tool ( 83 ) is effective. 23. The device according to claim 20, characterized in that the device is in the form of a plurality of workstations ( 12 to 17 ) comprehensive production line ( 10 ) through which the to be glued, mounted on the carriage carriage series ( 1 ) can be cyclically conveyed and in the individual Ar beitsstations ( 12 to 17 ) within a certain tolerance field can be fixed, the individual workstations ( 12 to 17 ) by the length of a body ( 1 ) plus a space for movement between adjacent vehicle bodies ( 1 ) creating additional distance. 24. The device according to claim 20, characterized in that for each surface section to be glued ( 3 , 4 , 5 ) in each case a roller stand ( 20 , 20 ', 20 '') and a stenter robot ( 35 , 35 ', 35 '' ) is provided and that in each such adhesive work station ( 12 , 13 ) with a stenter robot ( 35 , 35 ', 35 '') also a perforation robot ( 50 , 50 ') is net angeord. 25. The device according to claim 24, characterized in that in notchback sedans the roller stand ( 20 ) and clamping frame robot ( 35 ) for the hood ( 3 ) on the one hand and the roller stand ( 20 ') and clamping frame robot ( 35 ' ) for the rear cover ( 4 ) to the other in the same workstation ( 12 ) are arranged. 26. The apparatus according to claim 24, characterized in that the perforation robot ( 50 , 50 ') above the body ( 1 ) in the work station ( 12 , 13 ) are arranged such that their working space extends approximately centrally above the body ( 1 ) . 27. The apparatus according to claim 20, characterized in that the vehicle body ( 1 ) spanning portal ( 65 ) with the movable movable scraper ( 67 ) for pressing the glued protective film ( 44 ) in a separate press-Ar station ( 14 ) is provided , which is arranged only after the robot-equipped adhesive work stations ( 12 , 13 ). 28. The apparatus according to claim 27, characterized in that between the robot-equipped adhesive work stations ( 12 , 13 ) and the pressing work station ( 14 ) at least one empty station ( 15 ) is provided for - due to malfunction - manual work to be performed. 29. The device according to claim 20, characterized by the commonality of the following features:

• - In the roll stand ( 20 ), a suction bar ( 27 ) for positionally defined and wrinkle-free holding and providing the leading end ( 26 ) of the protective film ( 23 ) is attached, which with its perforated suction-effective underside ( 28 ) on the non-adhesive, upper side ( 24) the protective film ( 23 ) attacks,
• - The device ( 30 ) facing cutting edge of the squeegee ( 27 ) is crenellated contoured, the projections ( 29 ) are perforated on the underside suction effect sam, so that the protective film ( 23 ) to direct bar to the end of the film ( 26 ) held securely but accessible in the area between the projections ( 29 ),
• - The leading in the pulling direction (a) suction bar ( 38 ) of the clamping frame ( 37 ) is contoured on the away from the frame inside the long side also such that the projections ( 40 ) of the clamping frame suction bar ( 38 ) between the gaps of the upright suction bar ( 27 ) can be immersed until they come into contact with the protective film ( 23 ),
• - Only the end faces ( 41 ) of the protrusions of the tenter frame squeegee, which come into contact with the accessible areas of the foil side ( 26 ) provided on the stand side, are perforated with suction and can be subjected to negative pressure.

30. The device according to claim 29, characterized in that the projections ( 29 ) of the upright suction bar ( 27 ) are narrower (width b) than the projections ( 40 ) of the Spannrah men suction bar (38, width B) 31. The device according to claim 20, characterized in that in the roll stand ( 20 , 20 ', 20 '') an antistatic rail for discharging any static charges of the protective film ( 23 ) is arranged, which the protective film ( 23 ) in the area of a freely stretched Foil dream touched. 32. Apparatus according to claim 20, characterized in that in the roll stand ( 20 , 20 ', 20 '') a receptacle for at least two supply rolls is provided, one of which is in use and the other is kept in readiness and that the device is designed such that when the supply roll in use is fully used, the supply roll kept ready is automatically replaceable with the empty roll. 33. Apparatus according to claim 20, characterized in that in the reel stand ( 20 , 20 ', 20 '') a deflecting the protective film is arranged dancer roller ( 22 ) which is mounted in an approximately radial direction in relation to the supply reel ( 21 ) and is displaceable with controllable force to the extent of the supply roll ( 21 ) can be pressed. 34. Apparatus according to claim 20, characterized in that the dancer roller ( 22 ) is provided with a braking device. 35. Apparatus according to claim 20, characterized in that the supply of protective film ( 23 ) wound into a supply roll ( 21 ) is measured approximately for the need for a working layer. 36. Apparatus according to claim 20, characterized in that the tensioning frame suction bar ( 38 ) with pivotable gripping means ( 43 ) which can be applied to the end face ( 41 ) of the projections ( 40 ) which can be pressurized under prestress, for additionally holding the protective film ( 23 , 44 ). is provided. 37. Apparatus according to claim 20, characterized in that the tenter frame suction strip ( 38 , 39 ) in the tenter frame ( 37 , 37 ', 37 '') are held adjustable with respect to two directions parallel to the tenter frame. 38. Apparatus according to claim 20, characterized in that the two opposite clamping frame suction bar ( 38 , 39 ) in the clamping frame ( 37 , 37 ', 37 '') can be changed automatically with respect to their mutual distance. 39. Apparatus according to claim 20, characterized in that the clamping frame squeegee ( 38 , 39 ) acting on negative pressure due to a controllable by-pass from an edge of the received film blank ( 44 ) securely holding value to the film edge can only be reduced under the application voltage while holding the sliding value. 40. Device according to claim 20, characterized by an embodiment of the perforation tool ( 52 ) for perforating tear lines ( 45 , 45 ', 45 '') in the stretched-out protective film ( 44 ) according to the following features:

• at least one circular, freely rotatable te, toothed toothed washer ( 55 ) made of metal with a thickness of about 1 to 2 mm is provided,
• - The toothed disk ( 55 ) protrudes only with its toothed outer circumference between skids ( 56 ) which slide along it when the protective film ( 44 ) is perforated and limits the penetration depth (T) of the toothed disk ( 55 ) into the protective film ( 44 ) ,
• - in the covered region of the serrated disc (55) is within the perforating tool (52) a heating device (57) disc for controlled temperature heating of the exact teeth (55) are arranged.

41. Apparatus according to claim 40, characterized in that the perforation tool ( 52 ) is designed as a tandem tool with two heated toothed disks ( 55 ) arranged parallel to one another in such a way that two equidistant perforation lines ( 45 , 45 ') run into the protective film ( 44 ) can be laid. 42. Apparatus according to claim 40 or 41, characterized in that the perforation tool is designed as a multi-tool with at least two parallel, parallel arranged heated toothed disks ( 55 ), one of which is slidably mounted between two end positions and is coupled to a displacement drive, such that that either one toothed washer is or is effective in one end position in the other end position, so that either a single perforation line ( 45 '') or at the same time two equidistant perforation lines ( 45 , 45 ') lie in the protective film ( 44 ) can be laid. 43. Apparatus according to claim 40, characterized by an embodiment of the toothed circumference of the toothed disk ( 55 ) of the perforation tool ( 52 , 53 ) according to the following features:

• - On the circumference of the toothed disk ( 55 ), a plurality of teeth ( 58 ) of approximately 3 to 8 mm circumferential extent, delimited by tooth gaps ( 59 ) that spring back behind the skids, are arranged and perforate into the protective film,
• - At the front and rear end of each tooth ( 58 ) of the toothed disk ( 55 ) a tapered mandrel ( 60 ) of at least about 2 mm radial extension is formed,
• - Between the two mandrels ( 60 ) of a tooth ( 58 ) be sensitive tooth back ( 59 ) is in each case sharpened like a blade ( 61 ),
• - The width (Z) of the tooth gaps ( 59 ) on the circumference of the toothed washer ( 55 ) at the height of the skids ( 56 ) is approximately 1 to 3 mm.

44. Apparatus according to claim 40, characterized in that the toothed disc ( 55 ) consists of a corrosion-resistant steel. 45. Device according to claim 40, characterized thereby that the serrated disc is at a constant temperature in the area is heated from 120 to 180 ° C.