Abstract:
A device for producing a test adhesive strip roll, on which a test adhesive strip is wound, containing a thread access unit having a thread roll, on which a thread is wound; a thread cutting unit, which cuts a thread supplied by the thread access unit from the thread roll into the thread pieces having a predetermined length; an adhesive strip unrolling unit, which guides an adhesive strip; an assembly unit, which applies the thread pieces at a predetermined angle and a predetermined distance to one another to the surface of the supplied adhesive strip, so that a free end of a thread piece projects away from the edge of the adhesive strip; an unrolling unit, which unrolls a cover strip onto the surface of the adhesive strip and the thread pieces applied thereto to form the test adhesive strip, containing the adhesive strip, the cover strip, and the interposed thread pieces; and a rolling device, on which the test adhesive strip is rolled up.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of International Application No. PCT/EP2007/003130, filed Apr. 5, 2007, which was published under PCT Article 21(2) and which claims priority to German Patent Application No. 102006018133.6 filed Apr. 19, 2006 and of U.S. Provisional Patent Application No. 60/745,097 filed Apr. 19, 2006, the disclosure of which applications is hereby incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a device and a method for producing a test adhesive strip roll, on which a test adhesive strip is wound, on whose surface multiple thread pieces are implemented, which project beyond an edge of the test adhesive strip. A test adhesive strip wound on a test adhesive strip roll of this type may be used in particular for visualizing air currents on surfaces of a model to be tested. 
       BACKGROUND 
       [0003]    There are various possibilities for visualizing air currents on model surfaces in wind tunnels. One technique is the use of threads on the surface which is to be examined. The behavior of the threads provides a rapid overview of the air current conditions in the region examined. By illumination with UV light, white threads or threads made of fluorescent synthetic material are very well visible, so that these measurements may be documented using a video camera. The threads are typically glued onto the model surface, either in sequence using adhesive material droplets or using adhesive strip pieces, or they are stuck onto one side of an adhesive strip before the adhesive strip is attached to the model. In high-velocity areas, for example, the technique in which the threads are attached individually is used, because adhesive strips may not interfere with the surface of the model. In lower-velocity areas, however, preconfigured adhesive strips having threads may be used. The adhesive strips having the threads are cut to length by hand, which is time-consuming and cumbersome. 
         [0004]    In view of the foregoing, there may be a need to produce a possibility for providing threads for visualizing air currents, in such a way that they may be used rapidly and efficiently in the visualization of air currents on surfaces of a model. In addition, other need, desirable features and characteristics will become apparent from the subsequent summary and detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background. 
       SUMMARY 
       [0005]    The device according to an embodiment of the present invention for producing a test adhesive strip roll, on which a test adhesive strip is wound in one piece, on whose surface multiple thread pieces are implemented, contains a thread access unit having a thread roll, on which a thread is wound in one piece, a thread cutting unit, which cuts a thread supplied by the thread access unit from the thread roll into the thread pieces at a predetermined length, an adhesive strip unrolling unit, which supplies an adhesive strip, an assembly unit, which applies the thread pieces to the surface of the supplied adhesive strip at a predetermined angle and a predetermined distance from one another, so that a free end of each thread piece projects away from the edge of the adhesive strip, an unrolling unit, which unrolls a cover strip onto the surface of the adhesive strip and the thread pieces applied thereto to form a test adhesive strip, which comprises the adhesive strip, the cover strip, and the interposed thread pieces, and a rolling unit, on which the test adhesive strip is rolled up. 
         [0006]    The distance of the thread pieces to one another may always be constant. The thread pieces may be located perpendicular to the longitudinal direction of the adhesive strip on a surface thereof and extend beyond the edge of the adhesive strip. 
         [0007]    According to an embodiment of the present invention, the cover strip is a foam film. According to another embodiment, the cover strip is easily removable from the test adhesive strip, without the thread pieces being damaged and/or detached from the adhesive strip. 
         [0008]    The method according to an embodiment of the present invention for producing the above-mentioned test adhesive strip roll has the following steps: supplying a thread, which is wound on a thread roll, by a thread access unit, cutting the supplied thread into thread pieces of a predetermined length by a thread cutting unit, supplying an adhesive strip by an adhesive strip unrolling unit, applying the cut thread pieces at a predetermined angle and a predetermined distance from one another to the surface of the adhesive strip by an assembly unit, unrolling a cover strip onto the surface of the adhesive strip and the thread pieces attached thereto, in order to form the test adhesive strip, which contains the adhesive strip, the cover strip, and the interposed thread pieces, and rolling up the test adhesive strip on a rolling device, such as a spool. 
         [0009]    According to an embodiment of the present invention, the individual steps are performed automatically, so that the test adhesive strips may be produced and wound up on the rolling device continuously. 
         [0010]    A test adhesive strip produced by the method described above and/or the device described above may be used for visualizing air currents on surfaces by unrolling the test adhesive strip rolled up on the rolling unit, removing the cover strip, and sticking the test adhesive strip having the threads to the surface on which the air currents are to be visualized. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and 
           [0012]      FIG. 1  shows a schematic partial view of a device for producing the test adhesive strip according to the preferred exemplary embodiment from the side; 
           [0013]      FIG. 1   a  shows a schematic view to illustrate the movement capability of a robot unit shown in  FIG. 1 ; 
           [0014]      FIG. 2   a - 2   c  show a side, front, and top view of a thread access unit and a thread cutting unit from  FIG. 1 ; 
           [0015]      FIG. 3  shows a side view of pincers for gripping and holding a thread; 
           [0016]      FIG. 3   a  shows an interior view of the left pincer leg; 
           [0017]      FIG. 3   b  shows an interior view of the right pincer leg; 
           [0018]      FIG. 4  shows a side view of the thread cutting unit from  FIG. 1 ; 
           [0019]      FIG. 4   a  shows a top view of the thread cutting unit from  FIG. 1 ; 
           [0020]      FIG. 5  shows a schematic configuration of the device from  FIG. 1  from the front; 
           [0021]      FIG. 6  shows an assembly unit having the pincers shown in  FIG. 3 ; 
           [0022]      FIG. 7  shows a partial view of a model having an adhesive strip having threads; 
           [0023]      FIG. 8  shows a partial view of a mounting plate of the working area of the device from  FIG. 1 ; 
           [0024]      FIG. 9  shows a partial view of a base frame of the device from  FIG. 1  from the front; 
           [0025]      FIG. 10  shows a gripper of the assembly unit shown in  FIG. 6 ; 
           [0026]      FIG. 11  shows a rolling device for a test adhesive strip; 
           [0027]      FIG. 12  shows a partial view of the working area of the device from  FIG. 1 ; 
           [0028]      FIG. 13  shows a more detailed view of the rolling unit shown in  FIG. 12 ; and 
           [0029]      FIG. 14  shows a partial view of the device according to the preferred exemplary embodiment, which illustrates the cover strip unrolling unit. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background and summary or the following detailed description. 
         [0031]      FIG. 1  shows a partial view of a first exemplary embodiment of a device according to and embodiment the present invention. The device, as it is described in the following, is designed to glue thread pieces automatically to adhesive strips and to apply a cover film thereto to form a test adhesive strip, which is wound up automatically on a test adhesive strip roll. 
         [0032]    As shown in  FIG. 1 , the device contains a stand  1 , on which a stand plate  2  is mounted. A robot unit  31  is mounted on the stand plate  2 . The robot unit contains a robot base stand  31   a , which is mounted fixed on a surface of the stand plate  2 , a robot turntable  31   b , a robot rocker  31   c , a robot arm  31   d , a robot hand  31   e , and a robot flange  34   a . The individual movement directions of the robot elements are illustrated in  FIG. 1   a.    
         [0033]    As shown in  FIG. 1 , a thread access unit  4  and a thread cutting unit  5  are located neighboring the robot unit  31  on the surface of the stand plate  2 , which are described in greater detail with reference to  FIG. 2 . 
         [0034]    Furthermore, a mounting plate  6  extends from the stand plate  2 , which may be made of metal, for example, and contacts a side of an adhesive strip which is supplied by an adhesive strip unrolling unit (not shown). The mounting plate  6  is connected to a frame  25 , for example, which has rolls  9 , which are cushioned using a 1 cm thick plastic foam mat, for example. The mounting plate  6  preferably always has the same distance to the robot base stand  31   a.    
         [0035]    The robot unit  31  is mounted fixed on a rear area of the stand  1  and is equipped with a pneumatically operated gripper  50 , which is attached to the robot flange  34   a  using a gripper flange connection unit. For example, pincers  91  made of aluminum, as shown in  FIG. 3 , are attached to the jaws of the gripper  50 . 
         [0036]    As shown in  FIG. 1 , the stand  1  is supported on rolling device  60  and thus movable. Alternatively, the stand  1  may be connected fixed to the floor. 
         [0037]      FIG. 2   a  illustrates the thread access unit  4  and the thread cutting unit  5  from  FIG. 1 . The thread access unit  4  contains a thread roll  12 , which is mounted on a thread holder stand  10  so it is rotatable. A thread  11  is wound in one piece on the thread roll  12 . As the thread  11  is unwound, the end of the thread runs through a thread tube  13 . The thread end area  19  of the thread  11  projecting out of the thread tube  13  is supplied to the thread cutting unit  5 . The thread access unit  4  is positioned on the stand plate  2  of the stand  1  in such a way that the gripper  50  of the robot unit  31  may access it easily.  FIG. 2   b  shows a front view of the thread access unit  4  and  FIG. 2   c  shows a top view of the thread access unit  4  and the thread cutting unit  5 . 
         [0038]      FIG. 3  illustrates pincers  91  attachable to the gripper  50  for gripping a thread end area  19  of the thread end area  19 , which projects out of the thread tube  13 , as shown in  FIG. 2 , and for supplying the thread end area  19  to the thread cutting unit  5  shown in  FIG. 2 .  FIGS. 3   a  and  3   b  show an interior view of a left pincer leg  92  and a right pincer leg  93 , respectively. According to the preferred exemplary embodiment, the pincer legs  92 ,  93  are movable in relation to one another to be able to grip the thread end area  19 . As described above, the pincers  91  are connected via a gripper flange connection unit to the robot flange  34   a . The robot is capable of activating the pincer legs  92 ,  93  independently of one another. Furthermore, it is possible that the pincer legs  92 ,  93  are pre-tensioned, for example. 
         [0039]      FIG. 4  shows a side view of the thread cutting unit  5  and  FIG. 4   a  shows a top view of the thread cutting unit  5 . The thread cutting unit  5  is attached to the stand  1  from  FIG. 1 . 
         [0040]    As shown in  FIG. 4   a , a cutter  16 , which is pre-tensioned by a spring, strikes an anvil  14 , which is positioned diametrically opposite, by which the thread  11 , which is located in a free space  18 , is disrupted (cut). The cut thread (i.e., the thread piece  15 ), is then held by a thread clamp. 
         [0041]    The robot unit  31  is programmed in such a way that the pincers  91  grip the thread which projects out of the thread tube  13  and guide the thread 2 cm in the horizontal direction, for example, to the free space  18  of the thread cutting unit  5 . While the pincers  91  hold the thread  11 , a relay is actuated using a robot controller (not shown), which first triggers cutting of the thread and then causes the clamping device of the thread cutting unit  5  to open. Next, the robot unit  31  positions the pincers  91 , which still grip the thread piece  15 , over the mounting plate  6  in such a way that the pincers  91  may be opened, and the thread piece  15  falls onto a desired position of an adhesive strip, whose adhesive side lies facing up on the mounting plate  6  and is supplied continuously, for example. 
         [0042]    The procedure of gripping the thread  11 , cutting the thread  11 , applying the thread piece  15 , and pressing the thread piece  15  onto the adhesive strip is automatically performed repeatedly by the robot unit  31 , so that multiple thread pieces  15  on an adhesive strip, which is located on the mounting plate  6 , may be glued onto a surface of the adhesive strip. 
         [0043]      FIG. 5  shows the construction of the entire device from  FIG. 1 . 
         [0044]      FIG. 6  shows an assembly unit for applying thread pieces to an adhesive strip having a gripper  50 , which is attached to the robot flange  34   a . Furthermore, the pincers  91  having their pincer legs  92 ,  93  are mounted on the gripper  50 . The robot flange  34   a  is supplied with energy and control information via current and control cable  51  to open and close the pincer legs  92 ,  93  and/or rotate the gripper  50  in various directions, as shown in  FIG. 1   a.    
         [0045]      FIG. 7  shows a partial view of a model wing  7 , on whose surface air currents are to be examined. The thread pieces  8  are spaced uniformly, for example, and extend over equal lengths essentially perpendicularly to the longitudinal axis of the adhesive strip  24 . The free ends of the thread pieces  8  project away from the adhesive strip  24  and may be engaged by an air current, the free end of the thread pieces  8  orienting in accordance with the air current, by which it is possible to visualize the air current. The thread pieces may extend at various angles and have different distances to one another. 
         [0046]      FIG. 8  shows a partial view of the mounting plate  6 , which is connected fixed to the working area of the robot unit  31 . 
         [0047]      FIG. 9  shows a partial view of the stand  1 , on which a robot unit  31  is mounted. 
         [0048]      FIG. 10  shows the gripper  50  from  FIG. 6 , fastening areas  52  for the pincer legs  92 ,  93  being illustrated. The gripper  50  is attached to the robot flange  34   a  as described above. 
         [0049]      FIG. 11  shows a rolling device  60  in the form of a spool  27 . The rolling device is used for rolling up the test adhesive strip (not shown), which is formed by the adhesive tape strip  24 , the thread pieces  15  applied thereto, and a foam film  28  applied thereto, as shown in  FIG. 12 . The rolling device  60  may also have a form other than a spool to store the test adhesive strip. The test adhesive strip is wound in one piece onto the spool  27 . 
         [0050]      FIG. 12  shows a partial view of the area of the mounting plate  6  of the device from  FIG. 1 . The left half of  FIG. 12  shows an adhesive strip unrolling unit  26 , which supplies the adhesive tape strip  24  continuously in a support plate  61 , which is implemented as a support plate, for example. The adhesive side of the adhesive tape strip  24  is directed upward, so that thread pieces  15  are allowed to fall from the pincers  91  of the gripper  50  which is attached to the robot flange  34   a , so that the adhesive strip  24  having the thread pieces  8  shown in  FIG. 7  is formed. This adhesive tape strip  24  having the thread pieces  15  applied thereto is guided to the spool  27  and wound together with the foam film  28 , which is also supplied, onto the spool  27  in such a way that a test adhesive strip results, comprising the adhesive tape strip  24 , the thread pieces  15  applied thereto, and the foam film  28  applied thereto. The foam film  28  is used for the purpose of protecting the individual layers rolled onto the spool  27  from sticking together, and to ensure uniform winding independently of the increasing radius. The foam film  28  may be removed easily from the adhesive tape  24  and the thread pieces  15 , without damaging the thread pieces  15 . 
         [0051]    The spool  27  and the adhesive strip unrolling unit  26  are separately drivable via a motor, for example, to unroll the adhesive strip  24  from the adhesive strip unrolling unit  26  and/or to wind the adhesive strip  24  together with the thread pieces  15  applied thereon onto the spool  27 . A drive of the adhesive strip unrolling unit  26  is not necessary according to another exemplary embodiment. 
         [0052]      FIG. 13  shows a partial view of the device according to an embodiment of the present invention, in which the spool  27  is more clearly recognizable. 
         [0053]      FIG. 14  shows a partial view of the device according to an embodiment of the present invention, in which a foam film unrolling unit  29  is shown. 
         [0054]    In the following, the method for producing the test adhesive strip, as discussed above, is summarized. 
         [0055]    The robot unit  31  is programmed in such a way that it grips the thread of the thread roll  12  hanging out of the thread tube  13  using the pincers  91  of the gripper  50 , then draws the thread  11  over a length of 2 cm, for example, horizontally over the free space  18  of the thread cutting unit  5 . While the pincers  91  still hold the thread  11 , a relay is switched via a controller of the robot unit  31 , which first triggers cutting of the thread  11  into thread pieces  15 , and then opens the clamping device of the thread cutting unit  5 . In the next work step, the robot unit positions the pincer  91  still grasping the thread pieces  15  over the support plate  61  in such a way that the pincers may open and eject the thread pieces  15  at an angled position to the support plate  61 , having one end of the thread piece  15  contacting the adhesive tape strip  24 , onto the desired position and then press it into place. 
         [0056]    The beginning of the adhesive tape strip  24 , which was drawn out of the adhesive strip unrolling unit  26 , and the foam film  28 , which was simultaneously drawn from an unrolling unit  29 , are fixed on the spool  27  in such a way that the adhesive tape strip  24  and the foam film  28  are unrolled from their respective sources as the spool  27  rotates and rolled onto the spool  27 . Simultaneously, the adhesive tape strip  24  is drawn over the working area of the small support plate  61 . With the winding, the mechanism draws the adhesive tape strip  24  over the working area, so that the next thread piece  15  may be stuck on by the pincers  91  at an exactly maintained distance. 
         [0057]    The requirement that the distance between the glued thread pieces  15  is to remain constant is implemented by a procedure, using which the steps to be set on a stepping motor (not shown) may be calculated. When deriving this procedure, for example, it is taken into consideration that the radius of the test adhesive strip (adhesive tape strip/thread pieces/foam film  24 / 8 / 28 ) composite wound on the spool  27  becomes larger with each rotation. 
         [0058]    A result of the procedure described above is a spool  27  which is wound with an adhesive tape strip/thread piece/foam film  24 / 8 / 28  composite. For visualizing air currents in wind tunnel tests, for example, the required test adhesive strips of the equipped thread pieces  15  are uncoiled from the foam film  28  of finished wound spool  27  at the required length and stuck onto a model surface. 
         [0059]    Although the present invention was described above with reference to a preferred exemplary embodiment, it is obvious that modifications and alterations may be performed without leaving the scope of protection of the present invention. For example, it is possible to apply the thread pieces to the adhesive tape  24  using varying spacing. Furthermore, as an alternative to a foam film, another suitable cover material may also be used, which may be detached easily from an adhesive surface of the adhesive tape, without damaging the thread pieces applied thereto. Furthermore, different types of thread (thread brand, thread thickness, thread color) may be used. Moreover, while at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents.