Abstract:
A device for the application of balancing weights to the rim of a vehicle wheel comprises a program controlled manipulator device with a balancing weight application head. The application head is configured to first pick up a balancing weight from a dispenser and then to be transported by the manipulator device to the rim, where the application head can apply the balancing weight to the rim.

Description:
PRIORITY CLAIM 
       [0001]    This application is a continuation of co-pending International Application No. PCT/EP2014/050912 filed on Jan. 17, 2014, which designates the United States and claims priority from European Application No. 13151925.8 filed on Jan. 18, 2013 and European Application No. 13166084.7 filed on Apr. 30, 2013, each of which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to an automated handling system for applying balancing weights to rims of vehicle wheels. 
         [0004]    2. Description of Relevant Art 
         [0005]    A device for the application of balancing weights to go vehicle wheels is disclosed in U.S. Pat. No. 8,336,379 B2. A program-controlled manipulator device includes a movable working arm having a balancing head. The balancing head feeds a continuous weight strand of self-adhesive weights and applies these to a rim of a wheel. The drawback is that the strand of weights may only be delivered to specific rims and to specific locations thereof. Furthermore, the delivered strand of weights may have an optical appearance, which is often not desired. 
       SUMMARY OF THE INVENTION 
       [0006]    The embodiments are based on the object of providing a device and a method for applying individual balancing weights to rims of vehicle wheels. Such individual balancing weights preferably are pre-fabricated and have predetermined sizes and weights. Such balancing weights may also be made in various shapes and colors resulting in an aesthetic appearance. 
         [0007]    In an embodiment, a balancing weight application head is attached to a program controlled manipulator device. The balancing weight application head may pick up at least one individual balancing weight which my may be provided by a balancing weight dispenser. While the manipulator device moves the application head to the vehicle wheel, the balancing weight is firmly held by the application head. After the application head has been brought to the desired location for placing the balancing weight, the balancing weight is attached to the rim. Thereafter, the balancing head may be returned to the dispenser for picking up the next balancing weight. The balancing weight application head may also hold a plurality of balancing weights, therefore reducing movement time by the manipulator device. There may be different embodiments of the application head. The application head preferably has at least one means for holding a balancing weight at the application head and at least one means for pressing the balancing weight to a rim of a vehicle wheel. Both functions may be performed by the same means. 
         [0008]    A further embodiment relates to a method of applying balancing weights to the rim of the vehicle by using an application head. 
         [0009]    Another embodiment relates to an intermediate carrier for attaching the balancing weights. First, the intermediate carrier, to which the balancing weights are attached, is located within the rim. Then the intermediate carrier is expanded until the balancing weights touch the rim and are firmly pressed to the rim. Then the intermediate carrier may be deflated. 
         [0010]    A further embodiment relates to a method of applying balancing weights to the rim of the vehicle by using an intermediate carrier. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    In the following, the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment and with reference to the drawings. 
           [0012]      FIG. 1  shows a balancing weight and an application head of a first embodiment. 
           [0013]      FIG. 2  shows the basic function of the holding pins. 
           [0014]      FIG. 3  shows a further embodiment of an application head. 
           [0015]      FIG. 4  shows another embodiment with a plurality of pressure pieces. 
           [0016]      FIG. 5  shows a further embodiment with vacuum holder. 
           [0017]      FIG. 6  shows another embodiment with vacuum holder. 
           [0018]      FIG. 7  shows an embodiment with permanent magnet. 
           [0019]      FIG. 8  shows an embodiment with solenoid. 
           [0020]      FIG. 9  shows an embodiment with three holding pins. 
           [0021]      FIG. 10  shows a clip-on balancing weight held by three holding pins. 
           [0022]      FIG. 11  shows the embodiment of  FIG. 10  in a top view. 
           [0023]      FIG. 12  shows another embodiment of a balancing weight application device. 
           [0024]      FIG. 13  shows an intermediate step for applying balancing weights. 
           [0025]      FIG. 14  shows the final step for applying balancing weights. 
           [0026]      FIG. 15  shows an embodiment of an application tool for balancing weights. 
           [0027]      FIG. 16  shows the first step of attaching the balancing weight. 
           [0028]      FIG. 17  shows the next step of attaching a balancing weight. 
           [0029]      FIG. 18  shows the attached balancing weight. 
       
    
    
       [0030]    While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0031]    In  FIG. 1 , a first embodiment is shown. A first balancing weight  10  has a center section  11  and at least one side section  12 ,  13 . The center section  11  has at least one hole  14 ,  15 . Preferably, there are two holes. Whereas the center section  11  preferably has a standard size and a standard location of the at least one hole  14 ,  15 , the sections  12 ,  13  may vary in size with the weight of the balancing weight. There may be further side sections besides of the side sections  12  and  13 , which is specifically useful for heavy balancing weights. Low weight balancing weights may have a slightly extended center section without side sections. The balancing weight has an attachment surface for attachment to the rim of a vehicle wheel, which preferably bears an adhesive tape  16 , also called self-adhesive tape. In this figure, the adhesive tape is shown partially removed to show the holes  14 ,  15 . It is preferred, if the adhesive tape covers all the attachment surface, and therefore covers the holes. The application head  20  has a base  21  having at least one holding pin  22 ,  23 . The holding pins  22 ,  23  preferably may penetrate into the holes  14 ,  15 . Furthermore it is preferred, if at least one pressure lever  24 ,  25  is provided for pressing the balancing weight against the mounting surface  91  of rim  90 . The holding pins  22 ,  23  fit into the holes  14 ,  15  of the balancing weights and allow holding of the balancing weight at the application head during transport of the balancing weight from the dispenser to the rim. Preferably, at least one of the holding pins  22 ,  23  is movable to generate some retention force within the holes  14 ,  15  to clamp the balancing weight. In the embodiment shown, the holding pin  22  is fixed, while the holding pin  23  is movable. In another embodiment, at least one of the holding pins may have a conical shape or any other shape suitable for a form fit or press fit with at least one of the holes. In a further embodiment, at least one of the holding pins  22 ,  23  has such a length to contact the adhesive tape at the attachment surface through at least one of the holes to further increase the holding force of the balancing weight to the pin. The at least one pressure lever  24 ,  25  is provided for generating pressure to the whole surface of the balancing weight  10  and therefore to the whole area of the adhesive tape  16 . To adapt the pressure lever  24 ,  25  to various rim diameters, it is preferred, if the pressure lever may be adjusted or moved. Such a preferred direction of movement is shown by the arrows  26  and  27 . Instead of pressure levers, any other device performing a similar function may be used. 
         [0032]    In  FIG. 2 , the basic function of the holding pins is shown. There is a first holding pin  22  may be fixed to the base  21  of the application head, the second holding pin  23  may be movable, slidable or tiltable and preferably is spring-loaded by a spring  28  against the base  21 . Due to the spring loading, the application head may simply be pressed against the balancing weight in the dispenser. The holding pins will slide into the holes and the spring  28  will assert enough force to press the holding pins against the walls of the holes and to hold the balancing weight at the application head. After the balancing weight has been pressed to the rim, the adhesive tape holds the balancing weight thereon. Now, the application head may simply be pulled off and the holding pins will slide out of the holes. Furthermore, it is preferred, if the holding pins each have a head  29 , which improves holding of the balancing weight at the application head. Each head  29  may have a rounded shape to simplify insertion of the holding pin into the holder of the balancing weight. Preferably, the holding pins have a conical shape. Most preferably, they may be pressed into corresponding holes of the balancing weights, establishing a relatively tight fit. Furthermore, there may be some structure for increasing friction and improving the holding function. 
         [0033]    In  FIG. 3 , another embodiment of an application head  40  is shown. This application head is suitable for handling balancing weights without holes. Such balancing weights preferably have a plurality of segments. These segments may have the same weight and size or they may be different. Here, the balancing weights are clamped between an edge or sidewall  41 , which may be part of the base  21 , and which may improve alignment of the balancing weight, and a pressure piece  42 . This pressure piece preferably may have at chamfered edge  43 , which allows simple insertion of the balancing weights. The pressure piece  42  may be held by a lever element  44 , which may be moved into the direction indicated by arrow  45  to increase the gap between the pressure of peace  42  and the edge  41  to fit balancing weights in-between. Preferably, the pressure piece and/or the lever element may be spring-loaded. Either there may be a separate spring or the lever element itself may act as a spring. The pressure piece  42  may be varied in its width. In a first embodiment it may be as shown, therefore clamping only one or two segments of the balancing weight. In another embodiment, the pressure piece may be broader to clamp a plurality of segments or even the whole balancing weight. Instead, by using a pressure piece, the balancing weight may be held by using the adhesive surface, or an edge thereof. 
         [0034]    In  FIG. 4 , a further modification of the embodiment of  FIG. 3  is shown. Here a plurality of pressure pieces  42 , preferably having individual lever elements  44  are provided. As each lever element will be adjustable to the width of the balancing weight section it is holding, a constant holding force may be applied by each pressure piece independent of mechanical tolerances of the balancing weight. Therefore, this embodiment results in a better holding of balancing weights. 
         [0035]    In  FIG. 5 , another embodiment of an application head  50  having a vacuum holder is shown. Preferably, the application had has an empty inner space and or air duct which may be connected to at least one vacuum pipe which may be connected to a vacuum pump. Due to the vacuum of the application head, the balancing weights are held thereto. The vacuum may be switched on and off for holding and for releasing the balancing weigh. Alternatively, there may be a continuous vacuum, if the retention force of the adhesive tape is higher than the vacuum force. It is preferred, if there is a porous surface  51  for distributing the vacuum over the surface of the application head  51 . Such a process surface may be a fibrous web or a porous sintered material. It is preferred, if the balancing weights do not have holes, as this may lead to loss of vacuum. 
         [0036]    In  FIG. 6 , a further embodiment of an application head the  50  is shown. Here a plurality of suction cups  53  is provided to hold the balancing weights  30 . 
         [0037]    Another embodiment of an application head  60  having at least one permanent magnet  61  is shown in  FIG. 7 . Here, the balancing weights  30  are held by magnetic force. Preferably, the magnetic force is less than the retention force of the balancing weights held by the adhesive tape to the rim. The balancing weights  30  preferably comprise magnetic material. This magnetic material may be part of the body of the balancing weights or included therein. The magnetic material may also be at the outside of the balancing weights and may be part of coating or painting of the balancing weights. 
         [0038]    A further embodiment according to  FIG. 8  comprises a solenoid. This may be combined with a permanent magnet. Preferably, a solenoid coil  62  is provided in the application head  60 . Electrical current is delivered by cables  63 . The magnetic force applied it to the balancing weights may be switched on or off by switching the electric current through the solenoid. 
         [0039]    Another embodiment according to  FIG. 9  includes a plurality of holding pins, preferably three or four pins. Most preferably, the application head has a pair of fixed pins  71 ,  72  and one or two movable pins  73 . Preferably, the movable pin can be moved to words or away from the fixed pins to adapt the gap between the fixed pins and the movable pin to the size of a balancing weight. The balancing weight may be clamped in between the pins. It is preferred, if the movable pin is driven by an actuator, which may be a solenoid, a motor or a hydraulic or pneumatic drive. Is further preferred, if at least one fin, preferably or pins have a holding structure  76 ,  77  for holding the balancing weight. Such a holding structure may comprise one or a plurality of at least one of notches, recesses, holes, structured surfaces causing higher friction. Preferably, a notch  76  may be provided for balancing weights, which are clipped to a rim, while a recessed structure  77  may be used to hold adhesive balancing weights. It is also within the scope of this invention to exchange the fixed and movable pins, therefore moving the fixed pins and fixing the movable pins. 
         [0040]      FIG. 10  shows a clip-on balancing weight  80  held by two fixed pins  71 ,  72  and a movable pin  73 . 
         [0041]      FIG. 11  shows the same balancing weight  80  held by three pins in a top view. 
         [0042]      FIG. 12  shows a further embodiment of a weight that balancing weight-mounting device. An intermediate carrier  100  is provided within the rim  90 . The outer diameter of the intermediate carrier is smaller than the in the diameter of the rim. The intermediate carrier  100  holds at least one or a plurality of balancing weights  20 . These may be any type of balancing weights, like the balancing weights shown herein, preferably adhesive balancing weights. The balancing weights may be attached to the intermediate carrier  100  by using an application head according to any one of the previous embodiments. The intermediate carrier may be some tire or balloon, which may be expanded by compressed air or liquid. It may also be expanded by using any pressure cylinder, which may be driven by at least one of spring forces, compressed air or liquids. Alternate drive means include a motor or solenoid. 
         [0043]      FIG. 13  shows the next step in applying balancing weights. Here the intermediate carrier is expanded until it contacts the inner surface of the rim  90 . This will apply the balancing weights to the rim. 
         [0044]      FIG. 14  shows the final step of applying the balancing weights. The intermediate carrier is fully expanded and preferably, uniform pressure indicated by pressure arrows  102  is applied to the surface of the rim, uniformly pressing the balancing weights to the rim. After that, the intermediate carrier may be deflated and removed from the rim. 
         [0045]      FIG. 15  shows an embodiment of an application tool for balancing weights. The tool has an application head  120  comprising a balancing weight applicator  122  and a thrust plate  121 . The balancing weight applicator  122  has a surface as further described herein to hold balancing weights by any of the means described herein. Preferably, there are vacuum outlets  127  or vacuum pipes at the surface for holding balancing weights by vacuum. There may be an additional layer  19  on the surface of the applicator for evenly distributing vacuum and/or protecting the balancing weights. There may also be holding pins, clams, magnets or any other means for holding the balancing weights the balancing weight applicator  122 . An actuator  123  may be provided for actuating the application head. The actuator may be a hydraulic or pneumatic actuator, which may be supplied by pipes  124 . In an alternative embodiment, the actuator may be an electric actuator. In this case, there would be at least one supply cable  124 . In a further embodiment, the applicator may be operated manually. The application head  120  may also work without the actuator shown. For this purpose, it may for example be connected to an industrial robot. The thrust plate  121  and the applicator  122  are mounted slidable against each other, preferably into the direction of a main axis which is the actuators actuating axis. The thrust plate  121  preferably has two side wings which can be moved against two side wings of the balancing weight applicator  122 . When applying a balancing weight  10  to a rim, the balancing weight is placed at the applicator  122  and held by vacuum, magnetic force or any other means as described herein. Then, the applicator is brought into close proximity to the location of the rim, to which the balancing weights are to be applied. Preferably, the outer radius of the applicator is less than the inner radius of the rim. In this case, the balancing weight closest to the center of the applicator touches the rim first. Then, the thrust plate is further pressed into the direction of the rim. This causes the side wings of the thrust plate  125  to contact the side wings of the applicator  126  and to push them into the direction of the rim. This results in gradually pressing balancing weights starting from the center balancing weight outwards to the rim unto all balancing weights have been pressed to the rim. In this state, the radius of the applicator  126  is approximately equal to the radius of the rim. After all balancing weights have been pressed to the rim, the thrust plate is released, further releasing the applicator. To simplify handling movement, it is preferred, if there is a spring between the thrust plate and the applicator to hold the thrust plate and applicator in such a distance from each other, that the side wings of the thrust plate do not touch the applicator or at least put no significant force to the applicator or at least push the applicators side wings only so far, that the radius of the applicator remains smaller than the radius of the rim. When actuating the thrust plate  121 , the spring will be depressed allowing the thrust plate to assert force to the applicator. In another embodiment instead of a spring, the elasticity of the applicator&#39;s side wings is used. In this case, the elastic side wings of the applicator will push the thrust plate back when idle. 
         [0046]    In  FIG. 16 , a first step of the previous described method is shown. Here, the center balancing weight of three balancing weights  10  touches the rim  90 , whereas the other balancing weights are distant from the rim. 
         [0047]    In  FIG. 17 , a next step is shown. Here, the thrust plate  121  has further been moved into the direction  129 . The side wings of the thrust plate  121  assert pressure on the side wings of the applicator  122 , bending them towards the rim and pressing the balancing weights at the sides of the center balancing weight to the rim. 
         [0048]    In  FIG. 18 , the finally attached balancing weights are shown. For this step, the thrust plate  121  has still been moved further into the direction  129 . It now presses by its side wings the applicator&#39;s side wings in their full length to the balancing weights and the rim, causing the balancing weights to be pressed and to adhere to the rim. 
         [0049]    The embodiments disclosed herein may be combined together. For example, an application head may have vacuum and magnetic holding means. Furthermore, any application head may have holding pins and/or pressure levers. 
         [0050]    It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to provide a device for applying balancing weights to vehicle wheels. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims. 
       LIST OF REFERENCE NUMERALS 
       [0051]      10  balancing weight 
         [0052]      11  center section 
         [0053]      12 ,  13  first side section 
         [0054]      14 ,  15  holes 
         [0055]      16  adhesive tape 
         [0056]      20  application head 
         [0057]      21  base 
         [0058]      22 ,  23  holding pins 
         [0059]      24 ,  25  pressure lever 
         [0060]      26 ,  27  arrows indicating direction of movement 
         [0061]      28  spring 
         [0062]      29  holding pin head 
         [0063]      30  balancing weight 
         [0064]      40  application head 
         [0065]      41  edge 
         [0066]      42  pressure piece 
         [0067]      43  chamfered edge of pressure piece 
         [0068]      44  lever element 
         [0069]      45  arrow indicating direction of movement 
         [0070]      50  application head with first vacuum holder 
         [0071]      51  porous surface 
         [0072]      52  vacuum pipes 
         [0073]      53  suction cups 
         [0074]      60  application head containing a magnet 
         [0075]      61  permanent magnet 
         [0076]      62  solenoid 
         [0077]      63  cables 
         [0078]      70  application head with holding pins 
         [0079]      71 ,  72  fixed pins 
         [0080]      73  movable pin 
         [0081]      74  arrow indicating direction of movement 
         [0082]      75  actuator 
         [0083]      76 ,  77  holding structure 
         [0084]      80  clip-on balancing weight 
         [0085]      90  rim of a vehicle wheel 
         [0086]      91  mounting surface 
         [0087]      100  intermediate carrier 
         [0088]      101  direction of expansion 
         [0089]      102  direction of pressure 
         [0090]      120  application head 
         [0091]      121  thrust plate 
         [0092]      122  applicator 
         [0093]      123  actuator 
         [0094]      124  cables, pipes 
         [0095]      125  side wing of thrust plate 
         [0096]      126  side wing of applicator 
         [0097]      127  vacuum outlet