Abstract:
A fastening assembly for attaching and accurate positioning of a first workpiece, which defines a first main axis, on a second workpiece, which defines a second main axis and includes an anchor secured on a supporting surface of the second workpiece. The fastening assembly comprises a first member including a fastening portion for holding the first workpiece; a second member including a receptacle for the anchor; and wherein the first member and the second member are movable relative to each other in order to move the fastening portion toward or away from the supporting surface of the second member.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from German Patent Application No. DE 102012010429.4, filed on May 23, 2012, the disclosure of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a method for the positionally accurate fastening of a first workpiece, which has a first main axis, on a second workpiece, which has a second main axis, in such a manner that the first main axis and the second main axis assume an angle greater than zero degrees (0°). 
         [0003]    In addition, the present invention relates to a fastening device for the positionally accurate fastening of a first workpiece on a second workpiece, in particular for carrying out the abovementioned method. Finally, the present invention also relates to a fastening arrangement with a first workpiece, with a second workpiece on which an anchor is secured, and with a fastening device which is fixed in a positionally accurate manner on the second workpiece by means of a fixing member, wherein the first workpiece is secured on a fastening portion of the fastening device. 
         [0004]    In the area of fastening techniques, joining an anchor in the form of a stud onto a workpiece such as a sheet, for example by means of stud welding, is known. Securing fastening devices, which, as a rule, are produced from plastics material and are also called “clips”, on these types of studs, is also known. These types of clips frequently include a fastening portion on which another component can be secured, for example a brake line, a cable loom or the like. 
         [0005]    In this case, the clips, as a rule, are realized in one piece and secure the components on the workpiece in one position, the positioning of the component being subject to large tolerances. As these types of components are frequently mounted in a non-visible region of a motor vehicle or the like, positionally accurate fastening or fastening with small tolerances with regard to the positioning are not necessary. 
         [0006]    Securing a component such as a body sheet or a trim component at an accurate spacing on a workpiece such as a body sheet is also known in the prior art (for example DE 10 2005 005 519 A1). In this case, a stop disc can be screw-connected onto a threaded stud for applying the component, an accurate spacing between the component and the workpiece being adjustable by rotating the stop disc. 
         [0007]    In contrast, there is a requirement for a fastening method, by means of which workpieces can be fastened to each other in such a manner that their main axes can assume an angle greater than zero degrees (0°). For example, the workpieces can be a mud guard and a vehicle body. Mud guards, in this case, are visible in the outside region of a motor vehicle and define a so-called clearance with the body or components connected thereto (for example doors). To obtain an impression of high quality, it is important to keep the clearance small and to develop the transitions between these types of workpieces such that they are aligned, for example, flush with each other. However, the methods for producing workpieces are, as a rule, tolerance-encumbered such that it is desirable to create a fastening device by means of which a first workpiece can be fastened in a positionally accurate manner on a second workpiece, for example a mud guard on a vehicle body. In particular, it should be possible in this case, by means of the fastening device, to realize an adjustment of a relative position in at least one direction, preferably in two directions aligned transversely with respect to each other. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    This object is achieved on the one hand by a method for the positionally accurate fastening of a first workpiece, which has a first main axis, on a second workpiece, which has a second main axis, in such a manner that the first main axis and the second main axis can assume an angle greater than zero degrees (0°), said method including the steps of:
       arranging a fastening device on an anchor which is secured on the second workpiece, wherein the fastening device has a first member and a second member, wherein the first member has a fastening portion for the first workpiece, wherein the first member and the second member are movable relative to each other in such a manner that the fastening portion is positionable in at least a first direction with regard to the second workpiece;   moving the second member with regard to the first member for adjusting the position of the fastening portion in at least the first direction with regard to the second workpiece; and   fixing the fastening device on the second workpiece using a fixing member which engages the anchor.       
 
         [0012]    In addition, the above object is achieved by a fastening device for the positionally accurate fastening of a first workpiece, which has a first main axis, on a second workpiece, which has a second main axis, including a first member and a second member, wherein the first member has a fastening portion for the first workpiece, wherein the second member has a receptacle for an anchor secured on the second workpiece, wherein the first member and the second member are movable relative to each other in order to adjust the fastening portion in at least a first direction with regard to a supporting surface of the second member, wherein the first and the second member are rotatable against each other about an axis in order to adjust the fastening portion in at least the first direction with regard to the supporting surface of the second member. 
         [0013]    In addition, the above object is achieved by a fastening arrangement with a first workpiece, with a second workpiece on which an anchor is secured, and with a fastening device of the abovementioned type which is fixed in a positionally accurate manner on the second workpiece by means of a fixing member, wherein the first workpiece is secured on a fastening portion of the fastening device. Finally, the above object is achieved by a screw tool for a fastening device of the abovementioned type, including a hollow shaft, the outside circumference of which has a polygonal portion. 
         [0014]    The first and/or second workpiece can be elongated components, but in each case are preferably flat components. The first workpiece is preferably a mud guard of a vehicle body, and the second workpiece is preferably a portion of the chassis of the vehicle body. 
         [0015]    The anchor, which is secured on the second workpiece, can be a stud. The stud, in this case, can be secured on the second workpiece by means of arbitrary methods, for example by means of stud welding, by means of bonding or by means of thermoplastic welding. The first and the second workpiece can be produced from metal, but can also be produced from a plastics material or from a composite material. 
         [0016]    The second member of the fastening device is preferably supported on the second workpiece, by means of a supporting surface. 
         [0017]    The fixing member can be realized, for example, as a nut or as a screw, the anchor in this case preferably being realized as a stud with an external thread or an internal thread. 
         [0018]    The fastening device is preferably realized in a ring-shaped manner, both the first and also the second member being realized in a ring-shaped manner. In the case of a fastening arrangement according to the invention, the anchor in the form of a stud preferably passes through the first and the second member of the fastening device. The step of moving the first member with regard to the second member can be a rectilinear movement. In this case, it can be possible for the first member and the second member to engage each other by means of latching contours, such as, for example, tooth profiles. The step of fixing, in this case, can include that the first and the second member are fixed against each other in a relative position adjusted in this manner in order to fix the fastening device on the second workpiece in this manner. In other words, the step of fixing the fastening device can include the step of fixing the two members of the fastening device against each other, and also the step of securing the members, moved toward each other in this way, in this relative position on the second workpiece. 
         [0019]    In this case, the fastening device is preferably arranged in the axial direction between the second workpiece and the fixing member, the concept of the axial arrangement relating to an anchor main axis (stud axis). 
         [0020]    The first and the second member can be pre-assembled on each other such that the fastening device is available and manageable as a pre-assembled unit. The pre-assembly, in this case, can be effected by means of a latching device, which is released, for example, during the step of moving the second member with regard to the first member. The second member can maintain its rotational position in a substantial manner during the movement step. 
         [0021]    By means of the fastening device according to the invention, two workpieces can also be secured in a relative manner on each other, the main axes of which extend parallel to each other. For example, the fastening device according to the invention can also serve for securing two flat workpieces on each other at a positionally accurate spacing parallel to each other. 
         [0022]    The object is consequently completely achieved. 
         [0023]    In the case of the method according to the invention, it is particularly preferred when the first direction is aligned parallel to an anchor main axis of the anchor such as a stud axis of a stud. 
         [0024]    In the case of said embodiment, the moving of the first member with regard to the second member serves to adjust a vertical position of the first workpiece with regard to a surface of the second workpiece. 
         [0025]    An adjustment of the position of the fastening portion in a second direction, which is aligned transversely with respect to the first direction, is generally possible by the fastening device having a further member (third member), the first or the second member being movable relative to each other with regard to the third member in order to adjust the position of the fastening portion in the second direction with regard to the second workpiece. 
         [0026]    However, it is particularly preferred when the second member is arranged on the anchor such that, prior to the fixing step, it is movable in at least a limited manner in a second direction which is aligned transversely with respect to the first direction. 
         [0027]    In the case of said embodiment, the adjustability of the position of the fastening portion in the second direction is made possible by the fastening device or the second member being mounted on the anchor or the stud so as to be movable in at least a limited manner in said second direction. In other words, the adjustment in the second direction can be effected by means of relative movement of the fastening device or of the second member in the second direction, prior to the fixing step. 
         [0028]    In this way, the first workpiece can be fastened on the second workpiece in a positionally accurate manner in two directions. 
         [0029]    As mentioned above, the relative mobility of the first and of the second member can be realized such that said members are offset against each other in a linear manner, for example in the first direction. 
         [0030]    However, it is particularly preferred when the first and the second member are rotatable against each other in order to position the fastening portion in the first direction with regard to the second workpiece. 
         [0031]    In this connection, the first and the second member can be rotatable about an axis which, for example, is aligned parallel to an anchor main axis. 
         [0032]    In this case, the first and the second member can be connected together by means of a screw connection. 
         [0033]    However, it is particularly preferred when the first member has a first ramp device facing the second member and/or when the second member has a second ramp device facing the first member. 
         [0034]    In the case of said embodiment, high forces can be transmitted in the first direction by means of the fastening device. 
         [0035]    In the case of the method according to the invention, it is altogether preferred when, prior to the securing of the first workpiece on the fastening portion, a template is secured on the fastening portion, said template being fixed rigidly with regard to the second workpiece, wherein subsequently the position of the fastening portion is adjusted, wherein further subsequently the fastening device fixed on the second workpiece, and wherein finally the template is removed and the first workpiece is secured on the fastening portion. 
         [0036]    In the case of said embodiment, the adjustment of the fastening device can be effected by means of the template which, for example, is fixed on the second workpiece. For the case where the first workpiece is a mud guard, the template can be fixed for example to hinges for a door of a motor vehicle, and consequently can be fixed directly or indirectly with regard to the second workpiece. 
         [0037]    In the case of the fastening device according to the invention, it is additionally advantageous when the first and/or the second ramp device has a screw-shaped ramp portion which is arranged radially inside and a screw-shaped ramp portion which is arranged radially outside. 
         [0038]    In the case of said embodiment, it can be achieved that two contours of the first member and second member are always engaged with each other. This means that fastening device safety against tilting can be improved with regard to an anchor main axis. 
         [0039]    In this case, the ramp portions arranged on the inside and on the outside can be offset against each other in the circumferential direction in such a manner that the lowest points of the ramp portions are arranged offset by 180° with regard to a longitudinal axis of the fastening device. 
         [0040]    According to a further altogether preferred embodiment, the second member has a hollow shaft portion which is introduced into an axial recess of the first member. 
         [0041]    In this way, the first and the second member can be pre-assembled on each other. In this case, a latching device, which acts in a pre-assembly position between the first member and the second member, can also be provided. 
         [0042]    According to a further preferred embodiment, the hollow shaft portion has a polygonal shape on its inside circumference and/or on its outside circumference for applying a screw tool. 
         [0043]    In the case of this variant, it is advantageous for the adjustment of the relative position between the first member and the second member to be effected by rotating the second member, that is that member which rests on the second workpiece. This means that the basic position of the fastening portion of the first member can be maintained whilst the relative rotation of the first and second member is effected. 
         [0044]    In this case, it is particularly advantageous when the first member has an axial passage, through which the screw tool is introducible onto the or into the hollow shaft portion. 
         [0045]    In this connection, the rotation of the second member can be effected with regard to the first member by the screw tool being guided through the axial passage. In this way, it is not necessary to provide a portion for applying a tool on the outside periphery of the second member. As an alternative or in addition to this, the second member can be rotatable by hand (e.g. by grasping latching lugs provided on the second member). 
         [0046]    The first workpiece can be secured on the fastening portion of the first member in an arbitrary manner, for example by screw-connection or the like. 
         [0047]    However, it is particularly preferred when the fastening portion has latching means for securing the first workpiece in a positionally accurate manner. This means that the assembly of the first workpiece on the second workpiece can be simplified. 
         [0048]    In the case of the fastening arrangement according to the invention, it is advantageous when a hollow shaft portion of the second member of the fastening device has an inside diameter which is greater than an outside diameter of the anchor (in particular of the stud), in such a manner that, prior to its fixing, the fastening device is movable in the radial direction with regard to the anchor. 
         [0049]    The achievement of said measure is that the second member or the fastening device can be arranged on the anchor such that, prior to the fixing step, it is movable in at least a limited manner in a second direction (radial direction). 
         [0050]    In the case of said embodiment it is obvious that this means that mobility is possible not only in a second direction, which is aligned transversely with respect to the first direction, but also in a further (third) direction, which is aligned transversely with respect to the first direction. The second and the third direction, in this case, preferably span a plane which is parallel to a surface of the second workpiece. 
         [0051]    The above invention is additionally complemented by a screw tool for a fastening device according to the invention, the screw tool having a hollow shaft, the outside circumference of which has a polygonal portion. 
         [0052]    By means of such a screw tool, the second member can be rotated with regard to the first member by the hollow shaft being guided through the axial passage in the first member. 
         [0053]    In this case, the anchor (stud) can enter into the hollow shaft such that the anchor is not able to impede the adjusting operation. 
         [0054]    The first workpiece preferably has a lateral recess or through-bore into which the latching means can latch for securing the first workpiece on the first member in a positionally accurate manner. 
         [0055]    It is obvious that the abovementioned features and the features yet to be mentioned below are usable not only in the combination specified in each case, but also in other combinations or standing alone without departing from the framework of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0056]    Exemplary embodiments of the invention are shown in the drawing and are explained in the following description, in which, in detail: 
           [0057]      FIG. 1  shows an exploded representation of a schematic longitudinal sectional view through a first embodiment of a fastening arrangement according to the invention. 
           [0058]      FIG. 2  shows a perspective part sectional view of a more detailed embodiment of a fastening device according to the invention. 
           [0059]      FIG. 3  shows a perspective view inclinedly from below of a first member of the fastening device of  FIG. 2 . 
           [0060]      FIG. 4  shows a perspective view inclinedly from above of a second member of the fastening device of  FIG. 2 . 
           [0061]      FIG. 5  shows a longitudinal sectional view through the fastening device of  FIG. 2  in a pre-assembly position. 
           [0062]      FIG. 6  shows a representation comparable to  FIG. 5  after a rotation of the first and of the second member by approximately 180°. 
           [0063]      FIG. 7  shows a representation comparable to  FIG. 5  after a rotation of the first and of the second member by approximately 360°. 
           [0064]      FIG. 8  shows a perspective representation of a fastening arrangement by means of the fastening device of  FIGS. 2 to 7 . 
           [0065]      FIG. 9  shows a perspective representation of an embodiment of a screw tool according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0066]      FIG. 1  shows a schematic representation of a first embodiment of a fastening arrangement according to the invention which is given the general reference  10 . 
         [0067]    The fastening arrangement  10  has a first workpiece  12  such as, for example, a mud guard of a body of a motor vehicle which has a first main axis  14 . In addition, the fastening arrangement  10  has a second workpiece  16 , which can be, for example, a portion of a chassis of a vehicle body, the second workpiece  16  having a second main axis  18 . 
         [0068]    The first main axis  14  and the second main axis  18  are arranged with respect to each other at an angle  20  which is preferably greater than 0°. In particular, the first workpiece  12  and the second workpiece  16  are substantially at right angles with respect to each other. 
         [0069]    The fastening arrangement  10  additionally includes a fastening device  22 , by means of which the first workpiece  12  is fastenable on the second workpiece  16 . The fastening device  22  has a first member  24 . The first member  24  includes a fastening portion  26 , on which the first workpiece  12  is fastenable. 
         [0070]    In addition, the fastening device  22  has a second member  28  which is preferably realized as a separate component from the first member  24  and is mounted so as to be movable in the direction of rotation in relation to said first member  24 . The members  24 ,  28  are coupled in the radial direction, preferably in a positive-locking manner. 
         [0071]    In this case, the second member  28  is realized as a ring member which is arranged around an anchor in the form of a stud  30 . The stud  30  is joined onto a surface of the second workpiece  16 , for example by means of stud welding, by means of stud bonding, by means of thermoplastic welding or the like. The stud  30  has a stud main axis  32  which is aligned perpendicularly with respect to the surface of the second workpiece  16 . The second member  28  has a stud receptacle  34 , in which at least one portion of the stud  30  can be received. A surface of the second member  28  remote from the first member  24  serves as a supporting surface  36  for support on the surface of the second workpiece  16 . 
         [0072]    The first member  24  and the second member  28  are movable relative to each other such that the fastening portion  26  is adjustable in a first direction  40  with regard to the second workpiece  16 . The first direction  40  is preferably a direction which is aligned parallel to the stud main axis  32 , that is to say a vertical direction. Through the relative mobility of the first and of the second member  24 ,  28 , a first required position  42  can consequently be set in the first direction  42 . 
         [0073]    A fixing member  44 , which in the present case is realized, by way of example, as a nut with an internal thread  46 , serves to fix the first member  24  and the second member  28  on each other and to fix the fastening device  22  on the second workpiece  16 . In the case of the present embodiment, the stud  30  is preferably realized with an external thread  48 . Fixing is effected consequently by the fixing member  44  being screw-connected onto the stud  30 , the relative position between the members  24 ,  28  and the relative position of the fastening device  22  being fixed with regard to the second workpiece  16 . 
         [0074]    In addition, the first and the second member  24 ,  28  can be movable in a second direction relative to each other in order, in this way, to make it possible to adjust the fastening portion  26  also in a second direction  52  with regard to the second workpiece  16 . For example, this means that it is possible to set a second required position  54  which can be defined by the spacing between the stud main axis  32  and the fastening portion  26  (as shown at  54 ). 
         [0075]    In order to make adjustability in the second direction  52  possible, the fastening device  22  may additionally have a third member  56 , which is movable relative to the first member  24  or relative to the second member  28  in order to make adjustability in the second direction  52  possible. 
         [0076]    A template  60 , which is similar in shape to the first workpiece  12  in at least a fastening region and consequently can be inserted into the fastening portion  26 , is preferably used to fasten the first workpiece  12  on the second workpiece  16 . The template  60  is then temporarily fixed directly or indirectly with regard to the second workpiece  16  (shown at  62 ). This means that through relative movement between the first member  24  and the second member  28 , adjustment of the fastening portion  26  in the first direction  40  into the first required position  42  and, where applicable, adjustment in the second direction  52  into the second required position  54  can be effected. The two members  24 ,  28  are then fixed in the adjusted relative position, and the fastening device  22  is fixed on the second workpiece  16  all in all by means of the fixing member  44 . The template  60  can then be removed and the workpiece  12  can be inserted into the fastening portion  26  in order to realize, in this manner, positionally accurate fastening of the first workpiece  12  on the second workpiece  16 . 
         [0077]    The following figures show a further embodiment of a fastening arrangement  10  with a fastening device  22 ′, which corresponds in general to the fastening device  22  shown in  FIG. 1  with regard to design and method of operation. Identical elements are consequently marked by identical reference numbers. Essentially the differences are explained below. 
         [0078]    The first member  24  shown in  FIGS. 2 and 3  has a ring portion  68  which is aligned in a concentric manner with respect to the stud main axis  32 . The ring portion  68  includes an axial passage  70 , through which the stud  30  is guided when the fastening device  22 ′ rests on the surface of the second workpiece  16 . In this way, a fixing member  44  can engage the portion of the stud  30  protruding with respect to the fastening device  22 ′ in order to fix the fastening device  22 ′. 
         [0079]    A first ramp device  72 , which is realized essentially in a screw-shaped or helical manner and is facing the second member  28 , is realized on an under surface of the first member  24 . 
         [0080]    The fastening portion  26  is secured on an outside circumferential portion of the ring portion  68 . The fastening portion  26 , in this case, has a first fastening wall  74  which is connected to the ring portion  68  by means of a plurality of struts  76 . The first fastening wall  74  is aligned parallel to the first main axis  14  which, in its turn, is offset in parallel or inclinedly with respect to the stud main axis  32 . The fastening portion  26  also includes a second fastening wall  78 , which is aligned parallel to the first fastening wall  74  and is connected to said first fastening wall by means of a fastening base  80 . A first workpiece  12  in the form of a flat component can consequently be inserted between the first and the second fastening wall  74 ,  78  as far as up to the fastening base  80 . In the present case, the fastening device  22  also includes latching means  82  in the form of a latching tongue which is arranged on the second fastening wall  78 . When the first workpiece  12  is inserted, the latching tongue is deflected in relation to the second fastening wall  78  until the latching tongue latches into a latching recess of the first workpiece  12  (not shown in any more detail in the figures) such that the first workpiece  12  is securable in a positionally accurate manner on the fastening portion  26 . 
         [0081]    The second member  28  has a ring body  86 , the under surface of which forms the supporting surface  36 . The top surface of the ring body  86  has a second ramp device  88 , which is realized in a screw-like manner like the first ramp device  72 . The first and the second ramp device  72 ,  88  are adapted to each other in such a manner that the first required position  42  can be set by means of relative rotation of the first and of the second member  24 ,  28 . 
         [0082]    The ring body  86  has a hollow shaft portion  90  radially inside the second ramp device  88 . The hollow shaft portion  90 , which is shown with greater accuracy in  FIG. 4 , is realized in cross section preferably in a polygonal manner and its dimension is such that it is insertable into an axial recess  92  of the first member  24  (see  FIG. 3 ). 
         [0083]    At least one, preferably two diametrically opposed latching lugs  94  are provided on an outside circumference of the ring body  86 , said latching lugs being able to engage in corresponding latching indentations  102  of the first member  24  in a pre-assembly position. 
         [0084]      FIG. 2  shows that the second member  28  can be rotated in relation to the first member  24  (see reference  96 ) in order to adjust the position of the fastening portion  26  in the first direction  40  with regard to the second workpiece  16 . 
         [0085]    An inside diameter  112  of the hollow shaft portion  90 , in this case, is greater than an outside diameter  116  of the stud  30  such that the second member  28  and the first member  24  coupled hereto are movable in the second direction  52  in relation to the stud  30  (are movable in a limited manner) in order, in this way, to obtain adjustment in the second direction  52 . In this case, it is also possible to effect an adjustment in a third direction  98  which is aligned transversely with respect to the second direction  52  and with the latter spans a plane which is aligned parallel to the surface of the second workpiece  16 . 
         [0086]    A latching indentation  102  for a latching lug  94  is shown in greater accuracy in  FIG. 3 . 
         [0087]      FIG. 3  also shows that the first ramp device  72  has a first inside ramp portion  104  and a first outside ramp portion  106 . The ramp portions  104 ,  106 , in this case, are offset against each other by 180°. 
         [0088]      FIG. 4  shows that the second ramp device  88  has a second inside ramp portion  108  and a second outside ramp portion  110 . In the coupled state, the first inner ramp portion  104  rests on the second inner ramp portion  108 . In addition, the first outside ramp portion  106  rests on the second outside ramp portion  110 . The achievement of the offset arrangement of the ramp portions, in this case, is that force transmission is possible in the axial direction always by means of at least two surfaces, as a result of which the safety against tilting in relation to the stud main axis  32  is improved. 
         [0089]      FIG. 4  also shows the inside diameter  112  of the hollow shaft portion  90 . It can also be seen that the hollow shaft portion  90  can have a polygonal shape  114  both on the inside circumference and on the outside circumference. 
         [0090]      FIGS. 5 to 7  show the first and the second member  24 ,  28  in different relative rotational positions.  FIG. 5 , in this case, shows an initial position where the latching lugs  94  engage in the latching indentations  104 . This corresponds to a pre-assembly position of the fastening device  22 ′. 
         [0091]    It can be recognized in this connection that the outside diameter  116  of the stud  30  is smaller than the inside diameter  112  of the hollow shaft portion  90 . The inside diameter  112  is preferably 1.2 times as great as the stud outside diameter  116 , in particular at least 1.5 times as great as the stud outside diameter  116 . The inside diameter  112  is preferably smaller than three times the stud outside diameter  116 , preferably smaller than 2.5 times the stud outside diameter  116 . 
         [0092]    In the pre-assembly position shown in  FIG. 5 , a first required position  42   a  is set up which is the lowest possible required position. 
         [0093]    By rotating the second member  28  relative to the first member  24 , the first member  24  can be lifted in relation to the second member  28 , on account of the interaction between the first and the second ramp device  72 ,  88 . This means that, for example as shown in  FIG. 6 , in the case of a rotation about approximately 180°, a second required position  42   b  is set up which is higher than the first required position  42   a.    
         [0094]      FIG. 7  shows a representation where the two members  24 ,  28  are rotated in a maximum manner against each other. In this case a third required position  42   c  is set up which is higher than the second required position  42   b.    
         [0095]    It can be seen in  FIGS. 5 to 7  that at least two surfaces of the ramp devices  72 ,  88  always engage each other such that a high level of safety against tilting is ensured. 
         [0096]      FIG. 8  shows finally a completed fastening arrangement  10 ′ where the fastening device  22 ′ has been fixed with regard to the second workpiece  16  by means of a fixing member  44 ′. The fixing member  44 ′, in the present case, is realized as a nut with a comparatively large annular flange which rests in a flat manner on top of the first member  24 . 
         [0097]    In addition  FIG. 8  shows that a first workpiece  12  is inserted into the fastening portion  26  of the first member  24 . 
         [0098]      FIG. 9  shows a screw tool  120  which has a hollow shaft  122 , the inside diameter of which is greater than the stud outside diameter  116 . A polygonal portion  124 , which can engage the inside circumference of the hollow shaft portion  90  in order, in this way, to rotate the second member  28  with regard to the first member  24  and consequently to adjust the position of the fastening portion  26  in the first direction  40 , is realized on the outside circumference of the hollow shaft  122 . 
         [0099]    Although exemplary embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.