Abstract:
A windshield wiper device, in particular for a motor vehicle, comprising a carrier ( 12 ) for fixing to a first part ( 52 ), especially to the body of the motor vehicle. A locking element ( 40 ) having a predetermined breaking point ( 41 ) is also provided in order to enable the carrier ( 12 ) to be fixed to the first part ( 52 ) by a rotational connection.

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to a windshield wiper device, in particular for a motor vehicle. 
   Numerous windshield wiper devices featuring a carrier, which is fixed to a first part, for example the body of a motor vehicle, are already known. Normally, the carrier has openings through which screws or rivets can be drawn so that the windshield wiper device can be screwed down to the body with the aid of several screws and various damping elements. This is relatively expensive and cost-intensive since bore holes provided with threads have to be attached to the body of the motor vehicle or holes have to be provided onto which a screw nut has to be welded. 
   In addition, the windshield wiper device is very solidly connected with the body of the vehicle and this means that a pedestrian can be easily injured in an impact with the engine hood of the motor vehicle by the wiper shafts projecting from the body, which bear the wiper arms and wiper blades. 
   SUMMARY OF THE INVENTION 
   The windshield wiper device in accordance with the invention has the advantage that the windshield wiper device can be fixed in the simplest manner to the body of the motor vehicle by a rotational connection with a locking element. A rotational connection does not require any threads and can be closed by a rotation less than 360 degrees. As a result, the number of work steps before and during assembly can be reduced and the costs during manufacturing and assembly are reduced. In addition, a predetermined breaking point in the locking element allows simple and cost-effective pedestrian impact protection to be realized. 
   It is especially advantageous if the rotational connection features a catch, which serves as an orientation for the locking element and locks said locking element into a preferred position. The connection strength is increased in this way so that the connection will not detach by itself even in the case of strong, longer lasting vibrations like those that constantly occur when operating a vehicle. However, because of the predetermined breaking point, detachment of the connection in the case of a pedestrian impact on the wiper shafts of the windshield wiper device is guaranteed in spite of this. 
   The rotational connection is realized in an especially simple manner in that the carrier has an opening and the locking element in a closed state penetrates the opening. 
   To improve the damping and avoid acoustic bridges it is advantageous if an elastic damping bushing is arranged between the locking element and opening. 
   If the locking element features a first section, which is longer in cross section than it is wide, the windshield wiper device is stably fixed to the vehicle body and a predetermined breaking point can be provided in a simple way. 
   This can be realized in an especially simple manner by an elliptical cross section. 
   Because of a transverse groove to accommodate the first part, brackets are created on the first section of the locking element and these brackets further increase connection strength. In this case, it is of particular advantage if the width of the transverse groove is greater than the thickness of the first part. 
   It is especially advantageous if the first part is embodied as a stamped part or stamped bent part, which features a hole having the shape of the first section of the locking element. 
   In this connection, it is especially advantageous if the locking element penetrates the first part and the first part features a slant of such a type that the locking element is pulled into the first part during the closing process. In this way, the connection strength is increased and a thread-like effect is achieved without the thread having to be cut into the body of the motor vehicle. If a damping bushing is arranged between the locking element and the opening of the carrier, said carrier is pre-tensioned by the slant of the first part, thereby further improving damping. 
   It is advantageous if the locking element has an engagement, which enables it to cooperate with a tool. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One exemplary embodiment of the invention is depicted in the drawings and explained in greater detail in the following description. The drawings show: 
       FIG. 1  A schematic representation of a windshield wiper device in accordance with the invention 
       FIG. 2  An exploded representation of a wiper bearing, a windshield wiper device in accordance with the invention with the fixing area 
       FIG. 3  The connection area in the delivery state at the motor vehicle manufacturer 
       FIG. 4  The fixing area of a windshield wiper device in an assembled position 
       FIG. 5  A variation of the wiper bearing of the windshield wiper device from  FIG. 2 . 
   

   DETAILED DESCRIPTION 
     FIG. 1  shows a schematic depiction of a windshield wiper device  10  in accordance with the invention. It essentially includes a carrier  12  consisting of a tube with a wiper bearing  14 ,  16  arranged on each of its ends. Each wiper bearing  14 ,  16  features ears  18 ,  20  and each of these ears has an opening  22 ,  24 . Furthermore, wiper shafts  26 ,  28 , which are connected to wiper arms (not shown in this case), are positioned in the wiper bearings  14 ,  16 . The wiper shafts  26 ,  28  are driven via a crank mechanism  30 ,  32 , which is put into motion by a motor  34 . 
     FIG. 2  shows an exploded representation of a wiper bearing of a windshield wiper device in accordance with the invention. As a part of the carrier  12 , the wiper bearing  14  has an ear  18  with an opening  22 . The damping bushing  36 ,  38 , which is designed as two parts in this case, is inserted into the opening  22 . Of course, it is also conceivable to design the bushing  36 ,  38  as one piece. The damping bushings  36 ,  38  are embodied as rubber disks, which can also sit with positive engagement in the opening  22  of the carrier  12 . A locking element  40 , which essentially has three sections, is inserted into the opening  22  with the damping bushings  36 ,  38 . There is a first elliptical section  42  to which a second circular cylindrical section  44  is adjacent. Adjacent to this section, in turn, is a third circular discoid section  46 . The first discoid section  42  that is elliptical in cross section has a height of H 1  and possesses a transverse groove  48  with width B. 
   In addition, an engagement  50  is arranged in the third section  46 , which engagement is embodied for example as a polygon or as a slot, into which a tool can be inserted to easily rotate the locking element  40  during assembly. 
   The locking element  40  itself is inserted during assembly into a first part  52  and rotated relative to it by an angle of less than 360 degrees. In this case, the first part  52  is embodied as a sheet metal part, in particular a stamped bent part, has thickness D and is connected to the vehicle body. It also has a hole  54 , which has the same contour as the first section  42  of the locking element  40  so that said locking element can penetrate the first part  52 . Ideally, the first part  52  is embodied as one piece with the vehicle body. 
   The transverse groove  48 , whose width B is typically greater than the thickness D of part  52 , allows two brackets  49 ,  49   a  to be created, which project over the cross-sectional profile of the second section. In this case, the brackets  49 ,  49   a  feature predetermined breaking points  41 , which have a reduced resistance cross section. Alternatively, only one of the brackets  49 ,  49   a  can have a predetermined breaking point  41 . Naturally, instead of transverse groove  48  a simple step can be provided so that the brackets  49 ,  49   a  can also project beyond the contour of the second section. 
   As a further alternative, the predetermined breaking point  41  can also be arranged in the second section  44 . In this case, said second section can have one at least partially circumferential groove, which reduces the resistance cross section of the second section  44 . 
   Appropriately, the ends of the wiper shafts  26 ,  28 , which are connected to the wiper arms, are arranged on the side of the wiper bearing  14  facing the first part  52  so that the ears  18  are pressed away from the first part  52  when the wiper shaft  26 ,  28  is under stress. 
   During assembly, the first section  42  with the brackets  49 ,  49   a  of the locking element  40  penetrates the first part  52  through the hole  54 . By turning the locking element  40 , the carrier  12  of the windshield wiper device  10  is connected to the first part  52  as a part of the vehicle body. The part  52  has elevations or die-cuts of such a type in the area of the hole  54  that a radial, thread-like slant  56  is created, along which the brackets  49 ,  49   a  slide when the locking element  40  is rotated, so that the distance of the third section  46  of the locking element  40  and the first part  52  is reduced and the locking element  40  is pulled as it were into the part  52 . Provided on the high end of the slant  56 , is a catch  58 , embodied as a small depression, into which at least one bracket  49  slides. This prevents the bracket  49  from sliding down the slant  56  when the locking element  40  is situated in the closed position. Thus, a bayonet catch with high strength is produced. 
     FIG. 3  shows the fixing area of a carrier in the delivery state at the motor vehicle manufacturer. The locking element  40  is pulled through the opening  22  of the ear  18  of the wiper bearing  14  and is enclosed by the damping elements  36 ,  38 . The first section  42  with the brackets  49 ,  49   a  and the transverse groove  48  projects out of the damping element  38 . 
     FIG. 4  depicts the fixing area of the carrier  12  in an assembled representation. The locking element  40  has penetrated the damping elements  36 ,  38  as well as the opening  22  and the first part  52  through the hole  54  and was rotated by approx. 90° to its longitudinal axis. In this way, the brackets  49 ,  49   a  form holders on the part  52  in such a way that the carrier of the windshield wiper device  10  is clamped between the third section  46  of the locking element  40  and the brackets  49 ,  49   a  of the first section of the locking element. 
     FIG. 5  shows a variation of the windshield wiper device in accordance with the invention. The locking element  40  is again comprised of three sections. The first section  42  corresponds to a double keyhole contour and thereby forms two brackets  49 ,  49   a , which project over the cylindrical contour of the second section  44 . The second section  44  is directly adjacent to the first section  42  and together with it forms a step on the brackets  49 ,  49   a . Adjacent, in turn, to this second section  44  is the third section  46 , which features the engagement  50  to accommodate a tool. 
   Naturally, the third section  46  can also be embodied, for example in its outer contour, as a polygon and thereby itself serve as an engagement. The damping bushings  36 ,  38  are embodied here as one piece and can be inserted as a whole into the opening  22  of the wiper bearing  14  of the carrier  12 . The hole  54  of the first part  52 , in turn, has the contour of the double keyhole so that the hole is able to accommodate the first section  42  of the locking element  40 . 
   The locking element  40  is embodied as a plastic injection molded part, however, it can also be embodied of a metal, e.g., aluminum, an aluminum alloy or a zinc alloy. The damping bushings  36  are made of rubber or another elastic material, which has good damping behavior. The part  52  is permanently welded onto the vehicle body as a simple extension or embodied as one piece with said vehicle body. The wiper bearings  14 ,  16  of the carrier  12  can be embodied of plastic, but also of metal. In principle, the entire carrier  12  can also be injection molded from plastic as one piece.