Abstract:
A connecting piece for connecting a wiper arm with a wiper blade, having three different fastening systems for wiper arms, so that a multiplicity of wiper arms can be received.

Description:
BACKGROUND INFORMATION 
     Connecting pieces for connecting the wiper arm with the wiper blade are already known, for example from European Patent No. 0 863 058; however, the connecting piece presented there has a multipart construction, so that different adapter parts are used, partly according to the modular design system, for different wiper arms. 
     SUMMARY OF THE INVENTION 
     The connecting piece according to the present invention has the advantage that it can receive (accept) a multiplicity of standard types of wiper arm ends, and thus can also be used with a multiplicity of differently dimensioned wiper arms. In addition, it can be manufactured in one piece, for example, in an injection molding method, which results in a significant advantage during installation (assembly), because it is not necessary first to determine which adapter piece fits the wiper arm end in question. This is especially important in particular because, as a rule, the installation is carried out by the vehicle driver himself, i.e., by a layman, not an expert. 
     Due to the fact that the wiper arm end is constructed in the shape of a fork, there results a high degree of rigidity of the connection between wiper arm and wiper blade. In this way, the optimal angle between windshield and wiper blade can be precisely maintained. 
     A fitting adapter piece having a fork-shaped construction can also connect the connecting piece with a strip-shaped wiper arm end, as is standard for some wiper arms, without loss of rigidity. 
     If a region of the connecting piece is constructed as a flexible plateau an especially high dimensional tolerance is achieved. If the flexibility of the plateau is due to crosspieces that have an angle to the wiper arm of less than 90°, then when the connecting piece is removed from the wiper arm there results a self-arresting effect that further increases the strength of the connection between wiper arm and wiper blade. 
     Due to the fact that the flexible regions have stops for limiting the flexibility, a high degree of resistance to breaking is also ensured. 
     Through the clamp-type projections for arresting the wiper arms, a multiplicity of different wiper arms can be fastened securely to the wiper blade, since it is not necessary to use the arresting method used by the manufacturer of the wiper arm. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a schematic view of a part of a wiper apparatus having the inventive connecting piece, in the installed position. 
     FIG. 2 shows a box region of a center bracket of a wiper blade. 
     FIG. 3 shows a hook-shaped wiper arm end. 
     FIG. 4 shows a connecting piece according to the present invention and a pin-arm wiper arm end, in a perspective view. 
     FIGS. 5 and 6 show a connecting piece according to the present invention, each having a hook-shaped wiper arm end. 
     FIG. 7 shows a connecting piece according to the present invention having a strip-type wiper arm end and a fork-shaped adapter, in a perspective view. 
     FIG. 8 shows a section through an inventive connecting piece. 
     FIG. 9 shows a section through an adapter. 
    
    
     DETAILED DESCRIPTION 
     In FIG. 1, a connecting piece  10  having a wiper arm  11  and a wiper blade  12  can be seen. In the installed position, the wiper blade lies on a windshield  13 . Wiper arm  11  has two ends, its lower end being connected with a wiper motor  14 . Its upper end standardly has either a hook-type wiper arm end ( 11   a ), a pin-type wiper arm end ( 11   b ), or a strip-type wiper arm end ( 11   c ). 
     In FIG. 2, a box region  15  of a center bracket of a wiper blade  12  is shown. In this region there is located a connecting element  18 , often a rivet or a roll rivet, that connects the body of connecting piece  10  with wiper blade  12 . At the sides, box region  15  has various bored holes  21  that may have a border. 
     FIG. 3 shows a hook-shaped wiper arm end. It has a hook-shaped 180° bend having radius R. 
     FIG. 4 shows an inventive connecting piece  10  and a pin-type wiper arm end  11   b . Pin-type wiper arm end  11   b  has a pin  24  that in the installed position lies parallel to the windshield and perpendicular to wiper arm  11 , and whose diameter is diminished in a suitable segment. 
     The body of connecting piece  10  essentially has two side walls  30  that are held by three cross-connecting pieces  27   a ,  27   b , and  27   c , and that receive and support wiper blade  12  (see also FIG.  8 ). 
     On the front side, facing away from wiper arm  11 , of the connecting piece, side walls  30  extend beyond cross-connecting pieces  27   a, b, c , and are terminated by raised parts  33  This results in a clamp-type projection  31  that is used to arrest hook-type wiper arm ends  11   a.    
     Upper surface  27   a  is curved downward in the front region of the body, forming a radius  36 . 
     On its lower side, which in the installed state faces the windshield, the connecting piece has a transverse groove  37  that tapers upward and that terminates with a cylindrical opening  38  that receives connecting element  18  of wiper blade  12 . 
     In the rear region, facing the wiper arm, connection piece  10  has, on its side facing windshield  13 , slots  40  in lateral walls  30 , so that lower surface  27   b  is supported only by thin crosspieces  39 , and thus forms a flexible plateau. 
     The direction of slots  40 , and thus the direction of crosspieces  39 , is usefully selected such that when connecting piece  10  is removed from wiper arm  11   a , the adhesion of wiper arm  11   a  to lower surface  27   c  effects an increase of the contact pressure of lower surface  27   c  on wiper arm  11   a.    
     This is achieved in that when connecting piece  10  is withdrawn from wiper arm  11   a , the lowest surface  27   c  is moved slightly forward through its adhesion to wiper arm  11   a . The angle of crosspieces  39  to the wiper arm, and thus the distance between upper surface  27   a  and lower surface  27   c , is increased slightly by this, increasing the contact pressure of surface  27   c  against the bent over end of wiper arm  11   a.    
     In order to limit flexibility, flexible region  41  has stops  44  that prevent crosspieces  39  from breaking off. 
     Above plateau  27   c , connecting piece  10  has a hole  43  that extends through it transversely between the upper surface and the center surface. This hole  43  receives a pin-arm wiper arm  11   b.    
     For this purpose, center surface  27   b  is interrupted by a tongue-type clip  45  that extends from transverse groove  37  to behind hole  43 , and that reduces the diameter of hole  43  inside the body of connecting piece  10 . Clip  45  is bent upward behind hole  43 , and subsequently has a pressure surface  48  that runs in parallel alignment to upper surface  27   a.    
     If pin  24  of a pin-type wiper arm end  11   b  is now introduced into opening  43 , clip  45  is first bent downward so that it will then snap upward, due to the diminished diameter, when pin  24  is located in the desired position, thus snapping wiper arm  11  into place. 
     On the upper surface, the connecting piece has two openings  52  that can be used to fasten an adapter  55 . 
     In FIG. 5, a connecting piece  10  having a hook-type wiper arm end  11   a  is shown in the installed position. 
     FIG. 6 likewise shows a connecting piece  10  according to the present invention having a wiper arm  11   a , but here wiper arm  11   a  has a larger radius R than in FIG.  5 . For this reason, the bent-off end slides under flexible plateau  27   c , and presses this plateau slightly upward if necessary. Here the arresting via raised parts  33  of connecting piece  10  can be seen clearly. 
     FIG. 7 shows a connecting piece  10  according to the present invention together with an adapter  55  and a strip-type wiper arm end  11   c . Adapter  55  essentially has a long and a short longitudinal brace  58 ,  59 , connected with one another by a transverse brace  62  in such a way that a fork-type structure results. 
     FIG. 9 shows adapter part  55  in a sectional view. The long upper longitudinal brace  58  has on its lower side, in the front region facing connecting piece  10 , an arresting tongue  65  to whose end teeth  68  are attached that arrest adapter  55  in openings  52  of connecting piece  10 . On the side of adapter  55  facing wiper arm  11 , there is located an arm receptacle  71  made up of an opening and an arrest hole  74 . Arm receptacle  71  is fashioned in such a way that a strip-shaped wiper arm  11   c  can be inserted and is arrested via a wiper arm peg  77  (tab) that snaps into arrest hole  74 . 
     In the connection of adapter  55  with connecting piece  10 , short longitudinal brace  59  is inserted into the area between center and lower surfaces  27   b  and  c . Long longitudinal brace  58 , having arrest tongue  65 , of adapter  55  slides forward on upper surface  27   a  of connecting piece  10 . In the snapped-in state, teeth  68  engage in openings  52 . 
     It is also possible to attach an arrest pin to the lower side of short longitudinal brace  59 ; in the snapped-in state this bolt snaps into a hole located in the flexible plateau, i.e., surface  27   c.