Abstract:
A connection device is proposed, which serves the purpose of pivotably connecting a wiper blade, for windows of motor vehicles, to a wiper arm. The connection device has a coupling element on the wiper blade which is pivotably connectable to a coupling part on the wiper arm. The coupling element is disposed on an upper band face, in a center portion, of a band-shaped, elongated spring-elastic support element of the wiper blade. The wiper blade is provided with a spoiler, on the side of the upper band face, extending on both sides of the coupling element and defining a leading-edge face. Additionally, the coupling part is also provided with a leading-edge face extending longitudinally with the spoiler thereon to improve wiper blade function.

Description:
BACKGROUND OF THE INVENTION 
     A known connection device of the type is seated with its coupling element toward the wiper blade on the upper band face of the support element, which forms the termination of the wiper blade remote from the window (German Patent Disclosure DE 1972 98 65.6 A1). 
     However, if to avoid the tendencies of the wiper blade to lift away from the window at relatively high travel speeds, the wiper blade is to be provided with a spoiler, then the spoiler must be recessed accordingly in the mounting region provided for the connection device and located in the longitudinal center portion, so that the coupling element toward the blade can be fastened properly. In the case of a wiper strip made by die-pressing or molding, this must be accomplished with the aid of a complicated die-forming mold, while in the case of an extruded wiper strip, one additional work step is needed for this. Interrupting the course of the spoiler furthermore has a disruptive effect on the distribution of the contact force of the wiping action on the window. Furthermore, making an interruption in the leading- edge face that faces into the relative wind and is present on the spoiler undesirably increases the relative wind noise. 
     SUMMARY OF THE INVENTION 
     In the connection device of the invention, the leading-edge face is extended past the connection device, so that at most only a small gap remains, which in terms of the distribution of contact force and noise production can be ignored. 
     The leading-edge face of the coupling part can be embodied in a simple on a striplike protrusion disposed on the coupling part and aligned at least nearly with the spoiler. 
     If the striplike protrusion, originating at the end of the coupling part remote from the pivot axis of the connection device, extends toward the pivot axis, then a continuous transition from the leading-edge face of the spoiler to the leading-edge face of the connection device is assured, and in the region of the pivot axis, a small spacing, which is required for connecting the wiper blade to the wiper arm, can remain. 
     An especially advantageous embodiment in terms of ease of assembly of the coupling part toward the wiper arm is obtained if, in a refinement of the invention, the coupling part a U-shaped cross section; the bearing recesses are disposed on a longitudinal end portion in the legs of the U that cover the side cheeks of the coupling element; the striplike protrusion is disposed on the side of the base of the U remote from the legs of the U; and the striplike protrusion is provided with a leading-edge face and ends in spaced-apart fashion from the common pivot axis of the bearing recesses. 
     An extension of the concept of the invention is distinguished in that the base of the U, in the region of the pivot axis, is provided with a recess extending as far as the protrusion, and that the coupling element, on its side toward the base of the U of the coupling part, has a protrusion which penetrates the recess and on which a supplementary leading-edge face aligned with the leading-edge face of the protrusion is embodied. It is thus possible to extend the leading-edge face without interruption over its entire length without impairment of the work steps required for attaching the wiper blade to the wiper arm. As a result, especially good values in terms of the contact force distribution and noise development are attained. 
     The ease of assembly of a connection device of this kind is improved still further if the adjacent ends of the protrusion and of the protrusion each have a curved course, following a respective radius, and the centers of the radii of curvature are located on the pivot axis. 
     Economical manufacture of the connection device is attained if both the protrusions are integrally joined to the coupling part and the coupling element, respectively. 
     If in another embodiment of the invention, the striplike protrusion of the coupling part is longitudinally displaceable and lockable between an assembly position and an operating position, and in the operating position, the end of the protrusion toward the pivot axis is adjacent to the spoiler of the wiper blade, then the spacing between the spoiler and the protrusion which is required for assembly can be reduced afterward or eliminated entirely. 
     The protrusion can be integrated extensively into the course of the spoiler, if the striplike protrusion, on its end remote from the pivot axis and on its back side remote from its leading-edge face, has a free punch which measured longitudinally is approximately as long as the maximum longitudinal displacement path of the protrusion. 
     Expediently, both the coupling part and the coupling element are made from a plastic. 
    
    
     Further advantageous refinements and features of the invention are disclosed in the ensuing description of exemplary embodiments shown in the accompanying drawing. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawing: 
     FIG. 1 is a side view of a wiper blade which is connected by a connection device to a wiper arm; 
     FIG. 2, showing the connection device in plan view, is an enlargement of the detail marked II in FIG. 1; 
     FIG. 3 is a section taken along the line III—III through the connection device of FIG. 2, rotated by 90°; 
     FIG. 4 is a perspective side view of the arrangement of FIG. 2; 
     FIG. 5 is a perspective view of a different version of the coupling part; 
     FIG. 6 shows the coupling element, disposed in the middle portion of a wiper blade and belonging to the coupling part of FIG. 5; 
     FIG. 7 is a side view of the connection device, assembled from the components of FIGS. 5 and 6; 
     FIG. 8 is a side view of a further connection device, in which the coupling part of the wiper arm is shown in the assembly position; and 
     FIG. 9 shows the arrangement of FIG. 8, with the coupling part shown in the operating position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A wiper blade  10  shown in FIG. 1 has a bandlike-elongated, spring-elastic support element  12 . On the top side  14  of the band of the support element  12 , remote from the window to be wiped, there is a coupling element  18 , made from a plastic, which belongs to a connection device  16  and with the aid of which the wiper blade  10  can be separably connected to a wiper arm  20  that is guided on the body of a motor vehicle and is movable between turning points. For the sake of this separable connection, the wiper arm, on its free end, is provided with a coupling part  21 , made of plastic, which also belongs to the connection device  16 . On the underside  22  of the band of the support element  12 , oriented toward the window, there is an elongated, rubber-elastic wiper strip  24  parallel to the longitudinal axis of the support element. The wiper strip  24  extends with a striplike extension  26  past the top side  14  of the support element  12 ; this extension, on the top side of the support element, forms a spoiler that is provided with a leading-edge face or leading-edge throat  28 . The coupling part  21  and the coupling element  18  together form the connection device  16 , whose structure will be described in further detail herein. The wiper arm  20  and thus the wiper blade  10  as well are urged in the direction of the arrow  23  toward the window to be wiped, whose surface to be wiped is represented in FIG. 1 by a dot-dashed line  30 . Since the dot-dashed line  30  is meant to represent the greatest curvature of the window surface, it is clearly apparent that the curvature of the wiper blade  10 , resting with both ends on the window, is greater than the maximum window curvature. Under the contact pressure (arrow  23 ), the wiper blade  10  presses with its wiper lip  32 , over its full length, against the window surface  28 . In the process, a tension builds up in the spring-elastic support element  12 , and this tension assures a proper contact of the wiper strip  24  or wiper lip  32 , over its entire length, with the vehicle window. 
     The special embodiment of the connection device  16  will now be described in further detail. A first embodiment of the connection device  16  of the invention—shown in FIGS.  2 - 4 —is the same in its basic structure as the further embodiments of FIGS. 5-7 and FIGS. 8 and 9. As FIG. 4 in particular shows, the coupling element  18  toward the wiper blade is seated in a longitudinal recess  34  of the spoiler  26 , and this spoiler, because of the longitudinal recess  34  disposed in the longitudinal center portion of the wiper blade  10 , now has two segments. The coupling element  18 , preferably made of plastic, is seated on the top side  14  of the support element  12  and clasps its longitudinal edges  35  as far as the underside  22  of the support element (FIG.  4 ). As FIG. 3 shows, the support element  12  has two longitudinal rails  38 , spaced apart from one another. With a rib strip  40 , the wiper strip  24  intersects the plane of the support element  12  and forms an extension  26 , on the top side  14  of the support element, that has a leading-edge throat  28  (FIG.  3 ), which assures an improved contact pressure of the wiper lip  32  against the window surface  30  to be wiped. The coupling element  18  has one pivot pin  41  on each of its two opposed long sides, and each pivot pin protrudes from the respective long side of the wiper blade  10 . The two pivot pins  41  have a common longitudinal axis  42 , which extends transversely to the longitudinal direction of the wiper blade, in a plane spaced apart from the window (FIGS.  1  and  4 ). The pivot pins  41  form pivot means toward the wiper blade, which are each guided in a respective bearing recess  44  of the coupling part  21  toward the wiper arm. The longitudinal axes  42  of the pivot pins  41  and bearing recesses  44  form a pivot axis, about which a relative motion is possible between the coupling element  18  and the coupling part  21 , or between the wiper blade  10  and the wiper arm  20 . This is applicable to all the embodiments of the invention described here. The coupling part  21  has a substantially U-shaped cross section. The bearing recesses  44  for the pivot pins  41  are disposed in the legs  46  of its U. The bearing recesses  44  are open at the edge, via an introduction opening  50  for the pivot pins  41 , which are nonround in cross section. 
     In FIG. 4, only one of the two pivot pins  41  and one of the two bearing recesses  44  is shown. Since the other side of the connection device  16  is embodied the same way as the one long side that is visible, it needs no further description, especially since the dot-dashed line  42  in FIG. 2 indicates the common longitudinal axis of both pivot pins  41  and both bearing recesses  44 . 
     In order to close the longitudinal recess  34  for wiping operation, the coupling part  21 , on the side of the base  48  of the U remote from the coupling element  18 , has a striplike protrusion  52 , which extends longitudinally of the wiper blade  10  and hence also longitudinally of the spoiler  26 . The protrusion  52  is provided with a leading-edge throat  54 , which extends over the full length of the protrusion  52 . In this exemplary embodiment, the leading-edge throat  54  of the protrusion  52  is located slightly in front of the leading- edge throat  28  of the spoiler  26 . As a result, it is possible to provide the protrusion  52 , on its back side  55  remote from its leading-edge throat  54  and on its end remote from the pivot axis  42 , with a recess  56  that is so large that the protrusion is displaceable longitudinally by an amount  58  (FIG.  2 ). In FIGS. 2 and 4, the protrusion is shown in a position which enables problem-free mounting of the wiper blade  10  on the wiper arm  20 . Its operating position is shown in dot-dashed lines there. The assembly process will be described later herein, in conjunction with FIGS. 8 and 9. Once the connection device  16  has been put together (FIG.  4 ), when the legs  46  of the U of the coupling part  21  cover the side cheeks of the coupling element  18 , the protrusion  52  can be displaced by the amount  58  in the direction of the arrow  60 , so that in the operating position now reached, the end of the protrusion toward the pivot axis  42  is directly adjacent to the spoiler  26  of the wiper blade  10 . 
     If the recess  56  is disposed on the end of the protrusion  52  toward the pivot axis  42 , then it can be solidly joined to the coupling part  21 , without hindering the mounting of the wiper blade  10  on the wiper arm  20 . 
     Another embodiment  116  of the connection device will be described below in conjunction with FIGS. 5-7. FIG. 5 especially clearly shows the structure of the coupling part  121  toward the wiper arm, with its essentially U-shaped cross section. This basic structure is also present in the embodiment of FIGS. 2-4. FIG. 5 also shows the disposition of the bearing recesses  144  in the legs  146  of the U of the coupling part  121 . It can also be seen from FIG. 5 that one leg  146 , the rear leg of the U, is equipped with a receiving opening  145  for the wiper arm  20 . In this embodiment, a striplike protrusion  152  is also present on the outside of the base  148  of the U, integrally joined to it; the protrusion extends longitudinally of the wiper blade and is provided with a leading-edge throat  154 . The protrusion  152 , with its leading-edge throat  154 , forms one segment a supplementary spoiler that is joined solidly, preferably integrally, to the U-shaped base body of the coupling part  121  and that extends from the end, remote from the pivot axis  42 , of the coupling part  121  as far as a recess  150 , which is disposed in the base  148  of the U and extends from the striplike protrusion  152  as far as the end, toward the pivot axis, of the base  148 , where it is open at the edge. The protrusion  152  ends in spaced-apart fashion in front of the pivot axis  42 . FIG. 6 shows that a protrusion  157  is present on the surface  156 , toward the base  148  of the U, of the coupling element  118  toward the wiper blade. This protrusion forms an extension of the striplike protrusion  152  and is solidly, preferably integrally, joined to the coupling element  118  made from a plastic. This supplementary protrusion  157  extends from the end toward the pivot axis of the coupling element  118  and is adapted to the length of the recess  150 , whose length extends as far as the striplike protrusion  152 . The extension  157  of the striplike protrusion  152  essentially has a cross section that is identical to that of the protrusion  152 , and thus it likewise has a leading-edge throat  155 . The striplike protrusion  152  and its extension  157  toward the coupling element is aligned with the spoiler  26  of the wiper blade  10 , in the assembled state of the connection device  116 . It can also be seen from FIG. 7 that the adjacent ends  158  and  159  of the protrusion  152  and of its extension  157  each extend in curved fashion, following a radius, and that the centers of the radii of curvature  160  and  161 , respectively, are located on the pivot axis  42 . In this arrangement, unproblematic relative swiveling between the wiper arm  20  and the wiper blade  10  or between the coupling part  121  and the coupling element  118  is possible without creating any substantial gap in the region of the protrusion  152  and its extension  157 . The basic design of the coupling element  118  and its fastening to the support element  12  are as in the disposition and embodiment described for the exemplary embodiment of FIGS. 2-4. 
     A further, especially simple embodiment  216  of the connection device of the invention is shown in FIGS. 8 and 9. In this embodiment, the coupling element  218  toward the wiper blade corresponds to the coupling element  18  of FIG.  4 . The coupling part  221  toward the wiper arm has a protrusion  222 , integrally joined to it, which extends from the end remote from the pivot axis of the coupling part  221  in the direction of the pivot axis  42 . However, it ends with a spacing  219  in front of the pivot axis  42  (FIG.  9 ). This spacing  219  is required so that the wiper blade  10  can be joined to the wiper arm  20 , because for that purpose the wiper blade must be put in a position crosswise to the length of the wiper arm (FIG.  8 ). That is, the wiper blade must be joined to the wiper arm in this assembly position shown; with its pivot pins  41 , it enters the bearing recesses  44  of the coupling part  221  toward the wiper arm in the direction of the arrow  223 , after which it is then rotated into its operating position shown in FIG.  9 . As FIG. 8 shows, because of the projection  224  of the spoiler  26  past the pivot axis  42 , it is necessary that the spacing or free space  219  be maintained. Naturally, it continues to exist in the operating position as well, but a considerable portion of the longitudinal recess  34  is already closed then by the protrusion  222 . In this embodiment as well, there is a leading-edge throat  254  on the protrusion  222 ; this leading- edge throat directly adjoins the leading-edge throat  28  of the spoiler  26 . 
     It is common to all the exemplary embodiments that the wiper blade, on the side of the upper band face  14  of the support element  12 , is provided with a spoiler  26  that has a leading-edge face  28  and that extends on both sides of the coupling element  18 ,  118 , or  218  in the longitudinal direction of the wiper blade, and that a leading-edge face  54 , or  154 ,  156 , or  254  extending longitudinally of the spoiler  26  is embodied at least on the coupling part  21  or  121  or  221 , toward the wiper arm, of the connection device  16 ,  116 , or  216 , respectively. The leading-edge faces are expediently shaped as throats.