Abstract:
A device is proposed which is used to wipe windows of motor vehicles. The wiping device has an oscillatingly driven wiper arm ( 12 ), guided on the motor vehicle, on whose free end, remote from the oscillation axis ( 16 ), a wiper blade ( 22 ) which is elongated transversely to the oscillation direction, that can be placed against the window ( 24 ) is releasably hinged via a connection device ( 26 ) that has coupling parts of the wiper arm and of the wiper blade, and the hinge axis ( 32 ) extends substantially in the oscillation direction (double arrow  18 ). In such a wiping device, an especially low-wear hinge is obtained if the wiping device has at least one support shoulder ( 72  and  96 ), fixed to the wiper arm and pointing toward the oscillation axis ( 16 ), with which a check shoulder ( 74  and  102 ) fixed to the wiper blade and pointing away from the oscillation axis ( 16 ) is associated.

Description:
BACKGROUND OF THE INVENTION 
     The present invention deals with a wiping device of windows of motor vehicles with a wiper arm guided on the motor vehicle and oscillatingly driven in known wiping devices (German Patent Disclosure DE 32 20 274 A1), a considerable centrifugal force acts on the hinge connection between the wiper arm and the wiper blade during the oscillating working motion; particularly in so- called single-lever wiper systems—because of the comparatively large and thus heavy wiper blade—this force is further increased. This centrifugal force must be intercepted by a pin that forms the hinge axis and by a hairpin-like curvature, forming the pin bearing, of the free end of the wiper arm or a retention spring adapted to this curvature. Since furthermore the hinge connection is still exposed to environmental factors, such as road dirt, it can become deflected, because of the linear support of the pin in the curvature, which then impairs the wiping results, because in this hinge the requisite adaptation of the wiper blade to the course of the spherically curved surface of the window is done during the wiping operation. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a wiping device which avoids the disadvantages of the prior art. 
     In keeping with these objects, one feature of present invention resides, briefly stated, in the wiping device in which at least one support shoulder is fixed to the wiper arm and pointed toward the oscillation axis, to cooperate with a check shoulder fixed on the wiper blade and pointing away from the oscillation axis. 
     In the wiper blade of the invention with the hinge between the wiper arm and the wiper blade is completely relieved during wiping operation, since given careful adaptation of the check shoulder to the support shoulder, no centrifugal forces can act on the hinge. Since the support is effected on generally flat shoulders, the shoulders are subject to practically no wear. 
     For technical production reasons, it is advantageous to dispose the support shoulder fixed to the wiper arm on the coupling part of the wiper arm, and the check shoulder of the wiper blade on the coupling part of the wiper blade, the coupling parts being part of the connection device. 
     A wiping device of compact structure is obtained if the support shoulder and the check shoulder are disposed between the oscillation axis and the hinge axis. 
     An especially simple disposition of the support shoulders and check shoulders can be accomplished if, in a feature of the invention, the coupling part of the wiper arm has a wall located in a plane vertical to the window and extending substantially in the direction of the longitudinal axis of the wiper arm, adjacent to which wall is a surface of the coupling part of the wiper blade, and if furthermore the support shoulder is embodied on this wall and the check shoulder is embodied on this surface. 
     In a connection device of very low design, the invention can be realized if the coupling part of the wiper arm, crosswise to the longitudinal axis of the wiper arm, has a U-shaped cross section; if furthermore one bearing receptacle each for a pivot pin of the coupling part of the wiper blade is disposed in each of the legs of the U of this coupling part, which receptacle dips between the legs of the U of the coupling part of the wiper arm, and if finally the inside of at least one leg of the U forms the wall that is provided with the support shoulder. 
     Expediently, the coupling part of the wiper blade has an at least imaginary base body, in which the pivot pin is integrated in such a way that its two ends protrude from it, and furthermore at least one face of the base body forms the surface that is provided with the check shoulder. 
     If both the support shoulder and the check shoulder have a curved course about the axis of the hinge, and the respective radius of curvature corresponds to the respective spacing from the hinge axis, then a comparatively large-area contact of the two shoulders on one another is obtained, which minimizes their wear. 
     Wear of the shoulders can be further minimized if, in an extension of the concept of the invention, the support shoulder is embodied on a rib-like protrusion on the inside of one leg of the U, and the check shoulder is embodied on the side wall of a groove in the surface, toward this leg of the U, of the base body. 
     In this way, the shoulders are located inside the connection device and are thus largely protected against dirt from the road. 
     In certain applications, it can be advantageous if a plurality of support shoulders and check shoulders are embodied on each of the two coupling parts. 
     Technical advantages in terms of production are obtained if the two coupling parts are made from a plastic. 
     Further advantageous refinements and features of the invention are disclosed in the ensuing description of two exemplary embodiments shown in the associated drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     Shown in the drawing are: 
     FIG. 1, a wiping device of the invention in a side view; 
     FIG. 2, the wiping device of FIG. 1 in a plan view, rotated by  90 ; 
     FIG. 3, a side view on a larger scale of a coupling part of the wiper arm; 
     FIG. 4, a plan view on the coupling part of FIG. 3; 
     FIG. 5, the cut face of a section taken along the line V—V of FIG. 3; 
     FIG. 6, a side view on a larger scale of a coupling part of the wiper blade; 
     FIG. 7, a plan view on the coupling part of FIG. 6; 
     FIG. 8, a fragmentary side view of another version of the coupling part of FIG. 3, in a section taken along the line VIII—VIII of FIG. 9; 
     FIG. 9, a plan view on the coupling part of FIG. 8, in a section taken along the line IX—IX; 
     FIG. 10, a side view of another version of the coupling part of FIG. 6; 
     FIG. 11, a plan view of the coupling part of FIG. 10; and 
     FIG. 12, coupling parts of the wiper arm and wiper blade before the wiper blade is connected to the wiper arm, in an enlarged view, not to scale. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A wiping device  10  shown in FIGS. 1 and 2 has a wiper arm  12 , one end  14  of which is supported, so as to be capable of oscillation about an oscillation axis  16 , on a vehicle body, not shown. An elongated wiper blade  22  is pivotably connected to the end  20  of the wiper arm  12  remote from the oscillation axis  16 , and its length extends transversely to the oscillation direction (double arrow  18 ). The wiper blade  22  is placed in the direction of the arrow  25  against the surface to be wiped of a windshield  24  belonging to the motor vehicle. The connection between the wiper arm  12  and the wiper blade  22  is made via a connection device  26 , which includes a coupling part  28  of the wiper arm and a coupling part  30  of the wiper blade. The coupling part  28  is solidly connected to the wiper arm  12 , and the coupling part  30  is solidly connected to the wiper blade  22 . The hinge connection between the wiper blade  22  and the wiper arm  12  is made such that the axis  32  of the hinge extends substantially in the oscillation direction (double arrow  18 ), or in other words, transversely to the length of the wiper blade  22 . The design of the hinge means in a first embodiment according to FIGS. 1 and 2 will be described in further detail below in conjunction with FIGS. 3-7. 
     The coupling part  28  of the wiper arm, shown in FIGS. 3 and 4, has a retaining arm  34 , which serves the purpose of solidly connecting the coupling part  28  to the wiper arm  12 . The retaining arm  34  is adjoined by a hinge piece  36  of U-shaped cross section. One bearing receptacle  42  is disposed in each of the two legs  38  and  40  of the U. The other coupling part  30 , belonging to the wiper blade, is shown in FIGS. 6 and 7. It has a substantially block-shaped base body  44 , with two parallel side surfaces  46  and  48 , from which the two ends  50  of a pivot pin, which is conceptually integrated with the base body  44 , protrude. The longitudinal axis of this pivot pin—or the two aligned longitudinal axes of the pins  50 —correspond to the axis  32  of the hinge in FIG.  2 . The spacing  52  of the two side surfaces  46  and  48  of the base body  44  from one another is adapted to the spacing  54  (FIG. 5) between the legs  38 ,  40  of the U of the coupling part  28  in such a way that the base body  44  can dip with as little play as possible yet smoothly between the legs  38  and  40  of the U. This is the case whenever the wiper blade  22  is pivotably connected to the wiper arm  12 . It is in fact then that the two pin ends  50  are located in their bearing receptacles  42  of the coupling part  28  of the wiper arm. Since the bearing receptacles  42  in the two legs  38  and  40  of the U are aligned with one another, the joint bearing axis of the two bearing receptacles  42  is also equivalent to the axis  32  of the hinge. 
     To allow the two coupling parts  28  and  30  made from a plastic, or in other words the wiper arm  12  and the wiper blade  22 , to be joined together pivotably but in captive fashion, the bore-like bearing receptacles  42  in each of the legs  38  and  40  of the U of the coupling part  28  are open at the edge via a slit-like opening  56 . These opening slits are located substantially parallel to the surface of the window  24  to be wiped and point outward away from the oscillation axis  16 . The width  58  of the openings  56  is adapted to a spacing  60  between the flat faces  62 , toward the window  24 , of the pin ends  50  in such a way that the pin ends  50  can be introduced, via the two openings  56  respectively associated with them, into their bearing receptacles  42 , once the flat faces  62  have been oriented lengthwise of the openings. This arrangement, which also shows the mounting position, is shown enlarged in FIG.  12 . The work steps for connecting the wiper blade  22  to the wiper arm  12  will be described in further detail in conjunction with FIG.  12 . There, the two coupling parts  28  and  30  are represented by solid lines. For connecting the wiper blade  22  to the wiper arm  12 , the wiper blade is put in a position in which the flat faces  62  of the pin ends  50  are located in the extension of the openings  56  (FIG.  12 ). After that, the two pin ends  50  are introduced into their bearing receptacles  42 , in which the wiper blade is moved in the direction of the arrow  64  relative to the coupling part  28  of the wiper arm. Once the two pin ends  50  are located entirely in their bearing receptacles  42 , the wiper blade  22  is rotated in the direction of the arrow  66 , until the flat faces  62  reach the position shown in dot-dash lines in FIG. 12, in which they are aimed at the window  24 . FIG. 12 shows that the flat faces  62  are located inside an imaginary jacket face  68 , which in FIG. 12 is represented by the wall of the bearing receptacles  42 . It can be seen that in this operating position of the connection device  26 , shown in dot-dash lines, it is no longer possible to remove the wiper blade  22  from the wiper arm  12 . Since during wiping operation the wiper blade rests on the window  24  to be wiped, the wiper blade can also not be unintentionally pivoted counter to the directional arrow  66  to make it possible to release the connection. The result is thus a reliable plug-in and turn connection, which can also be released again in a simple way by pivoting the wiper blade  22 , raised from the window counter to the directional arrow  25 , approximately 90 counter to the direction of the arrow  66 . After that, it is possible to pass the pin ends  50  out through the openings  56  of the bearing receptacles  42 . 
     To prevent the centrifugal force (arrow  70 , FIG. 2) originating in the wiper blade  22  from being able to act on the hinge  32 ,  42 ,  50  during wiping operation, the wiping device has a support shoulder fixed to the wiper arm and pointing toward the oscillation axis  16 ; associated with it is a check shoulder fixed to the wiper blade and pointing away from the oscillation axis  16 . 
     In the exemplary embodiment of FIGS. 3 through 7, one support shoulder  72  is formed on each of the exposed end edges of the legs  38  and  40  of the U of the hinge piece  36 . The check shoulders  74  of the wiper blade are located on lateral protrusions  76  of the base body  44 , which protrude from the side surfaces  46  and  48 . Both the support shoulders  72  and the two check shoulders  74  have a course that is curved around the axis  32  of the hinge; the respective radius of curvature  78  corresponds to the respective spacing from the hinge axis  32 . The radii of curvature  78  are adapted to one another such that when the wiping device is in the operating position (FIG.  1 ), the support shoulders  72  with the hinge  42 ,  50  relieved rest on the check shoulders  74 , so that in this operating position the hinge between the wiper arm and the wiper blade remains without play and operates smoothly. If then during wiping operation centrifugal forces (arrow  70  in FIG. 2) seek to act on the hinge  32 ,  42 ,  50 , they are intercepted by the support shoulders  72  and the check shoulders  74  associated with them in such a way that the hinge  32  is unaffected by them. 
     Since during wiping operation the wiper blade in its length has to follow the course of the spherically curved windshield yet the wiper arm oscillates about its oscillation axis  16 , the result is a constant oscillating motion (arrow  80  in FIG. 1) of the wiper blade  22  relative to the wiper arm  12  about the axis  32  of the hinge. To assure cooperation of the support shoulder  72  with the check shoulder  74  even at the reversal points of the oscillation, the protrusions  76  protrude with the check shoulder  74  outward past the block-shaped base body  44  of the coupling part  30  of the wiper blade by a distance  82  (FIG.  6 ). 
     A second embodiment of the invention will now be described in conjunction with FIGS. 8 through 11. The coupling part  90  of the wiper arm is substantially equivalent to the coupling part  28  of the wiper arm already described. Once again, it has a U-shaped construction, with legs  92  of the U in which bearing receptacles  94  that correspond to the bearing receptacles  42  in the coupling part  28  are disposed. In a departure from the exemplary embodiment already described, the support shoulders  96  in this embodiment of the invention are embodied on rib-like protrusions  98 , which are present on the insides, facing one another, of the legs  92  of the U. In the side surfaces  100 , facing away from one another, of the coupling part  102  of the wiper blade, which again has a base body  44 —the construction of this coupling part is substantially equivalent to that of the coupling part  30  of the wiper blade—the check shoulders  104  pointing away from the oscillation axis  16  are embodied on the side walls at grooves  106 , which are disposed in the side faces  100  of the coupling part  102  of the wiper blade. In this embodiment as well, both the support shoulders  96  and the check shoulders  104  have a course curved about the axis  32  of the hinge, and the radii  108  of the support shoulders  96  and check shoulders  104  correspond to one another. The width  110  of the rib-like protrusions  98  also corresponds to the widths  12  of the grooves  106 . Thus a cooperation of the support shoulders and check shoulders is obtained during operation of the wiping device  10 , of the kind already described in conjunction with the first exemplary embodiment of the invention. 
     If one looks at FIGS. 3-7 and  8 - 10 , taking the above descriptions into account, along with FIG. 2, it can be seen that the respective support shoulders  72  and  96  and the check shoulders  74  and  104  associated with them are disposed, in the installed wiping device  10 , between the oscillation axis  16  and the axis  32  of the hinge  42 ,  50 . It is also then clear that the coupling parts  28  and  90  of the wiper arm are located in planes that are vertical to the window  24  and have walls  38 ,  40  and  92  extending substantially in the direction of the longitudinal axis of the wiper arm, and a respective surface  46 ,  48  and  100  of the coupling part  44  and  102  of the wiper blade is adjacent to each wall, and the support shoulder is formed on the walls while the check shoulder is formed on the surfaces. 
     In the operating position of the wiping device, in this embodiment as well, support shoulders  96  of the coupling part  90  of the wiper arm rest on the check shoulders  104  of the coupling part  102  of the wiper blade, so that the pin ends  50  are relieved of the centrifugal forces (arrow  70 ) caused by the wiper blade  22 . 
     A common feature of both exemplary embodiments is that the wiping device  10  has at least one support shoulder  72  and  96  fixed to the wiper arm and pointing toward the oscillation axis  16 , with which a check shoulder  74  and  104  fixed to the wiper blade and pointing away from the oscillation axis  16  is associated.