Abstract:
The invention relates to a windshield wiper device ( 50, 70 ) for a vehicle, in particular a motor vehicle. The windshield wiper device comprises a wiper blade ( 51, 71 ) with an elongated upper part ( 52, 72 ) which is designed to be at least partly flexible, an elongated lower part ( 53, 73 ) which is designed to be at least partly flexible, and multiple connection elements ( 18 ) for connecting the upper part ( 52, 72 ) and the lower part ( 53, 73 ). The connection elements ( 18 ) are mutually spaced along a longitudinal extension ( 8 ) of the wiper blade ( 51, 71 ), and the connection elements ( 18 ) are designed to allow the upper part ( 52, 72 ) and the lower part ( 53, 73 ) to move relative to each other with a movement component along a longitudinal extension ( 8 ) of the wiper blade ( 51, 71 ), a cross-section of the wiper blade ( 51, 71 ) perpendicular to the longitudinal extension ( 8 ) of the wiper blade being substantially trapezoidal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention concerns a windshield wiping device for a vehicle, especially a motor vehicle. 
         [0002]    Windshield wiping devices typically have a wiper arm or wiper lever, wherein a wiper blade, on which a wiper lip is attached, is moved on the window of a motor vehicle. The wiper arm is moved alternating between a first turning point and a second turning point. For this purpose, the wiper arm is connected via the drive shaft to a wiper motor. 
         [0003]    In the windshield wiping devices known in the prior art, it can happen that the wiper blade loses contact with the window when driving fast, especially on windshields with large changes in curvature. This can result in the formation of streaks and/or fogging. High requirements are also placed on windshield wiping devices during extreme weather conditions, such as the handling and removal of water and/or snow from the windshield. Especially in the case of snow, windshield wiping devices known from the prior art have drawbacks. Thus, a snow wedge is formed by traditional wipers, resulting in steadily increasing forces acting on the wiper or needing to be exerted by it. The field of vision can also be reduced, since the snow cannot be removed adequately from the windshield. 
         [0004]    There is thus a need to further improve windshield wiping devices, especially in terms of the avoidance of formation of streaks and/or fogging when driving fast and in terms of the ability to remove snow from the windshield. 
       SUMMARY OF THE INVENTION 
       [0005]    The problem which the present invention proposes to solve is to provide a windshield wiping device with which at least one or more of the aforementioned drawbacks is lessened or essentially does not occur. 
         [0006]    According to embodiments of the invention, a windshield wiping device is provided for a vehicle, especially a motor vehicle. The windshield wiping device comprises a wiper blade with an elongated upper part, which is at least partly bendable, an elongated lower part, which is at least partly bendable, several connection elements for connecting the upper part and the lower part, wherein the connection elements are spaced apart from each other along a lengthwise dimension of the wiper blade, and wherein the connection elements are designed to enable a movement of the upper part and the lower part relative to each other with a movement component along a lengthwise dimension of the wiper blade. In a cross section of the wiper blade perpendicular to its lengthwise dimension the upper part has a first dimension in a plane parallel to a wiping plane and the lower part has a second dimension in a plane parallel to the wiping plane, wherein the first dimension of the upper part is smaller than the second dimension of the lower part. 
         [0007]    According to embodiments of the invention, a windshield wiping device is provided for a vehicle, especially a motor vehicle. The windshield wiping device comprises a wiper blade with an elongated upper part, which is at least partly bendable, an elongated lower part, which is at least partly bendable, several connection elements for connecting the upper part and the lower part, wherein the connection elements are spaced apart from each other along a lengthwise dimension of the wiper blade, and wherein the connection elements are designed to enable a movement of the upper part and the lower part relative to each other with a movement component along a lengthwise dimension of the wiper blade. A cross section of the wiper blade perpendicular to its lengthwise dimension is essentially trapezoidal. 
         [0008]    Preferred optional embodiments and special aspects of the invention emerge from the dependent claims, the drawings, and the present description. 
         [0009]    According to the embodiments described here, windshield wiping devices and especially a fin ray windshield wiping device are provided for vehicle windshields, which prevent streaking and/or fogging during fast driving and have an improved ability to remove snow from the windshield. The trapezoidal cross section or the trapezoidal shape of the cross section of the wiper blade presents a reduced wind attack surface, so that a lifting of the wiper blade due to the wind can be reduced or even prevented, thereby preventing streaking and/or fogging when driving fast. Moreover, the shape offers the advantage that at least one edge is provided with an acute angle in the wiping direction, which acts as a knife and thus effectively removes the snow from the windshield. 
         [0010]    According to embodiments of the disclosure, the connection elements are spaced apart from each other along the lengthwise dimension of the wiper blade. In this way, cavities or windows can be provided between neighboring connection elements. The snow can be effectively transported away through these cavities or windows, which reduces or prevents the formation of a buildup of snow or a snow wedge during the wiping process. 
         [0011]    According to typical embodiments, the trapezium shape or the trapezium has two parallel sides, which are called the base sides, and two sides joining them, which are called the legs. 
         [0012]    According to some embodiments, the elongated upper part and the elongated lower part each form a base side of the trapezium shape or the trapezoidal shape. In typical embodiments, one base side is longer than the other. The longer of the two base sides can be called the base of the trapezium. For example, the elongated lower part forms the base of the trapezium shape or the trapezoidal shape. According to embodiments, the connection elements of the windshield wiping device can form the legs of the trapezium shape or the trapezoidal shape. Such a trapezium shape or trapezoidal shape presents in particular a reduced wind attack surface or wind lift surface and at least one edge with an acute angle, which can function as the knife described above. In particular, the edge can be formed by the elongated lower part and one of the legs. 
         [0013]    According to embodiments described here, the elongated upper part has at least one projection along the lengthwise dimension of the wiper blade. In certain embodiments, the elongated lower part has at least one projection along the lengthwise dimension of the wiper blade. The projection can function as a knife, which can effectively remove snow from the windshield, and in particular peel or scrape it away. 
         [0014]    In sample embodiments, the at least one projection extends beyond the trapezium, and especially beyond one leg of the trapezium. For example, the windshield wiping device can comprise two projections, one projection being provided each time in the two wiping directions. Thus, for example, the elongated lower part can extend beyond both legs of the trapezium shape, so that an edge, especially a knife edge, is formed in each wiping direction. This enables a removal of snow in both wiping directions, which further enhances the efficiency of the windshield wiping device. 
         [0015]    According to other typical embodiments, the at least one projection can be integrated with the elongated lower part, and in particular the at least one projection and the elongated lower part can consist of the same material. According to embodiments, the at least one projection can be integrated with the elongated upper part, and in particular the at least one projection and the elongated upper part can consist of the same material. This enables a simple and economical manufacture of the windshield wiping device. 
         [0016]    For example, the knife edge can have a bevel. The bevel can be a slanting surface which is present on the knife edge. This makes possible a further improvement in the efficiency of removal of snow from the windshield. 
         [0017]    According to embodiments of the disclosure which can be combined with other embodiments described herein, the at least one projection or the at least one knife edge can consist of a material from the group: TPE (thermoplastic elastomer), especially TPE-S, TPE-O, TPE-U, TPE-A, TPE-V, TPE-E; ethylene propylene diene rubber (EPDM); polychloroprene and natural rubber. The choice of the material of the projection and/or the knife edge allows one to adjust the physical properties of the projection and/or the knife edge. 
         [0018]    According to typical embodiments, at least one wiper lip is arranged on the elongated lower part. For example, the wiper lip is provided for a contact with the windshield. For example, the wiper lip is fashioned as a single part with the elongated lower part, in particular it can consist of the same material. According to some other typical embodiments, the wiper lip can be mounted on the elongated lower part, wherein the wiper lip and the elongated lower part can comprise different materials. The wiper lip can be fastened removably on the elongated lower part, so that the wiper lip can be replaced, for example, when worn down or damaged. This enables a cost reduction, since when the wiper lip is worn down it is not necessary to replace the entire windshield wiping device, but only the wiper lip. The separation of wiper lip and lower part of the windshield wiping device can also achieve inter alia a better choice of materials for the individual elements for many applications. 
         [0019]    According to other typical embodiments, the wiping lip can be an essentially L-shaped structure, an essentially C-shaped structure, a structure forming a closed cavity, or a U-shaped structure. Furthermore, the structure can also be multilayered, wherein several layers form the wiping lip. Thanks to the multilayered design, a layer can be removed or peeled off when the wiper lip or wiping edge becomes worn down, which increases the lifetime of the windshield wiping device. 
         [0020]    According to embodiments of the disclosure which can be combined with other embodiments described herein, the at least one wiper lip is made of a material from the group: TPE (thermoplastic elastomer), especially TPE-S, TPE-O, TPE-U, TPE-A, TPE-V, TPE-E; ethylene propylene diene rubber (EPDM); polychloroprene and natural rubber. The choice of the material of the wiping edge allows one to adjust the physical properties of the wiping edge. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    Sample embodiments of the invention are presented in the figures and are described more closely below. There are shown: 
           [0022]      FIG. 1A , a schematic representation of a windshield wiping device according to the prior art, 
           [0023]      FIG. 1B , a schematic representation of a cross section of the wiper blade of the windshield wiping device per  FIG. 1A , 
           [0024]      FIG. 2A , a schematic representation of a windshield wiping device according to embodiments of the disclosure, 
           [0025]      FIG. 2B , a schematic representation of a cross section of the wiper blade of the windshield wiping device per  FIG. 2A , 
           [0026]      FIG. 3 , a visual field comparison between the windshield wiping device according to the prior art and the windshield wiping device according to embodiments of the disclosure, 
           [0027]      FIGS. 4A, 4B and 4C , schematic representations of a windshield wiping device according to embodiments of the disclosure for removal of snow from a windshield, 
           [0028]      FIG. 5 , a schematic representation of a windshield wiping device according to embodiments of the disclosure, 
           [0029]      FIG. 6A , a schematic representation of a wiper blade of a windshield wiping device according to embodiments of the disclosure in a bottom position, 
           [0030]      FIG. 6B , a schematic representation of the wiper blade of a windshield wiping device according to embodiments of the disclosure per  FIG. 6A  in a position laid against a window, 
           [0031]      FIG. 7A , a schematic representation of another sample embodiment of a windshield wiping device according to the invention in the form of a wiper arm with integrated wiper blade in a bottom position, 
           [0032]      FIG. 7B , a schematic representation of the wiper arm with integrated wiper blade per  FIG. 7A  in a position laid against a window, and 
           [0033]      FIG. 8 , a schematic perspective representation of a wiper arm of a windshield wiping device according to embodiments of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    In the following, unless otherwise noted, the same reference symbols shall be used for identical and similarly functioning elements. 
         [0035]      FIG. 1A  shows a schematic representation of a windshield wiping device  40  according to the prior art, and  FIG. 1B  shows a schematic representation of a cross section of the wiper blade of the windshield wiping device of  FIG. 1A . 
         [0036]    The traditional windshield wiping device  40  comprises a wiper blade  41  with a lengthwise dimension  8  and with an upper part  42  and a lower part  43 , which are joined by several connection elements  18 . The cross section of the wiper blade  41  of the traditional windshield wiping device  40  has an essentially rectangular or square cross section. The cross section shown in  FIG. 1B  runs along the line designated by reference number  44  in  FIG. 1A . 
         [0037]    The traditional windshield wiping device  40  can have a fastening part  45  at the wiper blade side, which is designed to be connected for example to a fastening element on the motor vehicle. Thus, the windshield wiping device can be attached to the vehicle, especially in removable manner. 
         [0038]    The rectangular or square cross section of the traditional windshield wiping device  40  presents an increased wind attack surface, so that it may happen when driving fast that the wiper blade loses contact with the window. This may result in streaking and/or fogging. The rectangular or square cross section also means, for example when there is snow on the windshield, that a snow wedge builds up on the wiper blade, resulting in steadily increasing forces acting on the wiper or needing to be exerted by it. The field of vision can also be reduced, since the snow cannot be removed adequately from the windshield, for example. 
         [0039]    These drawbacks can be avoided by the windshield wiping device according to the embodiments of the disclosure. 
         [0040]    According to the disclosures described here, windshield wiping devices and especially a fin ray windshield wiping device are provided for vehicle windshields with trapezoidal cross section. The windshield wiping devices can thus prevent streaking and/or fogging during fast driving and furthermore have an improved ability to remove snow from the windshield. In particular, the trapezoidal cross section of the wiper blade presents a reduced wind lift surface, so that a lifting of the wiper blade due to the wind can be reduced or even prevented, thereby preventing streaking and/or fogging when driving fast. Moreover, the trapezium shape offers the advantage that at least one edge is provided with an acute angle in the wiping direction, which acts as a knife and thus effectively removes the snow from the windshield, and in particular peels or scrapes it off. 
         [0041]      FIG. 2A  shows a schematic representation of a windshield wiping device  50  according to embodiments of the disclosure, and  FIG. 2B  shows a schematic representation of a cross section of the wiper blade  51  of the windshield wiping device  50  per  FIG. 2A  along line  54 . 
         [0042]    The configuration of the windshield wiping device for the embodiments described here can be realized with the windshield wiping devices described as examples in  FIGS. 6A, 6B, 7A, 7B and 8 , especially a fin ray windshield wiping device. 
         [0043]    The wiper blade  51  of the windshield wiping device  50  comprises an elongated upper part  52  and an elongated lower part  53 , which are joined by a plurality of connection elements  18 . The lower part  52  during operation of the windshield wiping device  50  is turned toward a window, such as a window of a motor vehicle. The wiper blade  51 , as shown in  FIG. 2B , has an essentially trapezoidal cross section perpendicular to the lengthwise dimension of the wiper blade  51 . In this way, the formation of streaks and/or fog when driving fast can be prevented and there is an improved ability to remove snow from the windshield. The windshield wiping device  50 , and particularly the wiper blade  51 , also has a more slender appearance compared to the traditional windshield wiping device of  FIG. 1A  (for the same normal projected surface). This reduces the visibility of the wiper, which results in reduced viewing obstruction, for example to the rear, if the windshield wiping device is mounted at the rear. 
         [0044]    According to embodiments described here, which can be combined with other embodiments, the upper part  52  has, in a cross section of the wiper blade perpendicular to its lengthwise dimension, a first dimension (its width) in a plane parallel to a wiping plane and the lower part  53  has a second dimension (its width) in a plane parallel to the wiping plane, wherein the first dimension of the upper part is smaller than the second dimension of the lower part. Thanks to the smaller width of the upper part, a trapezoidal cross section or trapezium-like cross section is provided, which shall be called essentially trapezoidal in the context of the present disclosure. 
         [0045]    According to embodiments of the disclosure, the connection elements  18  are spaced apart along the lengthwise dimension  8  of the wiper blade  51 . In this way, cavities or windows can be provided between neighboring connection elements  18 . The snow can be effectively transported away through these cavities or windows, which reduces or prevents the formation of a buildup of snow or a snow wedge during the wiping process. 
         [0046]    According to typical embodiments, which can be combined with other embodiments, the trapezium shape or the trapezium has two parallel sides, which can be called the base sides, and two sides joining them, which can be called the legs. 
         [0047]    According to some embodiments, the elongated upper part  52  and the elongated lower part  53  each form a base side of the trapezium shape. In typical embodiments, one base side is longer than the other. The longer of the two base sides can be called the base of the trapezium. For example, as is shown in  FIGS. 2A and 2B , the elongated lower part  53  forms the base of the trapezium shape. According to embodiments, the connection elements  18  of the windshield wiping device can form the legs of the trapezium shape. Such a trapezium shape presents in particular a reduced wind lift surface and at least one edge  56  with an acute angle, which can function as a knife. In particular, the at least one edge  56  can be formed by the elongated lower part  53  and one of the legs. 
         [0048]    The windshield wiping device  50  according to embodiments can have a fastening part  55  at the wiper blade side, which is designed to be connected for example to a fastening element on the motor vehicle. Thus, the windshield wiping device  50  can be attached to the vehicle, especially in removable manner. 
         [0049]      FIG. 3  shows a visual field comparison between the windshield wiping device according to the prior art and the windshield wiping device according to embodiments of the disclosure. 
         [0050]    In the example shown in  FIG. 3 , the windshield wiping device is mounted at the rear of a vehicle  60 . The first enlarged cutout (left) shows the wiper blade  41  of the windshield wiping device from the prior art with the rectangular or square cross section. As shown in  FIG. 3 , the traditional wiper blade  41  blocks the field of vision through the rear window in its extent or with a first height  61 . In contrast, as shown in the second enlarged cutout (right) in  FIG. 3 , the trapezoidal wiper blade  51  according to embodiments of the disclosure covers the field of vision through the rear window in its extent or with a second height  62 , which is smaller by an amount  63  than the first height  61 . 
         [0051]    Thus, the windshield wiping device according to the embodiments of the disclosure, and especially the wiper blade, has a more slender appearance (for the same normal projected surface) as compared to the traditional windshield wiping device. This reduces the visibility of the wiper, which results in a reduced viewing obstruction, for example to the rear, when the windshield wiping device is mounted at the rear. 
         [0052]    Although  FIG. 3  shows an example of a rear window wiper, the embodiments of the disclosure are not confined to this. In particular, the embodiments of the disclosure can also be implemented for front windshield wipers. Moreover, the windshield wiping device  51  shown in  FIG. 3  can also be realized as one of the embodiments shown in  FIGS. 4A-C  and  5 . 
         [0053]      FIGS. 4A, 4B and 4C  show schematic representations of a windshield wiping device  70  according to embodiments of the disclosure and the removal of snow from a windshield  75  making use thereof. 
         [0054]    The wiper blade  71  of the windshield wiping device  70  comprises an elongated upper part  72  and an elongated lower part  73 , which are joined by a plurality of connection elements. The lower part  72  during operation of the windshield wiping device  70  is turned toward the window  75 , such as a window of a motor vehicle. The wiper blade  71  has an essentially trapezoidal cross section perpendicular to the lengthwise dimension of the wiper blade  71 . 
         [0055]    According to embodiments described here, which can be combined with other embodiments, the wiper blade  71  has at least one projection  79 . In particular, the elongated upper part  72  and/or the elongated lower part  73  can have the at least one projection  79  along the lengthwise dimension of the wiper blade  71 . For example, only the elongated upper part  72  or only the elongated lower part  73  can have a projection  79 , or both the elongated upper part  72  and the elongated lower part  73  can each have at least one, and especially two projections  79 . In the example shown in  FIG. 4A-C , the windshield wiping device  70  has four projections, two each on the elongated lower part  72  and on the elongated upper part  73 . The projection  79  can function as a knife, which can effectively remove snow from the windshield, and in particular peel or scrape it away. 
         [0056]    In sample embodiments, the at least one projection  79  extends beyond the trapezium, and especially beyond one leg of the trapezium, as is shown in  FIG. 4A-C . For example, the windshield wiping device  70 , and especially the elongated lower part  73 , can comprise two projections  79 , one projection  79  being provided each time in the two wiping directions. Thus, for example, the elongated lower part  73  can extend beyond both legs of the trapezium shape, so that an edge, especially a knife edge, is formed in each wiping direction. This enables a removal of snow in both wiping directions, which further enhances the efficiency of the windshield wiping device. 
         [0057]    According to some embodiments, the knife edge can have a bevel. The bevel can be a slanting surface which is present on the knife edge. This makes possible a further improvement in the efficiency of removal of snow from the windshield. 
         [0058]    According to other typical embodiments, the at least one projection  79  can be integrated with the elongated lower part  73 , and in particular the at least one projection  79  and the elongated lower part  73  can consist of the same material. According to embodiments, the at least one projection  79  can be integrated with the elongated upper part  72 , and in particular the at least one projection and the elongated upper part  72  can consist of the same material. This enables a simple and economical manufacture of the windshield wiping device. 
         [0059]    According to embodiments of the disclosure which can be combined with other embodiments described herein, the at least one projection  79  or the at least one knife edge is made of a material from the group consisting of: TPE (thermoplastic elastomer), especially TPE-S, TPE-O, TPE-U, TPE-A, TPE-V, TPE-E; ethylene propylene diene rubber (EPDM); polychloroprene and natural rubber. The choice of the material allows one to adjust the physical properties of the at least one projection  79  or the at least one knife edge. 
         [0060]    According to typical embodiments which can be combined with other embodiments described herein, at least one wiper lip  74  is arranged on the elongated lower part  73 . For example, the wiper lip  74  is provided for a contact with the windshield  75 . For example, the wiper lip  74  is fashioned as a single piece with the elongated lower part  73 , in particular it can consist of the same material. According to some other typical embodiments, the wiper lip  74  can be mounted on the elongated lower part  73 . In such a case, the wiper lip  74  and the elongated lower part  73  can comprise different materials. The wiper lip  74  can be fastened removably on the elongated lower part  73 , so that the wiper lip  74  can be replaced, for example, when worn down or damaged. This enables a cost reduction, since when the wiper lip  74  is worn down it is not necessary to replace the entire windshield wiping device, but only the worn-down or damaged wiper lip  74 . The separation of wiper lip  74  and elongated lower part  73  of the windshield wiping device  70  can also achieve inter alia a better choice of materials for the individual elements for many applications. 
         [0061]    According to other typical embodiments, the wiper lip  74  can be an essentially L-shaped structure, an essentially C-shaped structure, a structure forming a closed cavity, or a U-shaped structure. Furthermore, the structure can also be multilayered, wherein several layers form the wiper lip  74 . Thanks to the multilayered design, a layer can be removed or peeled off when the wiper lip  74  becomes worn down, which increases the lifetime of the windshield wiping device. 
         [0062]    In the example of  FIG. 4A-C , a C-shaped structure is shown. For example, the at least one C-shaped wiper lip  74  can be arranged with its opening toward the middle of the wiper blade  71 , and in particular toward the middle of the elongated lower part  73 . In particular, two C-shaped wiper lips  74  can be present on the elongated lower part  73 , which can be arranged as mirror images, for example. In such a case, the openings of the C-shape can be arranged opposite each other, as also shown in the example of  FIG. 4A-C . 
         [0063]    According to other embodiments which can be combined with other embodiments described herein, a variable stiffness, i.e., spatially variable stiffness of the wiper lip  74  can be provided along the length of the windshield wiping device  70 , i.e., along the lengthwise dimension of the windshield wiping device  70 . In this way, any possibly existing bearing force fluctuations along the lengthwise dimension of the windshield wiping device  70  can be adapted through the adapted stiffness of the wiper lip  74 . 
         [0064]    According to embodiments of the disclosure which can be combined with other embodiments described herein, the at least one wiper lip  74  is made of a material from the group consisting of: TPE (thermoplastic elastomer), especially TPE-S, TPE-O, TPE-U, TPE-A, TPE-V, TPE-E; ethylene propylene diene rubber (EPDM); polychloroprene and natural rubber. The choice of the material of the wiper lip  74  allows one to adjust the physical properties of the wiper lip  74 . 
         [0065]    In what follows, the mode of functioning of the windshield wiping device is explained with the help of  FIG. 4A-C . 
         [0066]    Referring to  FIG. 4A , snow  76  is present on the windshield  75  of the vehicle. The windshield wiping device  70  has the projection or knife edge  79 . Although the windshield wiping device  70  in  FIG. 4A-C  is shown with the projections  79  and the wiper lips  74 , the present disclosure is not limited to this. In particular, the windshield wiping device can also be configured as that in  FIGS. 2A and 2B  and provide the same or similar functionalities as are described below. 
         [0067]    Referring to  FIG. 4B , the windshield wiping device  70  and especially the wiper blade  71  moves in a wiping direction  77 . The edge or the projection  79  of the wiper blade  71  cuts into the snow  76 , and thereby removes the snow in effective manner from the window  75 . As shown in  FIG. 4C , a torsional movement  78  of at least one part of the bendable wiper blade  71  can occur especially thanks to an elasticity of the at least one wiper lip  74 . This torsional movement  78  results in an altered angle or angle of incidence of the edge/projection  79  relative to the window  75 , which results in a further increase in the efficiency of the process of removal of snow  76  from the window  75 . 
         [0068]    With traditional wipers, a snow wedge builds up constantly, which can result in constantly increasing forces and a reduced field of vision. The windshield wiping device according to the present disclosure can scrape or peel the snow off from the window in slices like a potato peeler by means of the elongated lower part (bending beam), which functions as a knife. The snow can be transported away through the cavities (windows) which are present in the wiper blade, especially thanks to the spaced apart connection elements. Thanks to the trapezium shape, the bottom side of the wiper makes contact first with the snow, which results in a torsion, such as a clockwise torsion, and thus produces a particular angle of incidence, which is especially well suited to peeling and scraping. Alternatively, the knife edge can be provided with a bevel to improve the cutting action. The edge can be made of a rubberlike material, in order to minimize the danger of injury. 
         [0069]      FIG. 5  shows a schematic representation of a windshield wiping device  80  according to embodiments of the disclosure. The windshield wiping device  80  can also be designed as a windshield wiping device shown in  FIGS. 2A and 2B or 4A -C. 
         [0070]    The windshield wiping device  80  of  FIG. 5  has a wiper blade  81  with an elongated upper part  82 , an elongated lower part  83 , and wiper lips  84 . As is shown in  FIG. 5 , a wind attack surface or wing lift surface for driving wind  85  can be formed essentially by a surface of the elongated upper part  82 . One reason for this can be the spaced apart connection elements, between which cavities or windows can be present, and through which air can flow. The trapezoidal cross section of the wiper blade of the windshield wiping device  80  provides a reduced or minimal surface of the elongated upper part  82 , which results in a reduced wind lift surface. In this way, a wind-related lifting of the wiper blade can be reduced or even avoided, so that streaking and/or fogging during fast driving is prevented. 
         [0071]    In the following, sample embodiments of windshield wiping systems are described, for which the windshield wiping device described herein can be used. 
         [0072]      FIGS. 6A and 6B  show schematic representations of a wiper blade  2  in a bottom position ( FIG. 6A ) and in a position ( FIG. 6B ) placed against a window according to embodiments of the windshield wiping device of the disclosure. The wiper blade  2  serves to wipe a window  4  of a vehicle, which is for example a motor vehicle, especially an auto. Usually the wiper blade  2  is placed on a window wiping arm, which is driven by means of a motor for the wiping. For this, the wiper blade  2  has a support  6 , at which it can be fastened on the window wiping arm. The wiper blade  2  in  FIG. 6A  is in a bottom position, in which it is at least partly lifted from the window  4 . The windshield wiping device, and especially the wiper blade  2 , can be configured according to the embodiments of the disclosure, as are described above with reference to  FIGS. 2 to 5 . 
         [0073]    The wiper blade  2  has the lengthwise dimension  8  and the elongated upper part  10  and the likewise elongated lower part  12 . The lengthwise dimension of the upper part  10  and the lower part  12  basically correspond to the lengthwise dimension  8  of the wiper blade  2 . The wiper blade  2  here has a trapezoidal cross section perpendicular to the lengthwise dimension  8  according to the embodiments of the disclosure. 
         [0074]    Both the upper part  10  and the lower part  12  are bendable beams or can be designed as bendable beams, each of them being a single piece as an example shown in  FIGS. 6A and 6B . This enables an especially stable design. It is likewise possible to have only one part in each case of the upper part  10  and/or lower part  12  being bendable. Moreover, it is alternatively possible for the upper part  10  to consist of two pieces, wherein then one end of the two pieces of the two-piece upper part  10  is fastened to the support  6 . 
         [0075]    According to many embodiments which can be combined with the other embodiments described here, a material is used for the upper part  10  and/or the lower part  12  which has a modulus of elasticity lying in a range between 0.005 kN/mm 2  and 0.5 kN/mm 2 , especially 0.01 kN/mm 2  and 0.1 kN/mm 2 . This enables a suitable bendability of the upper part  10  and the lower part  12 . Together with a suitably designed cross sectional area of the upper part  10  and the lower part  12 , one thus gets an optimal bendability. The upper part  10  and the lower part  12  are disposed so that they lie opposite each other. Both ends of the upper part  10  are firmly connected at outer connection positions  14  and  16  to one end apiece of the lower part  12 . Otherwise, the upper part  10  and the lower part  12  are spaced apart. 
         [0076]    The upper part  10  and the lower part  12  are joined together by connection elements  18 . In particular, in the bottom position of the wiper blade  2 , these extend roughly transverse to the lengthwise dimension  8  of the wiper blade  2 . The connection elements  18  are attached by rotary joints  20  at mutually facing inner lengthwise sides of the upper part  10  and the lower part  12 . The rotary joints  20  here are hinges. In particular, the rotary joints  20  can be designed as film hinges. This is especially advantageous when upper part  10 , lower part  12  and/or connection elements  18  are made from a plastic material or coated with a suitable plastic material. 
         [0077]    According to typical embodiments described here, which can be combined with other embodiments described here, a rotary joint is chosen from the following group consisting of: a hinge, a film hinge, a narrowing of the material to produce less stiffness along a torsion axis, a joint with an axis of rotation, a means of connecting the upper part to the connection element or connecting the lower part to the connection element allowing a sliding of the lower part in relation to the upper part along the lengthwise dimension, etc. 
         [0078]    Embodiments in which the joint is provided by a film hinge thus provide a very simple means of providing the joints for a fin ray wiper. The wiper blade  2  can be a single piece, in particular, tooled. According to typical embodiments, the film hinges have good stretchability. This can be provided, for example, by a material chosen from the group of PP, PE, POM and PA. Alternatively, the film hinges can be made from one or more materials of a group consisting of: TPE (thermoplastic elastomer), such as TPE-S, TPE-O, TPE-U, TPE-A TPE-V and TPE-E. 
         [0079]    The connection elements  18  are spaced apart from each other along the lengthwise dimension of the wiper blade  2 . The distances between every two neighboring connection elements  18  are equal. But they can also be chosen to be different. The distances are advantageously less than 50 mm, especially less than 30 mm. In this way, an especially high flexibility of the windshield wiping device can be assured, especially of its lower part, and good adaptation to the curvature and changes in curvature of the window being wiped.  FIG. 6A  shows a distance  22  as representative of the distances between every two connection elements  18 . The connection elements  18 , especially in the bottom position of the wiper blade  2 , are attached to the lower part  12  such that their lengthwise axes subtend angles  26  with the lower part  12  which are between 65° and 115°, especially between 75° and 105°. Especially advantageously, the angles lie between 80° and 100°. This advantageously assures an especially good transmission of a force acting on the lower part to the upper part. Moreover, an especially stable windshield wiping device can be achieved in this way. The same holds for the attachments of the connection elements  18  to the upper part  10 . 
         [0080]    The same holds in the present sample embodiment for the attachments of the connection elements  18  to the upper part  10 . 
         [0081]      FIG. 6A  shows one lengthwise axis  24  as an example of the lengthwise axes of the connection elements  18  and one angle  26  as an example for the angles between the connection elements  18  and the lower part  12 . The distances between the upper part  10  and the lower part  12  are primarily determined by the lengths of the connection elements  18 . The lengths of the connection elements  18  increase, starting from the two outer connection positions  14 ,  16  to approximately those positions at which the support  6  arranged on the upper part  10  begins. In this way, upper part  10  and lower part  12  in lateral view looking at the wiper blade  2  per  FIG. 6A  form a double wedge, the vertices of the two wedges pointing in opposite directions. The connection elements  18  are of buckle-proof design. The wiper blade  2  here has a trapezoidal cross section perpendicular to the lengthwise dimension  8  according to the embodiments of the disclosure. 
         [0082]      FIG. 6B  shows a schematic representation of the wiper blade  2  of  FIG. 6A  in a position placed against the window  4 . Since the window  4  has a curvature, contact pressure forces act on the lower part  12  when the wiper blade  2  is placed against the window  4 . Since the upper part  10  and the lower part  12  are bendable beams and the connection elements  12  are mounted rotatably on the upper part  10  and lower part  12 , the upper part  10  and lower part  12  can slide relative to each other. Thanks to the pressure forces acting on the lower part  12  from below, the wiper blade  2  bends in the direction from which the pressure forces are arriving, and adapts itself precisely to the curvature of the window  4 . 
         [0083]    Thanks to the design of the embodiments described here, when a force acts on the lower part (through the window  4 ) there is a bending of the lower part in the direction from which the force is acting. This is dictated by the connection of the upper part  10  and the lower part at a connection position  14  and/or  16 , the shape, and rotary joints at the connection between the connection elements and the upper and lower part. 
         [0084]    In the representation of  FIG. 6B , a slight spacing is present between the wiper blade  2  and the window  4 , which serves here only to illustrate the window  4  and the wiper blade  2  and is for the most part not present in reality when the wiper blade  2  bears against the window  4 . Furthermore, a wiper lip is typically present at the bottom side of the lower part  12 , facing away from the upper part  10 , according to the embodiments described here, which is placed on the window  4  for the wiping process. For reasons of clarity, the wiper lip is not shown in  FIGS. 6A and 6B . 
         [0085]    A windshield wiping device according to the embodiments described here uses the tail fin effect of certain fish, which when pressure comes from the side do not give way in the direction of the pressure, but instead arch themselves in the opposite direction, i.e., the direction from which the pressure is arriving. This principle is also known as the fin jet or “fin ray” principle. Thus, a windshield wiping device according to the embodiments described herein has the advantage of a better adaptation to a window of a motor vehicle. With a traditional windshield wiping device, its upper part is usually rigid, i.e., not bendable in design. 
         [0086]      FIGS. 6A and 6B  show a wiper blade  2  with lengthwise dimension  8 , which extends essentially between the connection positions  14  and  16 . Such an arrangement is often used for front windshield wipers. Alternatively, however, a windshield wiping device can also have only one connection position, which by analogy with  FIGS. 6A and 6B  corresponds to a cutting of the windshield wiping device in half, and wherein a rotary axis is provided at one position of the support  6  as an example. Such an arrangement is often used for rear window wipers. This is shown, as an example, in  FIGS. 7A and 7B . Optional configurations and details which are described in the individual embodiments can generally be used for both variants of arrangement of a windshield wiping device. 
         [0087]      FIG. 7A  shows a schematic representation of another sample embodiment of the windshield wiping device according to the invention in the bottom position. The windshield wiping device here is a wiper arm with an integrated wiper blade  2 , which is arranged on a fastening part  30 . The fastening part  30  is connected to a wiper motor  32 , which drives the fastening part  30  to wipe the window  4 . The wiper blade  2  is wedge shaped, one end of the upper part  10  being firmly connected at an outer connection position  34  to one end of the lower part  12 . The respective other end of the upper part  10  and the lower part  12  are attached to the fastening part  30 . Regarding the basic design and especially the attachments of the connection elements  18 , the windshield wiping device of  FIG. 7A  corresponds basically to that of  FIG. 6A . The wiper blade  2  here has a trapezoidal cross section perpendicular to the lengthwise dimension  8 , according to the embodiments of the disclosure. 
         [0088]      FIG. 7B  shows a schematic representation of the wiper blade  2  with integrated wiper arm  30  per  FIG. 7A  in a position laid against the window  4 . Here as well, pressure forces act from below from the direction of the window  4  on the lower part  12  of the wiper blade  2 , so that the lower part  12  and the upper part  10  bend in the direction of the window  4 . 
         [0089]    In both  FIG. 6A  and  FIG. 7A  the wiper blade is shown in its position not placed against the window, so that the lower part  12  is essentially straight. According to yet other embodiments, which can be combined with other embodiments, the lower part in the unloaded state is convex in configuration, i.e., with a vaulting which projects away from the upper part in a middle region. The windshield wiping device according to the embodiments described here can typically take on the corresponding concave shape of the lower part, adapting to the window, upon making contact with a window and starting from the convex shape of the lower part. 
         [0090]      FIG. 8  is a schematic perspective representation of a wiper blade  2  of a windshield wiping device according to embodiments of the disclosure. As shown in  FIG. 8 , the wiper blade  2  has an outer width W E  at the outer connection positions where the ends of the elongated upper part  10  and the lower part  12  are joined to each other. According to typical embodiments, the outer width W E  is at least 15 mm, especially at least 20 mm, in particular at least 25 mm. 
         [0091]    According to embodiments of the disclosure, which can be combined with other embodiments, the width of the wiper blade  2  increases from the outer connection positions in the direction of the fastening part  30  or the support  6  on which the wiper blade can be attached to the window wiping arm. In  FIG. 8 , for example, an inner width is designated as W M . According to typical embodiments, the inner width W M  is at least 20 mm, especially at least 25 mm, especially at least 30 mm.