Abstract:
The invention relates to a device and a method for releasably connecting a wiper blade to a drivable wiper arm. In one embodiment, the invention is characterized in that the coupling section has a tongue-like insertion section, in that the connecting element has a seat for the insertion section, and in that the coupling section and the connecting element have securing sections for providing a mutual permanent connection.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a device and a method for releasably connecting a wiper blade to a drivable wiper arm, wherein the wiper blade comprises a wiper strip which faces the windscreen to be wiped, at least one strip-like elongate support element, a slide element which is connected to the support element, and a connecting element for connection to a coupling section of the wiper arm, which connecting element is mounted on the slide element in a manner such that it can pivot. 
     Such a device is known for example from WO 02/40328 A1. The device described therein, by means of which a flat wiper blade can be connected to the coupling section, has a large number of complex components which are difficult to manufacture. Moreover, the operation of connecting the coupling section of the wiper arm to the connecting element of the wiper blade is relatively complex and requires a certain amount of skill. 
     SUMMARY OF THE INVENTION 
     So what is needed, therefore, is an improved system and method that improves and simplifies the connection of the wiper arm to the wiper blade. 
     It is therefore an object of the present invention to propose a device for releasably connecting a wiper blade to a drivable wiper arm, in which the operation of connecting the connecting element to the coupling section can be carried out in a simple manner. Moreover, it is to be ensured that the coupling section is joined in a permanently secure manner to the connecting section, wherein the wiper blade can nevertheless be released from the wiper arm in a simple manner. 
     According to the invention, this object is achieved by a device of the type described above in that the coupling section has a tongue-like insertion section, in that the connecting element has a seat for the insertion section, and in that the coupling section and the connecting element have securing sections for providing a mutual permanent connection, wherein, in order to reach a preassembly position in which the longitudinal axis of the wiper arm and the longitudinal axis of the connecting element enclose an angle α in the range from approximately 10° to 100°, the insertion section can be inserted in a substantially rectilinear manner into the seat, and wherein, in order to reach a final assembly position, the wiper arm and the connecting section can be pivoted onto one another about the insertion section/seat contact area until the securing sections allow a permanent mutual connection. 
     The invention has the advantage that only two steps which are simple to carry out are required in order to connect the wiper blade to the wiper arm, namely firstly rectilinear insertion of the insertion section into the seat provided on the connecting element, and pivoting of the coupling section or of the wiper arm and of the connecting element onto one another. 
     Moreover, such a device has the advantage that it is of a very flat and very narrow design. On the one hand, wind noise is minimized as a result. On the other hand, the view of the vehicle driver is only slightly impaired by the wiper blade and the wiper arm. Furthermore, force introduction preferably takes place over the longitudinal axis of the wiper blade, substantially perpendicular to the windscreen to be wiped, and as a result the occurrence of tilting moments is suppressed. 
     Preferably, the insertion direction for reaching the preassembly position lies in the plane of pivoting for reaching the final assembly position. This has the advantage that the two movements lie in one plane, and as a result the assembly operation is simplified. 
     One embodiment of the invention is characterized in that the coupling section is designed to be U-shaped in cross section and comprises a back and two legs, wherein the insertion section is designed in a hook-like manner and is arranged in a stand-alone manner on the back of the coupling section. 
     The coupling section, which is designed to be U-shaped in cross section, advantageously engages over the connecting element at least in part in the final assembly position. As a result, transverse forces acting on the connecting element can be absorbed by the legs of the coupling section. 
     The insertion section is preferably designed such that it is arc-shaped at the free end, in the direction of the extension of the wiper arm and in side view in the direction of the windscreen to be wiped, in such a manner that it does not protrude beyond the back. This has the advantage that the insertion section, in the final assembly position, does not protrude in a disruptive manner beyond the back of the coupling section. Given a suitably designed connecting element, the insertion section is not visible in the final assembly position. 
     It is advantageous if the region of the connecting element which cooperates with the insertion section and adjoins the insertion opening is designed to be complementary to the insertion section. In this way it can be ensured, in the final assembly position, that the insertion section bears reliably against the complementarily designed region of the connecting element. 
     A further embodiment of the invention is obtained when the region of the connecting element and of the insertion section which cooperates with the insertion section is designed to be arc-shaped, and in particular shaped like a segment of a circle, in longitudinal section. When the coupling section and the connecting element are pivoted onto one another in the final assembly position, this ensures that during the pivoting movement the insertion section bears with a substantial part of its surface against the region of the connecting element which cooperates with the insertion section. This ensures reliable guidance when assembling the device from the preassembly position to the final assembly position. Stress peaks are avoided on account of the large-surface bearing. 
     One further embodiment is obtained when the connecting element is designed to be U-shaped in cross section and comprises a back and two legs. On account of the U-shaped design of the connecting element, a spoiler section of the wiper strip which faces away from the windscreen to be wiped can extend between the two legs of the connecting element in the longitudinal direction of the wiper blade. Furthermore, the connecting element can advantageously be coupled at the legs to the slide. 
     Advantageously, the insertion opening is designed as a cut-out on the back. This has the advantage that the insertion opening can be clearly seen on the wiper blade in plan view, as a result of which insertion of the insertion section into the insertion opening is simplified. 
     According to the invention, it is furthermore conceivable that, in the final assembly position, the coupling section covers the connecting element at least in part. In the state mounted on the wiper arm, the inner sides of the legs of the U-shaped coupling section then preferably bear against the outer sides of the legs of the U-shaped connecting element. The outer side of the back of the connecting element preferably bears against the inner side of the back of the coupling section. 
     A further advantageous embodiment of the invention is obtained when the securing sections are designed as locking sections. When the coupling section and the connecting element are pivoted onto one another, the locking sections advantageously lock with one another in the final assembly position. 
     It may be provided that the connecting element has, on its side facing away from the insertion opening in the longitudinal direction, on the legs, in each case a locking tongue which extends in the longitudinal direction and is elastically flexible in the transverse direction, which locking tongues cooperate with locking edges provided on the legs of the coupling section. 
     In order to ensure secure locking, it may advantageously be provided that the locking edges of the locking tongues and the locking edges of the legs enclose an acute angle, in particular an angle in the range from approximately 30° to 80°, with the longitudinal axis of the wiper blade in the final assembly position. 
     In order to release the locking connection, and thus to release the wiper blade from the wiper arm, in a further embodiment of the invention it may be provided that actuating sections are provided on the free ends of the locking tongues. The actuating sections are designed in such a way that the locking tongues can be pressed towards one another, as a result of which the locking edges of the locking tongues can come out of engagement with the locking edges on the legs of the coupling section. 
     In order to allow easier locking, it is advantageously provided that the sides of the locking tongues which face the back of the coupling section and meet the legs of the coupling section when pivoted into the final assembly position are bevelled. 
     Easier locking is also assisted if the sides of the legs of the coupling section which face the windscreen and which are met by the facing sides of the locking sections when pivoted into the final assembly position are bevelled. Shortly prior to reaching the final assembly position, the bevelled sides of the locking tongues consequently cooperate with the bevelled sides of the legs of the coupling section in such a way that the locking tongues are pivoted out in directions towards one another. In the final assembly position, the locking tongues snap behind the locking edges of the coupling section in directions facing away from one another. 
     In order to prevent a wiper blade from being arranged the wrong way round on a wiper arm, the coupling section may have a suitable coding. Incorrect assembly of the wiper blade, for example on the incorrect wiper arm, is thus prevented. A coding may be produced for example by a suitable bezel on the coupling section and by a suitable web on the connecting element which cooperates with the bezel. 
     A further advantageous embodiment of the invention is obtained when the legs of the connecting element are designed as double-walled legs which are slightly elastically flexible in the transverse direction. Such double-walled legs have a better friction behaviour with respect to the slide element against which they are pivotably arranged. Advantageously, the connecting element has, between the legs, a hinge pin which is mounted in a hole on the slide element for the pivotable arrangement of the connecting element. 
     Another embodiment of the invention provides that the slide element has a bearing bolt or alternatively two hinge pins which project with their ends from the slide element and on which the connecting element is pivotably mounted by bearing holes in its legs, which bearing holes are designed in a corresponding manner and are arranged so as to be aligned. In this case, the bearing bolt is or the bearing pins are connected fixedly against rotation to the slide element, and the connecting element is mounted on the slide element in a manner such that it can rotate or pivot. When a wiper blade is replaced, therefore, the entire bearing device is exchanged. 
     According to a further embodiment of the invention, the bearing holes provided in the legs of the connecting element are opened above in each case a slot towards the edge, which slot runs radially with respect to the bearing hole. This may advantageously be used to simplify the assembly of the individual parts. 
     According to another embodiment, if the slot in each case runs from the bearing hole to the edge of the leg which lies opposite the back of the connecting element, the risk of the bearing bolt or bearing pin undesirably sliding out of the bearing hole is small. 
     One further advantageous embodiment provides that in each case the slot expands from the bearing hole towards the edge of the leg, wherein the narrowest point of the slot is smaller than the diameter of the bearing bolt or the alternative bearing pins. This embodiment allows simplification of assembly and disassembly. The bearing bolt or bearing pins can be pressed in radially through the slot in the manner of a locking connection, negotiating the narrow point. Likewise, the bearing bolt or bearing pins can also be removed in the opposite direction, again negotiating the narrow point. To this end, it may be necessary for the connecting element to be made of a suitable plastics material which allows the narrow point of the slot to be negotiated by the bearing bolt or bearing pins. The slide element and/or the bearing bolt or the bearing pins may be made of metal or likewise made of a suitable plastics material. 
     A further, advantageous embodiment of the invention provides that the legs of the connecting element have stud-like raised areas on the side facing the windscreen. These raised areas serve for support on either the wiper rubber or the support element, as a result of which easier assembly and disassembly of the wiper blade is made possible. 
     The coupling section and the connecting element are preferably designed in such a way that, in the final assembly position, they have a substantially closed and substantially smooth surface. To this end, the sections of the connecting element which are covered by the coupling section may lie deeper than the sections of the connecting element which are visible in the final assembly position, the difference in depth being the wall thickness of the coupling section. 
     Further advantageous refinements are provided in order to improve the aerodynamic behaviour of the wiper arm/wiper blade combination, particularly at high travelling speeds or airflow velocities, and thus to counteract in particular the known effect of lifting of the wiper blade connected to the wiper arm off the windscreen to be wiped. 
     By virtue of the measure that the coupling section of the wiper arm has at least one opening suitable for air to flow through, a dynamic pressure which arises below the U-shape of the coupling section is substantially broken down. As a result, the lifting force on the wiper arm is reduced. 
     It is particularly advantageous to provide the at least one opening in the back of the coupling section. However, an improvement is also possible if one or more airflow openings are placed in the legs of the coupling section, in particular in the lee-side leg. The maximum effect can probably be achieved by a combination of the individual possibilities. 
     Another embodiment provides that at least one spoiler-like air guide means is provided on the coupling section of the wiper arm. In this way, the incoming air can be guided in such a way that the effect of the wiper blade or wiper arm being lifted off the windscreen is counteracted. It is advantageous in this connection for the at least one air guide means to be arranged on the back of the coupling section. A spoiler acts particularly effectively at this location. 
     The advantages of an embodiment, according to which the air guide means is formed by a section cut free from the back of the coupling section and bent upwards in a spoiler-like manner, are to be seen in the combination of the effects of the spoiler and of the airflow opening formed in this way. The pressing force is thus directly increased and at the same time the dynamic pressure inside the coupling section is reduced. Moreover, an air guide means produced in this way is particularly cost-effective. 
     A further advantageous embodiment provides that at least one spoiler-like air guide means which is preferably made in one piece with the connecting element is arranged on the back of the connecting element, and that this at least one air guide means protrudes through a, preferably corresponding, opening in the back of the coupling section. Since the connecting element is advantageously made of plastics material, a very large number of design possibilities are provided for the shape of the spoiler-like air guide means with regard to particularly favourable fluidic properties. 
     The object mentioned in the introduction is also achieved by a method of assembling a device according to the invention, which method is characterized in that, in order to reach a preassembly position in which the longitudinal axis of the wiper arm and the longitudinal axis of the connecting element enclose an angle α in the range from approximately 10° to 100°, the insertion section is inserted in a substantially rectilinear manner into the seat, and in that, in order to reach a final assembly position, the wiper arm and the connecting section can be pivoted onto one another about the insertion section/seat contact area until the securing sections enter into a permanent mutual connection. 
     Further details and advantages of the invention can be found in the following description in which the invention is described and explained in more detail with reference to examples of embodiments shown in the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  shows a device according to the invention in a perspective view; 
         FIG. 2  shows the device of  FIG. 1  without the wiper arm; 
         FIG. 3  shows a partial section through  FIG. 2 ; 
         FIG. 4  shows a view from below of the coupling section shown in  FIG. 1 ; 
         FIG. 5  shows a partial section through the device of  FIG. 1  in a preassembly position; 
         FIG. 6  shows a partial section through the device of  FIG. 5  in the final assembly position; 
         FIG. 7  shows another embodiment of a device according to the invention in a perspective view; 
         FIG. 8  shows a further embodiment of a device according to the invention in a perspective view; 
         FIG. 9  shows a final embodiment of a device according to the invention in a perspective view; 
         FIG. 10  shows the device of  FIG. 9  without the wiper arm; and 
         FIG. 11  shows another embodiment of a device according to the invention without the wiper arm. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a device  10  according to the invention for releasably connecting a wiper blade  12 , shown in part, to a drivable wiper arm  14  which is likewise shown in part. The wiper blade  12  has a wiper strip  16  which faces the windscreen to be wiped (not shown) and comprises two strip-like elongate support elements  18 ,  20 , a slide element  22  which is connected to the support elements  18 ,  20 , and a connecting element  24  which is arranged on the slide element  22  in a manner such that it can pivot. The connecting element  24  serves for connection to a coupling section  26  on the wiper arm  14 . 
     The coupling section  26  has, as can be seen in particular in  FIG. 4 , a tongue-like insertion section  28  which, in the final assembly position shown in  FIGS. 1 and 6 , engages in a seat  30  which can be clearly seen in  FIG. 2 . The connecting element  24 , which like the coupling section  26  is U-shaped in cross section, has a back  32  and two legs  34 . The seat  30  is provided in the back  32  of the connecting element  24 . A bearing hole  36  for a bearing bolt  38 , which bearing hole extends in the transverse direction, is provided on the legs  34  of the connecting element  24 . On account of the bearing hole  36 , and the bearing bolt  38 , a pivoting arrangement of the connecting element  24  with respect to the slide element  22  is obtained. In order to achieve a certain flexibility of the legs  34  while having sufficient stiffness, the legs  34  are designed to be double-walled. 
     As can likewise be seen from  FIG. 2 , the connecting element  24  has, on its side facing away from the insertion opening  30  in the longitudinal direction, on the legs  34 , in each case a locking tongue  40  which extends in the longitudinal direction and is elastically flexible in the transverse direction. The locking tongues  40  each comprise a locking edge  42  and an actuating section  44 . The region of the connecting element  24  which is covered by the coupling section  26  in the final assembly position is set back from the other regions of the connecting element  24  which are formed essentially by the two actuating sections  44  and a head section  46  which lies in the axial extension of the coupling section. As a result, in the final assembly position, the coupling section  26  and the connecting element  24  form a substantially closed and substantially smooth surface. 
     As can be seen from  FIG. 3 , the region  48  which cooperates with the insertion section  28  and adjoins the insertion opening  30  is designed to be complementary to the insertion section  28 . As can be seen from  FIGS. 4 and 5 , the insertion section  28  is designed in an arc-shaped manner in the direction of the extension of the wiper arm  14  and in side view in the direction of the windscreen to be wiped. Correspondingly, as can be seen from  FIGS. 3 and 5 , the region  48  is likewise designed to be arc-shaped, in particular in the shape of a segment of a circle. 
     It can be seen from  FIG. 4  that the coupling section is designed in a U-shaped manner in cross section and has a back  50  and legs  52 ,  54  which adjoin the back. The insertion section  28  is in this case arranged in a stand-alone manner in the extension of the back  50 . Provided on the legs  52 ,  54  are locking edges  56  which enclose an angle β of approximately 70° with the longitudinal axis  58  of the wiper arm  14  ( FIGS. 5 and 6 ). The locking edges  42  of the locking tongues  40  enclose a corresponding angle β. In the final assembly position shown in  FIG. 6 , the locking edges  42  of the locking tongues  40  bear against the locking edges  56  of the legs  52 ,  54  of the coupling section  26 . 
     It can be seen from  FIGS. 2 and 5  that the sides  60  of the locking tongues  40  which face the back  50  of the coupling section  26  are slightly bevelled. In a corresponding manner, the sides  62  of the legs of the coupling section  26  which face the windscreen and cooperate with the sides  60  of the coupling section  26  when pivoted into the final assembly position are also slightly bevelled. 
     For assembly of the coupling section  26  to the connecting element  24 , in order to reach a preassembly position which is shown in  FIG. 5 , the insertion section  28  is inserted into the seat  30  in a substantially rectilinear manner in the direction of the arrow  64 . In this preassembly position, the longitudinal axis of the wiper arm  14  and the longitudinal axis of the connecting element  24  or of the wiper blade  12  enclose an angle α which may lie in the range from approximately 10 to 100°. In the example of embodiment shown in  FIG. 5 , the angle α has a value of approximately 40°. In order to reach the final assembly position, which is shown in  FIG. 1  and  FIG. 6 , the wiper arm  14  and the connecting section  24  are pivoted onto one another about the contact area  66  in which the insertion section  28  bears against the region  48  of the seat  30 . On account of the complementary design of the insertion section  28  and the region  48 , the pivoting operation is carried out to a limited extent. Shortly prior to reaching the final assembly position, the bevelled sides  62  of the coupling section  26  and the correspondingly bevelled sides  60  of the locking tongues  40  meet one another in such a way that the locking tongues  40  are pivoted elastically in a direction facing one another. Upon reaching the final assembly position, the locking tongues  40  snap behind the locking edges  56  of the legs  52 ,  54  of the coupling section  26  in a direction facing away from one another. As a result, the coupling section  26  is permanently held on the connecting element  24  in the final assembly position. In the final assembly position, the coupling section  28  bears against the region  48  of the connecting element  24  over a large part of its surface. Furthermore, the end side  68  of the coupling section  26  which faces the head area  46  of the connecting element  26  bears against a bearing edge  70  of the connecting element which corresponds thereto. 
     On account of the locking edges  42 ,  56  which are not perpendicular to the longitudinal axis of the wiper blade but rather enclose an acute angle β with the longitudinal axis, in the assembled state the coupling section  26  is acted upon in the direction of the head section  46 . As a result, a play-free connection is obtained in the axial direction. Moreover, by virtue of the obliquely arranged locking edges  42 ,  56 , the coupling section  26  is acted upon in the direction of the wiper blade  12 , as a result of which a play-free connection is produced in the direction perpendicular to the wiper blade. The insertion section  28  in this case bears against the contact region  48  of the connecting element  24  with slight prestress. 
     In order to release the connection, the actuating sections  44  are pressed towards one another. As a result, the locking edges  42  of the locking tongues  40  come out of the engagement region of the locking edges  56  of the coupling section  26 . Since the actuating sections are arranged opposite one another, the actuating sections  44  can be pressed together by a simple hand grip, using one hand. The coupling section  26  is then pivoted away from the connecting element  24  until the preassembly position reached in  FIG. 5  is almost reached. The insertion section  28  is then moved out of the seat  30  in the direction counter to the arrow  64 . 
     As can be clearly seen in  FIG. 5 , it may be provided that the legs  34  of the connecting element have stub-like raised areas  72  on the side facing the windscreen. These raised areas serve for support on the slide element  22 . The raised areas  72  restrict the pivoting range of the connecting element  24  with respect to the slide element  22 . As a result, easier assembly and disassembly of the wiper blade  12  from the wiper arm  14  is possible. 
     In the bent region of the insertion section  28 , a material cut-out in the form of a cylindrical hole  74  is provided. 
     In order to prevent it from being possible for the wiper blade, which has a spoiler-like projection  76  on its side facing away from the wiper strip  16 , to be mounted on the incorrect wiper arm, a coding may be provided on the connecting element  24  and on the coupling section  26 . Such a coding may be formed for example by a bevelled corner  78  on the leg  54  of the coupling section  26 , as shown in a corresponding manner in  FIG. 4 . The bevelled corner  78  may in this case correspond to a material deposit at the corresponding location on the connecting element  24 , which material deposit is designed in a complementary manner and is not shown in the figures. Since only one of two wiper blades, the respective right-hand or left-hand wiper blade, has a corresponding material deposit on the connecting element, a clear assignment of the right-hand or left-hand wiper blade to the right-hand or left-hand wiper arm is ensured. 
     For the example of embodiment shown in  FIG. 7 , in general the same description as above in respect of the first example of embodiment shown in  FIGS. 1 to 6  applies. The same references have thus been used in  FIG. 7  as in  FIG. 1 . 
     The essential difference of the example of embodiment shown in  FIG. 7  is that an opening  80  is additionally provided in the back  50  of the coupling section  26  belonging to the wiper arm  14 . This opening  80  makes it possible for air flowing below the U-shape of the coupling section to leave the space formed below the U-shape on a relatively short path by flowing through the opening  80 . In this way, the dynamic pressure below the coupling section  26  is reduced compared to an embodiment without the opening  80 , and this leads to a comparative reduction in the lifting force of the wiper arm  14  as air flows through. 
     Instead of the one opening  80 , it would also be possible for a number of openings  80  to be provided in the coupling section  26 , wherein one or more openings  80  may also be made in one of the two legs  52 ,  54  or in both legs  52 ,  54 . The size, shape and position of the one or more openings  80  should be optimized with regard to as considerable an effect as possible in a manner depending on the geometric conditions of the individual components of the device  10  and of the device  10  as a whole. Likewise, the shape and size of the one or more openings  80  may be adapted to the design of the coupling section  26 . 
     Also for the further example of embodiment shown in  FIG. 8 , the same description as that given above in respect of the first example of embodiment shown in  FIGS. 1 to 6  applies. 
     The essential difference of the example of embodiment shown in  FIG. 8  is that a spoiler-like air guide means  82  is formed on the back  50  of the coupling section  26 . In order to produce the air guide means  82 , a more or less rectangular section which is oriented in the longitudinal direction of the coupling section  26  has been cut free from or punched out of the back  50  of the coupling section  26 , at its two narrow sides and on one longitudinal side, and bent upwards out of the plane of the back  50 . In this case, the air guide means  82  may be given a rounded, wing-like shape. The air guide means  82  is connected on its longitudinal side facing the incoming air to the back  50 . By virtue of the bending-out operation, the opening  80  in the back  50  is made at the same time behind the air guide means  82 , which opening can be flowed through by a stream of air. In  FIG. 8 , the reference line belonging to reference  80  is shown in dashed line because the view of the opening  80  is hidden by the air guide means  82  in this perspective view. The air guide means  82  and the opening  80  may be produced from steel sheet as a punched and bent part in a cost-effective manner by punching and bending during the process of manufacturing the coupling section. 
     The aerodynamic advantages of such a design are on the one hand the pressing force produced by the air guide means, which pressing force acts on the wiper arm  14 , and on the other hand the reduction in the dynamic pressure below the U-shape of the coupling section  26 . 
     The special feature of the example of embodiment shown in  FIGS. 9 and 10  is that an opening is provided in the back  50  of the coupling section  26  and that a spoiler-like air guide means  84  arranged on the back  32  of the connecting element  24  passes through this opening to the top side of the coupling section  26 . When air flows across the air guide means  84 , the pressing force of the wiper arm  14  is increased and the lifting force is reduced. 
     In  FIG. 9 , it can be seen that the shape and the size of the opening in the coupling section  26  and the base area of the air guide means  84  are adapted to one another. Moreover, the air guide means  84  is connected to the back  32  of the connecting element  24  via a pedestal  86 . The height of the pedestal  86  corresponds to the wall thickness of the back  50  of the coupling section  26 , so that the top side of the back  50  adjoins the air guide means  84  at least virtually free of any clearance or shoulder. As a result, the aerodynamics are improved and airflow noises are reduced. 
     Unlike the diagram in  FIGS. 9 and 10 , the opening in the back  50  of the coupling section  26  may advantageously also be greater than the base area of the air guide means  84  or the pedestal  86  thereof. In this case, only part of the opening would be filled by the air guide means  84 . The part of the opening which is not filled thus acts as an airflow opening, and as a result the dynamic pressure below the U-shape of the coupling section  26  is in turn reduced. This embodiment is not shown in the drawing. 
     Another embodiment which is not shown in the drawing consists in that, in a device as shown in  FIGS. 9 and 10 , additionally at least one opening is provided in the back and/or in at least one of the legs  52 ,  54  for reducing the dynamic pressure below the U-shape of the coupling section  26 . 
     A final example of embodiment is shown in  FIG. 11 . This example of embodiment corresponds in a very large number of features to the embodiment shown in  FIG. 2 , which is why the fundamental design will not be repeated here and the same reference numerals are used for identical parts and elements. 
     In the example of embodiment shown in  FIG. 11 , the slide element  22  has two bearing pins  88  which are arranged so as to be aligned with one another and which project from the slide element  22  transversely with respect to the longitudinal direction of the wiper blade  12 . The bearing pins  88 , only one of which can be seen in  FIG. 11  on account of the perspective view, are made in one piece with the slide element  22 . The slide element  22  will advantageously be manufactured as a whole as a diecast metal part or as an injection-moulded plastic part. 
     Bearing holes  90  which are aligned with one another are formed in the two legs  34  of the connecting element  24 , said connecting element having essentially the shape of a U in cross section, once again only one of the bearing holes  90  being visible in  FIG. 11  on account of the perspective view. The bearing holes  90  are adapted to the bearing pins  88  in such a way that pivoting of the slide element  22  relative to the connecting element  24  can take place in as play-free a manner as possible. One essential difference compared to the embodiment shown in  FIG. 2  is that the bearing holes  90  are each opened radially above a slot  92  which runs from the bearing hole  90  towards the lower edge of the leg  34 , that is to say the edge opposite the back  32  of the connecting element  24 . The slot  92  expands from the edge of the bearing hole  90  towards the edge of the leg  34 . The narrow point of the slot  92  is in this case narrower than the diameter of the respective bearing pin  88 . Upon assembly or disassembly of the slide element  22  and the connecting element  24 , the bearing pins  88  are pressed radially into the bearing holes  90  or out of the latter through the slots  92  in the manner of a locking connection, negotiating the narrow point. As a result, these processes are considerably simplified, and moreover a sufficiently reliable seating or holding of the bearing pins  88  in the bearing holes  90  is ensured. 
     Usually, the connection of a wiper blade  12  provided with such a slide element  22  and such a connecting element  24  to a wiper arm  14  or to the coupling section  26  of a wiper arm  14 , and removal thereof in the opposite direction, take place in the same general manner, as has been described in connection with  FIGS. 1 to 6 . However, in the embodiment shown in  FIG. 11 , there is also the possibility firstly of attaching the connecting element  24 , separated from the wiper blade  12 , in this general way to the coupling section  26  of the wiper arm  14  and then mounting the slide element  22  connected to the wiper blade  12  on the connecting element  24  by pushing the bearing pins  88  radially through the slots  92  into the bearing holes  90 . It is also conceivable to carry out a disassembly operation by reversing the sequence of these last-mentioned steps. 
     Devices for releasably connecting a wiper blade to a wiper arm which correspond to the examples of embodiments shown in  FIGS. 1 to 10  are suitable in particular for use in wiper systems for front windscreens of vehicles, whereas the device corresponding to the example of embodiment shown in  FIG. 11  is suitable in particular for use in wiper systems for rear windows of vehicles. 
     All of the features found in the description, the drawings and the claims may be essential to the invention both individually and in any desired combination with one another. 
     While the method herein described, and the form of apparatus for carrying this method into effect, constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise method and form of apparatus, and that changes may be made in either without departing from the scope of the invention, which is defined in the appended claims.