Abstract:
A wiper arrangement for a windscreen of a motor vehicle having a screwless fixing device, which has at least three fixing members arranged at a distance from one another, two of which lie on a connecting line and the third of which is arranged at a distance from the connecting line, and which includes appropriate receiving devices, in which the fixing members can engage and at least one fixing member includes a thickened section for axial securing. The receiving device of the wiper arrangement includes a recess designed to complement the thickened section and in which the thickened section can be received in the manner of a snap-locking connection.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a national stage application based on International Application No. PCT/EP02/12151 filed Oct. 31, 2002. 

   FIELD OF THE INVENTION 
   The present invention relates to a wiper arrangement for a windscreen of a motor vehicle having a screwless fixing device, which has at least three fixing members arranged at a distance from one another, two of which lie on a connecting line and the third of which is arranged at a distance from the connecting line, and which comprises appropriate receiving devices, in which the fixing members can engage, at least one fixing member comprising a thickened section for axial securing. 
   BACKGROUND OF THE INVENTION 
   A wiper arrangement of this type is disclosed by DE 198 33 404 A1. The windscreen wiper arrangement disclosed therein comprises a support structure, on which a total of three fixing members, designed as cylindrical socket pins, are provided. These are inserted axially into receiving apertures, which are arranged in special holders fixed to the body of the vehicle. To secure it axially, a socket pin is provided with a thickened section at the free end, this thickened section engaging behind a receiving aperture provided in a rubber socket and thereby preventing the wiper arrangement becoming detached from the motor vehicle. 
   The screwless socket connection makes the known wiper arrangement very easy to fit and securely prevents it from “falling off” the motor vehicle. This wiper arrangement, however, does not always ensure precise positioning of the fixing members in an axial direction. 
   SUMMARY OF THE INVENTION 
   The object of the present invention therefore is to further develop a wiper arrangement of the aforementioned type so that so that it can be precisely positioned in relation to the motor vehicle. 
   This object is achieved by the features of the pre-characterising clause of claim  1  in that the receiving device comprises a recess designed to complement the thickened section, in which the thickened section can be received in the manner of a snap-locking connection. 
   The wiper arrangement according to the invention differs from the prior art in that the receiving device has a special recess, which permits a precise positioning of the fixing member and thereby of the wiper arrangement in relation to the receiving device, and therefore in relation to the motor vehicle. At the same time it retains the advantages of a snap-locking connection. 
   Advantageous developments of the invention are specified in sub-ordinate claims. 
   In one development the fixing member comprises a socket pin. This is a part which is easy to manufacture and to handle. 
   In another development the fixing member comprises a damping element, on which the thickened section is arranged. In order to be able to produce a snap-locking connection, a certain flexibility is required, either in the fixing member or in the receiving device. Since a damping element, which is made of an elastic material, is often used in order to prevent vibrations being transmitted between wiper arrangement and motor vehicle, it is particularly advantageous to provide the thickened section on the damping element. This makes the snap-locking connection according to the invention simple and inexpensive to produce. 
   At the same time, that development in which the fixing member has, in particular, a conical insertion taper at its protruding end is especially preferred. This makes the wiper arrangement easy to fit to the vehicle and increases the speed of assembly when positioning. 
   It is also advantageous if the thickened section is arranged at an axial distance from the end of the fixing member. This ensures secure guidance of the fixing member in the receiving device not only during assembly but also in the fitted state. 
   In one simple development of the thickened section, which to a certain extent is tolerant of production tolerances, the thickened section is spherical. In this case the corresponding recess on the receiving device would be hemispherical. 
   Alternatively the thickened section may be conical. In this case a correspondingly conical recess would have to be provided in the receiving device. 
   The outstanding feature of another development of the invention is that the receiving device comprises a damping element, which in turn comprises the recess. This also allows the snap-locking connection to exploit the existing flexible characteristics of the damping element. 
   In this case it is particularly preferred if the recess has an insertion taper, since this facilitates handling when fitting the wiper arrangement and speeds up the fitting operation. 
   In order to compensate for production tolerances on the part of the wiper arrangement and on that of the fixing device, in a preferred development at least one of the receiving devices is designed as an elongated hole. The corresponding fixing member, for example a socket pin with a spherical or conical thickened section, is then axially secured in a corresponding, complementary recess in the radially inner wall of the elongated hole but is free to move along the extent of the elongated hole. 
   The present invention also relates to a wiper arrangement of the aforementioned type in which a recess is provided on at least one fixing member, the recess interacting with the receiving device in the manner of a snap-locking connection. Such a wiper arrangement of “reversed” design construction has all the advantages of the wiper arrangement initially described and it also lends itself to the corresponding developments. 
   Such a wiper arrangement is particularly suitable, however, where the receiving device comprises a sheet-metal neck insert. Such a sheet-metal neck insert is easy and inexpensive to produce and can engage in the corresponding recess in the fixing member. 
   In order to prevent the exposed edge of the sheet-metal neck insert from damaging the recess on the fixing member and in order to obtain a better support for the fixing member in the receiving device, in a further development the free end of the sheet-metal neck insert is provided with a bent-over section extending radially outwards, preferably one bent over by an angle of approximately 40° to 50°. 
   The invention finally also relates to a wiper arrangement of the type described above, in which at least one fixing member on the driver&#39;s side and one receiving device on the driver&#39;s side have the snap-locking connection. In order to give the driver an optimum wiped area, the positioning of the wiper arrangement in respect of the driver&#39;s side A-pillar is particularly important. The said development takes account of this, because with this development the precise positioning afforded by the snap-locking connection is provided at least on the driver&#39;s side fixing member and the corresponding receiving device. 
   Examples of embodiments of the invention will be explained in detail below with reference to the drawing attached, in which: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG.  1 : shows a perspective view of a windscreen wiper arrangement having a screwless fixing device, but without any receiving device; 
     FIG.  2 : shows a section through the plane II—II in  FIG. 1 , a receiving device also being represented; 
     FIG.  3 : shows a view similar to that in  FIG. 2  of a second example of an embodiment of a wiper arrangement; 
     FIG.  4 : shows a top view of a third example of an embodiment of a receiving device for a wiper arrangement; 
     FIG.  5 : shows a sectional view along the line V—V in  FIG. 4 , a fixing member also being represented; 
     FIG.  6 : shows a sectional view through a fourth example of an embodiment of a fixing device for a wiper arrangement; 
     FIG.  7 : shows a sectional view similar to that in  FIG. 6  of a fifth example of an embodiment; 
     FIG.  8 : shows a sectional view similar to that in  FIG. 6  of a sixth example of an embodiment. 
   

   DETAILED DESCRIPTION 
   A windscreen wiper arrangement for a motor vehicle in  FIG. 1  carries the overall reference number  10 . It comprises a rod-like supporting body  12 , which at both ends supports a bearing body  14  and  16  respectively. A wiper shaft  18  and  20  for receiving a windscreen wiper arm is axially secured and rotatably supported in each bearing body  14  and  16  respectively. 
   Seated on the supporting body  12 , approximately on its centre section, is a drive device  22 , which operates a connecting linkage  24 . One end of the connecting linkage  24  is articulated to a link  26 , which is in turn rigidly coupled to the wiper shaft  18 . The other end of the connecting linkage  24  is articulated to a link  28 , which is rigidly connected to the wiper shaft  20 . 
   The windscreen wiper arrangement  10  can be fixed to a motor vehicle by means of a screwless socket connection beneath a windscreen (not shown) of a vehicle body. For this purpose each bearing body  14 ,  16  carries a cylindrical socket pin  32 ,  34 , which projects from the bearing bodies  14  and  16  parallel to one another and in the same direction and at right-angles to the wiper shafts  18  and  20 . A further cylindrical socket pin bears the reference number  36  and is rigidly fixed to a spacer element  37  on that side of the drive device  22  remote from the supporting body  12 . 
   Whilst the socket pins  32  and  34  lie approximately in the plane spanned by the supporting body  12  and the connecting linkage  24 , the socket pin  36  stands at right-angles to this plane, that is to say also at right angles to the longitudinal extent of the two socket pins  32  and  34 . Overall, the socket pins  32 ,  34 ,  36  lie at the vertices of a triangle and form a stable support base. 
   Approximately midway along their longitudinal extent the socket pins  32 ,  34 ,  36  each have a spherical thickened section  38 ,  40  and  42  respectively. In the example of the socket pin  36  shown in  FIG. 2  this is fixed in a receiving device  39 , which has a receiving aperture  41 . The socket pins  32  and  34  are correspondingly fixed. 
   The spherical thickened section  42  on the socket pin  38  engages in a corresponding, complementary hemispherical recess  44  in the receiving aperture  41 , which is provided in a rubber socket  46 . In its outer peripheral wall the rubber socket  46  has an annular groove  48 , into which a retaining plate  42  having an aperture  50  engages. The retaining plate  52  is fixed to the vehicle, for example by spot welding. In one example of an embodiment (not shown), however, the aperture  50  may also be provided in a structural plate of the vehicle, so that an additional retaining plate can be dispensed with. 
   As can be seen from  FIG. 2 , the socket pin  36  at its protruding axial end has a conical insertion taper  54 . Analogously with this, insertion tapers  56  and  58  are provided on the receiving aperture  41  in the rubber socket  46  above and below the hemispherical recess  44 . The same naturally also applies to the socket pins  32  and  34  and the corresponding rubber sockets. 
   In order to fix the windscreen wiper arrangement  10  to a vehicle, the socket pin  36  is now simply inserted into the receiving aperture  41  in the rubber socket  46 . The elasticity of the rubber socket  46  means that it is expanded by the spherical thickened section  42  until the latter is received in the hemispherical recess  44  in the manner of a snap-locking connection. The insertion tapers  54 ,  56 , and  58  facilitate insertion (the lower insertion taper  58  makes it easier to draw the socket pin  36  back in the event that it has been inserted too far into the receiving aperture  41  in the rubber socket  46 ). A similar procedure is followed with the socket pins  32  and  34 . In this way it is possible to achieve a precise and at the same time firm positioning of the windscreen wiper arrangement  10  in relation to the vehicle. 
   In the second example of an embodiment represented in  FIG. 3  parts performing an equivalent function to parts described in connection with  FIG. 2  carry the same reference numbers and are not described in more detail here. 
   In contrast to the first example of an embodiment, the thickened section  42  in this case is of conical rather than spherical shape. The same likewise applies to the complementary recess  44  in the receiving aperture  41  in the rubber socket  46 . In this way the socket pin  36  is secured even more firmly in the rubber socket  46 , preventing it being pulled out of the receiving aperture  41 . 
   The remarks concerning reference numbers etc. made with regard to  FIG. 3  apply analogously to  FIGS. 4 and 5 . Although the thickened section  42  in the example of an embodiment represented in  FIGS. 4 and 5  is spherical and the corresponding recess  41  hemispherical, the receiving aperture  42  in the rubber socket  46  is, like the aperture  41  in the retaining plate  52 , designed as an elongated hole. In this way it is possible to compensate for production tolerances on the windscreen wiper arrangement  10  and in the distance between the receiving devices  39  on the vehicle side. It should be pointed out here that the thickened section can also be provided on a flexible damping element which is pre-fitted to a socket pin. 
   The remarks concerning reference numbers etc. made with regard to  FIG. 3  again apply analogously to the examples of embodiment represented in  FIGS. 6  to  8 . 
   The socket pin  36 , as can be seen from  FIG. 6 , has an essentially cylindrical, annular recess  60 , such that a conical cap  62  is formed at the protruding end of the socket pin  36 . The socket pin  36  is furthermore fitted directly to the drive device  22 . The recess  60  is therefore formed between the cap  62  and the drive device  22 . 
   A damping element  46  made of an elastic material, into the radially outer circumferential surface of which an annular groove  44  is formed, is pushed or moulded on to the socket pin  36 . The axial boundary faces  64  and  66  of the groove  44  are perpendicular to the base surface  68  of the groove  44 . 
   The receiving device  39  on the vehicle side consists of a sheet-metal neck insert, which forms a tubular section  42 . The inside width of the tubular section  42  is approximately equal to the diameter of the groove  44  in the damping element  46 . 
   To fix the windscreen wiper arrangement  10  to the vehicle (not shown), the damping element  46  is first pushed over the cap  62  on to the socket pin  36 . The socket pin  36  with the damping element  46  is then inserted into the corresponding receiving device  39  with the sheet-metal neck insert forming the tubular section  44 . The tubular section  44  then snaps into the groove  44 , thereby snap-locking the windscreen wiper arrangement  10  securely to the vehicle. 
   In the example of an embodiment represented in  FIG. 6 , axial oscillations of the socket pin  36  in relation to the retaining plate  52  can, under unfavourable operating conditions, result in damage to the damping element  46  in the area of the joint between the free end of the tubular section  42  and the lateral face  66  of the grove  44  in the damping element  46 . In order to avoid this, in the examples of embodiment represented in  FIGS. 7 and 8 , sections  70  bent over radially outwards are provided at the free end of the tubular section  42 , these sections being bent over by an angle of approximately 45° in the example of embodiment represented in FIG.  7  and by an angle of approximately 90° in the example of embodiment represented in FIG.  8 . 
   In  FIGS. 2  to  8 , the various examples of embodiment have been explained throughout using the “middle” socket pin  36  and the corresponding receiving device  39  as an example. Not shown in the drawing, but particularly preferred, however, is a design in which this snap-locking connection is provided on the driver&#39;s side fixing member and the driver&#39;s side receiving device. This is preferred because the precise positioning of the windscreen wiper arrangement in relation to the driver&#39;s side A pillar is of primary interest owing to the importance of an optimum wiped area for the driver. In the case of the windscreen wiper arrangement  10  represented in  FIG. 1  this would therefore relate to the socket pin  34 .