Abstract:
The invention starts with a wiper arm ( 10, 28; 42, 44 ) with at least one fan nozzle ( 20, 46, 70, 88 ) through which wash water is sprayed on an as-needed basis in a fan stream ( 22, 54, 76, 78, 90, 94, 98, 102, 106, 110, 114 ) onto a part of vehicle window ( 68 ) lying in the wiper direction ( 58, 59 ) in front of a wiper blade ( 16, 18; 36, 48 ), wherein the fan stream ( 22, 54, 76, 78, 90, 94, 98, 102, 106, 110, 114 ) hits the vehicle window ( 68 ) in the area of an impact line ( 24, 56, 80, 82, 92, 96, 100, 104, 108 ). It is proposed that the impact line ( 24, 56, 80, 82, 92, 96, 100, 104, 108 ) essentially runs parallel to the wiper blade ( 16, 18; 36, 48 ).

Description:
BACKGROUND OF THE INVENTION 
   A wiper arm which has spray nozzles arranged on its articulated part or rather on a wiper rod connected as a single piece to the articulated part is known from DE 198 15 171 A1 These spray nozzles are located in a nozzle body, which is housed in an indentation of the articulated part with a spray opening for the spray stream or clipped in, projecting downward, in a lateral holding device on the wiper rod. Even two nozzle bodies can be provided, which are connected to one another by a rigid or flexible connecting piece. The nozzle bodies are easy to replace and are well protected against environmental influences. 
   Fan nozzles are also known, which generate a fan stream by the nozzle opening being embodied as a slot that the fan plane determines or by several nozzle outlets being arranged in a fan plane. The fan nozzles are arranged on the side of the wiper arm that points in the upward direction and its fan stream has a slight inclination toward the vehicle window, wherein the impact line of the fan stream on the vehicle window is inclined and runs at a considerable distance to the wiper blade. Therefore, the fan stream provides the air stream with a large contact surface so that it blows a great portion of the wash water over the vehicle window into the surrounding area. As a result, a relatively large amount of wash water is required, which increases costs and harms the environment, particularly if cleaning compounds and antifreeze agents have been added to the wash water as usually is the case. 
   SUMMARY OF THE INVENTION 
   According to the invention, the impact line of the fan stream essentially runs parallel to the wiper blade so that the impact line can run very close alongside the wiper blade. As a result, the fan stream lies in the area of the wiper blade and wiper arm that is sheltered from the wind and provides the air stream with little or no contact surface. Because of the small steam path length, a high percentage of the wash water reaches the window and can therefore be used optimally for cleaning. In addition, this is advantageous because the wetting of the vehicle window occurs only for a short time, the cleaning compound is washed away again relatively quickly and is therefore hardly perceptible to the driver. However, it is crucial that the cleaning process take place without obstructing visibility, something that represents a substantial gain in safety. The fan nozzles can also be arranged on both sides of the wiper arm, which even though this is connected with greater expense, it offers the advantage that wash water can be sprayed in a timed process in both an upward direction as well as a downward direction always in front of the wiper blade. 
   It has been shown that favorable wiper results are achieved if, in accordance with an embodiment of the invention, the fan plane of the fan stream encloses, with a longitudinal center plane of the wiper blade, an angle α that is less than thirty degrees. 
   Since the distance between the wiper blade and the impact line of the fan stream is very small, it is advantageous that the fan nozzle be embodied in such a way that the length of the impact line corresponds approximately to the length of the wiper blade. This results in a uniform water distribution over the length of the wiper blade. However, the fan nozzle can also features several nozzle outlets and generate several fan streams, whose impact lines correspond in terms of the sum of their lengths to the length of the wiper blade. This type of fan nozzle is expediently arranged approximately in the center of the wiper blade, i.e., in the area of the articulated connection between the wiper arm and the wiper blade. Thus, a fan stream can run in the direction of the articulated part, while another fan stream is directed toward the free end of the wiper blade. Under some circumstances, a third fan stream between the cited fan streams can have a direction component directed transverse to the wiper blade. In order to achieve optimal wetting of the vehicle window, it is advantageous if the fan streams are somewhat offset transverse to the wiper blade so that their impact lines can overlap in the longitudinal direction of the wiper blade without the fan streams having a mutual negative effect. 
   As a rule, the fan nozzles are actuated during the upward movement of the wiper blade, wherein the fan streams lie in the area of the wiper blade and wiper arm that is sheltered from the wind during a great majority of the wiper movement. In the case of wiper arrangements in which the wiper blade is also subjected to air flow in the longitudinal direction, something that is frequently the case on the passenger side of the vehicle, it is expedient that several fan nozzles be provided in an offset manner in the longitudinal direction of the wiper arm instead of one central fan nozzle with several nozzle outlets and that the fan streams from these fan nozzles be directed towards the free end of the wiper blade. As a result, the fan stream operates in the same direction as the inflow of the air stream in the case of longitudinal inflow. 
   The fan nozzle arrangement in accordance with the invention is suitable for all wiper arm concepts, i.e., for all wiper arms, which are connected in accordance with a top-lock principle or a side-lock principle with a conventional wiper blade with a supporting bracket system or with a non-articulated wiper blade. Moreover, it is not important whether the wiper arm follows the wiper blade in an upward motion or runs in front of it. Finally, the invention can also be used for wiper arms, which do not feature a fastening part and articulated part, but are manufactured from a continuous elastic element. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Additional advantages are yielded from the following description of the drawings. Exemplary embodiments of the invention are depicted in the drawings. The drawings, the description and the claims contain numerous features in combination. The expert will also observe individual features expediently and combine them into additional, meaningful combinations. 
     The drawings show: 
       FIG. 1  A schematic side view of a wiper arm in the downward direction with a conventional wiper blade. 
       FIG. 2  A top view of a wiper arm according to  FIG. 1 . 
       FIG. 3  A schematic side view of a wiper arm in the downward direction with a non-articulated wiper blade. 
       FIG. 4  A top view of a wiper arm according to  FIG. 3 . 
       FIG. 5  A variation of  FIG. 4 . 
       FIG. 6  A cross-section corresponding to Line VI-VI in  FIG. 4 . 
       FIG. 7  A variation of  FIG. 4 . 
       FIG. 8  A wiper arm combination for the driver&#39;s side and the passenger side of a motor vehicle. 
       FIG. 9  A variation of  FIG. 8 . 
       FIG. 10  A variation of  FIG. 7 . 
       FIG. 11  A variation of  FIG. 4 . 
       FIG. 12  A variation of  FIG. 11 . 
   

   DETAILED DESCRIPTION 
   A wiper arm  10  in accordance with  FIGS. 1 and 2  has a fastening part  12 , which is connected in an articulated manner with an articulated part  14 . Linked to this is a wiper blade with a supporting bracket system  16  of a convention design according to the top-lock principle in the usual manner. The supporting bracket system  16  holds a wiper strip  18 , which glides in the usual manner over a vehicle window  68  during wiper movement ( FIG. 6 ). An arrow  58  indicates the upward direction of the wiper arm  10  during wiper movement. It essentially corresponds to the inflow direction of the air stream in the wiper arm&#39;s  10  parked position. Fan nozzles  20  are provided in an offset manner in the longitudinal direction of the wiper arm  10  on the side of the wiper arm  10  facing away from the air stream, and the fan streams  22  of these fan nozzles hit the vehicle window  68  in the area of an impact line  24 . The total of the lengths of the impact lines  24  essentially corresponds to the length of the wiper strip  18 . Moreover, as  FIG. 2  shows, the impact lines  24  essentially run parallel to the wiper strip  18  or the supporting bracket system  16  and are at a short distance from it. A spoiler  26  is fastened on the supporting bracket system  16  or on the articulated part  14  on the side of the wiper arm  10  that faces the air stream. 
   In the embodiment according to  FIGS. 3 and 4 , a wiper arm  28  has a fastening part  30  and an articulated part  32 , which is connected via an articulated connection  34  according to the side-lock principle with a non-articulated wiper blade  36 . In addition to a spoiler  38 , the non-articulated wiper blade  36  has a wiper strip  40  in which spring rails  60  are laterally embedded as supporting elements. The articulated connection  34  and a spoiler  26  are fastened to these ( FIG. 6 ). The articulated part  32  follows the wiper blade  36  in the upward movement  58 . On the side of the spoiler  26  that faces away from the air stream, two fan nozzles  20  are provided in an offset manner on the articulated part  32  in the longitudinal direction. These fan nozzles are supplied with wash water via a water channel  62 .  FIG. 6  clearly shows that the fan stream  22  of the fan nozzle  20  lies in the area of the wiper blade  36  that is sheltered from the wind. In this connection, it is expedient that the impact line  24  of the fan stream  22  lies close to the wiper blade  36 . The fan plane  66  of the fan stream  22  expediently forms, with a center wiper blade plane  64 , an angle α that is less than thirty degrees. 
   The embodiment according to  FIG. 5  shows the articulated part  42  of a wiper arm, which is linked via an articulated connection  44  to a non-articulated wiper blade  48  according to the side-lock principle. The articulated part  42  lies in the upward direction  58  in front of the wiper blade  48 , which includes a spoiler  50  and a wiper strip  52 . On the side of the articulated part  42  that faces away from the air stream, a fan nozzle  46 , which generates fan streams  54  with associated impact lines  56 , is provided in both the area of the articulated connection  44  and offset towards the drive-side end of the articulated part  42 . The fan streams  54  are protected from the air stream by the wiper blade  48  and the articulated part  42  and are indicated by a dashed line. 
   Instead of the two fan nozzles  20  or  46  arranged in an offset manner in the longitudinal direction, the variation according to  FIG. 7  has one central fan nozzle  70  with two nozzle outlets  72  and  74 , and the nozzle outlet  72  generates a fan stream  76  pointing towards the free end of the wiper blade  36 , whose impact line is designated with  80 . The other nozzle outlet  74  generates a fan stream  78  in the direction towards the fastening part  30 . The fan stream  78  has an impact line  82 . 
     FIG. 8  depicts a wiper arrangement for a motor vehicle, in which the both wiper arms, i.e., the one for the driver&#39;s side  84  and the one for the passenger side  86 , are configured in the same manner. The wiper arms  28  are depicted in the initial position, the parked position. In a reverse position, the wiper arm  28  is subjected to air flow in the longitudinal direction primarily on the passenger&#39;s side  86 , wherein it is advantageous if the fan streams  22  are directed in the direction towards the free end of the wiper blade  36  and operate in the direction of the inflowing air. Since the wiper arm  28  on the driver&#39;s side  84  is actuated as a rule via a smaller pivoting angle, it is subjected to air flow by the air stream only with a negligible component in the longitudinal direction. As a result, the more economical variation as per  FIG. 7  with one central fan nozzle  70  can be selected on the driver&#39;s side  84 . 
   The central fan nozzle  88  according to  FIG. 10  also has several nozzle outlets, which generate fan streams,  90 ,  94 ,  98  with associated impact lines  92 ,  96 ,  100 . In this connection, the fan streams  90 ,  94 ,  98  are somewhat offset transverse to the wiper blade  36  so that their impact lines  92 ,  96 ,  100  can overlap in the longitudinal direction of the wiper blade  36 . Thus, one fan nozzle  88  can cover the entire length of the wiper blade  36  with a uniform water distribution. 
   The variation according to  FIG. 11  depicts a solution with two fan nozzles  20 , which generate fan streams  102  and  106  with corresponding impact lines  104  and  108 . In this connection, the impact line  104  runs offset to the impact line  108  transverse to the wiper blade  36  and overlaps the impact line  108  in a center area of the wiper blade  36 . Since the fan streams  102 ,  106  are directed in the direction of a possible longitudinal inflow of air against the wiper blade, this arrangement is especially suitable for a mixed inflow of air against the wiper blade  36 . 
   The variation according to  FIG. 12  depicts a wiper arm  28  with several fan nozzles  20 , three of which are arranged on the forward side of the wiper arm  28  in the upward direction  58 , while a fourth fan nozzle  20  is provided on the opposite side or on the front side of the wiper arm  28 . Two of the fan nozzles  20  each generate a fan stream  102  or  106 , whose impact lines  104  or  108  lie in the upward direction in front of the wiper blade  36 . The two other fan nozzles  20  each generate a fan stream  110  or  114 , whose impact lines lie in the downward direction  59  in front of the wiper blade  36 . Reference number  112  designates the impact line of the fan stream  110 , while the wiper arm  28  obscures the impact line of fan stream  114 . The fan nozzles  20  are triggered in a timed manner in accordance with the wiper movement of the wiper arm  28  or wiper blade  36  so that fan streams  102 ,  106 , or  110 ,  114  are generated only on the side of the wiper blade  36  that is forward in terms of the wiping direction.