Abstract:
The invention is based on a wiper blade ( 10 ) with a supporting element ( 12 ) which has two interconnected spring rails ( 30 ), and with a wiper strip ( 14 ) which is received by the spring rails ( 30 ) in a manner allowing it to be exchanged. It is proposed that one end of the wiper strip ( 14 ) is connected fixedly to a thickened portion ( 74, 98, 100, 108, 110, 112, 114 ) by means of which the wiper strip ( 14 ) can be fixed relative to the supporting element ( 12 ).

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     The invention is based on a wiper blade with a supporting element. 
     DE 10 2004 051 467 A1 discloses a wiper blade of the type in question. Its supporting element comprises two spring rails which run parallel to each other and are connected to each other at their ends by a bridge. In order to receive a wiper strip, the spring rails form a longitudinal gap, and therefore the wiper strip can be threaded in the longitudinal direction onto the supporting element. The wiper strip is secured in the longitudinal direction relative to the supporting element by end caps. The latter have an element with a spike which is pressed at the end of the installation into a top strip of the wiper strip. In the fitted state, the spike bears against the bridge end side which faces away from the end of the wiper strip. In one exemplary embodiment, the spike is located on a spring tongue which is pressed against the top strip by a flap with an eccentric. The pivot axis of the flap runs transversely with respect to the longitudinal direction of the wiper blade. In another embodiment, the spike is arranged directly on the flap, with the pivot axis of the flap being provided in the vicinity of the outer end wall of the end cap. 
     According to the invention, one end of the wiper strip is connected fixedly to a thickened portion by means of which the wiper strip can be fixed relative to the supporting element. This expediently takes place in that the thickened portion can be placed against a bridge which connects the spring rails to each other, or against an end side of the spring rail. In this position, the wiper strip is fixed relative to the supporting element in an advantageous manner by an end cap. The latter can engage over the thickened portion and the bridge and can latch in the position by means of releasable latching means. In the event of removal of the wiper strip of the wiper blade, the latching means are released, and therefore, after removal of the end cap, the wiper strip can be pulled out of the supporting element. The design according to the invention results in a simple means of fixing the wiper strip to the supporting element which requires little construction space, and therefore the end cap can harmonically adjoin the profile of a wind-deflecting strip of the wiper blade. This reduces flow losses and wind noises at the wiper blade. 
     The thickened portion can be realized by different design elements, for example by separate structural elements which are connected to the wiper strip, or by integrally formed parts which bring about a local cross-sectional enlargement of the cross-sectional profile of the wiper strip at the end of the wiper strip. The former measures include clips made of metal or plastic or a combination of these materials, for example plastic-coated metal clips or bow-shaped plastic parts which are fastened to the wiper strip by metal clips. In the simplest case, staples suffice, the limbs of which, facing the wiping lip, are pressed by the upper part of the head strip and are bent over towards the web which runs between the longitudinal grooves for the spring rails. 
     Another possibility is that the staple runs in the longitudinal direction of the wiper strip while its limbs pierce the web between the longitudinal grooves transversely with respect to the longitudinal direction and are bent over inwards on the opposite side of the web. If the thickened portion is integrally formed on the wiper strip, it can completely or partially fill the longitudinal grooves in the end region thereof. Furthermore, it can protrude as a bead or projection over the normal cross-sectional profile of the wiper strip. These may be parts of the wiper strip which are joined to it by injection moulding or extrusion and are made of an identical or similar material. In principle, it is also possible to connect said parts to the wiper strip as separate parts by adhesive bonding, vulcanization or welding. 
     According to a refinement of the invention, at least one end cap is provided which has an opening which can be opened and closed. A flap or a slide closing the openings is used for this. The flap is connected to the cap via a film hinge, the pivot axis of which runs in the longitudinal direction of the wiper blade. In the closed state, the flap latches with a latching edge on a connecting web of the end flap, with the one end side being placed by means of a rib against the bridge of the supporting element. The outer contour of the closed flap ends flush with the approach flow surface or moulding of the end cap, and therefore, even in the case of high speed vehicles, wind noises are not produced at the end cap. 
     In another embodiment, the opening is provided on the outer end side of the end cap. It serves, inter alia, for the installation and removal of the wiper strip. The opening can be closed by the slide which can be displaced transversely with respect to the longitudinal direction of the wiper blade and is fixed in a closed position by a latching element. For better handling, grippy surface structures, for example in the form of bumps, scores or roughened portions, can be provided on the flap and on the slide. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages emerge from the description below of the drawings. The drawing illustrates exemplary embodiments of the invention. The drawing, the description and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and put them together to form meaningful further combinations. 
       In the drawing: 
         FIG. 1  shows a perspective illustration of a wiper blade, 
         FIG. 2  shows a section corresponding to the line II-II in  FIG. 1 , 
         FIG. 3  shows a section through a wind-deflecting strip according to  FIG. 2 , 
         FIG. 4  shows a perspective view of one end of a wiper strip, 
         FIG. 5  and  FIG. 6  show a wiper strip according to  FIG. 4  with a supporting element, 
         FIG. 7  to  FIG. 9  show a wiper strip according to  FIG. 6  with an end cap, 
         FIG. 10  to  FIG. 17  show variants of a wiper strip according to  FIG. 4 , 
         FIG. 18  and  FIG. 19  show a variant of the end cap according to  FIG. 7  and  FIG. 8 , and 
         FIG. 20  shows a section corresponding to the line xx-xx in  FIG. 19 . 
     
    
    
     DETAILED DESCRIPTION 
     A wiper blade  10  has a resilient supporting element  12 , which is elongate in the manner of a band and is in the form of two spring rails  30  running parallel to each other at a distance ( FIGS. 1 and 2 ). The latter are inserted by means of their mutually facing, inner edge strips  32  into longitudinal grooves  34  of a top strip  20  of a wiper strip  14  while their outer edge strips  36  protrude laterally for a distance out of the longitudinal grooves  34 . Towards a vehicle window  22 , the top strip  20  is adjoined via webs  28  by a wiping lip  26  which slides over the vehicle window  22  during a wiping movement in the direction of a double arrow  18 . For this purpose, a wiper arm  16  drives the wiper blade  10  via a connecting device, the wiper-blade-side part  15  of which can be connected in an articulated and releasable manner to the wiper arm  16  while it sits fixedly in the central region of the wiper blade  10  on the supporting element  12  thereof. At the same time, the wiper arm  16  loads the wiper blade  10  with a contact pressure  24  in the direction of the vehicle window  22 . The wiper arm  16  and the vehicle window  22  are indicated by chain-dotted lines. 
     The sharpest curvature of the vehicle window  22  is smaller than the curvature of the as yet unloaded wiper blade  10 , which rests with its two ends on the vehicle window  22  ( FIG. 1 ). Under the contact pressure  24 , the wiper blade  10  comes to rest against the vehicle window  22  over its entire length by means of its wiping lip  26 . At the same time, a stress builds up in the resilient supporting element  12 , which is manufactured from metal, this stress ensuring proper contact of the wiper strip  14  or wiping lip  26  with the vehicle window  22  over its entire length and uniform distribution of the contact pressure  24 . 
     It is apparent from  FIG. 2  that, in the exemplary embodiment, the spring rails  30  of the supporting element  12  are arranged in a common plane approximately parallel to the vehicle window  22 . They are secured in their longitudinal grooves  34  by the wiper-blade-side part  15  of the connecting device in the central region of the wiper blade  10  and by end caps  38  arranged at each end of the wiper blade  10 . For this purpose, said structural elements  15  and  38  engage around the outer edge strips  36  of the spring rails  30 . Subsections  40  of a wind-deflecting strip  42  are arranged between the part  15  and each of the two end caps  38 . The arrangement of the wind-deflecting strip  42  with respect to the wiper strip  14  and the configuration can be gathered from  FIGS. 2 and 3 . 
     The wind-deflecting strip  42 , which is composed of an elastic material, for example of a plastic, and its two subsections  40  sit on the upper band side  11  of the supporting element  12 . As seen in cross section, the wind-deflecting strip  42  has diverging limbs  44  and  46  which are connected to each other on a common longitudinal back  48 . The free ends  50  and  52  of the limbs  44  and  46  face the vehicle window  22  and are supported on the wiper blade  10  and on its supporting element  12 , respectively. An approach flow surface  54 , which is moulded in the exemplary embodiment, is formed on the one limb  44 , on the outside thereof, and is primarily approached by the flow of the relative wind during the operation of the wiping device. The cross-sectional shape, which is apparent from  FIGS. 2 and 4 , of the wind-deflecting strip  42  and of its subsections  40  can be the same over the entire length, and therefore the subsections  40  can be extruded cost-effectively. The subsections  40  of the wind-deflecting strip  42  are connected fixedly with their free ends  50  and  52  of the limbs  44 ,  46  to the wiper blade  10  and to its supporting element  12 . 
     For this purpose, the free ends  50  and  52  of the limbs  44 ,  46  of the wind-deflecting strip  42  are expediently adhesively bonded to the supporting element  12  of the wiper blade  10 . To this end, the free ends  50  and  52  of the limbs  44  and  46  are provided with claw-like extensions  56 ,  58  which engage in a fitting manner around the outer edge strips  36  of the supporting element  12  that face away from each other. Those surfaces of the claw-like extensions  56 ,  58  which bear against the edge strips  36  serve as adhesive bonding surfaces with which the subsections  40  of the wind-deflecting strip  42  are adhesively bonded to the supporting element  12 . For a particularly stable adhesive bonding connection, the claw surfaces  60  ( FIG. 3 ) which bear against the upper band side  11  of the supporting element  12  have a greater width  62  than the claw surfaces  64  which engage on the lower side  13  and the width of which is provided with the reference number  66  in  FIG. 3 . It can be seen from  FIG. 1  that the moulded approach flow surface  54  of the subsections  40  continues both on the end caps  38  and on the part  15  of the connecting device. The moulding of the end cap  38  has the reference number  68  in  FIG. 1  while the moulding of the component  15  is provided with the reference number  70 . 
     In the case of the embodiment according to  FIG. 4  to  FIG. 6  and  FIG. 11 , the thickened portion  74  is formed by a clip, the limbs  76  of which engage in the longitudinal grooves  34 . The limbs  76  are pressed against the upper wall of the clip  74  until the clip  74  is fastened to the top strip  20  of the wiper strip  14  by a sufficient frictional connection. The wiper strip  14  equipped in this manner is pushed in the longitudinal direction  72  into the supporting element  12  between the spring rails  30  which are connected to each other at their ends by a bridge  78 . The feet  80  of the bridge  78  are generally welded, adhesively bonded or riveted to the spring rails  30 .  FIG. 6  shows the final installation position of the wiper strip  14 , in which the mutually facing end sides of the bridge  78  and of the thickened portion  74  bear against each other. 
       FIG. 7  to  FIG. 9  show the installation of the end cap  38  and a number of details. The end cap  38  has a flap  82  which is connected to the end cap  38  via a film hinge  84 . The flap  82  includes a grippy surface  85 . The pivot axis of the film hinge  84  runs in the longitudinal direction  72  of the wiper strip  14 , with it being possible for the flap to be opened on the approach flow side of the wiper blade  10  and, in the process, the flap opening up an opening  96 . In the opened state of the flap  82 , the end cap  38  can be pushed over the end of the wiper strip  14 . In this case, the end cap  38  engages over the thickened portion  74  and the bridge  78 . In this position, the flap  82  is closed in the actuating direction  86 , with a latching edge  92  on the lower part of the flap  82  latching on a connecting web  94  which connects that part of the end cap  38  which points towards the end to the oppositely directed part. In the closed state of the flap  82 , an end side  88  which faces the end of the wiper strip  14  bears with a rib  90  against the facing end side of the bridge  78  such that the supporting element  12  is fixed relative to the wiper strip  14  by the spring rails  30 . The closed flap  82  ends with its outer contour flush with the moulding  68  of the end cap  38 . 
     The embodiment according to  FIG. 11  differs from the embodiment according to  FIG. 4  in that, during the installation, the clip which forms the thickened portion  74  is compressed laterally in the pressing direction  102  until it sits fixedly on the top strip  20  of the wiper strip  14 . 
     In the embodiment according to  FIG. 10 , a plastic part  98  is pushed onto the top strip  20  and engages in the longitudinal grooves  34 . In order to fix the plastic part  98  on the top strip  20 , use is made of a staple  100 , the limb  104  of which (cf.  FIG. 12 ) penetrates through the plastic part  98  into the top strip  20 . In a simple case, the staple  100  can also serve as a thickened portion without the plastic part  98  by its limb  104 , which initially points towards the wiping lip  26 , being pressed in the installation direction  106  by the upper part of the head strip  20  and being bent over inwards in the region of the longitudinal grooves  34 . The staple  100  can also be fitted in the longitudinal direction  72  of the wiper strip  14  by it being pressed in the pressing direction  102  at the end of the longitudinal grooves  34  by the web  29  between the longitudinal grooves and being bent over on the other side of the web  29 . 
     In the embodiments according to  FIG. 14  to  FIG. 17 , thickened portions  108 ,  110 ,  112  and  114  are integrally formed as a single piece on the wiper strip  14 . At the end of the wiper strip  14 , the thickened portion  108  forms a projection which protrudes outwards on that side of the top strip  20  which faces away from the wiping lip  26 . The thickened portion  110 ,  FIG. 15 , is formed by the longitudinal grooves  34  being partially filled at their ends, whereas the thickened portion  112  is produced by complete filling of the ends of the longitudinal grooves  34 . For a thickened portion  114  according to  FIG. 16 , firstly, the ends of the longitudinal grooves are filled and, secondly, in addition to this measure or as a sole measure, the thickened portion  114  can be formed by a bead which protrudes outwards over the contour of the top strip  20 . 
     The embodiment according to  FIG. 18  to  FIG. 20  comprises an end cap  116  which, on its end wall which points towards the end of the wiper strip  14 , has a slide  118  which can be displaced transversely with respect to the longitudinal direction  72  of the wiper strip  14  in a guide  120 . A latching element  122  secures the slide  118  in the closed position while, in an open position, the slide  118  opens up an opening  124  through which the wiper strip  14  can be fitted and removed. For easier actuation of the slide  118 , bumps  128  between which scores  126  are arranged are provided on its outside. Instead of the scores  126  and bumps  128 , use can also be made of other grippy surface structures, for example the surface can be roughened. The wiper strip  14  is fixed with its spring rails  30  relative to the supporting element  12  by the wiper strip  14  being supported with its thickened portions  112  on the closed slide  118  and the end cap  116  being supported, on the other hand, via latching elements  130  on that end side of the bridge  78  which faces away from the slide  118 .