Abstract:
The invention relates to wiper blades of various dimensions for windows of motor vehicles, with band-like, elongated, spring-elastic support elements ( 14 ), each for a respective wiper strip ( 22 ), which is associated with each wiper blade ( 10 ), can be placed against the window ( 12 ), and is disposed on the lower band surface ( 21 ) oriented toward the window, where in a longitudinal midsection of each support element, the upper band surface ( 15 ) oriented away from the window supports a wiper blade half ( 16 ) of a connecting device ( 18 ). In order to supply wiper blades of different dimensions with a single type of such a connecting device half and to thereby reduce the costs for the wiper blades, the widths ( 36 ) of the support elements in this longitudinal midsection are the same size independent of the other dimensions of these support elements.

Description:
BACKGROUND OF THE INVENTION 
     In the design of wiper blades, a multitude of criteria predetermined by lawmakers and vehicle manufacturers must be taken into account, e.g. the window region to be wiped by the wiper blades, window size, window curvature, contact pressure of the wiper blades against the window, course of air flow in front of the window, etc. For obvious reasons, this results in the fact that specific support elements for the wiper strips resting against the window are required for practically every vehicle type and even for the wiper blade on the driver&#39;s side versus the one on the passenger side. These support elements must then be provided with the wiper blade half of a connecting device by means of which the wiper blade can be connected to the wiper arm, which is equipped with the other half of the connecting device. 
     In this context, the effort to comply with specifications predetermined by the vehicle manufacturer has yielded support elements that vary particularly in terms of their different lengths and widths. In addition, in support elements of this kind, for example their width can also vary over their length, where the cross section of the support element or its width tapers starting from the seat position of the connecting device half. In known wiper blades of this type, DE 19729865.6 A1), the device half engages the support element on its outer longitudinal edges with hook-like projections so that it is affixed to the support element. However, since for the above-mentioned reasons, the maximal width of the support element differs from case to case, for each of these cases, a particular device half, which is adapted to the width of the support element, must be kept on hand, even if the variations in width are relatively slight. This is because the device half must always, even during wiping operation, be connected to the support element so that it does not move lateral to the longitudinal direction of the wiper blade because of the other wiper blade half of the connecting device. 
     This requirement causes a multitude of device halves to be required since as a rule, each of these halves can be used for only one wiper blade of a single vehicle type. 
     Comparable problems arise in the two end sections of the support elements, to which cap-like holders must be attached. These caps are intended, for example, to reduce the risk of injury presented by the end edges of the support elements during handling of the wiper blades, for example when replacing them. In known wiper blades of this type (DE 19802451.7 A1), these caps can also aid in the connection between the wiper strip and the support element if they engage the support element, for example with claws, and hold the wiper strip. It is also true of these caps and for their seat positions on the support elements that for the reasons mentioned above, the width of the support elements at their ends varies in size from case to case. Therefore, correspondingly adapted caps must also be produced for each different use, which starting with the manufacturing apparatuses for these caps, down to the storage and the danger of mixing them up during installation, is very cost-intensive. 
     SUMMARY OF THE INVENTION 
     With the wiper blade according to the invention, by standardizing the width of the support elements in the above-mentioned longitudinal midsection, at least several support element types can be provided with the same device halves so that the manufacturing costs for these halves are reduced and the storage of them is simplified. 
     Since the wiper blade half of the connecting device embraces the two remote outer longitudinal edges of each support element in a form-fitting manner with longitudinal shoulders, the immobility of the connection between the halves of the connecting device and the support element is further improved. 
     The multitude of caps can be fundamentally reduced and consequently, the costs for the wiper blade can be considerably reduced. 
     The above-described features have no influence on the support element design because both in the longitudinal midsection and in the end sections of the support elements, they are continuously stiffened by the add-on pieces positioned there, which already has to be approximately taken into consideration in their dimensioning. 
     A proper fit of the caps on the support element ends is achieved if the caps embrace the two remote outer longitudinal edges of each of the support element in a form-fitting manner with longitudinal shoulders. 
     In certain application instances, it is advantageous if the support elements are embodied as one-piece bands, which have the same width in the vicinity of the seat position of the device halves. 
     With a width of the support elements that exceeds a particular fit measurement in its effective spring regions, it is useful if the width of the seat position is constituted by a partial, lateral constriction of the support element. 
     However if the support element design falls below the width fit measurement predetermined for the support element, then the width of the seat position can be simply constituted by a partial, lateral widening of the support element. 
     If the length of the constriction is matched to the length of the wiper blade device half, then an exactly determined seat position for the device half is achieved without having to carry out other measures. 
     For certain application instances, it is advantageous if the support elements are embodied as one-piece bands, which have the same width in the vicinity of the seat position of the cap. 
     In order to adapt the fit measurement of the support element width in the vicinity of the seat positions of the caps, the fit measurement can be maintained as a function of the respective width determined by the support element design by virtue of the fact that the width of the seat position for the caps is determined by a partial lateral constriction of the support element or the width of the seat position for the caps is determined by a partial lateral widening of the support element. 
     The embodiment of the support elements by means of two spring strips, which are disposed parallel to and spaced apart from each other, can in many application instances represent an advantageous alternative to the one-piece support elements. 
     In this connection, these spring strips that comprise a single support element can be disposed in longitudinal grooves in the wiper strip, which are disposed in a common plane spaced apart from the window and whose bases are spaced apart from each other. 
     Other advantageous improvements and embodiments of the invention are disclosed in the following description of exemplary embodiments shown in the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a side view of a wiper blade according to a first embodiment of the invention, 
     FIG. 2 shows a top view of the wiper blade according to FIG. 1, enlarged and rotated by 90°, 
     FIG. 3 shows the sectional plane of a section through the wiper blade along the line III—III in FIG. 2, enlarged and rotated by 90°, 
     FIG. 4 shows the sectional plane of a section through the wiper blade along the line IV—IV in FIG. 2, enlarged and rotated by 90°, 
     FIG. 5 shows a perspective, partial view of a differently embodied wiper blade according to the invention, 
     FIG. 6 shows the sectional plane of a section through the wiper blade according to FIG. 5, along the line VI—VI, rotated correspondingly, 
     FIG. 7 shows the sectional plane of a section through the wiper blade according to FIG. 5, along the line VII—VII, rotated correspondingly, 
     FIGS. 8 to  10  show top views of differently designed support elements, which belong to the wiper blade according to FIGS. 1 to  4 , and 
     FIGS. 11 to  13  show top views of differently designed support elements, which belong to the wiper blade according to FIGS. 8 to  10 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A wiper blade  10  for windows  12  of motor vehicles shown in FIGS. 1 and 2 has an elongated spring-elastic support element  14 . On the top side  15  of the support element  14  oriented away from the window  12  to be wiped, the wiper blade half  16  of a connecting device  18  is disposed, with the aid of which the wiper blade  10  can be detachably connected to a driven wiper arm  20 , which is indicated with dot-and-dash lines in FIG.  1  and is guided on the body of a motor vehicle. On the underside  21  of the support element  14  oriented toward the window  12 , an elongated rubber-elastic wiper strip  22  is disposed with its longitudinal axis parallel to the support element. The wiper arm  20  and therefore also the wiper blade  10  are loaded in the direction of an arrow  24  toward the window to be wiped, whose surface to be wiped is indicated in FIG. 1 by a dot-and-dash line  26 . Since the dot-and-dash line  26  is intended to represent the sharpest curvature of the window surface, it is clear that the curvature of the unloaded wiper blade  10 , with its two ends resting against the window  12 , is sharper than the maximal window curvature. With the contact pressure (arrow  24 ), the wiper blade  10  rests with its wiper strip  22  against the window surface  26  over its entire length. As a result, a tension is built up in the band-like spring-elastic support element  24 , which assures a proper contact of the wiper strip  22  against the motor vehicle window  12  over its entire length. FIGS. 1 and 2 also shown that a cap  28  is respectively disposed at the two ends of the wiper blade  10  and the function of this cap will be discussed in more detail below. 
     The specific design of a first embodiment of the wiper blade according to the invention will be explained in detail below. As shown by the section through the wiper blade in FIG. 3, the wiper blade half  16  of the connecting device  18  has a plate-like base  30 , which is provided with coupling means, not shown in detail, for the free end of the wiper arm  20 . The base plate  30  has L-shaped projections  32  on its longitudinal sides, with which their one L-legs  31 , embrace the remote outer longitudinal edges  34  of the support element  14  and with their other L-legs  33 , engage under the support element  14  and rest against the underside  21  of the support element  14 . The distance  36  between the two insides of the one L-legs  31  oriented toward each other corresponds to a fit measurement, which the support clement  14  has where the half  16  is positioned. 
     In the two exemplary embodiments of the invention given here, this seat position of the half  16  is shown in the longitudinal midsection of the wiper blade and the support element  14 . The term “longitudinal midsection”, however, does prevent this seat position from also being located close to one of the two end sections of the wiper blade and the support element or even from coinciding with one of the two end sections of the support element so that the half  16  also performs one of the functions of the caps  28 . 
     In the exemplary embodiment according to FIGS. 1 to  4 , the support element is embodied as a one-piece band. In the vicinity of the seat position of the device half  16 , the two longitudinal edges  34  extend essentially parallel to each other, thus producing a fit measurement  36  that is constant over the entire seat position for the half  16 . Since the distance between the two L-legs  31 —which, considered in and of themselves, can be also be referred to as longitudinal shoulders that cooperate with the longitudinal edges  34 —are spaced apart at a distance  36 , which corresponds to the fit measurement, this produces a favorably snug fit between the support element  14  and the half  16  in terms of the working direction of the wiper blade  10  (double arrow  37  in FIG.  2 ). FIG. 3 also shows that the support element  14  of the wiper blade  10  is disposed at a distance  38  from the window  12  to be wiped when the wiper blade  10  with its wiper strip  22  assumes its operating position in relation to the window  12 . Finally, FIG. 2 also shows that the width of the support element  14 , starting from the seat position for the half  16 , tapers towards its two ends. This can also be seen by comparing the fit measurement  36  for the seat position of the half  16  to a second fit measurement  40  for the caps  28  (FIG.  4 ). The caps  28  have an essentially U-shaped cross-section, whose U-base  42 —just like the base plate  30  of the half  16 —rests against the top side  15  of the support element  14  oriented away from the window  12 . The two U-legs  43  of the caps  28  are spaced apart from each other by a distance that corresponds to the fit measurement  40 . At the free ends of the U-legs  43 , the caps are provided with claws  44  oriented toward each other, which engage in longitudinal grooves  45  of the wiper strip  22 . In the exemplary embodiment, the end surface  47  of the wiper strip  22  oriented away from the window  12  is connected to the underside  21  of the support element  14  by means of a glued connection. Since the glued connection is subjected to a high, constant, alternating stress during wiper operation, the caps disposed at the ends of the support element  14  contribute significantly to the securing of the glued connection between the wiper strip  22  and the support element  14  when they engage with their claws in the wiper strip. 
     As explained at the beginning, since the wiper blades of the entire array of wiper blades offered by the manufacturer must have different dimensions, an essential factor of the invention will be discussed in detail below for the above-explained exemplary embodiment of a wiper blade, in conjunction with FIGS. 8 to  10 . It should be noted that the support elements  114  (FIG.  9 ),  214  (FIG.  8 ), and  314  (FIG. 10) depicted in these figures are not shown to scale, particularly in the longitudinal direction, and therefore can in no way be taken for working drawings. Assuming that the support element  114  shown in FIG. 9 corresponds in its contour to the support element  14  in FIG. 2, then this is preferably conceived for midsized wiper blades. It has a fit measurement  36  in the vicinity of the seat position  115  for the half  16  of the connecting device  18 . At its two end sections  116 , which represent the seat positions for the two caps  28 , the width of the support element  114  corresponds to the fit measurement  40 . 
     The embodiment of the support element  214  shown in FIG. 8 is as a rule conceived for wiper blades that are wider and longer than the wiper blades that are used with the support element  114  (FIG.  9 ). Therefore, the support element  214  is wider in its two regions between the seat position  215  for the half  16  and the two seat positions  216  for the caps  28  than it is in the corresponding regions of the support element  114  (FIG.  9 ). So that the same halves  16  can be used with this support element  214  as with the support element  115 , this support element  214  is provided with opposing constrictions  217  on its two longitudinal sides in the vicinity of the seat position  215 , whose lengths  218  are matched to the length of the half  16 . The depth of the constrictions  217  is dimensioned to produce the fit measurement  36  in the vicinity of the seat position  215 . A corresponding embodiment is provided at both ends of the support element  214 . Constrictions  219  of the support element  214  are also provided at these two ends to produce a width there in the vicinity of the seat positions  216  of the caps  28 , which corresponds to the fit measurement  40  so that wiper blades with a support element  214  according to FIG. 8 can use not only the halves  16  but also the caps  28  that are also used in wiper blades with a support element according to FIG.  9 . 
     Considering the explanations made of the beginning, the support element  314  according to FIG. 10 is preferably conceived for wiper blades that are smaller than the wiper blades in which the support elements  114  and  214  according to FIGS. 9 and 8 are used. However, so that the same halves  16  that are used with the support elements  114  and  214  can be used here, this support element  314  is provided with partial lateral widenings  317  on its two longitudinal sides in the vicinity of the seat position  315  for the half  16 . The widenings  317  on both sides of the support element  314  in the vicinity of the seat position  315  of the half  16  are dimensioned to produce a width of the support element  314  there, whose size coincides with the fit measurement  36 . It is thus possible to use the same halves  16  of the connecting device  18  for this support element  314  as for the support elements  114  and  214 . In addition, the two end regions of the support element  314 , which comprise the seat position  316  for the holders  28 , likewise have widenings  318  disposed opposite each other, which are dimensioned to produce a fit measurement in the vicinity of the seat positions  316  for the caps  28 , which corresponds to the fit measurement  40  according to FIG.  4 . It is thus possible in wiper blades with support elements  314  according to FIG. 10 to also use the same caps  28  that are used with the elements  114  and  214 . 
     As shown in FIGS. 5 to  7 , another embodiment of the wiper blade  50  according to the invention has a support element  55 , which is divided in its longitudinal direction and consequently includes two spring strips  56 . This wiper blade  50  has a wiper strip  52 , which, at a distance  53  from the window  12 , is provided with lateral, opposing longitudinal grooves  54 , which serve to contain the two spring strips  56  comprising the support element  55 . In the exemplary embodiment, the two spring strips  56  are disposed in a common plane, but this is not absolutely necessary. The bases of the two longitudinal grooves  54  are spaced apart from each other by a distance  57  (FIG.  6 ). The width of the two spring strips  56  is dimensioned so that they protrude with edge regions from the longitudinal grooves  54  containing them. This is particularly important where the seat positions must be provided for the half  16  of the connecting device  18  and the caps  28 . Since the wiper strip  52  in this exemplary embodiment has a top strip  59  disposed on the top side  58  of the support element  55 , the half  16  must be provided with a corresponding receiving groove for the top strip  59 . In this embodiment as well, on the longitudinal sides of a base plate  60  of the half  16 , L-shaped projections  61  are provided, where the L-legs  62  cross the plane of the spring strips  56  and the other L-legs  63  engage under the support element  55  or its spring strips  56 . The distance between the opposing L-legs  62  corresponds to a fit measurement  36 , which is composed of the width of the spring strips  56  in the vicinity of the seat position for the cap  28  plus the measurement  57  between the two bases of the longitudinal grooves  54  (FIG.  6 ). In this embodiment (FIG.  7 ), the caps have a design that corresponds to the design of the half  16  according to FIG.  6 . The longitudinal sides of a cap base plate  64  are adjoined by claw-like projections  65 , which engage under the respective spring strip  56 . The distance between the two claws  65  in the vicinity of the spring strips  56  is dimensioned to produce a fit measurement  40 , which is composed of the width of the two springs  56  in the vicinity of the two ends of the support element  55  plus the measurement  57  between the two bases of the longitudinal grooves  54  that are spaced apart from each other. The fit measurement  40  is smaller than the fit measurement  36  because the two spring strips  56 , starting from the seat position for the half  16 , taper toward the seat positions for the caps  28 . Since the wiper strip  52  is normally produced by means of the extrusion process, its cross sections are identical in the vicinity of the seat position for the half and also in the vicinities of the seat positions of the caps. Consequently, the cap  28  must also be provided with a receiving groove for the top strip  59 . 
     FIGS. 11 to  13  showed different embodiments of the support element  55 . The support element according to FIG. 12 is labeled with the reference numeral  414 . The embodiment of the support element according to FIG. 11 has the reference numeral  514 . FIG. 13 shows another embodiment of the support element, which is labeled with the reference numeral  614 . The support element  414  according to FIG. 12 has two spring strips  456 , which are disposed parallel to each other and spaced apart from each other by a distance that corresponds to the distance  57  (FIG. 6) between the two bases of the longitudinal grooves  54  in the wiper strip  52 . This also applies for the spring strips  556  and  656  in the embodiments of the support elements  514  and  614  shown in FIGS. 11 and 13. Apart from the longitudinal division of the support element in the exemplary embodiments according to FIGS. 11 to  13 , everything said about the embodiments according to FIGS. 8 to  10  (support elements  114 ,  214 , and  314 ) applies to the embodiments here. Thus, in the vicinity of the seat position  415  for the half  16  of the connecting device  18 , the support element  414  has a width that corresponds to the fit measurement  36 . In addition, the width of the spring strips in the vicinity of the seat positions  416  for the caps  28  is dimensioned to produce a fit measurement  40 . 
     So that the wider support element  514  according to FIG. 11, in the vicinity of the seat position  515  for the half  16 , can be matched to the fit measurement  36 , constrictions  517  are likewise provided in this vicinity on each of the spring strips  556 , which correspond to the constrictions  217  according to the support element  214  (FIG.  8 ). In this instance as well, the length of the constrictions  517  is matched to the length of the half  16 . The same is also true for the disposition and design of the two ends of the support element  514  in the vicinity of the seat positions  516  for the caps  28 . Here, too, the corresponding constrictions  519  are provided, which are dimensioned in order to produce a fit measurement  40 . In the embodiments according to FIGS. 11 to  13 , both the caps  28  and the half  16  assure a proper securing of the spring strips in the longitudinal grooves  54  of the wiper strip  52 . 
     With the exception of the longitudinal division of the spring strips  656  and the associated distance  57  between them, the embodiment of the support element according to FIG. 13 corresponds to the embodiment of the support element  314 , which is shown in FIG.  10 . In the vicinity of the seat position  615  for the half  16 , each spring strip has an outwardly directed widening  617  so that a fit measurement  36  is also provided in this narrow support element  614 . The same goes for the embodiment of the two ends of the support element  614 . Corresponding widenings  618  are also provided there so that a fit measurement  40  is produced in the vicinity of the seat positions for the holders  28 . In the embodiments according to FIGS. 11 to  13 , both the caps  28  and the half  16  assure a proper securing of the spring strips in the longitudinal grooves  54  of the wiper strip  52 . 
     As explained above and also shown in the drawings, it goes without saying that with all longitudinally divided support elements  414 ,  514 ,  614 , the distance  57  must be taken into consideration in the dimensioning of the fit measurement  36  and  40 . It is consequently clear that for both of the described embodiments according to FIGS. 1 to  4  and  8  to  10 , as well as FIGS. 5 to  7  and  11  to  13 , through a corresponding embodiment of the support elements  114 ,  214 ,  314 , and  414 ,  514 ,  614 , the same halves  16  of the connecting device  18  and the same holders  28  can be used, even if the wiper blades have different dimensions, particularly in length and width. This is possible because the widths of all of the support elements in the vicinity of these seat positions for the halves and caps is the same size, independent of the other dimensions of these support elements and of the wiper blades. It is therefore possible to operate a wide variety of wiper blades of different dimensions with a single type of connecting device halves and caps.