Abstract:
The invention is based on a wiper system with at least one wiper support ( 10,12,14,16 ), which, in a pre-mounted state, has a part ( 18 ) that is guided through a mounting opening ( 20 ) of a vehicle and is fastened to it. The proposal is made that while being mounted, the wiper support ( 10,12,14,16 ) rests against the rim of the mounting opening ( 20 ), tilts under the influence of gravity and as a result, is held in the mounting opening ( 20 ) with frictional, non-positive engagement and/or positive engagement.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a wiper system. 
     Usually a wiper drive mechanism of a wiper system, by way of a rod assembly, drives one or a number of drive shafts that are supported in wiper supports and have wipers attached to them. The drive shafts protrude out from openings of a vehicle body and move the wipers over a windshield of the motor vehicle. In order to be able to favorably mount the individual components or pre-mounted subassemblies of the wiper system onto the vehicle body, preferably the wiper drive mechanism, rod assembly, wiper supports, and drive shafts are pre-mounted onto a mounting plate. 
     The pre-mounted wiper system is correspondingly positioned and fastened to the vehicle body. Usually the wiper supports are guided through assembly openings that can be either let directly into the vehicle body or let into additional mounting plates. Then, the wiper supports are screw-mounted to the vehicle body or the mounting plate with a central nut. 
     Additional securing points are produced in the vehicle body in order to support the mounting. Due to the limited mounting space, these are difficult to lay out and are usually insufficient to completely and reliably secure the wiper system. Therefore while being mounted, the wiper system must be held in the appropriate position with one hand while the wiper supports must be fastened to the mounting plates with the other hand. Furthermore, the securing plates represent additional components which must be correspondingly disposed and integrated into the vehicle body, which is connected with additional expenses. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a wiper system which avoids the disadvantages of the prior art. 
     The invention is based on the knowledge that the wiper supports in the mounting openings tilt under the influence of the gravitational force of the wiper system and are consequently wedged in the mounting openings so that they do not easily fall out again up to the end of the assembly, particularly when the mounting opening is only slightly larger in diameter than the support diameter of the wiper supports. 
     According to the invention, the tilting motion can furthermore be used to secure the wiper supports in the mounting openings with positive engagement by virtue of the fact that when tilted, positive engagement elements are brought into a holding position behind the mounting opening. Such positive engagement elements can be suitably embodied by a shoulder on the circumference of the wiper support, which engages behind the mounting opening when the wiper support is tilted. 
     The completely or only partially pre-mounted wiper system is slid with the wiper supports through the mounting opening, the force of gravity tilts the wiper support in the mounting opening around a support edge, by means of which the wiper support, with its region disposed opposite from the support edge, comes into contact with the rim of the mounting opening. The wiper system is reliably and precisely fixed during further mounting. An assembler can use both hands for the further attachment without having to hold the wiper system with one hand. The mounting therefore becomes simpler, faster, more reliable, more comfortable for the assembler, and therefore becomes more reasonably priced on the whole. Additional securing devices and their assembly are no longer necessary. 
     Furthermore, the securing device can be easily and quickly detached during disassembly by virtue of the fact that the wiper system is lifted up counter to the tilting moment and the positive engagement and/or frictional, non-positive engagement is thereby released. Now, the wiper supports can be withdrawn from the mounting openings without thereby damaging components or having to use additional holding devices. 
     It is particularly advantageous if the wiper support has a shoulder on its outer circumference by way of which the wiper system can be supported counter to the mounting direction after the wiper support is slid into the mounting opening and is then wedged or engages in detent fashion. 
     The shoulder can be constituted by a collar that is fastened to the wiper support or is embodied of one piece with it, or can be constituted by a rim of a circumferential groove. 
     As a rule, it is sufficient for the shoulder to extend over only a part of the circumference of the wiper support in the vicinity of the tilting edge and/or in the diametrically opposite region. If the wiper support is inserted into the mounting opening off-center and is then centered in the mounting opening, shoulders that protrude from the circumference contour of the wiper support overlap the rim of the mounting opening and consequently produce a positive engagement which supports and secures the frictional, non-positive engagement that is produced by the gravity-induced tilting moment. 
     According to one embodiment of the invention, after a protruding shoulder is slid off-center through the mounting opening, the wiper support is centered in the mounting opening through the use of a centering ring and as a result, the protrusion is slid past the rim of the mounting opening. The wiper support is thus secured with positive engagement in the mounting opening before the wiper support is tilted, which prevents the danger of the wiper support slipping out from the mounting opening. Furthermore, the protruding shoulders can be disposed in arbitrary circumference regions of the wiper support. 
     An elastic centering ring is particularly advantageous which deforms upon insertion and then centers the wiper support by means of its elastic resilience and at the same time, slides the protruding shoulder in the mounting direction past the rim of the mounting opening and holds it in this position. The wiper support is secured in the mounting opening by the centering ring. 
     Preferably the mounting plate, e.g. a tubular mounting plate, is supported in the mounting direction on the rim of the mounting opening by way of a support collar on the wiper support and by way of an annular damping element on the support collar. The damping element is usually made of an elastic material and is normally installed between the vehicle body and the wiper system in order to prevent vibrations and noise from being transmitted from the component to the vehicle body. 
     According to one embodiment of the invention, the damping element is simultaneously embodied as a centering ring. The centering ring is thus advantageously made of elastic material and furthermore, an additional component can be eliminated. It is also possible that the protrusion is embodied by the damping element or centering ring that is fastened to the wiper support, for example by means of a tension ring or another fastener. 
     The wiper support usually has a tubular, cast outer part into which a support sleeve for the drive shaft is inserted. The protrusion can thus be easily cast onto the outer part in the form of one or a number of projections or in the form of a recess, by means of which additional components are eliminated. It is also possible that a projection is attached in a subsequent process, for example by means of positive engagement, frictional non-positive engagement, and/or material adhesion or that a recess is subsequently produced, for example by means of milling, etc. 
     In order to prevent body noise, in particular from the wiper drive mechanism, from being transmitted to the rim of the mounting opening or to the vehicle body by way of the wiper supports and the protruding shoulder, the shoulder is spaced apart from the rim of the mounting opening after the mounting is complete. The shoulder is encircled by a spacer ring, which bridges over the distance between the rim of the mounting opening and the central fastening nut and has a damping coating toward the mounting plate. The spacer ring can also be embodied of one piece with the fastening nut. 
     In order to prevent the vehicle body panel from being damaged during mounting and removal, in another embodiment, the wiper support can be completely or partially covered with plastic or a softer material, particularly in the vicinity of the protrusion. It is also possible for the projection or even the entire outer part of the wiper support to be comprised of softer material, for example plastic. 
     Moreover, a frictional connection can be supported by a corresponding coating of the wiper support. For example, with a sufficiently soft coating, ka combination between frictional and positive engagement can also be produced by virtue of the fact that the rim of the mounting opening digs into the coating. 
     The active lever arm that is applied by gravity decreases with the inclination angle of the wiper support to the mounting opening. As a result, the frictional, non-positive engagement and the a perpendicular force exerted on the rim by the wiper support only slightly larger than the greatest external diameter of the wiper support to be guided through the mounting opening, by means of which a positive and/or frictional, non-positive connection can be achieved with a small inclination angle, which connection has high perpendicular forces and a secure hold. 
     Exemplary embodiments of the invention are depicted in the drawings. Numerous features are shown and described in context in the description and in the claims. One skilled in the art can also take the features into consideration individually and can combine them into other meaningful combinations. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a wiper system, 
     FIG. 2 shows a section along the line II—II in FIG. 1, through the outer part of the wiper support during mounting, 
     FIG. 3 shows a wiper support according to FIG. 2 when secured, 
     FIG. 4 shows a wiper support according to FIG. 2, with a centering ring during mounting, 
     FIG. 5 shows a wiper support according to FIG. 4, when slid in, 
     FIG. 6 shows a section through a wiper support, with a recess when secured, and 
     FIG. 7 shows a section through a wiper support, which is secured by means of frictional, non-positive engagement. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a wiper system with a mounting plat in the form of a tubular mounting plate  46 , to which a wiper drive mechanism  86  and two wiper supports  10 ,  12  are attached. With cylindrical fastening parts  48 , 50 , the wiper supports  10 ,  12  are laterally press-fitted in an oversized fashion into the tubular mounting plate  46  or the tubular mounting plate  46  is crimped in the vicinity of the fastening parts  48 ,  50 . Drive shafts  52 ,  54  are supported in the wiper supports  10 , 12  and are driven by the wiper drive mechanism  86  by way of a crank  56  and a joint ball  58  on the wiper drive mechanism  86 , by way of a rod assembly that is not shown in detail, and respectively via a crank  60 ,  62  and a joint ball  64 ,  66  on the wiper support  10 ,  12 . 
     With the mounting of the wiper system, the drive shafts  52 ,  54  and a part  18  of the wiper support  10 ,  12  are slid through a mounting opening  20  in a mounting plate  68  so that the drive shafts  52 ,  54  protrude out from the mounting opening  20  on the vehicle body (FIG.  3 ). Instead of being let into a mounting plate  68 , the mounting opening  20  can also be let directly into the vehicle body. On the part  18  of the wiper support  10 ,  12  that is slid through, there is a thread onto which a central nut  90  is screwed from the ends of the drive shafts  52 ,  54  (FIG.  5 ). The wiper supports  10 ,  12  are thus pulled into the mounting openings  20  until support collars  70  disposed on the outer circumference of the wiper supports  10 ,  12  are supported in the mounting direction  32  against the mounting plate  68  by means of a damping element  72 . Then, wipers that are not shown are attached to the drive shafts  52 ,  54 . 
     The gravitational force of the wiper system and in particular of the wiper drive mechanism  86  acts in the direction  24  by way of a lever arm  22  on the wiper supports  10 ,  12  that have been slid into the mounting openings  20 , as indicated in FIGS. 2 and 5. The resulting moment is used according to the invention to secure the wiper support  10 ,  12 ,  14 ,  16  in the mounting opening  20  and thereby the wiper system with positive engagement or with frictional engagement until the wiper system is screwed to the vehicle body (FIGS. 1 to  7 ). 
     FIG. 2 shows a section along the line II—II in FIG.  1  through the outer part of the wiper support  10  into which a support sleeve for the drive shaft  52  can be inserted. A projection  36  is cast onto the outer circumference of the wiper support  10  on one side, by means of which a protruding shoulder  26  is formed. The mounting opening  20  is only minimally larger than the greatest diameter  40  of the wiper support  10  to be guided through the mounting opening  20 , in the region of the projection  36 , so that the wiper support  10  has to be introduced into the mounting opening  20  off-center. Furthermore, the axial distance  76  between the damping element  72  and the projection  36  is only slightly greater than the material thickness  78  of the mounting plate  68 . When the wiper support  10  has been inserted and centered, the projection  36  overlaps the rim  30  of the mounting opening  20  (FIG.  3 ). The wiper support  10  is placed against the support collar  70  and tilts under the influence of gravity so that the projection  36  is now supported on the rim  30  of the mounting opening  20 . Even with a slight inclination angle  74  and a small moment, the wiper support  10  is securely held in the mounting opening  20  with positive engagement. It is also possible that the wiper support  10  is not supported with the support collar  70  or the damping element  72  on the rim  30  of the mounting opening  20 , but is supported directly on the circumference, as shown in FIG.  6 . 
     Since in the centered position of the wiper support  10 , the projection  36  overlaps the rim  30 , the wiper support  10  is particularly assured of not slipping out of the mounting opening  20 . 
     After the wiper support  10  is securely held in the mounting opening  20 , it can be completely screwed into position in the mounting opening  20  by means of a nut  90  and a thread on the end  88  of the wiper support  10  that points in the mounting direction  32 . Thereby, the wiper support  10  is pulled against the mounting plate  68  with the damping element  72  resting against the support collar  70 . The wiper support  10  is thereby aligned perpendicular to the mounting opening  20 . The projection  36  is detached from the rim  30  of the mounting opening  20 , which results in the fact that body noise is not transmitted from the wiper system to the mounting plate  68  and to the vehicle body by way of the wiper support  10  and the projection  36  (FIG.  5 ). A spacer ring  94  with a damping coating  96  is provided between the nut  90  and the mounting plate  68  and bridges over the distance between these components. 
     When being removed, the wiper support  10  can simply be pulled perpendicularly and eccentrically out from the mounting opening  20  without components having to be destroyed or additional fastening parts having to be detached. 
     In the exemplary embodiment shown in FIGS. 4 and 5, a centering ring  34  is disposed on the support collar  70  and simultaneously is a damping element. If the wiper support  10  is introduced into the mounting opening  20 , an elastic deformation occurs on the side of the centering ring  34  disposed opposite from the projection  36 . Once the wiper support  10  has been inserted, the centering ring  34  returns to its initial shape and thereby centers the wiper support  10  in the mounting opening  20  (FIG.  5 ). The projection  36  is slid by the elastic resilience of the centering ring  34  over the rim  30  of the mounting opening  20 . The wiper support  10  is securely held in the mounting opening  20  by the elastic resilience before the wiper support  10  is tilted by the moment, which produces a particularly secure positive engagement. Fundamentally, it is also possible for the wiper support  10  to be held in the mounting opening  20  solely by the elastically deformable centering ring  34 . 
     The further mounting is the same as with the wiper support  10  shown in FIG.  1 . FIG. 5 shows the position of the wiper support  10  in relation to the mounting plate  68  when completely mounted. With the wiper support  14  shown in FIG. 6, instead of being formed by a projection  36 , a shoulder  28  is formed by the rim of a recess  38  that is cast into the wiper support, in which the rim  30  of the mounting opening  20  engages with positive fit. On the end disposed opposite from the recess  38 , the wiper support  14  is supported with its outer circumference against the rim of the mounting opening  20 . The mounting opening  20  is only slightly larger than the diameter  42  of the wiper support  14 , which achieves a secure positive engagement with a small inclination angle. 
     The wiper support  16  depicted in FIG. 7 is held in the mounting opening  20  by means of frictional engagement. The mounting plate  68  is usually thin and sharp-edged and the surface of the wiper support  16  is rough, which produces a secure frictional engagement. 
     The further the wiper support  16  in the mounting opening  20  is tilted, the smaller the lever arm  22  via which gravity acts on the wiper support  16  (FIG. 2) and the smaller a perpendicular force  80 ,  82  acting between the wiper support  16  and the rim  30  of the mounting opening  20 . However, sharp-edged corners of the rim  30  of the mounting opening  20  engage more favorably in the surface of the wiper support  16  the further the wiper support  16  in the mounting opening  20  is tilted. 
     The diameter  44  of the wiper support  16  and the diameter  84  of the mounting opening  20  are matched to each other so that the best possible frictional engagement is achieved.