Abstract:
A rear window for a flexible rear roof section of an openable roof vehicle. The rear window is comprised of a transparent plastic material such as a polycarbonate material, and a fastening section that connects the rear window to the flexible covering of the open roof vehicle. The fastening section forms a single piece with the rear window and is offset relative to the plane of the rear window.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority to German application Serial No. 10 2005 029 301.8 filed Jun. 22, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a rear window in a rear roof section of an openable roof vehicle.  
         [0004]     2. Background Art  
         [0005]     Rear windows in the rear roof section of an openable roof vehicle give motor vehicle drivers the ability to see clearly toward the rear, even when the vehicle roof is closed. Rear windows in the rear roof section of an openable roof vehicle have a fastening section to connect the rear window to a flexible covering of the vehicle roof.  
         [0006]     German Application DE 41 29 492 A1 discloses a method for connecting a rear window with the flexible covering of an openable roof vehicle. This patent requires the use of an adhesive that connects the rear window to a frame. Bolts are used to connect the frame to the flexible covering of the vehicle roof. The disadvantage with this patent is that the frame and the bolts necessary to fasten the flexible covering not only are clearly visible but also protrude. Thus, this design not only spoils the visual appearance, but also could represent a safety risk.  
         [0007]     German application DE 42 10 487 A1 discloses another way to connect a rear window with the flexible covering in an openable roof vehicle. However, this patent requires additional design and assembly expense in order to cover the necessary functional parts and additional interior covering.  
         [0008]     German application DE 196 28 107 C1 discloses a third method of connecting a rear window with the flexible covering of an openable roof vehicle. This patent requires the rear window be connected with the flexible covering of the vehicle roof by means of an additional sealing frame engaging two plastic profiles. Here, the additional sealing frame and plastic profiles are required to connect the rear window with the flexible covering. The disadvantage with this patent is that these functional connecting elements are clearly visible from both the inside and outside.  
         [0009]     The present invention is an improvement over the above references, as summarized below.  
       SUMMARY OF THE INVENTION  
       [0010]     One objective of this invention is to improve the visual appearance and integration of the functional parts necessary for connecting the rear window with the covering of the vehicle roof of an openable roof vehicle.  
         [0011]     One advantage of the invention is that the outside surface of the rear window is flush with the flexible covering of the openable vehicle roof in the area of the fastening section. The entire outside surface is smooth except for the visible seam that represents the flush transitional area between the outside rear window and the flexible covering. The invention provides an advantage in visual appearance because the transitional area is flush with the roof surface.  
         [0012]     Another advantage of the invention is that the rear window may have different wall thicknesses. The rear window can have a lower wall thickness toward its middle for weight optimization. In addition, the fastening section of the rear window can have a thinner wall thickness. Furthermore, this step in the thickness of the rear window allows an offset that accommodates the functional parts that connect the flexible covering and the rear window. To accomplish this seamless transition, the wall thickness of the rear window can be conically tapered down to a thickness close to zero in the direction of the flexible covering. This offset creates a seamless transition between the rear window and the flexible covering from the inside.  
         [0013]     A further advantage of the invention is that the fastening section of the rear window may have an offset that lies in a plane that is different than that of the rear window. This offset allows the rear window to have the same wall thickness near its fastening section, but requires a drop or bend in order to accommodate the flexible covering and/or the necessary functional elements. Thus, the offset allows a flush connection between the rear window, the flexible covering, and the functional elements.  
         [0014]     Another advantage of the invention is that the fastening section may have an upward bend which makes the rear window more stable, and provides a better connection between the rear window and the flexible covering. The upward bend can be at a certain angle, preferably up to 90°. In addition, the upward bend is provided in the fastening section of the rear window. Furthermore, the flexible covering of the vehicle roof should be located on the upward bend.  
         [0015]     Another advantage of this invention is that the rear window can be produced using a polycarbonate (PC) injection molding. Furthermore, polycarbonate has properties which are favorable for vehicle construction and is easy to provide in an injection molded process. In addition, the injection mold can be designed in such a way that the rear window produced has a shape that is beneficial for later installation in an openable roof vehicle. Some examples of a beneficial injection molded rear window include an offset, a step, and/or different wall thickness. Therefore, economical benefits are gained in using an injection mold in the production of the rear window.  
         [0016]     Other advantages and improvements achieved by the Applicants&#39; invention will be apparent to one of ordinary skill in the art in view of the attached drawings and following detailed description of the illustrated embodiment. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  is a perspective view of a vehicle that has a rear window in a rear roof section of an openable roof vehicle;  
         [0018]      FIG. 2  is a cross-section view of an integrated rear window having an offset in the area of the fastening section of the rear roof section;  
         [0019]      FIG. 3  is a cross-section view of a rear window, similar to  FIG. 2 , having a material thickness offset formed in the rear window;  
         [0020]      FIG. 4  is a rear window view similar to those shown in  FIGS. 2 and 3  having the offset formed in the rear window by a step in material thickness, and wherein the material thickness of the rear window tapers toward the flexible covering of the rear roof section; and  
         [0021]      FIG. 5  is a rear window similar to those shown in  FIGS. 2-4  having the offset formed in the rear window that has a step in material thickness on one end of the offset and a 90° upward bend on the other end of the offset. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0022]      FIG. 1  shows a rear window  1 , that is adapted to be installed into an openable vehicle roof  3  of a vehicle  5 .  FIG. 1  shows the vehicle  5  with the openable vehicle roof  3  in the closed position. The vehicle interior is covered by a vehicle roof  3  that is comprised of a flexible covering  7 . The rear window  1  has a fastening section  9  where the rear window  1  is connected with the flexible covering  7  of the vehicle roof  3 . The fastening section  9  has corresponding fasteners (not shown in  FIG. 1 ), which may include foams, adhesives, clamps, clips, frames, bolts, rivets, or similar objects.  
         [0023]      FIG. 2  shows a partial sectional illustration of the fastening section  9  of the rear window  1 . The rear window  1  is made of a transparent material, so that it allows the driver a clear view toward the rear when vehicle roof  3  is closed. The transparent material used is a polycarbonate which is processed by injection molding. The injection molded polycarbonate parts can have drops, bends, changes in the wall thickness, and other advantageous embodiments. This makes it possible to optimize the weight by varying the material thickness toward the middle of the window. In areas where the geometric and kinematic properties of the vehicle roof  3  expose the rear window  1  to lower loads, it can have a relatively thin wall thickness. In addition, in some areas it is also possible to vary the wall thickness of the rear window in such a way as to produce optics that affect the path of the light. For example, it would be possible to integrally form a wide-angle lens  10  in a localized area of the rear window  1  that could reduce the existing blind spot of the vehicle  5 . The localized area may have a convex or concave configuration formed during the injection molding process that forms the rear window  1 .  
         [0024]      FIG. 2  further illustrates an offset  11  between the rear window  1  and the fastening section  9 . The offset  11  is realized by means of a bend  13 . The bend  13  is designed in such a way that it lowers the outer surface  15  of the rear window  1 . The offset extends approximately parallel to that of the rear window. When viewed in the orientation of  FIG. 2 , the fastening section  9  of rear window  1  is located to the left of the bend  15  of the rear window  1 . The offset  11  is designed in such a way that the fastening elements (not shown in  FIG. 2 ) and a flexible covering  7 , that borders the rear window  1 , are flush. The offset  11  allows an outer surface  17 , of the flexible covering  7 , and an outer surface  15 , of the rear window  1 , to be flush at a seam  19  where they meet. As shown in  FIG. 2 , the flexible covering  7  has a fold  21  in the area of seam  19 .  
         [0025]      FIG. 3  shows a further illustration of the rear window  1 . In an area of the seam  19  where the fastening section  9  meets the rear window  1 , a step in material thickness occurs, producing a step  23  in the rear window. The offset  11  is provided by the step  23  in which is received the flexible covering  7  and the fasteners (not shown). The outer surfaces  17  and  15  of the covering  7  and the rear window  1  are flush where they meet at the seam  19 . The height of the step  23  of the rear window  1  can be adapted to the thickness of the covering  7  and the fasteners (not shown). The offset  11  at the step  23  may have any depth or height to reduce the seam  19  that would otherwise visually stand out without the offset.  
         [0026]      FIG. 4  illustrates another embodiment of the rear window  1  in which the offset  11  of the rear window  1  may contain a taper  25  in the thickness of the material. If no additional ceiling is provided, taper  25  of the rear window  1  is visible from the vehicle interior. Taper  25  makes it possible for the interior transition  27  between the rear window  1  and the flat covering  7  to have a substantially flush visual appearance.  
         [0027]      FIG. 5  illustrates an upward bend  29  at the offset  11  of the rear window  1 . The upward bend  29  located at the outer edge of rear window  1  that stands at an angle to outer surface  15  or to surface  31 . It is preferable for the upward bend  29  to form an angle of up to 90° relative to surfaces  15  and  31 . The upward bend  29  can have corresponding fastening elements  33  to fix the covering  7  to the rear window  1 . However, the area of the surface  31  of the offset  11  located in the fastening section  9  of the rear window  1  can use any conceivable type of fasteners or fastening techniques. Some examples of fastening techniques that don&#39;t use fasteners may include adhesives, fusions, or similar techniques.  
         [0028]     The connection described in  FIGS. 2 through 5  between the flexible covering  7  and the rear window  1  can be further supplemented by an additional interior connection point, corresponding fastening section, and corresponding offset. The connection point can be provided in the vehicle interior opposite the offset  11 , and can be used to fasten an interior ceiling of the vehicle  5  to the vehicle roof  3 . This connection point makes it possible to cover the functional elements of the connection and the functional elements of the kinematics which are necessary for adjusting the vehicle roof  3 .  
         [0029]     While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in this specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.