Abstract:
A sliding roof for a motor vehicle comprises a shiftable cover arranged for opening and closing a vehicle roof and at least one electrical light source attached to the cover.

Description:
TECHNICAL FIELD  
         [0001]    The invention relates to a sliding roof for a motor vehicle.  
         BACKGROUND OF THE INVENTION  
         [0002]    A sliding roof that comprises a shiftable cover arranged for opening and closing a vehicle roof is known from DE 199 02 244 A1. In this arrangement, a sliding headliner which is shiftable underneath the glass cover, is provided with a planar light fixture in order to provide a non-glaring interior space lighting that does not dazzle the driver. There is the desire to slightly illuminate the interior space during night trips, in order to better make out e.g. operating elements, whilst the illumination must not get reflections in the window panes and dazzle the driver. A sliding headliner usually is a very lightweight plate that is made of plastics or compressed fiber materials and can be inserted into an accommodation space; the plate itself and its guide are to be as light as possible and equipped as simply as possible. Due to the arrangement of a lighting device, however, the sliding headliner has to be more rigid and, thus, has a higher weight in order to avoid vibration of the lighting device.  
           [0003]    The invention provides a sliding roof with an integrated illumination, in which the tendency of the light source to vibrate, as well as the expenditure for accommodating the latter are very small.  
         BRIEF SUMMARY OF THE INVENTION  
         [0004]    According to the invention, a sliding roof for a motor vehicle comprises a shiftable cover arranged for opening and closing a vehicle roof and at least one electrical light source attached to the cover. The stable, movable cover that closes the outer skin of the vehicle is, anyway, provided with a very stable guide and for its part is configured stable, so that no enhanced expenditure has to be made for reducing the tendency to vibrate. The lighting for the interior space may be set to such a low level, where appropriate, that it may remain in the ON-state during driving and gives a pleasant feel in the vehicle compartment.  
           [0005]    According to one embodiment, the light source is a two-dimensional light source which is attached to the cover, for instance an electroluminescence light source as is installed in digital clocks for background lighting. In U.S. Pat. No. 4,775,964, which is incorporated herein by reference, and the Patent Documents mentioned therein, there are described such extremely thin, two-dimensional or, in other words, sheet-shaped lighting devices. Single, high-power light sources tend to be dazzling or they get reflections in the window panes, which is why a sheet-shaped light exit does not only provide for a more pleasant light, but also for a light which is more suitable for illuminating the interior space.  
           [0006]    Further, the light source may be at least one filament bulb, an LED or a gas discharge lamp.  
           [0007]    It is furthermore provided for that a lightwave component extends along at least a portion of the edge of the cover and emits light preferably in a direction inwardly of the edge. Due to such arrangement of the lightwave component, the light is emitted in a horizontal plane that is situated above the occupant and does not or only slightly radiate obliquely downwards, so that dazzling of the driver will not occur. This results in a type of indirect lighting in which spot-like light sources are provided actually, the light of which is, however, radiated through the one or more lightwave component(s).  
           [0008]    The lightwave components are, for example, optical waveguides or plexiglass bodies.  
           [0009]    According to the invention, the cover has at its inner side a foamed backing or an injection-molded backing provided on the edge of the cover. Preferably, the light source or the lightwave component may be arranged on or in the backing concerned. The foamed backing or the injection-molded backing forms, for instance, a bead-like frame on the inner side of the cover, the lateral surface area of which frame points inwards and comprises a light exit surface area. The light exit surface area may be configured as a surrounding light band or, in other words, a circumferentially extending ring-shaped light exit area, for instance by the light band or the lightwave component being laid on the inner side on the frame and embedded in the foamed or injection-molded backing.  
           [0010]    Preferably, the light source likewise is arranged in the foamed or injection-molded backing, which can be done in a very simple manner in that an appropriate accommodation space is left empty during foaming or injection-molding of the backing.  
           [0011]    The preferred embodiment of the invention provides for that the cover is a glass cover.  
           [0012]    If appropriate, the plate of glass may be coated such or may be roughened on its inner side such that it has an enhanced reflectivity for light from the light source in the direction towards the interior space, as compared with a corresponding plate that is not coated or is not roughened on its inner side. In this embodiment it is considered that the light leaves the light source or the lightwave component at a location very close to the glass plate and at the edge thereof, so that the angle of incidence may be very flat with respect to the inner side of the glass plate and light is hardly reflected in downward directions. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 shows a top view onto a vehicle roof with an integrated sliding roof according to the invention,  
         [0014]    [0014]FIG. 2 shows a perspective bottom view of the cover of a sliding roof according to a first embodiment,  
         [0015]    [0015]FIG. 3 shows a section through the cover edge along line III-III in FIG. 2,  
         [0016]    [0016]FIG. 4 shows a section through the cover edge along line IV-IV in FIG. 2,  
         [0017]    [0017]FIG. 5 shows a section through the cover edge along line V-V in FIG. 2,  
         [0018]    [0018]FIG. 6 shows a perspective bottom view of a cover of a sliding roof according to a second embodiment of the invention,  
         [0019]    [0019]FIG. 7 shows a section through the cover edge along line VII-VII in FIG. 6,  
         [0020]    [0020]FIG. 8 shows a section through the cover edge along line VIII-VIII in FIG. 6,  
         [0021]    [0021]FIG. 9 shows a section through the cover edge along line IX-IX in FIG. 6,  
         [0022]    [0022]FIG. 10 shows a perspective bottom view of the cover of a sliding roof according to a third embodiment of the invention,  
         [0023]    [0023]FIG. 11 shows a section through the cover edge along line XI-XI in FIG. 10,  
         [0024]    [0024]FIG. 12 shows a section through the cover edge along line XII-XII in FIG. 10, and  
         [0025]    [0025]FIG. 13 shows a section through the cover edge along line XIII-XIII in FIG. 10. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]    In FIG. 1 there is shown a sliding roof of a vehicle, which has a shiftable cover  10  and a frame (bordered by broken lines) that surrounds the cover and has guides for the cover  10 . The vehicle roof, to be more precise, the opening in the sliding roof can be opened or closed by opening or closing the cover  10 , in order to optionally vent the vehicle interior space.  
         [0027]    The cover shown in FIG. 2 is configured as a glass cover, comprising a glass plate  14  that is provided on the outer side and closes the outer skin of the vehicle body, this glass plate being provided on the inside with a foamed or injection-molded backing that extends along the entire edge in a continuously surrounding manner. Reference numeral  16  stands for the backing (which may either be a foamed or injection-molded backing) which forms a type of bead-like frame on the inner side and comprises a continuously surrounding surface area  18  pointing laterally inwards and extending virtually at 90° with respect to the inner side of the glass plate. The backing  16 , e.g. a PU foam, slightly projects with respect to the lateral circumferential edge of the glass plate  14 , a hollow section seal  20  being provided at the lateral circumferential edge of the backing  16  for sealing purposes.  
         [0028]    An electrical line  22  is embedded in the backing  16 , this line being guided to a two-dimensional light source  24  that annularly surrounds the edge of the glass plate  14  visible from the inside and that is fixed to the glass plate  14  and configured as thin as a film. The light source  24  is, for example, a so-called electroluminescence light source.  
         [0029]    The two-dimensional or sheet-shaped light source  24  is a pleasant, nonglare light source which gives a pleasant feel in the vehicle compartment. By the light source  24  being directly adjacent to the bead-like backing  16  on the inner side, its radiation is screened off in the direction towards the windshield by the surface  18 , so that it does not get reflections in the windshield, which would be troublesome for the driver.  
         [0030]    The following embodiments are to some extent similar to the embodiment described so far, so that parts with equal function will bear the reference numerals already introduced.  
         [0031]    In the embodiment according to FIGS.  6  to  9 , there are accommodated in the backing  16  two light sources  14  in the form of filament bulbs or appropriate gas discharge lamps (both being symbolized by reference numeral  26 ). A lightwave component in the shape of an annular plexiglass body  28  is embedded in the backing  16  during providing the glass plate  14  with the backing. The plexiglass body  28  forms part of the surface  18  pointing or facing laterally inwards, this part being indicated as light exit surface area  30  which is approximately at right angles to the glass plate  14 . A closed light band is produced which dependent on the plexiglass body  28  radiates towards inside, preferably in a horizontal plane. Corresponding to the dimension of the filament bulbs  26 , there are provided accommodation chambers for the filament bulbs  26  in the plexiglass body  28 . For replacing the filament bulbs  26  there is provided one flap  34  each which is connected by a film hinge  36  in one piece with the backing  16 , i.e. forms a part of the latter. In FIG. 8 the flap  34  is shown in the open state. The flap itself bears a contact (not shown) which serves for delivering power to the filament bulb  26 . In the region of the filament bulbs  26 , the backing  16  has appropriate bulges  38 , as can be seen in FIG. 10, in order to make possible the accommodation of the plexiglass body  28  that is enlarged in this region.  
         [0032]    In FIG. 9 there can be seen that the plexiglass body  28 , at places remote from the filament bulbs  26 , may be configured so as to be relatively thin.  
         [0033]    The plexiglass body  28  may even be composed of several individual pieces which form segments of the continuous ring.  
         [0034]    As the inner side of the glass plate  14  is also illuminated through the plexiglass body  28 , the corresponding inner surface can also be employed for reflecting the incident light. For improving the reflection in downward direction, the glass plate  14  is coated or roughened on the inner side, the corresponding coated or roughened portion being provided with reference numeral  40 .  
         [0035]    In the embodiment according to FIGS.  10  to  13 , there are accommodated two LED&#39;s  50  in a cavity  52  in the bulges  38 , the LED&#39;s being embedded in plastic plugs  54  which are put into the cavities  52  from below. The LED&#39;s  50  beam at a lightwave component in the form of an optical waveguide  56 , which has numerous ends that form spot-like light exit surface areas  58  at the lateral surface area  18  pointing inwards. The spot-like light exit surface areas are well to be seen in FIG. 10, they forming a disrupted, surrounding light band. The optical waveguide  56  is embedded in the backing  16  during the foaming or injection-molded process.