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:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to German Patent Application Number 101 34 641.7 filed on Jul. 17, 2001. 
    
    
     TECHNICAL FIELD 
     The invention relates to a sliding roof for a motor vehicle. 
     BACKGROUND OF THE INVENTION 
     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 blind the driver. There is the desire to slightly illuminate the interior space during night trips, in order to better see, for example, operating elements, while the illumination must not produce reflections in the window panes and blind 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. 
     The invention provides a sliding roof with an integrated illumination device that minimizes the tendency of the light source to vibrate and reduces the expenditure for accommodating the light source. 
     BRIEF SUMMARY OF THE INVENTION 
     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 provided with a very stable guide and for its part is configured stably, 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. 
     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 that is often 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 blinding or create reflections in the window panes, which is why a sheet-shaped light exit not only provides a more pleasant light, but also for a light which is more suitable for illuminating the interior space. 
     Further, the light source may be at least one filament bulb, an LED or a gas discharge lamp. 
     It is further 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 submitted above the occupant and does not or only slightly radiate obliquely downwards, so that the driver will not be blinded by the light. This results in a type of indirect lighting in which spot-like sources are provided, but where the light is radiated through the one or more lightwave component(s). 
     The lightwave components are, for example, optical waveguides or plexiglass bodies. 
     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. 
     Preferably, the light source is arranged likewise 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. 
     The preferred embodiment of the invention includes a glass plate to form a glass cover. 
     If appropriate, the glass plate 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 
     FIG. 1 shows a top view onto a vehicle roof with an integrated sliding roof according to the invention, 
     FIG. 2 shows a perspective bottom view of the cover of a sliding roof according to a first embodiment; 
     FIG. 3 shows a section through the cover edge along line III—III in FIG. 2, 
     FIG. 4 shows a section through the cover edge along line IV—IV in FIG. 2, 
     FIG. 5 shows a section through the cover edge along line V—V in FIG. 2, 
     FIG. 6 shows a perspective bottom view of a cover of a sliding roof according to a second embodiment of the invention. 
     FIG. 7 shows a section through the cover edge along line VII—VII in FIG. 6, 
     FIG. 8 shows a section through the cover edge along line VIII—VIII in FIG. 6, 
     FIG. 9 shows a section through the cover edge along line IX—IX in FIG. 6, 
     FIG. 10 shows a perspective bottom view of the cover of a sliding roof according to a third embodiment of the invention. 
     FIG. 11 shows a section through the cover edge along line XI—XI in FIG. 10, 
     FIG. 12 shows a section through the cover edge along line XII—XII in FIG. 10, and 
     FIG. 13 shows a section through the cover edge along line XIII—XIII in FIG.  10 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1 there is shown a sliding roof of a vehicle  12 , 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  12 , 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. 
     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, the glass plate is 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 polyurethane foam, slightly projects with respect to the lateral circumferential edge of the glass plate  14 . A hollow section seal  20  is provided at the lateral circumferential edge of the backing  16  for sealing purposes. 
     An electrical line  22  is embedded in the backing  16  and is guided to a two-dimensional light source  24  that annularly surrounds the edge of the glass plate  14 . In this embodiment, the light source  24  is visible from the inside and 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. 
     The two-dimensional or sheet-shaped light source  24  is a pleasant, nonglare light source which gives a pleasant feel in the vehicle compartment. Because the light source  24  is 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 backing surface  18  so that it does not create reflections in the windshield, which would be troublesome for the driver. 
     The following embodiments are to some extent similar to the embodiment described so far, so that parts with equal functions will bear the reference numerals already introduced. 
     In the embodiment according to FIGS. 6 to  9 , two light sources  14  in the form of filament bulbs or appropriate gas discharge lamps (both being symbolized by reference numeral  26 ) are disposed in the backing  16 . A lightwave component in the shape of an annular plexiglass body  28  is embedded in the backing  16  when attaching the glass plate  14  to 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 provided which, depending on the characteristics of the plexiglass body  28 , radiates in an inside direction, preferably in a horizontal plane. Corresponding to the dimensions 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 on flap  34  each which is connected by a film hinge  36  integrally formed 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 to deliver 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 accommodate the plexiglass body  28  that is enlarged in this region. 
     In FIG. 9 it 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. 
     The plexiglass body  28  may even be composed of several individual pieces which form segments of the continuous ring. 
     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  may be coated or roughened on the inner side, the corresponding coated or roughened portion being provided with reference numeral  40 . 
     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 are 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 from 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 easily seen in FIG.  10  and form a disrupted, surrounding light band. The optical waveguide  56  is embedded in the backing  16  during the foaming or injection-molded process. 
     The foregoing description is exemplary rather than defined by the limitations within. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention.