Abstract:
The present invention relates to a cover for a sliding roof system having at least two guide elements, which are movably arranged on two opposite sides of the cover such that the distance between them is variable. The two guide elements are each attached in a sliding guide, which predefines a displacement direction for the guide elements that differs from the displacement direction of the cover, such that the cover is centered with regard to the two guide elements. The invention also relates to a sliding roof system having two guide tracks, which extend along a roof of a motor vehicle at a changing distance, and a cover.

Description:
REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present invention claims the benefit of German Patent Application No. 102 53 401.2, filed Nov. 15, 2002.  
         [0002]     1. Technical Field  
         [0003]     The present invention relates to a cover for a sliding roof system having at least two guide elements that are movably arranged on two opposite sides of the cover, such that the distance between them is variable. The present invention also relates to a sliding roof system having two guide tracks and to a cover of this type.  
         [0004]     2. Background of the Invention  
         [0005]     German Laid-Open Document DE 100 02 457 describes a sliding roof system that employs two straight guide tracks extending roughly in the longitudinal direction of a vehicle along the roof. The distance between the guide tracks decreases from front to back. To guide the cover in the tracks, two guide elements are provided, each of which is contained in one of the guide tracks and connected to the cover by a parallelogram guide. This makes it possible for the distance between the two guide elements to change as the distance between the guide tracks changes.  
         [0006]     In theory, the two parallelogram guides would also prevent the cover from twisting about its vertical axis or from being laterally displaced. In practice, however, the cover is prevented from twisting and displacement due to the guide elements precisely guided in the guide tracks and due to the cover being prevented from tilting. In other words, every force acting upon the cover to displace it laterally or to twist it about its vertical axis leads, as a result of the parallelogram guides, to rotational forces being applied to the two guide elements in the guide tracks. As a result, the entire sliding roof system is relatively hard to move and tends to jam. In addition, the parallelogram guide is only suitable for straight-line guide tracks that lie parallel to each other, not guide tracks whose distance from each other varies along the length of the track.  
         [0007]     There is a desire to refine a sliding roof system to support the cover in a centered position relative to the guide tracks without risking the possibility that the guide elements may jam in the guide tracks or that the entire system may be subjected to undue strain.  
       SUMMARY OF THE INVENTION  
       [0008]     One embodiment of the invention is directed to a cover for a sliding roof system having at least two guide elements that are movably arranged on two opposite sides of the cover so that the distance between them is variable. The two guide elements are each attached in a sliding guide, which predefines a displacement direction for the guide elements that differs from the displacement direction of the cover such that the cover is centered with regard to the two guide elements. The sliding guide in the invention greatly reduces the risk that the components will tilt relative to each other, thus assuring ease of motion in the system.  
         [0009]     According to one embodiment of the present invention, each guide element is connected in an articulated fashion to a guide bar, which is received in the sliding guide. The articulated joint between the guide bar, which is movably guided on the cover, and the guide element ensures that no torque can be transmitted from the cover to the guide element, preventing the guide element from being jammed in the guide track in which it is contained. The articulated joints attaching the guide elements also makes it possible to use curved guide tracks while preserving smooth sliding performance.  
         [0010]     According to one embodiment of the present invention, each guide bar is connected in an articulated fashion to a lever, and a coupling lever is supported on the cover so that it is able to swivel about a swivel axis. The levers are both connected in an articulated fashion to the coupling lever on each side of the swivel axis. In this manner, the cover can reliably be centered with respect to the two guide elements with minimal production expense.  
         [0011]     According to another embodiment of the present invention, each guide bar is connected to a toothed rack that may be designed as an integral part of the guide bar. A gear wheel is rotatably supported on the cover with both toothed racks meshing in the gear wheel. This embodiment employs constrained guidance of the cover to ensuring centering of the cover with respect to the two guide bars with minimal production expense.  
         [0012]     According to a further embodiment of the present invention, a second, supplemental pair of guide elements is provided with guide bars, each of which is supported on the cover in a sliding guide. The displacement direction of the first pair of guide elements is in a mirror-symmetrical fashion and obliquely oriented with respect to the displacement direction of the cover, and the displacement direction of the second pair of guide elements is perpendicular to the displacement direction of the cover. In this embodiment, no coupling between the guide bars of the guide elements is necessary because the spatial orientation of the displacement direction of the guide elements alone assures that the cover will remain centered between the two guide tracks in which the guide elements are movably contained.  
         [0013]     The above-mentioned object of the present invention is also achieved by a sliding roof system having two guide tracks that extend along the roof of a motor vehicle at a changing distance and a cover as described above. Regarding the advantages of a sliding roof system of this type, reference is made to the above explanations. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The present invention is described below on the basis of various embodiments, which are depicted in the attached drawings in which  
         [0015]      FIG. 1  depicts a schematic top view of a sliding roof system according to the invention in accordance with a first embodiment;  
         [0016]      FIG. 2  depicts a schematic top view of a sliding roof system according to the invention in accordance with a second embodiment;  
         [0017]      FIG. 3  depicts a schematic top view of a sliding roof system according to the invention in accordance with a third embodiment; and  
         [0018]      FIG. 4  depicts a schematic top view of a sliding roof system according to the invention in accordance with a fourth embodiment. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0019]      FIG. 1  illustrates a sliding roof system having two guide tracks  10  and a cover  12 .  
         [0020]     Both guide tracks  10  extend roughly in the longitudinal direction of a vehicle roof (not shown). In the illustrated embodiment, both guide tracks  10  are designed to be curved in two planes, specifically about one axis parallel to the vertical axis of the vehicle and about an axis that is parallel to the transverse axis of the vehicle. In this manner, both guide tracks  10  can follow the shape of the side edges of the vehicle roof, particularly because modern vehicle roofs are usually curved and have a width that changes from front to back. Accordingly, the distance of the guide tracks from each other may also change as a function of the position that is being observed along the vehicle&#39;s longitudinal axis.  
         [0021]     The cover  12  is displaceable in the guide tracks in a basically familiar manner. The cover position can be changed from a closed position, in which the cover  12  closes an opening in the roof of the vehicle, into an open position, in which the opening in the roof is exposed, by a drive mechanism (not shown). For the present invention, no emphasis is placed on the details of the displacement mechanism for the cover  12  or on the materials used for the cover  12 ; the present invention encompasses covers made of any material and having any position (e.g., covers made of metal, plastic, transparent material, etc.; covers that are moved outside the roof, covers that are moved inside the roof, etc.).  
         [0022]     A guide element  14  is arranged in each guide track  10 . In the illustrated embodiment, the guide element  14  is designed as a slider. The drive mechanism (not shown) for the cover  12  engages the guide elements  14 . A guide bar  18  is mounted on each guide element  14  via an articulated joint  16 , which in each case is movably contained in a sliding guide  20 . Each sliding guide  20  is fixedly attached to the cover  12 . A lever  24  is attached at the end of each guide bar  18  that is facing away from guide element  14  via another articulated joint  22 . The lever  24  is also connected to one end of a coupling lever  28  via a further articulated joint  26 . The coupling lever  28  is rotatably supported on cover  12  by a swivel axle  30  that is arranged centrally between both articulated joints  26 .  
         [0023]     By rotating coupling lever  28 , the distance of the guide elements  14  from each other can be varied via the levers  24  and the guide bars  20  and can therefore be adjusted to adapt to the specific distance between guide tracks  10  at any given point. Because the coupling lever  28  is fixedly mounted on the cover  12  via the swivel axle  30 , the cover  12  is centered between both guide elements  14 . Due to the displacement direction predefined by both sliding guides  20 , which is perpendicular to the displacement direction P of the cover  12 , the mechanism for moving the guide elements  14  cannot jam. This eliminates the need for an additional guide. However, a second guide having guide elements, guide bars, sliding guide, and coupling lever may be provided, if desired, to guide the cover in an even more stable fashion.  
         [0024]      FIG. 2  illustrates another embodiment of the inventive sliding roof system. For the components that are common with the first embodiment, the same reference numerals are used, and in this respect reference is made to the above explanations.  
         [0025]     In the second embodiment, the guide bars  18  are each equipped with a toothed rack  32 , which is designed as an integral part of the guide bars  18  in the illustrated embodiment. Alternatively, the toothed racks  32  may be separate components attached to their respective guide bars  18  via any known mechanism. A gear wheel  32  is rotatably mounted on a swivel axis  30  and attached to the cover  12 . The toothed racks  32  are disposed so that the sides opposite each other mesh in the gear wheel  34 .  
         [0026]     A coupling mechanism configured in this manner makes it possible to adjust the distance of guide elements  14  from each other while at the same time keeping the cover  12  centered by the swivel axis  30  with respect to the guide elements  14 .  
         [0027]      FIG. 3  illustrates a third embodiment of the invention. For the components that are the same as the preceding embodiments, the same reference numerals are used, and reference is made to the above explanations.  
         [0028]     In this embodiment, the guide bars  18  of the guide elements  14  are not coupled to each other at all. Instead, the guide bars  18  can be moved freely in the sliding guides  20  attached to the cover  12 . Additionally, the displacement direction V of the guide bars  18 , which is predefined by the sliding guides  20 , is oriented to be oblique with regard to the displacement direction P (i.e., at an angle α that is not 90°). The angle α in this example is identical for both guide bars  18 ; the guide bars are therefore mirror symmetrical with regard to a central axis of cover  12  that runs parallel to the displacement direction P. Alternatively, the angle α may be different for different guide bars  18 , if desired.  
         [0029]     In addition to the first pair of sliding guides and guide elements, a second, supplemental pair of guide elements  40  is provided, which are mounted on a second, supplemental pair of guide bars  42  in an articulated fashion, the guide bars in turn being movably contained in supplemental sliding guides  44 , which are fixedly mounted on the cover  12 . Both supplemental sliding guides  44  define a displacement direction for both guide bars  42  that is perpendicular to displacement direction P of the cover  12  and therefore also perpendicular to the central axis of the cover  12 .  
         [0030]     Due to the different orientations of the sliding guides  20  and the supplemental sliding guides  44 , this embodiment ensures that the cover  12  is centered between the guide elements  14  and also between the second pair of guide elements  40 . In addition, because all of the guide elements  14 ,  40  are attached by articulated joints to the guide bars  18 ,  42  and because the sliding guides  20  furnish a friction-free guide for the guide bars  18 ,  42 , the cover  12  is reliably prevented from being tilted relative to the guide tracks  10 , thus assuring ease of action of the sliding roof system.  
         [0031]      FIG. 4  illustrates a fourth embodiment of the invention. Here, too, for the components that are the same as in the preceding embodiments, the same reference numerals are used, and reference is also made to the above explanations.  
         [0032]     In this embodiment, two sliding guides  20  are disposed perpendicular to the displacement direction P of the cover. Each guide bar  18  arranged in the sliding guides  20  is supported by a resilient member, such as a spring  46 , on a limit stop  40 . The resilient member  46  is mounted in the center of the cover  12 . In this way, the cover  12  is centered in the middle between the two guide tracks  10 .  
         [0033]     It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby.