Abstract:
An assembly for a shade system of a motor vehicle, such as a roll-up shade or a sliding sunroof, includes a guide rail and a slide movable in the guide rail. The slide includes a braking element engageable in a braking groove of the guide rail to stop the slide in a desired position in the guide rail. The slide has a swivel pin and a support element acted upon by a spring and set apart from the swivel pin. The support element is supported on the guide rail so that the braking element is forced into the braking groove to stop the slide in the guide rail.

Description:
REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application claims priority to German patent application DE 102 48 958.0 filed on Oct. 21, 2002.  
         TECHNICAL FIELD  
         [0002]    The present invention relates generally to an assembly including at least one guide rail and one slide moveable in the guide rail and used in a shade system, such as a roll-up shade or a sliding sunroof of a motor vehicle.  
         BACKGROUND OF THE INVENTION  
         [0003]    A slide of a guide rail assembly should be easily moveable in a guide rail so that only small activating forces are required to move the roll-up shade or the sun screen forwards or backwards. However, it is necessary that the slide remains in a set or desired position in the guide rail to prevent the roll-up shade or the sun screen from moving unintentionally during vehicle motion, especially under the influence of a return spring.  
         SUMMARY OF THE INVENTION  
         [0004]    The assembly of the present invention includes a slide that is moveable in a guide rail and that can be retained in a desired position. The guide rail includes at least one braking groove. The slide includes at least one braking element engageable in the braking groove to stop the slide in the guide rail. The slide has a swivel pin and a sliding segment set apart from the swivel pin. The sliding segment is under the influence of a spring supported on the guide rail that forces the braking element into the braking groove. When the roll-up shade or sun screen is moved forwards or backwards, the slide is rotated about the swivel pin, pulling the braking element out of the braking groove and allowing the slide to easily move in the guide rail. When the roll-up shade or sun screen is released, the slide is swiveled by a support element such that the braking element is pressed into the braking groove, securely stopping the roll-up shade or sun screen.  
           [0005]    The support element can be joined to the slide by a plate spring that generates a torque about the swivel pin of the slide to press the braking element into the braking groove.  
           [0006]    The support element and the slide may be configured as one piece and joined by an elastically flexible arm. The entire slide can be manufactured as one piece by, for example, injection molding. By appropriately selecting the geometry of the arm that joins the support element to the body of the slide, and by appropriately selecting the properties of the material of the slide, the desired spring characteristics can be generated without having to utilize an additional component.  
           [0007]    Preferably, the guide rail has two parallel braking grooves and the slide has two braking elements that engage in the two braking grooves in fork-like fashion to further increase the braking effect of the braking elements in the guide rail. To further increase the braking effect, the two braking elements are elastically pressed apart when forced into the braking grooves.  
           [0008]    Preferably, the swivel pin extends beyond the guide rail to allow attachment of a cross bar on the swivel pin. The forward end of the roll-up shade or the sun screen can then be attached to the cross bar. Additionally, the cross bar can be provided with a handle to manually move the roll-up shade or sun screen.  
           [0009]    The various features and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows: 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 depicts a schematic longitudinal section of a guide rail and a slide that is disposed in the guide rail according to one embodiment of the invention;  
         [0011]    [0011]FIG. 2 depicts a cross-sectional view along plane II of FIG. 1;  
         [0012]    [0012]FIG. 3 depicts a cross-sectional view along plane III of FIG. 1;  
         [0013]    [0013]FIG. 4 depicts a side view of the slide;  
         [0014]    [0014]FIG. 5 depicts in a top view of the slide;  
         [0015]    [0015]FIG. 6 depicts in a front view of the slide;  
         [0016]    [0016]FIG. 7 depicts the slide in the guide rail in an arrested and a released state;  
         [0017]    [0017]FIG. 8 depicts a cross-sectional view along plane VII of FIG. 7; and  
         [0018]    [0018]FIG. 9 depicts an alternate embodiment of the slide in the guide rail. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]    [0019]FIG. 1 illustrates a guide rail  10  and a slide  12  movably arranged in the guide rail  10 . In one embodiment, two opposing parallel guide rails are attached to a roof of a vehicle and run roughly parallel to the longitudinal direction of the vehicle. A slide  12  is provided in each guide rail  10 . That is, two slides  12  are provided opposite each other. The slides  12  are joined by a cross bar  13  running transversely with respect to the longitudinal direction of the vehicle.  
         [0020]    A roll-up shade or sun screen connected to the cross bar  13  is arranged underneath a roof opening. The roof opening is closed by a cover of a sliding roof system. The roll-up shade is accommodated in a housing in the rear end of the vehicle and can be pulled forwards out of the housing in opposition to the force of a return spring (not shown). The cross bar  13  and both the slides  12  are fixed to the front end of the roll-up shade. The slides  12  guide the roll-up shade and stop it in a desired position in the guide rail  10 , preventing the roll-up shade from unintentionally retracting into the housing by the return spring.  
         [0021]    In one embodiment, each guide rail  10  is extruded of an aluminum alloy and has a hollow interior  14  in which the slide  12  is arranged. The hollow interior  14  is bordered on a lower side by a support surface  16 , and two braking grooves  18  separated by a rib  20  are provided on the opposing upper side.  
         [0022]    As shown in FIGS. 2, 3 and  8 , the guide rail  10  includes a through slot  22  that joins the hollow interior  14  to the exterior of guide rail  10 .  
         [0023]    As shown in FIGS. 4, 5 and  6 , the slide  12  has a swivel pin  30  extending the entire width of slide  12 . The cross bar  13  is fixedly joined to the swivel pin  30 . A sliding segment  32  connected to the swivel pin  30  has an exterior surface  34  concentric to the central axis C of the swivel pin  30 . An elastically flexible arm  36  is integrally joined to sliding segment  32 . As shown in FIGS. 5 and 6, two braking elements  38  extend from a base segment  37  on the upper side of the arm  36  and are configured next to each other as fork-shaped projections.  
         [0024]    A cylindrical support element  40  is integrally joined to the end of the arm  36  opposite the swivel pin  30 . The axis of the support element  40  runs parallel to central axis C.  
         [0025]    The slide  12 , including the arm  36 , the braking elements  38 , and the support element  40 , is made out of plastic in one piece. Preferably, the slide  12  is extruded and made of POM (Polyoxymethylene). The slide  12  can also be injection molded. By appropriately selecting the geometry of the arm  36  that joins the support element  40  to the body of the slide  12 , and by appropriately selecting the properties of the material of the slide  12 , the desired spring characteristics can be generated without having to utilize an additional component.  
         [0026]    When the slide  12  is arranged in the hollow interior  14  of the guide rail  10 , the exterior surface  34  of the sliding segment  32  and the support element  40  are supported on the support surface  16  of the guide rail  10 . The swivel pin  30  extends through the through-slot  22  beyond the guide rail  10 . In the initial position, as shown in FIGS. 1 and 2, no external forces act upon the slide  12  and the arm  36  exerts a torque upon the slide  12  in the direction of arrow M about central the axis C of the swivel pin  30 . The arm  36  pushes the support element  40  downwardly, as shown in FIG. 1. As a result of the torque exerted, both braking elements  38  are pressed into the braking grooves  18  and contact both sides of the rib  20 . Both the braking elements  38  are elastically deformed to create high frictional forces that arrest the slide  12  in the guide rail  10 .  
         [0027]    As shown in FIG. 7, if a user moves the cross bar  13 , and therefore the roll-up shade or sun screen, the user pulls on a handle (not shown) attached to the cross bar  13  (indicated by force F), swiveling the cross bar  13  about the central axis C of the swivel pin  30  from the position indicated by the solid lines to the position indicated by the broken lines. The swivel motion is transmitted by the swivel pin  30  to the sliding segment  32 , and the sliding segment  32  swivels in the counterclockwise direction in opposition to the torque acting in the direction of arrow M. Due to the swivel motion of the sliding segment  32 , the right end of the arm  36  is pushed downwardly, elastically pressing the arm  36  into the position  36 ′ (indicated by a broken line). Simultaneously, as further shown in FIG. 8, both braking elements  36  move downwardly into the position  38 ′ (indicated as a broken line) in which the braking elements  38  do not engage in the braking grooves  18 . In this position, the slide  12  can freely move in the guide rail  10  so the user can freely slide the roll-up shade or sun screen into a new position.  
         [0028]    When the user releases the handle, and therefore the cross bar  13 , the slide  12  and the cross bar  13  are swiveled by the spring action of the arm  36  into the position shown in FIG. 1 in which both the braking elements  38  engage in the braking grooves  18 . As a result, the slide  12 , the cross bar  13 , and the attached roll-up shade or sun screen are stopped in the desired position.  
         [0029]    [0029]FIG. 9 illustrates an alternate embodiment in which the arrangement of the support surface  16  and the braking grooves  18  is reversed. In the initial position, both the braking elements  38  are pressed downwardly into the two braking grooves  18 . To release the slide  12 , the cross bar  13  is pressed upwardly as indicated by arrow F. When the cross bar  13  is released, the sliding segment  32  is swiveled by the elastically biased arm  36  in the counterclockwise direction, and both the braking elements  38  engage in both the braking grooves  18 . The slide  12  is then stopped in the guide rail  10  in the desired position.  
         [0030]    The foregoing description is only exemplary of the principles of the invention. 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, so that 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.