Patent Abstract:
A sliding block guide for openable motor vehicle roofs or vehicle hatches, with a guideway which has a guide channel ( 40 ), and a sliding block ( 11 ) which is movably guided in the guide channel along the guideway, the guideway has at least one essentially linear guideway area ( 47, 48 ) and at least one curved guideway area ( 49 ). To improve the curve handling capacity of the sliding block, the guide channel ( 40 ) is made wider in the area of the curved areas ( 49 ) of the guideway ( 12 ) than in the area of the essentially linear guideway areas ( 47, 48 ).

Full Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a sliding block guide for openable motor vehicle roofs, with a guideway which has one guide channel, and a sliding block which is movably guided in the guide channel along the guideway, the guideway being provided with at least one essentially linear guideway area and at least one bent guideway area. 
   2. Description of Related Art 
   Sliding block guides of this type are known among others from German Patent DE 100 33 887 C1 and corresponding U.S. Pat. No. 6,568,750. In a first embodiment, a sliding block is permanently connected to respective carrier part and is essentially rhomboidal or cuboidal in the lengthwise cross section, its dimension in the horizontal direction being greater than its dimension in the vertical direction. The height (width) of an essentially horizontally running guideway area is matched to the vertical dimension of the sliding block, while the width of a guideway area, which runs steeply obliquely or vertically, corresponds to the horizontal dimension of the sliding block. In the transition area between these two guideway areas, the guideway width changes continuously from one value to the other. In a second embodiment, the sliding block has an oval shape in the lengthwise cross section and the guideway width is constant. In both cases, the curve handling capacity of the sliding block leaves something to be desired. The first embodiment is, moreover, structurally very complex. 
   SUMMARY OF THE INVENTION 
   A primary object of this invention is to devise a structurally relatively simple sliding block guide with good curve handling capacity of the sliding block. 
   This object is achieved in accordance with the invention by a sliding block guide of the initially mentioned type which has a guide channel in the area of the curved areas of the guideway is made wider than in the area of the essentially linear guideway areas. 
   The sliding block guide of the invention is characterized by improved curve handling capacity with reduced wear. It avoids or reduces at least unwanted rattling noise. In particular, the widening of the guide channel in the curve areas of the guideway is dimensioned such that the sliding block conforms to the guide channel walls essentially without deformation when these curve areas are traversed. 
   The desired curve handling capacity of the sliding block can be further improved by the sliding block being pivotally supported. 
   Preferably, the execution is such that the sliding block has a rubber-elastic sliding block body and a sliding cap which is seated on the sliding block body, and a carrier part is inserted in the rubber-elastic sliding block body which has a higher strength and stiffness than the sliding block body and is pivotally supported for its part on the support pin. 
   The carrier part can be made of high-strength plastic or of metal. Preferably, the support pin is made of metal and is injection-coated with the plastic which forms the carrier part so that the carrier part can turn without play on the support pin from the start. Optionally, the carrier part can also be injection molded separately and can be clipped on the support pin. 
   The carrier part for highly loadable support of the sliding block body and the sliding cap can have a hub which surrounds the carrier pin and two wings which project essentially radially from opposing sides of the hub. 
   The sliding block body is preferably made essentially cap-shaped with a peripheral wall and an end wall which adjoins one side of the peripheral wall and is slotted in the area of its peripheral wall, the slots extending feasibly in the lengthwise direction of the sliding block and/or in the transverse direction of the sliding block. 
   The sliding block can have an essentially cuboidal shape and is made mirror-symmetrical both in the lengthwise direction and also in the transverse direction. 
   The sliding cap is preferably clipped onto the carrier part, and in the interest of high stability, is connected essentially without play to the carrier part in the lengthwise direction of the sliding block. For the carrier part it can have especially a peripheral wall, with the carrier part resting against its inside in the area of the narrow sides of the sliding block, since tolerance equalization is unnecessary in the lengthwise direction of the sliding block. 
   However, preferably the sliding cap is elastically movable for especially effective tolerance equalization with reference to the carrier part both in the transverse direction of the sliding block and also in the rotary direction around the axis of the support pin. Here, the sliding block can have a peripheral wall, from the inside of which the carrier part lies at a distance in the area of the lengthwise sides of the sliding block. 
   The rubber elastic sliding block body, advantageously, occupies essentially the entire space between the carrier part and the sliding cap. 
   The sliding surfaces of the sliding cap which slide-engage the walls of the guide channel, preferably, as is known from German Patent DE 100 33 887 C1 and corresponding U.S. Pat. No. 6,568,750, integrate stripping lips which run obliquely relative to the displacement direction and eliminate dirt particles which can have penetrated into the sliding block guide during operation. 
   The invention is explained in detail below with reference to the accompanying drawings by way of example. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of a sliding block guide in accordance with the invention, 
       FIG. 2  is a side view of the sliding block of FIG.  1  and the support which bears the sliding block, 
       FIG. 3  shows, on a larger scale, a detailed view of the broken line encircled part of  FIG. 2 , 
       FIG. 4  is a sectional view taken along line A—A of  FIG. 3 , 
       FIG. 5  is a sectional view taken along line B—B of  FIG. 3 , 
       FIG. 6  is a perspective view of the sliding block on a still larger scale, 
       FIG. 7  is an enlarged side view of the sliding block guide as show in  FIG. 1 , 
       FIG. 8  shows a partial view of an openable motor vehicle roof equipped with the sliding block guide as shown in  FIGS. 1  to  7  with the cover in the closed position, and 
       FIG. 9  a partial view similar to that shown in  FIG. 8  but with the cover raised. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1 ,  8  and  9  show an embodiment of a sliding block guide  10  in an application for the front lifting and sliding mechanism of the motor vehicle roof known from German Patent DE 100 33 887 C1 and corresponding U.S. Pat. No. 6,568,750. However, it goes without saying that the sliding block guide of the present invention can also be advantageously used for any other mechanism for actuating an openable motor vehicle roof or for a mechanism for actuating a motor vehicle hatch. 
   The sliding block guide  10  includes a multi-part, essentially rectanguloidal sliding block  11  and a guideway  12 . The sliding block  11  is made essentially mirror symmetrical with respect both to the lengthwise axis and also the transverse axis, and it has a preferably metallic support pin  13 . The support pin  13  is attached, for example, riveted, to a support  14  which is likewise metallic in this embodiment. On the support pin  13 , a carrier part  15  is supported to be able to turn around the axis  16  of the support pin  13 . The carrier part  15  can be made of high strength plastic and can be produced, for example, directly by injection around the support pin  13 . This has the advantage that the injection molded plastic carrier part can turn without play on the support pin  13 , and thus, is free of rattling without further effort. However, the plastic carrier part can also be injection molded separately, and then, can be clipped onto the support pin  13 . In particular, if the sliding block guide  10  is intended for very high stresses, the carrier part  15  can also be made of metal and can be slipped onto the carrier pin  13 . The carrier part  15  has a hub  17  which surrounds the support pin  13  and has two wings  18  which project essentially radially outward from the sides of the hub  17  which are diametrically opposite one another. 
   A rubber-elastic sliding block body  20 , which is can be made of rubber, is slipped onto the carrier part  15 . The sliding block body  20  has less strength and stiffness than the carrier part  15  and thus it provides for tolerance equalization and damping. The overall essentially cap-shaped sliding block body  20  has a peripheral wall  21  and an end wall  22  which adjoins one end of the peripheral wall  21 . The inside of the end wall  22  adjoins the side of the wing  18  which is turned away from the support  14 . The peripheral wall  21  is slotted in the lengthwise direction of the sliding block at  23  and in the transverse direction of the sliding block at  24 . 
   Finally, a sliding cap  26  with a peripheral wall  27  and an end wall  28  which adjoins one side of the peripheral wall  27  is slipped onto the sliding block body  20 . In the area of the narrow sides of the sliding block  11 , the inner side of the peripheral wall  27  of the sliding cap  26  is in contact with the narrow sides of the carrier part  15 , while the inside of the peripheral wall  27  in the area of the lengthwise sides of the sliding block is at a distance from the lengthwise sides of the carrier part  15 . The rubber-elastic sliding block body  20  essentially fills the entire space between the carrier part  15  and the sliding cap  26 . The wings  18  can have an essentially constant thickness over their entire length according to either embodiment, and can taper in a radially outward direction. Accordingly, the peripheral wall  21  of the sliding block body  20 , in the area of the wings  18 , has an essentially constant thickness ( FIGS. 7  to  9 ) or this thickness increases in the direction toward the wing ends which lie away from the hub  17  ( FIGS. 1  to  6 ). In both cases, the explained arrangement provides for the sliding cap  26  to be able to move to a limited degree using the elastic properties of the sliding block body  20  with reference to the carrier part  15  both in the transverse direction of the sliding block  11  and also in the direction of rotation around the axis  16  of the carrier pin  13 . Moreover, the sliding block  11  can be compressed to a limited degree as a whole in the transverse direction, if the sliding cap  26  has limited elasticity. Conversely, the sliding cap  26  and the carrier part  15  engage one another in the lengthwise direction of the sliding block  11  essentially without play. 
   The inside of the end wall  28  adjoins the outside of the end wall  22  of the sliding block body  20 . On the side of the peripheral wall  27 , facing the support  14  in the area of the narrow sides of the sliding block  11 , there are catch projections  29 . The catch projections  29  lie against a shoulder  30  which is made on the side of the carrier part  15  facing the support  14 . In this way, the-carrier part  15 , the sliding block body  20  and the sliding cap  26  are held securely together. The end wall  28  of the sliding cap  26  has a lengthwise slot  33 . 
   The sliding cap  26  is preferably made of a plastic with good sliding properties and favorable noise behavior, for example, from polyethylene (PE) or polytetrafluorethylene (PTFE). High density polyethylene (HDPE), such as the material marketed under the trademark RIGIDEX®, is especially well suited for this purpose. The two lengthwise outer sides of the peripheral wall  27  of the sliding cap  26  form two opposite sliding surfaces  34 ,  35 . If desired, the outside of the end wall  28  of the sliding cap  26  can be used as another sliding surface. Embossed stripper ribs  36 , which run obliquely to the direction of displacement, are formed on the sliding surfaces  34 ,  35 . The stripper ribs  36  provide, on the one hand, for linear contact of the sliding surfaces  34 ,  35  of the sliding block  11  with the sliding surfaces  41 ,  42  of the guideway  12 , and on the other hand, they form a stripping means for dirt particles. The use of such stripping ribs is known and described in detail in German Patent DE 43 36 222 C1, so that the stripping ribs  36  and their function do not require further explanation. 
   The guideway  12  has a guide channel  40  into which the sliding block  11  dips ( FIGS. 7  to  9 ). Here, the sliding surfaces  34 ,  35  of the sliding block  11  are slide-engaged with the sliding surfaces  41 ,  42  of the guideway  12  (FIG.  7 ). 
   In the embodiment shown in  FIGS. 1 ,  8  and  9  the sliding block guide  10  is part of the front lifting and displacement mechanism for the cover  45  of an openable motor vehicle roof  46 . Here, the cover  45  can be raised by means of a corresponding mechanism and can be pushed over the roof surface, as is described in DE 100 33 887 C1 and corresponding U.S. Pat. No. 6,568,750. The support  14  which is connected to the support pin  13  of the sliding block  11  is attached to the bottom of the cover  45 . The guideway  12  which is formed, for example, from at least one guide rail and/or guide slot is angled forward and down at its front area (which is on the left in  FIGS. 8 &amp; 9 ) so that there is a curved guideway area  49  between the front parallel guideway area  47  which runs obliquely essentially in a straight line and a parallel guideway area  48  which runs essentially horizontally in a straight line and which is located rearward in the lengthwise direction of the motor vehicle. The path of force F indicated in  FIG. 7  proceeds from the cover  45  via the support  14  and the support pin  13  to the relatively strong carrier part  15 . The carrier part  15  and the sliding block body  20  which surrounds it reduce the surface pressure between the sliding cap  26  and the sliding partner, i.e., the guide rail or guide slot which forms the guideway  12 . 
   For passage of the sliding block  11  from one to another of the guideway areas  47 ,  48 ,  49  without problems even in long term operation, what is important is good curve handling capacity of the sliding block  11  in the guideway  12 . The feature that the guideway  12  is widened in curved areas, such as the guideway area  49 , also contributes to this curve handling capacity here, in addition to the above explained structure of the sliding block  11 . This means that the width W′ ( FIG. 8 ) of the curved guideway area  49  is made larger than the width W of the parallel guideway areas  47  and  48  (FIG.  7 ). The difference of the widths W′ and W is preferably chosen such that the sliding block  11  is only pushed and turned, but not deformed, as it traverses the sequence of guideway areas  47 ,  48 ,  49 , if the sliding block  11  and the guideway  12  have their theoretical dimensions. In the curve areas, then “triple-line support” of the sliding surfaces  34 ,  35  of the sliding block  11  on the sliding surfaces  41 ,  42  of the guideway  12  occurs. The deformation capacity of the sliding block  11  can be fully used for tolerance compensation which may become necessary. 
   The described sliding block guide enables high cover weights to be supported. The sliding block wears little over the service life of the system and it provides reliably for the absence of rattling of the system.

Technology Classification (CPC): 4