Abstract:
A seat guide for mounting a car seat and to its positional adjustment in a direction of an axis of displacement. The seat guide has two guide rails installed parallel to the axis of displacement and support rollers which cooperate with and move relative to the guide rails to support a vertical load. Lateral guide devices are provided for lateral support in a direction of a lateral axis running essentially perpendicular to both the axis of displacement and the guide rails. The relative motion of the lateral guide devices cooperates with the guide rails overcoming any conditions of elastic rolling friction.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field of the Invention 
     The present invention relates to a seat guide for mounting a car seat and for its positional adjustment in the direction of an axis of displacement, with two guide rails installed parallel to the axis of displacement, and with support rollers which, by rolling, cooperate with and move relative to the guide rails to support the vertical load. 
     2. Discussion 
     These kinds of seat guides have a special problem, in that large dimensional tolerances appear because of the large number of sheet metal parts used to manufacture the body, so that the clearance of the seat&#39;s guide components, measured in the direction of a vehicle&#39;s horizontal lateral axis (Y-axis), can even differ in the range of several millimeters. Furthermore, dimensional tolerances in the manufacture of the seat frame cannot be neglected. All of these tolerances have to be compensated so that the seat guide operates without trouble, i.e. to guarantee above all that there is no jamming when the position is adjusted. This problem is particularly important for bench seats above all, because their large width (span between the lateral guides) also makes them susceptible to rocking motion around a vertical axis (Z-axis), which can result in wedging of the bench seat. 
     A seat guide of the generic type is known from DE19547034A1. Here, two double-conical rollers (guide rolls) run on each of two guide rails and are guided axially movable in movable bearing arrangements on at least one side to compensate tolerances. This seat guide is basically very functional, but practice has shown that this design can only be realized at relatively high cost, because the bearings have to withstand certain forces, which can be quite high in a collision, above all. Special materials must therefore be used for the bearings. It has furthermore been shown, that no absolutely jam-free adjustment of the bench seat can be achieved in the longitudinal direction, even with this known design. 
     DE4330133A1 describes another rail guide for car seats, which is moreover designed as a slip-in guide with plastic slide blocks guided slidable in the guide rails. To compensate tolerances, support pieces are installed on the seat, which first of all have a bearing arrangement that can pivot around their longitudinal axis, and which secondly can slide in the direction of their longitudinal axis on at least one side of the seat. Externally, these support pieces feature plastic slide blocks, which slide in the longitudinal guide rails. 
     DE3920077A1 similarly deals with a car seat guided in rails, whereby the seat is guided on slide supports in the rails. Here, a fastening device, which is also supposed to compensate lateral play in the rails caused by structural tolerances, is provided to prevent rattling. This fastening device features a bolt, which is mounted in a fastening fastened to the seat and rests tightly against one of the rails under the force of a spring. 
     Finally, DE-OS11680269 describes a device for fastening a seat onto a floor. Here, we are dealing with a slip-in guide with interlocking rails, whereby it has one pair of rails whose rails interlock perpendicularly to the rails&#39; longitudinal axis without any significant play, whereas the rails of all the remaining pairs can slide relative to each other transversely to the seat. Work tolerances are thereby supposed to be compensated by sliding the rails of the latter pairs transverse to the seat. 
     It is the objective of the present invention, to create a seat guide of the generic type, that guarantees steady operation without trouble during longitudinal adjustment, without jamming in particular, using inexpensive resources. 
     SUMMARY OF THE INVENTION 
     In accordance with the teachings of the present invention, a seat guide for positional adjustment of a vehicle seat along an axis of displacement is provided. The seat guide includes a first guide rail positioned parallel to the axis of displacement and a second guide rail spaced apart from the first guide rail along a lateral axis and positioned parallel to the axis of displacement. At least one support roller is operably associated with and moveable relative to the first guide rail and the second guide rail. Additionally, at least one lateral guide device is operably associated with and moveable relative to the first guide rail and the second guide rail with at least a portion of the at least one lateral guide device being moveable about an axis substantially perpendicular to the axis of displacement. 
     This is achieved in accordance with the invention, that in combination with the support rollers known by themselves, special lateral guide devices, cooperating with the guide rails by elastic rolling friction, are provided for lateral support in the direction of a lateral axis running essentially perpendicular to both the axis of displacement and the guide rails, especially guide rollers whose rolling and relative motion cooperates with the guide rails. 
     When the car seat is adjusted, the embodiment in accordance with the invention will only produce elastic rolling friction, because it deals with pure guide rollers. If the seat should tilt while its longitudinal position is being adjusted, i.e. tilting around its vertical axis, then at least one part of the lateral guide rollers will become arranged on at least one assigned guide surface of the respective guide rail, so that only very small rolling friction will also occur here, whereby catching or even wedging will be safely eliminated during seat adjustment. 
     One favorable embodiment of the invention allocates at least two guide rollers, separated in the direction of the axis of displacement, to each of the two guide rails. The clearance of each lateral pair&#39;s two guide rollers should be chosen as large as possible, depending on structural factors. The seat guide in accordance with the invention is thereby particularly suitable for wide bench seats, two-person or three-person bench seats for example. If there is any tipping, two guide rollers diagonally opposite each other will both become arranged on the two guide rails, so that jamming will be completely eliminated. 
     The seat guide in accordance with the invention can be realized with inexpensive resources, because conventional rolling bearings can be used as rollers. 
     The compensation of lateral dimensional tolerances can also be achieved without problem, because the rollers can be guided in the guide rails with a known permissible lateral play. Two minor lateral movements of the seat are indeed possible here, but these are favorably bounded by the guide rollers of the lateral guide devices, without a significant amount of extra friction occurring during adjustment. 
     In another favorable embodiment of the invention, compensating means are provided for relative support of the seat in a direction opposite to that in which the support rollers bear the load. In principle, slip-in guides can be used here, but it is particularly preferable if the compensating means on the side of each guide rail feature at least one compensating roller for resting and rolling on a supporting surface on the guide rails that is opposite the direction of load-bearing. It is the objective of these compensating means, to prevent rocking motion of the seat around its lateral axis or to minimize such motion, respectively. 
     To prevent any noise, especially rattling while driving, it is preferable to provide each provided roller with a raceway composed of an elastic material. This could possibly be dispensed with only for the support rollers, because these always abut the guide rails because of their weight. 
     If there are large stresses on the car seat, the provided rollers alone may not be capable of directing the working forces out of the seat, through the guide rails, and into the vehicle floor. To ensure that the car seat is securely supported in this case, a preferred embodiment of the invention provides special features to directly support the seat on stationary body components. These features can be built by providing the seat guide&#39;s components with web-like impact profile cutouts that interlock with playing distance, whereby these cutouts arrange against each other in the event large stresses occur. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further features and advantages of the invention will become apparent from the following discussion and accompanying drawings, in which: 
     FIG. 1 is a half of a seat guide in accordance with the invention, assigned to the side of a seat, in a perspective exploded view of its individual components; 
     FIG. 2 is an enlarged cross section through the region of the guide rail in the plane II—II of FIG. 1; 
     FIG. 3 is a cross section of the entire seat guide (with left and right guide parts) in the plane III—III of FIG. 1; 
     FIG. 4 is a cross section through the seat guide in the plane IV—IV of FIG. 1; 
     FIG. 5 is a corresponding cross section in the plane V—V of FIG. 1; 
     FIG. 6 is an enlarged crosssectional illustration of the seat guide half (guide part) labeled VI in FIG. 3; 
     FIG. 7 is an enlarged illustration of the seat guide half labeled VII in FIG. 4; 
     FIG. 8 is an enlarged illustration of the view VIII from FIG. 5; and 
     FIG. 9 is an enlarged cross section through the half of the seat guide in plane IX—IX of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following description of the preferred embodiment is merely exemplary in nature, and is in no way intended to limit the invention or its application or uses. 
     The same parts are always provided with the same labels in the drawing&#39;s various figures and will therefore generally only be described once. 
     As can first be deduced in FIG. 1, a seat guide in accordance with the invention is, first of all, for fastening an unillustrated car seat, especially a bench seat, within the vehicle, and secondly for linear adjustment of the seat as a unit, relative to its position in a direction of an axis of displacement A. FIG. 1 furthermore displays the three dimensional coordinate system with the axes X, Y, and Z, that is conventional in the automotive industry, where X represents the vehicle&#39;s horizontal longitudinal axis, Y the horizontal lateral axis, and Z the vertical axis. The axis of displacement A normally corresponds to the direction of the X-axis (seat&#39;s longitudinal displacement). 
     In accordance with FIGS. 3 through 5, the seat guide features two mirror-symmetrical guide rails  2  arranged parallel to the axis of displacement A. Support rollers  4 , which, by rolling, cooperate with and move relative to the guide rails  2 , are provided for vertical load-bearing in the Z direction (See FIGS. 1,  3 , and  6 ). Moreover (at least) two support rollers  4 , separated in the direction of the axis of displacement A, are assigned to each of the two guide rails  2  and are mounted to rotate around rotational axes  6  that are perpendicular to the axis of displacement A, i.e. to parallel the Y-axis. The car seat is therefore resting on (at least) four support rollers  4 . 
     As can be determined from FIGS. 1,  4 , and  7 , lateral guide devices  8  are provided in accordance with the invention for lateral support in the direction of a lateral axis B (which as a rule corresponds to the vehicle&#39;s lateral axis Y), running essentially perpendicular to both the axis of displacement A and the guide rails  2 . These lateral guide devices  8  in accordance with the invention feature guide rollers  10 , which cooperate with and move relative to the guide rails  2  and roll. Moreover, (at least) two guide rollers  10 , separated from each other in the direction of the axis of displacement A, are appropriately assigned to each of the two guide rails  2  (See FIG. 1, in particular). In accordance with FIGS. 4 and 7, each guide roller  10  is mounted so that it can rotate around a rotational axis  12  approximately perpendicular to both the axis of displacement A and the lateral axis B (and consequently perpendicular to the direction of the Y-axis). The guide rollers  10  are preferably arranged shifted relative to the support rollers  4  in the direction opposite the load-bearing direction (upwards) (See FIGS.  3  and  4 ). 
     In accordance with FIG. 2, each guide rail  2  is designed as a rectangular profile, essentially C-shaped in cross section, whereby these rectangular profiles forming the guide rails  2  are designed open on the sides facing each other. Each guide rail  2  features an inside running tread  14  to support the support roller  4 . For the guide roller  10  in accordance with the invention, each guide rail  2  features a first lateral guide surface  16  on its inside opposite the open side, and, preferably opposite it, a second lateral guide surface  18  formed by a bar section  17  bent on the open side. As is best seen in FIG. 7, each of the guide rollers  10  is guided in the guide rails  2  with a lateral playing distance between the guide surfaces  16  and  18 , so that each can become arranged on only one of the two guide surfaces  16  or  18  when the seat is adjusted. 
     As illustrated, the guide rollers  10  are designed as rollers, especially conventional rolling bearings, each with a raceway  20 , whereby the raceway is preferably made of an elastic material, such as plastic. Rattling caused by play can thereby be efficiently eliminated or reduced, respectively. The guide rollers  10  can each feature a slightly ball-shaped (convex) bearing face corresponding to the illustration in FIG.  1 . 
     In the illustrated preferred example of the invention, the guide rails  2  are provided for stationary attachment to the vehicle, whereas the support rollers  4  and the guide rollers  10  can be fastened to the seat. This means that the “bottom” of the support rollers  4  will rest on the running tread  14 . 
     As can now be determined from FIGS. 1,  5 , and  8 , additional compensating means  22 , for relative support of the seat in a direction opposite the direction of load-bearing, are preferably provided. In the illustrated embodiment with guide rails installed stationary in the vehicle, the compensating means  22  rest vertically “upwards,” i.e. in the +Z direction, within the guide rail  2 . Preferably, (at least) one compensating roller  24 , which abuts one of the supporting surfaces  26  of the respective guide rail  2  opposite the respective running tread  14  and rolls on it when the seat is adjusted, will be provided on the side of each guide rail  2  for this purpose. Moreover, there exists playing distance between each compensating roller  24  and the running tread  14 , see FIG. 8 in particular. Each compensating roller  24  is mounted so that it can rotate around a rotational axis  28  that is approximately parallel to the lateral axis B, and also to the Y-axis. Appropriately, each compensating roller  24  is also designed as a roller, especially a roller bearing, with a raceway  30  preferably consisting of an elastic material. 
     As is now furthermore derived from FIG. 1, all rollers  4 ,  10 ,  24  are each attached to one of two support units  32 , which can be fastened to the seat. These support units  32  are preferably designed as molded metal parts. The support rollers  4  and the preferably provided compensating rollers  24  are appropriately mounted directly on the respective support unit  32  by axle pins  60  and  62 , as shown in FIGS. 3,  5 ,  6 , and  8 . The guide rollers  10  are each attached to a separate support piece  34 , which is especially made of sheet metal and fastened to support unit  32 . Each support piece  34  is basically designed U-shaped, whereby axle holes extend through two parallel sides of the U, and the guide rollers  10  are each mounted into these axle holes by axle pins  64  in accordance with FIGS. 4 and 7. 
     Preferably, every support unit  32  can be fastened to the seat in such a way that it can be elastically deformed locally to compensate lateral dimensional tolerances which appear between the guide rails  2 . In the illustrated example, this is achieved in that each support unit  32  is only fastened in its top vertical region  66 , so that it can be elastically deformed, together with the rollers, in the remaining bottom region  68  in the direction of the lateral axis B. In addition or alternatively, it can also be provided, that each support piece  34  is suitably fastened to its support element  32  in such a way, that it can be elastically deformed locally to compensate lateral dimensional tolerances between the guide rails  2 . In the illustrated example, this is specially achieved, in that each support piece  34  is only fastened to the support unit  32  on the end  70  that lies opposite the respective roller  10 . In this manner, the end  72  of the support piece  34  facing the roller  10  can move elastically relative to the support unit  32 . 
     As far as the fastening of the guide rails is now concerned, each guide rail  2  is preferably fastened in a mounting rail  36 , which can be mounted stationary on the vehicle. In accordance with FIGS. 3 through 9, the mounting rails  36  are only fastened onto a vehicle floor  38  (only drawn locally), specifically in the region of side rails (also called rocker panels), possibly also around the center tunnel. The mounting rails  36  feature an approximately C-shaped profile, whose open side is directed toward the vehicle&#39;s axis of central symmetry (perpendicular longitudinal plane Y 0 , see FIGS.  3  through  5 ). 
     As can be seen from FIGS. 1,  2 , and  9  above all, extra features  40  are preferably provided, to directly support the seat on stationary body components in case deformations occur in the region of the rollers  4 ,  10 ,  24 . In the illustrated example, these features  40  deal with web-like profile cutouts, that interlock with playing distance and belong to support units  32  and/or support pieces  34  on the one hand, as well as to guide rails  2  and, if necessary, mounting rails  36  on the other hand. In accordance with FIG. 9, the guide rail  2 , on its open side opposite the bar section  17 , features a border ledge  42  which is bent facing away from the bar section  17 . Preferably, the mounting rail  36  will also have a suitable border ledge  44  in this region. For this, the support unit  32  features a U-shaped edge  46 , bent around 180°, which engages the border ledges  42 ,  44  above and below with playing distance. In addition, the support pieces  34  each feature a bent bar  48 , which engages the bar section  17  of guide rail  2  that forms the second lateral guide surface  18  with playing distance. In this manner, profile cutouts are formed, which arrange together in the region of the rollers thereby supporting the seat on stationary body components if deformation occurs in this region. 
     Additionally, let is still be mentioned, that in accordance with FIG. 1, each guide rail  2  features latch holes  50 , which are located distributed along at least part of its length, and which cooperate with an unillustrated locking device fastened on the respective support element  32 , to arrest the car seat in its adjusted position. As illustrated, the latch holes  50  are located especially in the respective guide rail  2  on the wall that features the first lateral guide surface  16 . 
     The invention is not restricted to the examples that have been illustrated and explained, but also includes all embodiments which work in a manner identical to the meaning of the invention. Furthermore, the foregoing discussion discloses and describes a preferred embodiment of the invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that changes and modifications can be made to the invention without departing from the true spirit and fair scope of the invention as defined in the following claims.