Abstract:
An adjustment system for a vehicle seat with two rail pairs aligned in longitudinal vehicle direction, which are connected with each other via a carrier element oriented in transverse vehicle direction, which carries an electromotive driving device which via drive shafts is connected with a longitudinal adjustment device of the rail pairs. For use with different track gages of the rail pairs, the carrier element is formed as multipart element with at least two carrier element parts shiftable against each other in transverse vehicle direction.

Description:
[0001]    CROSS-REFERENCE TO A RELATED APPLICATION 
         [0002]    This application is a National Phase Patent Application of International Patent Application Number PCT/EP2014/052572, filed on Feb. 11, 2014, which claims priority of German Patent Application Number 10 2013 202 327.8, filed on Feb. 13, 2013. 
     
    
     BACKGROUND 
       [0003]    This invention relates to an adjustment system for a vehicle seat with two rail pairs aligned in longitudinal vehicle direction. 
         [0004]    From DE 10 2007 027 322 A1 there is known a rail adjustment system for a motor vehicle seat with two rail pairs aligned parallel and at a distance to each other in longitudinal direction of the motor vehicle or in X-direction of the motor vehicle system of coordinates, which each consist of a stationary lower rail connected with the motor vehicle floor and an upper rail connected with the motor vehicle seat, which is longitudinally shiftably guided in the lower rail. The upper rails of the rail pairs are connected with each other via a holding element aligned in transverse vehicle direction or in Y-direction of the motor vehicle system of coordinates, which carries a drive motor which on both sides cooperates with spindle gear units of the rail pairs via rigid or flexible drive shafts for the longitudinal adjustment of the rail pairs. Via the drive shafts and the spindle gear units, a rotary movement of the drive motor is converted into a longitudinal adjustment of the respective upper rail against the corresponding lower rail of the rail pairs. 
         [0005]    Since the holding elements are adjusted to the track gages or mutual distances of the rail pairs and are able to compensate track gage tolerances only in a small range of few millimeters, a plurality of holding elements and drive shafts is to be provided for the connection of motor vehicle seats of different manufacturers because of the different track gages of the rail pairs required for the motor vehicle seats, which renders the manufacture and stockkeeping of the holding elements much more expensive and complicates the assembly. 
       SUMMARY 
       [0006]    Therefore, it is an object of the present invention to provide an adjustment system as mentioned above, which is usable for different track gages of rail pairs for the longitudinal adjustment of vehicle seats. 
         [0007]    According to the invention, this object is solved with the features as described herein. 
         [0008]    The solution according to the invention provides for the manufacture of a carrier element for accommodating an electric driving device for the longitudinal adjustment of vehicle seats, which is usable for different track gages of the rail pairs for accommodating the vehicle seat. 
         [0009]    The at least two carrier element parts of the multipart carrier element according to the invention, which are shiftable against each other in transverse vehicle direction, thus can be inserted into rail pairs for vehicle seats with different track gage down into the centimeter range, so that all vehicle seats customary for the market, which require different track gages of the rail pairs, can be covered. 
         [0010]    For adaptation to the respective track gage of the rail pairs in the manner of a rail adjustment system, the carrier element parts are shiftable against each other in an interlocking manner and have a closed or open profile. 
         [0011]    A preferred embodiment of a closed profile of the carrier element is formed tubular, wherein the one tubular carrier element part is insertable into the other tubular carrier element part with variable depth for track gage compensation. 
         [0012]    This type of connection of two carrier element parts ensures a high stability of the carrier element and an easy assembly, in that the end of the one carrier element part of the at least two carrier element parts inserted into each other for track gage compensation is connected with the one rail pair and the other carrier element part is moved to the other rail pair and connected with the same by utilizing the track gage compensation. 
         [0013]    A preferred embodiment of an open profile of the carrier element consists of at least two carrier element parts, which have a box-like or rectangular cross-section and are inserted into each other in the manner of a drawer, wherein a first carrier element part has a closed rectangular profile or a rectangular profile open at the bottom, which includes an upper surface, two side faces and selectively a bottom surface as well as a flange portion for connecting the first carrier element part with one of the two rail pairs, and the second carrier element part has a rectangular profile open at the top, which consists of a bottom surface, an open upper surface, two side faces angled towards the upper surface, and a flange portion for connecting the second carrier element part with the other one of the two rail pairs. 
         [0014]    Carrier element parts formed differently long provide for the connection of the electromotive driving device with the shorter one of the two differently long carrier element parts and hence a minimum load acting on the carrier element due to the arrangement of the electromotive driving device close to the connection of the carrier element to one of the two rail pairs. 
         [0015]    In the case of differently long carrier element parts, the longer one of the two differently long carrier element parts has a terminal adjusting portion which is insertable into a counter-adjusting portion of the shorter one of the two differently long carrier element parts. 
         [0016]    In a preferred embodiment, the carrier element part is formed in three parts with an open or closed profile and includes a first carrier element part connected with the one rail pair, a second carrier element part connected with the other rail pair, and a third carrier element part arranged between the first and the second carrier element part, which is shiftable with respect to the first carrier element part and is connectable with the second carrier element part via a plug-in or flange connection, wherein the electric driving device in particular is arranged in or at the middle, third carrier element part or between the second and the third carrier element part. 
         [0017]    The three-part formation of the carrier element provides for the arrangement of the track gage compensation in the connection of the middle, third carrier element part with the first carrier element part, which is connected with the one rail pair, and for an easy insertion of a drive motor into the connection of the middle, third carrier element part with the second carrier element part which is connected with the other rail pair, wherein in a preferred embodiment the first carrier element part is longer than the second and third carrier element parts connected with each other. 
         [0018]    A clip connection which connects the carrier element parts accommodating the electric driving device with each other provides for an easy, fast assembly and connection of the carrier element with the two rail pairs. 
         [0019]    Preferably, the two carrier element parts of the two-part carrier element or the first and second carrier element parts of the three-part carrier element are connected with the one or other rail pair by means of terminal connecting flanges. 
         [0020]    For weight minimization, the carrier element parts are made of a plastic material and include reinforcement ribs for increasing the stability, in particular for increasing the bending strength of the carrier element. 
         [0021]    For transmitting the driving force of the electromotive driving device to the longitudinal adjustment devices of the rail pairs, rigid or in particular flexible drive shafts are connected with the electromotive driving device and for example each with a spindle nut of a spindle gear unit for the longitudinal adjustment of the rails. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    With reference to two exemplary embodiments illustrated in the drawing the idea underlying the invention will be explained in detail. 
           [0023]      FIG. 1  shows a perspective exploded representation of the individual parts of an adjustment system for vehicle seats with a three-part carrier element with closed profile and integrated track gage compensation. 
           [0024]      FIG. 2  shows a perspective representation of the completely mounted adjustment system. 
           [0025]      FIG. 3  shows a section through the adjustment system along line III-III according to  FIG. 2  with a side view of the carrier element with closed profile and integrated track gage compensation, which is arranged between two rail pairs. 
           [0026]      FIG. 4  shows a perspective representation of a two-part carrier element with an open profile and integrated track gage compensation. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    In a perspective exploded representation,  FIG. 1  shows the parts of an adjustment system for a vehicle seat with rail pairs  1 ,  2  arranged opposite each other at the distance of a track gage S and extending parallel to each other, which each contain a lower rail  11 ,  21  firmly connected with the vehicle floor and an upper rail  12 ,  22  longitudinally shiftably mounted in the respective lower rail  11 ,  21  in X-direction of the X-Y system of coordinates schematically indicated in  FIG. 1 , to which rails the vehicle seat is attached. 
         [0028]    With the upper rails  12 ,  22  of the rail pairs  1 ,  2  a three-part carrier element  3  is connected, which thus extends transversely to the orientation of the rail pairs  1 ,  2 , i.e. in Y-direction of the system of coordinates. The three-part carrier element  3  includes a first, long carrier element part  4  which includes a retaining tab  40  connectable with the upper rail  12  of the first rail pair  1  by means of fastening screws, rivets or clips  10 , a second, short carrier element part  5  which includes a retaining tab  50  connectable with the upper rail  22  of the second rail pair  2  by means of connecting screws, rivets or clips  10 , and a third, middle carrier element part  6  arranged between the first and the second carrier element part  4 ,  5 . All three carrier element parts  4 ,  5 ,  6  have a closed profile and are formed as tubular injection-molded plastic parts with rib and/or grating structures for increasing the stiffness. 
         [0029]    The first carrier element part  4  is longer than the second and third carrier element parts  5 ,  6  put together and contains a rib structure portion  41  as well as an adjusting portion  42  which with a sliding fit is insertable into a counter-adjusting portion  62  of the third, middle carrier element part  6 . The third carrier element part  6  includes a hollow cylindrical receiving portion  61  adjoining the counter-adjusting portion  62 , into which a drive motor  7  can be inserted. By inserting a hollow cylindrical connecting portion  51  of the second carrier element part  5  into the hollow cylindrical receiving portion  61  of the third carrier element part  6 , the second carrier element part  5  is connected with the third carrier element part  6  via a clip connection  52 ,  63 . 
         [0030]    Into the guide channel formed in the interior space of the tubular first carrier element part  4  a first drive shaft  8  is inserted and connected on the one hand with the drive motor  7  arranged in the third carrier element part  6  and on the other hand with the longitudinal adjustment device of the first rail pair  1 . In the same way, a second drive shaft  9  is put through the guide channel formed in the tubular interior space of the second carrier element part  5  and connected on the one hand with the drive motor  7  and on the other hand with the longitudinal adjustment device arranged in the second rail pair  2 . 
         [0031]    The drive shafts  8 ,  9  can be formed both as rigid and as flexible drive shafts. 
         [0032]    After connecting the retaining tab  40  of the first carrier element part  4  with the upper rail  12  of the first rail pair  1 , the flange portion  50  of the second carrier element part  5  connected with the third carrier element part  6  can be moved to the fastening points of the upper rail  22  of the second rail pair  2 , wherein the length of the carrier element  3  is adapted to the track gage S of the two rail pairs  1 ,  2  by the track gage compensation A arranged between the adjusting portion  42  of the first carrier element part  4  and the counter-adjusting portion  62  of the third carrier element part  6 . 
         [0033]    Alternatively, it is of course possible to first move the retaining tab  50  of the second carrier element part  5  with the fastening points of the upper rail  22  of the second rail pair  2  and subsequently the flange portion  40  of the first carrier element part  4  connected with the third carrier element part  6  via the track gage compensation A to the fastening points of the upper rail  12  of the first rail pair  2 . 
         [0034]      FIG. 2  shows the carrier element  3  in the assembled state between the two rail pairs  1 ,  2 , wherein the length of the carrier element  3  without retaining flanges  40 ,  50  corresponds to the track gage S, i.e. the mutual distance of the rail pairs  1 ,  2  aligned parallel to each other, which in particular can be taken from the section along line III-III according to  FIG. 2 , which is shown in  FIG. 3 . 
         [0035]    For adapting the length of the carrier element  3  to the track gage S, the adjusting portion  42  of the first carrier element part  4  engages into the counter-adjusting portion  62  of the third carrier element part  6  within the maximum possible track gage compensation A indicated by a double arrow in  FIG. 3  to such an extent that the carrier element  3  has a length corresponding to the track gage S of the rail pairs  1 ,  2  spaced from each other. 
         [0036]    The drive shafts  8 ,  9  guided in the guide channels of the carrier element parts  4 ,  5 ,  6  protrude into the cavity formed between the upper rails  12 ,  22  and lower rails  11 ,  21  of the rail pairs  1 ,  2  and for example are connected there with a worm gear of a spindle gear unit, which meshes with a spindle nut of the spindle gear unit. A rotary movement of the drive motor  7 , which is arranged in the hollow cylindrical receiving portions  21 ,  61  of the second and third carrier element parts  5 ,  6 , which are firmly connected with each other via the clip connection  63 ,  52 , is transmitted to the spindle nut via the drive shafts  8 ,  9 , which for the longitudinal adjustment of the vehicle seat is rolling on a threaded spindle connected with the lower rails  11 ,  21 . 
         [0037]      FIG. 4  shows a perspective representation of a two-part carrier element  3 ′ with an open profile for a floating mount of two carrier element parts  4 ,  5 . 
         [0038]    The two-part carrier element  3 ′ with open profile is composed of a first carrier element part  4  and a second carrier element part  5  accommodating the first carrier element part  4 . Both carrier element parts  4 ,  5  have a box-like or rectangular cross-section and substantially are guided in each other along their entire length. The first carrier element part  4  has a rectangular profile selectively closed or open at the bottom, which includes an upper surface  46 , two side faces  44 ,  45  and a bottom surface  43  or in the open form no bottom surface  43  as well as a flange portion  40  which is connected with one of the two rail pairs  1 ,  2  analogous to the representations in  FIGS. 1 to 3 . 
         [0039]    The second carrier element part  5  accommodating the drive motor  7  includes an open upper surface, a bottom surface  53  and two side faces  54 ,  55  with angled upper edges  56  as well as a flange portion  50  for connecting the second carrier element part  5  with the other one of the two rail pairs  1 ,  2 . 
         [0040]    A guiding groove  47  at the upper edges of the first carrier element part  4 , which are formed between the upper surface  46  and the side faces  44 ,  45 , is enclosed by the angled upper edges  56  of the second carrier element part  5  to form a slideway between the first carrier element part  4  and the second carrier element part  5 , so that the first carrier element part  4  is guided in direction of the double arrow B within the angled upper edges  56  of the second carrier element part  5  in the manner of a drawer system. 
         [0041]    This second embodiment of the solution according to the invention provides for a larger track gage compensation, which with an open base surface  43  of the first carrier element part  4  reaches from the complete coverage of the open profile of the second carrier element part  5  up to an extraction of the carrier element part  4 , which is given by a safety-relevant minimum engagement of the first carrier element part  4  into the second carrier element part  5 .