Abstract:
An adjusting device is disclosed for performing at least one adjusting function, such as in a vehicle seat. The device comprises a drive having a drive means and an output, a braking device that generally prevents torque from the output acting on the drive means. At least one spring is arranged between the drive and the braking device.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from and the benefit of PCT Application No. PCT/EP2009/005386, filed on Jul. 24, 2009 and German Patent No. DE 10 2008 034 800.7, filed on Jul. 24, 2008; both entitled “Adjusting Device, Particularly for a Vehicle Seat”, which are herein incorporated by reference. 
       BACKGROUND 
       [0002]    The invention relates to an adjusting device for performing at least one adjusting function, particularly for adjusting a motor vehicle seat, having a drive, which has a drive means and an output, and a braking device, which very largely prevents any torques from the output acting on the drive means. 
         [0003]    Adjusting devices of this kind are known, for example, from U.S. Pat. No. 4,211,451, DE 32 01 309 and US 2005/0245348 A1 and are suitable for electric or, preferably, manual actuation of a device for adjusting the height of a motor vehicle seat, for example. In this case, the adjusting device converts an input drive torque into a higher output torque, which is used for angular adjustment of components connected thereto, e.g. of the seat height adjuster. In order at least to reduce torques from the drive unit acting on the planetary gear, the adjusting devices have braking devices. However, the adjusting devices known from the prior art are of comparatively complex construction and/or are difficult to assemble. Another disadvantage is that the number of actuations of the adjusting device for the desired adjustment travel is too great. 
         [0004]    It was therefore the object of the present invention to make available an adjusting device which does not have the disadvantages of the prior art. 
       SUMMARY 
       [0005]    The object is achieved by means of an adjusting device for performing at least one adjusting function, particularly for adjusting a motor vehicle seat, having a drive, which has a drive means and an output, and a braking device, which very largely prevents any torques from the output acting on the drive means, wherein at least one spring means is arranged between the drive and the braking device. 
         [0006]    With the adjusting device according to the invention, it is possible to perform any desired adjustments at an adjusting mechanism. However, the adjusting device according to the invention is preferably used to adjust a motor vehicle seat. For example, the adjusting system according to the invention can be used to vary the height of the seat surface, the slope of the backrest relative to the seat surface and the shape of the seat. The adjusting system according to the invention can be driven either manually or by motor. The adjusting device according to the invention is of simpler construction than adjusting devices in accordance with the prior art and is easier to manufacture. With the adjusting device according to the invention, the same adjustment travel is achieved with a smaller number of actuations. 
         [0007]    By means of the braking device, torques from the output acting on the drive are at least partially and preferably completely eliminated. The braking device preferably acts in two directions of rotation. 
         [0008]    According to the invention, the adjusting device has at least one and preferably more spring means between the drive and the braking device. Any spring means known to a person skilled in the art which reassumes its original shape after an elastic deformation may be considered as spring means. The spring means can be manufactured from plastic and/or steel. 
         [0009]    The spring means preferably moves the drive back into a starting position after each actuation, particularly preferably immediately after each actuation. During this process, the spring means preferably decouples the drive from the braking device. By virtue of this preferred embodiment, the adjusting device according to the invention has less free play. Moreover, the risk of the braking device unlocking itself is at least prevented. 
         [0010]    In a preferred embodiment, the drive has an actuator, and the braking device has a braking part. The spring means is arranged between them. During a movement, preferably a rotation, of the actuator, which the braking means does not accompany, at least not in full, the spring means is deformed. As soon as the driving force disappears, the spring means moves the actuator and/or the braking means back into the starting position thereof, in which they are, in particular, no longer in engagement with one another. 
         [0011]    The spring means is preferably mounted with nonpositive and/or positive engagement in the actuator and/or in the braking part. This is accomplished, in particular, by means of recesses which are situated in the actuator and/or the braking part and which each partially accommodate the spring means. 
         [0012]    The braking device preferably acts in two directions of rotation. 
     
    
     
       DRAWINGS 
         [0013]    The invention is explained below with reference to  FIGS. 1-7 . These explanations are given purely by way of example and do not restrict the general inventive concept. 
           [0014]      FIG. 1  shows an exploded drawing of an adjusting device. 
           [0015]      FIG. 2  shows the braking device. 
           [0016]      FIG. 3  shows the interaction between the braking device and the drive. 
           [0017]      FIG. 4  shows an exploded drawing of the adjusting device according to the invention. 
           [0018]      FIG. 5  shows details of the actuator and of the braking part. 
           [0019]      FIG. 6  shows the spring means between the actuator and the braking part. 
           [0020]      FIG. 7  shows how the spring means is arranged in the braking part. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    The adjusting device  1  illustrated schematically and by way of example in the following figures has a ribbed housing  2  made of plastic  2 , for example, from which the drive shaft  3 , which is provided with a fine toothing and is supported in the housing  2 , projects. A hand wheel for manual actuation of the adjusting device  1  can be mounted subsequently on this toothing, or a motor can be connected thereto. The housing  2  furthermore has holes  4  for attachment of the adjusting device  1  to the lateral member of the metal structure of a seat part, for example. The housing  2  is provided on the inside with an internal toothing  5 , which extends coaxially with respect to the drive shaft  3  and in which three planetary gearwheels  6  revolve around an external toothing  7  on the drive shaft  3 , said toothing projecting into the housing  2 . As the drive shaft  3  rotates, the axes  8  of the planetary gearwheels  6  thus orbit on a circular path in the housing  2  at a lower speed of revolution than the drive shaft  3 . The drive shaft  3  can have a compensation means, e.g. a compensation ring, by means of which manufacturing tolerances are compensated, noise is reduced and/or a perceptible resistance to rotation is produced. The rotation of the drive shaft  3  is received by an annular planet carrier  9 , which can be rotated coaxially with respect to the drive shaft  3 . Parallel to its axis of rotation, the planet carrier has journal pins  10  projecting from the axial surface thereof in the direction of the planetary gearwheels  6 . The planetary gearwheels  6  are rotatably mounted on these journal pins  10 . The components (subassembly A) described above thus form a planetary gear. The planetary gear can be rotated in two directions of rotation. 
         [0022]    The planet carrier  9  is the interface with a braking device (subassembly B) of the one-way clutch type, which is intended to isolate the planetary gear (subassembly A) as fully as possible from torques acting on the adjusting device  1  from the output side. These torques can act in two directions of rotation. The subassembly  13  comprises a brake ring  11  punched out of a steel sheet, which has outward-extending lugs  12 . The brake ring  11  is pushed into the housing  2 , which has a complementary shape, with holes  13  in the lugs  12  coinciding with holes  4  in the housing  2 . The brake ring  11  is furthermore provided with a circular aperture  14 , which is coaxial with the drive shaft  3  and accommodates the inner ring  15  of the braking device. 
         [0023]    Arranged in the gap  16  between the brake ring  11  and the inner ring  15  are pairs of cylindrical rolling contact elements  17 ,  17 ′, the rolling contact elements  17 ,  17 ′ of each pair being spread apart by an elastomer body  18  situated therebetween and acting as a spring means. However, a person skilled in the art will realize that this can be any other spring means, e.g. a spiral spring. The outer circumference of the inner ring  15  is configured in such a way that the gap  16  is larger in the region of each elastomer block  18  than the diameter of the rolling contact elements  17 ,  17 ′, which are similar, but narrows in the direction away from the elastomer block  18  to a height less than the diameter of the rolling contact elements  17 ,  17 ′. Each pair of rolling contact elements  17 ,  17 ′ is thus trapped in a partial area of the gap  16 . When the inner ring  15  is rotated relative to the brake ring  11 , one rolling contact element  17  of each pair is jammed in the narrowing region of the gap  16  owing to a spiral geometry  36  on the inner ring  15  in the direction of the rolling contact element  17 ,  17 ′, with the result that further rotation is prevented. When the inner ring  15  is rotated in the opposite direction, jamming is accomplished by means of the other rolling contact element  17 ′ of the pair. This prevents the significant torques which occur in the case of an accident from being transmitted to the planetary gear. 
         [0024]    On its side facing away from subassembly A, the planet carrier  9  is equipped with pairs of projections  19 ,  19 ′, which project between the pairs of rolling contact elements  17 ,  17 ′ and into the gap  16 . The interspaces  21  between each pair of projections  19 ,  19 ′ interact, subject to play, with bosses  20  on the outer circumference of the inner ring  15 , while those surfaces of the projections  19 ,  19 ′ which face away from the interspaces  21  act alternately on the rolling contact elements  17 ,  17 ′ when the inner ring  15  is rotated. When the inner ring  15  is rotated, the jammed rolling contact elements  17 ,  17 ′ are thereby released first of all, with the play between the projections  19  of each pair and the bosses  20  being used up. As soon as each projection  19  is resting against the associated boss  20 , a torque is transmitted directly from the planet carrier  9  to the inner ring  15 . During rotation in the opposite direction, this takes place in a corresponding way through contact between the bosses  20  and projections  19 ′. 
         [0025]    Arranged on the inner ring  15 , on the side facing away from subassembly A, is a thrust washer  22 , which rotates with the inner ring  15  and rests against the housing cover  23 . The outer contour of the housing cover  23 , which can be locked to the housing  2 , is designed to be congruent with the brake ring  11 , thus allowing them to be inserted into the housing  2  in the same way. The housing cover  23  is provided with a rim hole  24 , which is aligned coaxially with respect to the drive shaft  2  and in which the output shaft  25  is supported. In this case, the housing cover is preferably manufactured from a metallic material. However, the housing cover can be manufactured from plastic if it is required only for protection. The housing cover is mounted with positive and/or nonpositive engagement on the preassembled unit, being screwed or riveted on, for example. However, the cover  23  is preferably mounted on the housing  4  by means of a quick-release fastener, e.g. a snap fastener. The output shaft  25 , which extends coaxially with respect to the drive shaft  3 , has a cylindrical region  26  suitable for support, adjoining which toward the outside is the output pinion  27 . On the opposite side, the output shaft  25  is provided with a polygonal profile  28 , which engages without play in an aperture  29  of complementary configuration in the inner ring  15 . A person skilled in the art will realize that the output shaft  25  and the inner ring  15  can be embodied in one piece. 
         [0026]    When the adjusting device  1  is actuated, the drive torque is thus transmitted via the drive shaft  3 , the planetary gearwheels  6  and the planet carrier  9  to the inner ring  15  and, from there, to the output pinion  25 . A torque acting from the output side is transmitted via the output shaft  25  to the inner ring  15  and is then taken by the brake ring  11  through the jamming of the rolling contact elements  17  or  17 ′. The planet carrier  9 , the planetary gearwheels  6  and the housing  2  are thereby relieved of load and can be given correspondingly weaker dimensions. This adjusting device is described in detail in patent application DE 10 2007 017 617.3, which is incorporated herewith as a reference and thus counts as part of the disclosure. 
         [0027]      FIG. 4  shows an embodiment of the adjusting device according to the invention which is based on the adjusting device in accordance with  FIGS. 1-3 , and a person skilled in the art will realize that the adjusting device according to the invention is not limited to this embodiment but includes any adjusting device which has a drive part and a braking part. From  FIG. 4 , it can be seen that a spring means is arranged between the drive A and the braking device B. In particular, the drive unit A has an actuator  9 , and the braking device B has a braking part  39 . 
         [0028]    The spring means  42  is arranged between these two parts  9 ,  39 . As soon as a torque is exerted on the actuator  9 , the spring means  42  is deformed elastically until the positive and/or nonpositive engagement means  20  of the actuator  9  is resting against the positive and/or nonpositive engagement means  19 ,  19 ′ of the braking part  39 . As soon as there is no longer a torque being applied to the actuator  9 , the actuator, in particular, is moved back into its starting position and the means  20  thus no longer rests against the means  19 ,  19 ′. 
         [0029]      FIG. 5  shows details of the actuator  9  and of the braking part  39 . It is clearly apparent that both have recesses  40  and  41 , respectively, each of which at least partially accommodate the spring means  42 . 
         [0030]      FIG. 6  once again shows the actuator  9  and the braking part  39  and the spring means  42  arranged therebetween. 
         [0031]      FIG. 7  shows how the spring means  42  is fitted into the braking part  39 . The spring means  42  is fitted into the recess  40  in the actuator  9  in a similar manner. 
       LIST OF REFERENCE SYMBOLS 
       [0000]    
       
         
           
               1  adjusting device 
               2  housing 
               3  drive means, drive shaft 
               4  hole 
               5  internal toothing 
               6  planetary gearwheel 
               7  external toothing 
               8  axis 
               9  planet carrier, actuator 
               10  journal pin 
               11  brake ring 
               12  lug 
               13  hole 
               14  aperture 
               15  inner ring 
               16  gap 
               17 ,  17 ′ rolling contact element, braking element 
               18  elastomer block, spring means 
               19 ,  19 ′ projection, recess, positive and/or nonpositive engagement means 
               20  boss, depression, positive and/or nonpositive engagement means 
               21  interspace 
               22  thrust washer 
               23  housing cover 
               24  rim hole 
               25  output shaft 
               26  cylindrical region, 
             output real 
               28  polygonal profile 
               29  cylindrical area 
               30  hole 
               31  pin 
               32  hole 
               33  inner circumference 
               34  annular projection 
               35  compensation means, compensation ring 
               36  driver geometry, spiral geometry 
               37  shoulder 
               38  projection, nose 
               39  braking part 
               40  recess 
               41  recess 
               42  spring means 
             A planetary gear, drive 
             B braking device