Abstract:
The present invention relates to a device for adjustment of level of inclination of back part of a motor vehicle seat having a device part ( 2 ) affixed to the seat part and a device part ( 3 ) affixed to the back part, which can be pivoted counter to each other about a pivot axis ( 14 ), wherein both device parts ( 2, 3 ) have parts of gearings ( 4, 5 ) forming a swash mechanism, which roll on each other under the action of eccentric elements ( 11 ) that can be rotated about a pivot axis ( 14 ). The eccentric elements ( 11 ) are comprised of an eccentric ring ( 12 ), on which two regionally covering mirroring wedge segments ( 13 ) lie These are urged away from each other in the sense of an increase in eccentricity (e) by spring elements ( 15 ) arranged one of their front surfaces ( 13.3 ). The object of the invention is to provide a device for adjustment of the level of inclination, wherein the space between the fronts of the wedge segments loaded by the spring elements is free of support elements in order to facilitate the incorporation of the spring elements. This object is achieved in that the support of the wedge segment ( 13 ) is on its other surface ( 13.4 ), in that there radial stop surfaces ( 31.1 ) are provided on the wedge segments ( 13 ) and radial stop surfaces ( 30.1 ) are provided on the eccentric ring ( 12 ), whereby the stop surfaces ( 31.1, 30.1 ) each are formed on projections ( 31. 30 ) of the wedge segment ( 13 ) or of the eccentric ring ( 12 ).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the priority of German Patent Application 10 2004 013 272.0 filed on Mar. 18, 2004, the entire contents of which is hereby incorporated in total by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention. 
   The present invention relates to a device for adjustment of the level of inclination of the back of a motor vehicle seat. 
   2. Description of Related Art. 
   This type of device for adjustment of the level of inclination has an inside and an outside gearing, which are manufactured by forming using cutouts of the metal plate of the device parts. Here the outer gearing has one less tooth than the number of teeth on the inside gearing and one of the devices is mounted on a cam means that can be rotated about the pivot axis, said eccentric means in turn is mounted on the other device. In the device concerned here for adjustment of the level of inclination the cam means are comprised of two wedge segments, which are mounted directly or indirectly on the one device part and are urged apart from each other by means of an energy storage device, most generally a spring, in terms of an increase of the eccentricity in the peripheral direction. By doing so, any play in the gearing and in the mounting is avoided. In a drive of the eccentric means about the pivot axis of the device for adjusting inclination the inside gearing or the one device part rolls on the outside gearing of the other device part, whereby a pivoting is obtained corresponding to the difference in toothing of the device part affixed to the back part vis-a-vis the device part affixed to the seat. Devices of this type for adjusting the level of inclination are, for example, known form DE 30 13 304 A1, DE 199 38 666 A1 and DE 101 44 840 1. In these devices the eccentric rings are joined so as not to rotate with a rotary adjusting member that introduces torque. The carrier means for loading the wedge segments are configured on the eccentric ring. For release of the wedge segments, the eccentric ring must initially be rotated against the frictional force and the forces acting from the backrest on the wedge segments, whereby at the start of the adjustment there is a substantial mechanical friction (tightness). 
   In these prior art devices for adjusting inclination, stops are provided for the purpose of limiting the load on the spring elements arranged between the wide front surfaces of the wedge segments beyond the spring elements&#39; limit of elasticity. These consist of either projection oriented to each other and formed on the wide front surfaces of the wedge segments or, however, of spacers disposed in the space between said front surfaces. These support elements have the drawback that they make assembly of the spring element more difficult by constricting the installation space between the front surfaces of the wedge segments. 
   DE 101 57 273 A1 discloses a device for adjusting inclination, wherein the carrier means, in this case a pair of carrier fingers, are arranged separated from the eccentric ring force free in the device for adjusting inclination. The eccentric elements in this device for adjusting inclination are also comprised of an eccentric ring and two wedge segments mounted thereupon. The eccentric ring is assembled from two mirrored disks arranged behind one another and which have mounting holes, into which one of each of the ends of a omega spring engage, so that the two disks of the eccentric ring are biased relative to each other in the peripheral direction. In order to release the wedge segments the rotary adjusting element is turned, so that one of the carrier fingers carries one of the disks of the eccentric ring. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is to provide a device for adjusting inclination, wherein the space between the faces of the wedge segments loaded by the spring element for facilitation of installation of the spring means is free of support elements. 
   This object is achieved according to the invention using a device for adjusting inclination described in this disclosure. 
   Thus, according to the invention, the support elements are moved, for preventing overloading the spring element, from the constricted space between the front surfaces of the wedge segments loaded by the spring elements at the other front surfaces of the wedge segments. The space between the front surfaces of the wedge segments loaded by the spring element is now free from “internals”, which facilitates the assembly of the spring elements. 
   By providing a gap between the alternating stop surfaces of the wedge segments and the eccentric ring, it is possible to shift the wedge segment loaded by the carrier element on the eccentric ring so that the wedge segment is released. If the stop surfaces of the wedge segment and the eccentric ring come in contact, then the driven wedge segment carries the eccentric ring; that is, it rotates it about the pivot axis of the device for adjusting inclination. In virtue of the rotation of the eccentric ring the wedge segment not loaded by the carrier means is released and he stop surface of the wedge segment comes into contact at the associated stop surface of the eccentric ring. By doing this, overloading the spring element is avoided. 
   These and other features of the invention will be more fully understood by reference to the following drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  represents the components of a device for adjusting inclination according to the invention in a perspective exploded view; 
       FIG. 2  is a representation according to  FIG. 1 , for a different point of view; 
       FIG. 3  represents a side view of the assembled device for adjusting inclination; 
       FIG. 4  represents a perspective view onto the representation according to  FIG. 3  opposite to the direction of the arrow A with the cover removed; 
       FIG. 5  is a representation according to  FIG. 3  in the direction of the arrow A; 
       FIG. 6  represents a section B—B according to  FIG. 5 ; 
       FIG. 7  represents a section C—C according to  FIG. 3 , and 
       FIG. 8  represents an enlarged section D according to  FIG. 7 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   During the course of this description, like numbers will be used to identify like elements according to the different views that illustrate the invention. 
   The device for adjusting inclination  1  represented in the figure is part of an motor vehicle seat (not shown) having a seat part and a back part, whereby the back part can be adjusted in its inclination relative to the seat part by using a device for adjusting inclination  1 . To do this, the inclination adjustment device  1  has a device part  2  affixed to the seat part and a device part  3  affixed to the back part. The two device parts  2 ,  3  are deep-drawn steel plates, wherein the device part  2  has an outside gearing  4  pressed from the plate and device part  3  has an inside gearing  5  pressed from the plate. The outside gearing  4  has—in the same module—a gearing with one tooth less than that of the inside gearing  5 . In the assembled device for adjusting inclination  1  the outside gearing  4  would come together with the inside gearing  5 . 
   In addition, the device part  3  has a passage  6  expressed concentrically to the inside gearing  5  with a circular passage opening  7 . An inner bearing ring  8  can be slipped onto the passage  6 . The device part  2  also has a circular passage  9  concentrically arranged relative to the external gearing  4 , into which an outer bearing ring  10  can be inserted. 
   The bearing rings  8 ,  10  serve to bear eccentric elements  11 . These consist of an eccentric ring  12  and two identical, mirrored wedge segments  13  arranged on it. In the assembled condition the eccentric ring  12  is pushed onto the inner bearing ring  8 , the wedge segments  13  lie with their inner surfaces  13 . 1  on the outside surface  12 . 1  of the eccentric ring  12  and the outer surfaces of the outer surfaces  13 . 2  of the wedge segments  13  are supported on the inside  10 . 1  of the outside bearing ring  10 . This arrangement can be best seen in the representation according to  FIG. 7 . In order to avoid the presence of only one contact point between the inside bearing ring  8  and the inside surface  12 . 2  of the eccentric ring  12 , which results in a “tilting” of the device part  3  on device part  2 , the inside surface  12 . 2  of the eccentric ring  12  is imperfectly round compared to the inside bearing ring  8 , so that there are at least two contact points between these to components. The wedge segments  13  also do not flatly lie with their inside surfaces  13 . 1  on the outsides of  12 . 1  of the eccentric ring  12 . The alternating curvature of the inside surfaces  13 . 1  and the outside surfaces  12 . 1  are designed so that between them there is linear contact. The outside surfaces  13 . 2  of the wedge segment  13  have, on the other hand, the same curvature as that of the inside  10 . 1  of the outside bearing ring  10 . The wedge segments  13  consequently lie flatly on the outside mounting ring  10 . 
   The outside  12 . 1  of the eccentric ring  12  covered by the wedge segments  13  rises wedgelike opposite its inside  12 . 2 . The increasing wall thickness of the eccentric ring  12  resulting therefrom is utilized at the end of the rise for forming a projection  30  having a radially outwardly oriented stop surface  30 . 1 , wherein said protrusion  30  is formed by a material reversal to a smaller dimension of the eccentric ring  12 . Stop surfaces  31 . 1  are associated with these stop surfaces  30 . 1  of the eccentric ring  12 , which are provided with a radially inwardly oriented projection  31  at a zone of the narrow surface  13 . 4  of the wedge segment  13 . Between the stop surfaces  30 . 1  and  31 . 1  there is a space b in the un-operated eccentric element  11 , which is best represented in  FIG. 8 . In virtue of the cuneiform rise of the outside  12 . 1  of the eccentric ring  12  the insides  13 . 1  of the wedge segments  13  have contact with an opposing wedge surface. This opposing wedge formation makes possible an optimum layout of the wedge angle of the wedge segments  13 . 
   A stop cam  32  having two radial stop surfaces  32 . 1  symmetrical to the two projections  30  of the eccentric ring  12  is formed by its free zone wedge segments  13  by strengthening of the wall thickness of the eccentric ring  12 . 
   Because of this intervention of the eccentric element  11  between the two device parts  2  and  3  there is an eccentricity e between the central axis of the passage opening  7  of the device part  3  forming the pivot axis  14  of the device for adjusting inclination and the central axis  16  of the passage opening  9  of the device part  2  (see  FIGS. 3 and 6 ). This eccentricity e assures that the outer gearing  4  in extension of the direction of the eccentricity e is urged into the inner gearing  5  of the device part  3 . In order to form this engagement of outer gearing  4  and inner gearing  5  and the bearing of the two device parts  2  and  3  without any play, the wedge segments  13  are loaded by spring elements in such a fashion that they are urged away from each other peripherally on the eccentric ring  12  in terms of an increase of eccentricity e. In the present exemplary embodiment an omega spring  15  is provided as the spring element, whose rectangular members  15 . 1  abut on the facing surfaces  13 . 3  of the wedge segments  13  and urge these, as described, apart from one another. 
   The arrangement described above ensures that the device for adjusting inclination  1  is arrested without play in each set inclination of the back part, because the forces acting from the back part radially are absorbed by the wedge segments  13 ; that is, no controlling torques act upon them. The tension exerted by the omega spring  15  on the wedge segments  13  can be relieved only by the peripheral forces acting on the wedge segments  13 . In order to introduce such actuating movement on the eccentric element  11 , a two-part carrier comprised of a carrier hub  17  and a carrier disk  18  is provided. The carrier will be more completely described in the following. 
   Both the carrier hub  17  and the carrier disk  18  are made of metal. In this case the carrier hub  17  is executed as a die casting—or as a forged part—and the carrier disk  18  is a metal plate punched part. The carrier hub  17  has a cylindrical center section  17 . 1 , a collar  17 . 2 , which projects over the cylindrical center section  17 . 1  at a diameter, and a flange  17 . 3 , which is somewhat smaller in diameter and having an out-of-round cross-section; that is, a cross-section for transferring a torque. In the installed state, the center section  17 . 1  extends beyond the passage opening  7  of the passage  60  with low radial clearance, while its collar  17 . 2  lies externally on the device part. On the other side of the device for adjusting inclination  1  the carrier disk  18  is slipped onto the flange  17 . 3  of the carrier hub  17 . In order to do this, the carrier disk  18  has a central opening  18 . 1  having the same out-of-round cross-section as the flange  17 . 3 . After slipping on of the carrier disk  18  on the flange  17 . 3 , the carrier disk  18  is thus seated non-rotationally on the carrier hub  17 . For axial fastening of the carrier disk  18  to the carrier hub  17  material of the flange  17 . 3  is displaced onto the carrier disk  18 , so protruding lugs  19  occur that vis-a-vis the cross-section of the central opening  18 . 1  of the carrier disk  18 , as shown in  FIG. 6 . Consequently, the carrier hub  17  and the carrier disk  18  are bonded together by the lugs  19 . 
   As can be seen also in the representation of  FIG. 6 , there is an axial clamping of the two device parts  2  and  3  in addition to the retainers (not shown in the figure) in virtue of the collar  17 . 2  of the carrier hub  17  abutting on the device part  3  and the carrier disk  18  abutting on the device part  2  on the other side of the adjusting device  1 . These retainers are welded using weld bridges  20  to the device parts  2  and  3  and overlap the respective other device part  2  or  3  zonally on the periphery of the inner gearing  4  or the outer gearing  4 . 
   The carrier disk  18  has to expressed carrier fingers  21 . In the assembled device for adjusting inclination  1  these carrier fingers  21  reach over into an interspace formed between the eccentric ring  12  and the outer mounting ring  10 . When this is done, their one surface  21 . 1  with un-operated eccentric elements  11  lies peripherally at a distance c from the surfaces  13 . 4  of the wedge segments  13  facing away from the omega spring  15 . This peripheral space c between the surfaces  21 . 1  and  13 . 4  is provided so that the actuation movement of the wedge segments  13  by the omega spring  15  is not limited by premature contact with these two surfaces  13 . 4  and  21 . 1 . The other surfaces  21 . 2  of the carrier finger  21  lie in this situation at a distance a from the stop surfaces  32 . 1  of the stop cam  32 . 
   Along with the carrier fingers  21 , the carrier disk  18  also has openings  22  and  23 . The opening  22  serves as the passage for the member  15 . 1  of the omega spring  15 , while the openings  23  are used for locking a plastic cover  24  on the carrier disk  18 . To achieve this catch nubs  25  are provided on the cover  24 , which can be pushed into the openings  23  and can be locked in back of the holes. As a supplemental locking means a spring tab  26  is provided on the cover  24 , which passes through the opening  22  of the carrier disk  18  and latches behind it. 
   The cover  24  is used to cover the omega spring  15  and the carrier disk  18 ; particularly, however, covering of the open articulation zone of the device for adjusting inclination  1 , in order to protect it from contamination, especially at the time of painting operations. 
   The cover  24  has a hub formed by four tabs  27 , which is insertable positive fittingly into a central recess  28  of the carrier hub  17 . When this is done the inner surfaces of the tabs  27  form an out-of-round cross-section  29 , in the case of this exemplary embodiment a square cross-section, for positive reception of a drive rode (not shown) (see  FIG. 5 ). This drive rod serves in the introduction of a torque into the device for adjusting inclination  1  and can be part of a hand wheel or a motor-driven shaft. At the ends of the tabs  27  of the cover  24  latching projections  27 . 1  are provided projecting radially outwardly. These latch behind their collars  17 . 2  after pushing through the tabs  27  through the carrier hub  17 , as shown in  FIG. 6 . With the incorporated drive rod the tabs  27  can now no longer cushion radially, whereby the latching between the projections  27 . 1  and the collar  17 . 2  is secured. 
   The secured configuration of the cover  24  assures, in co-operation with the carrier hub  17  for their secure axial hold on the device for adjusting inclination  1 , and for an additional axial clamping of the two device parts  2  and  3 . In addition, the plastic tabs  27  arranged between the drive rod and the carrier hub  17  prevent a metal-to-metal contact between the drive rod and the carrier hub  17 , whereby undesired rattling noise is avoided. 
   For actuation of the device for adjusting inclination  1  a torque is transferred to the carrier disk  18  via the drive rod, driven by the handwheel or a motor-driven unit, the tabs  27  of the hub of the cover  24  and the carrier hub  17 . When this is done, the front  21 . 1  of one of its carrier fingers  21  reaches, depending on in which direction it is rotated, by overcoming the space c in contact with the front  13 . 4  of the wedge segments  13  associated with said carrier finger  21 . Upon further rotation of the carrier disk  18  work is applied against the force of the omega spring  15 ; that is, the tension of the wedge segment  13  loaded by the carrier fingers  21  between the eccentric ring  12  and the outside bearing  10 , is released by overcoming the space b. The stop surfaces  31 . 1  and  30 . 1  of the projections  31  and  30  of wedge segment  13  now lie adjacent to each other, so that the eccentric ring  12  is rotated about the pivot axis  14 . When this is done, the other wedge segment  13  is released, so that a radial clearance intervenes for displacement of the device for adjusting inclination  1 . Upon further drive by the drive rod, the wedge segments  13  co-rotate together with the eccentric ring  12  about the pivot axis  14 . Because of this rotary movement of the eccentric element  11 , the direction of the eccentricity e and thus also the point of action of the outer gearing  4  shifts into the inner gearing  5 . A swash rolling movement of the outer gearing  4  on the inner gearing  5  consequently occurs and the device part  3  pivots on the stationary device part  2 . Once the induction of the rotary movement of the device for adjusting inclination  1  is terminated, the omega spring  15  urges the wedge segments  13  again into its original position; that is, the eccentricity e is again increased, whereby the radial clearance required for the displacement movement is eliminated and the back part is again arrested. 
   An overloading of the omega spring  15  upon displacement of the device for adjusting inclination  1  is not possible, because the smallest possible space between the members  15 . 1  of the omega spring  15  is defined by the stop of the projections  31  and  30  of the wedge segments  13  or the eccentric ring  12 . 
   In  FIG. 7  it can be seen that the space between the surfaces  13 . 3  of the wedge segments  13  is free of any structural elements, so that the omega spring  15  can be satisfactorily mounted. 
   It has been described above, with the driving of the eccentric element  11  the spaces b between the stop surfaces  31 . 1  and  30 . 1  of the projections  31  and  30  as well as c between the surface  13 . 4  of the loaded wedge segments  13  and the front surface  21  of the loaded carrier finger  21  are overcome. The sum of the spaces b and c corresponds to the space a between the front surface  21 . 2  of the carrier finger  21  and the stop surfaces  32 . 1  of the stop cam  32 . This means that when displacing the eccentric element  11 , not only the spaces b and c are eliminated; that is, the projection  31  of the loaded wedge segment  13 , the associated projection  30  of the eccentric ring  12  and the loaded carrier finger  21  lie in block, but also the space a is eliminated; that is, the carrier finger  21  not loading the wedge segments  13  lies in abutment on the stop cam  32 . Because of this arrangement, the carrier fingers  21  of the carrier disk  18  have two contact points with the eccentric ring  12 , that are separated over 90° from each other. Accordingly, the carrier disk  18  centers itself on the eccentric ring  12 , so that the carrier hub  17  non-rotatingly jointed with the carrier ring  18  is also centered in the passage opening  7  of the passage  6  of the device part  3 . When this is done, the carrier hub  17  runs principally friction-free in the device part  3 , which acts advantageously on the smoothness of the device for adjusting inclination  1 . 
   While the invention has been described with reference to the preferred embodiment thereof, it will be appreciated by those of ordinary skill in the art that modifications can be made to the parts that comprise the invention without departing from the spirit and scope thereof.