Patent Abstract:
An adjusting armature for a back rest of a vehicle seat, wherein the back rest is incline-adjustable about a first axis and can fold relative to the seat part about a second axis, has a rotary bracket connected to the back rest for pivoting with the back rest. A locking bolt receptacle is stationarily arranged on the seat part and has a planar support surface. A locking bolt is axially moveably arranged on the rotary bracket and spring-loaded in a locking direction for engaging releasably the locking bolt receptacle. A stop bolt is stationarily arranged on the seat part and cooperates with a stop receptacle on the rotary bracket. The locking bolt has a guide section and a locking section having a radially changing support curve. The guide section can rotate causing the radially changing support curve to be supported on the planar support surface for eliminating play.

Full Description:
[0001]    This application is a continuation of International Application No. PCT/EP00/10643, filed on Oct. 28, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The invention relates to an adjusting armature for the back rest of vehicle seats, in particular, of motor vehicles seats, wherein the back rest, which is optionally adjustable about a first axis of rotation in an inclined position and lockable in the adjusted inclined position by means of an adjusting device, can be folded forwardly and backwardly about a second external axis of rotation, positioned at a distance from the first axis of rotation, and is secured in its folded-back position on a locking bolt receptacle, stationarily arranged on the seat, by means of a locking bolt, engaging releasably the locking bolt receptacle and axially moveably arranged on a rotary bracket pivoting with the back rest and spring-loaded in the locking direction, and is supported by means of a stop receptacle on a stop bolt stationarily arranged on the seat.  
           [0004]    2. Description of the Related Art  
           [0005]    A similar device is disclosed in European patent application 0 937 603 A1. In this document an adjusting armature for the back rests of motor vehicle seats is described in which, on the one hand, the back rest is adjustable with regard to its incline about an axis and, on the other hand, is foldable about another axis. Locking is possible in the upright position of the back rest by means of a pin that is spring-loaded or receives a conical end which engages in a springy fashion a corresponding receptacle. A play-free arrangement is not ensured in all directions.  
           [0006]    In an adjusting armature of the aforementioned kind of the present assignee, described in the German patent application 199 18 737.1-16, the armature component, which effects the adjustment and locking of the inclined back rest position and has a first axis of rotation, is arranged adjacent to a further armature component having a second axis of rotation. In order to transfer the back rest into a forwardly folded position which provides a table function, the second axis of rotation is arranged at a spacing above the first axis of rotation. For this purpose, generally on the frame of the seat part or on a locking plate fixedly connected thereto, an armature part of the armature component, which enables the inclination of the back rest in a position of use for the user of the seat, is secured detachably by means of a stop bolt and a locking bolt that is axially moveable in the locking direction and loaded by a force storing device.  
           [0007]    Moreover, a bearing bracket of the second armature component is fixedly connected with the frame of the seat part or the locking plate and extends upwardly and past the first axis of rotation. This bearing bracket at its upper area is connected by means of an axle bolt with a rotary bracket to form a joint which provides the second axis of rotation of the adjusting armature. The rotary bracket is connected to the armature part that is detachably secured with the stop bolt and the locking bolt on the seat part and is pivotable therewith. As a result of the second axis of rotation being positioned higher, the back rest can be placed above the upholstery of the seat part in a table function position such that the backside of the back rest forms a horizontal plane without the upholstery of the back rest and of the seat part counteracting this. For securing this table function position, a pneumatic spring is arranged between the axis of rotation and the bearing bracket.  
           [0008]    In this known solution, the axially movable locking bolt has a circular cross-section and engages in the locking situation a matching bore which, however must be slightly greater than the diameter of the locking bolt because of unavoidable tolerances. As a result of this unavoidable play, rattling cannot be prevented when the vehicle drives on bumpy roads.  
         SUMMARY OF THE INVENTION  
         [0009]    It is an object of the invention to improve an adjusting armature of the aforementioned kind such that a securing or bracing is possible that eliminates play of the rotary bracket relative to the locking plate.  
           [0010]    In accordance with the present invention, this is achieved in that the axially movable locking bolt has a guide section and a locking section and is subjected on its guide section, in addition to its axial guiding, also to a controlled rotational movement, based on which a radially changing support curve provided on the locking section can be supported on a planar support surface of the locking bolt receptacle so as to eliminate play.  
           [0011]    By superimposing on the axially movable locking bolt a rotary movement such that its locking section with the adjustable radially changing support curve automatically readjust on a planar support surface of the locking bolt receptacle as a result of the spring loading action, a bracing that eliminates play is obtained in the locking situations so that the adjusting armature is free of rattling noises independent of its unavoidable tolerances.  
           [0012]    For forming the radially changing support curve in connection with a support surface contacting it, the locking section of the annular pin has a periphery as follows: a first partial peripheral area extends about approximately 180° with a constant radius and is adjoined by a peripheral area of approximately 90° in which the support curve extends which, starting with the constant radius of the first partial peripheral area, has a continuously decreasing radial spacing from the center of the locking bolt, and then has a transition into at least one planar area which then adjoins finally the aforementioned first partial peripheral area with the constant radius. The locking bolt receptacle has, in addition to a circular circumferential area, a support surface which can be brought into contact with the support curve.  
           [0013]    The support curve which has a continuously decreasing radial spacing from the center of the locking bolt can be designed as a logarithmic spiral with which the manufacturing tolerances and play can be compensated which do not reach the adjusting range resulting from the support curve and which are within the tolerances.  
           [0014]    According to one embodiment of the invention, for axially guiding the locking bolt and providing a superimposed rotary movement derived from this axial movement, the guide section of the locking bolt is arranged axially slidably in a bushing secured on the rotary bracket and engages with at least one sliding block at least one sliding gate extending spirally in the bushing like a thread. In this connection, the bushing is advantageously surrounded by a trigger sleeve which has at least one guide groove ascending in the axial direction and whose slant or gradient is greater than the slant of the thread-like sliding gate of the bushing. The sliding gate is engaged by the sliding block which penetrates it and engages the guide groove of the trigger sleeve.  
           [0015]    In order to prevent a malfunction which could possibly occur as a result of canting, according to a further embodiment of the invention the sliding gate as well as the guide groove are positioned on two locations of the bushing and the trigger sleeve which are diametrically opposite one another, wherein the sliding block is comprised of two guide pins which are arranged on the guide section of the locking bolt, penetrate through the sliding gate, and project into the guide groove. Moreover, an actuation device which is located remote from the locking mechanism for releasing the locking bolt can be realized in that the trigger sleeve has a connecting finger provided for attaching a pulling means thereto, such as a Bowden cable, for introducing a rotary movement into the trigger sleeve.  
           [0016]    Since in the inactive position of the trigger sleeve the locking bolt projects from the bushing as a result of spring loading of the locking bolt in the locking direction, it is advantageous for the return movement of the back rest from its forwardly folded position when a guide rail is provided on the seat which projects into the pivot path of the locking bolt and has a slanted surface. This ensures that in the inactive state of the trigger sleeve the return pivot movement can be performed to such an extent until the locking bolt is able to drop into the locking bolt receptacle provided on the seat part.  
           [0017]    Even though it is conceivable to arrange the guide rail and the locking bolt receptacle directly on the frame of the seat part, it may be advantageous for manufacturing-technological reasons when the bearing bracket together with the locking plate that is provided with the locking bolt receptacle as well as the guide rail is fixedly connected with the seat part.  
           [0018]    In order for a safe correlation of the locking bolt to the locking bolt receptacle to be possible at the end of the return folding movement, on the one hand, and to provide a 3-point bracing of the rotary bracket relative to the seat part, on the other hand, the locking plate advantageously has underneath its locking bolt receptacle a stop for the rotary bracket and an armature part that is connected to the rotary bracket and comprises the first axis of rotation.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0019]    In the drawing:  
         [0020]    [0020]FIG. 1A shows a seat in a schematic side view, comprising an adjusting armature according to the invention arranged between the seat part and the back rest, wherein the back rest is in a position of use for the user of the seat;  
         [0021]    [0021]FIG. 1B shows the seat illustrated in FIG. 1A in a schematic side view wherein the back rest has been pivoted forwardly into a table position;  
         [0022]    [0022]FIG. 2 shows the adjusting armature according to the invention in a perspective view at an angle from behind;  
         [0023]    [0023]FIG. 3 shows the adjusting armature, also in a perspective view analog to FIG. 2, in which however the bearing bracket and the trigger sleeve have been removed;  
         [0024]    [0024]FIG. 4 shows the adjusting armature of FIG. 2 in a side view onto its exterior side;  
         [0025]    [0025]FIG. 5 shows the adjusting armature shown in FIG. 4 in an end view;  
         [0026]    [0026]FIG. 6 shows the adjusting armature of FIG. 4 in a section according to section line VI-VI of FIG. 4;  
         [0027]    [0027]FIG. 7 shows the adjusting armature according to FIG. 4 in a side view onto its inner side;  
         [0028]    [0028]FIG. 8A shows in section the area of the adjusting armature receiving a locking bolt, the adjusting armature in the position illustrated in FIG. 1A wherein, however, the locking bolt is illustrated in its release position;  
         [0029]    [0029]FIG. 8B shows the locking area of the adjusting armature illustrated in FIG. 8A in a broken-away view onto the inner side;  
         [0030]    [0030]FIG. 9A shows the sectional view illustrated in FIG. 8A of the locking area in which the locking bolt is shown in a position in which it has dropped into the locking bolt receptacle;  
         [0031]    [0031]FIG. 9B shows the locking area illustrated in FIG. 9A in a broken-away view onto the inner side of the adjusting armature;  
         [0032]    [0032]FIG. 10A shows the locking area of the adjusting armature illustrated in FIG. 8A in section, wherein the locking bolt has been positioned so far into the locking bolt receptacle that play in the system is eliminated;  
         [0033]    [0033]FIG. 10B shows the locking bolt illustrated in FIG. 10A in the locking bolt receptacle in a broken-away side view of the adjusting armature;  
         [0034]    [0034]FIG. 11A shows the locking area illustrated in section in analogy to FIG. 10A, wherein the locking bolt is in a rotary position which compensates tolerances and is play-free;  
         [0035]    [0035]FIG. 11 b  shows the locking bolt illustrated in FIG. 11A in a broken-away side view onto the inner side of the adjusting armature;  
         [0036]    [0036]FIG. 12 shows the locking bolt of FIG. 10B in an enlarged representation relative to FIG. 10B, wherein the locking bolt is arranged in the locking bolt receptacle in a play-eliminating position.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0037]    [0037]FIG. 1A shows a vehicle seat with a seat part  10  and a back rest  11  wherein the back rest  11 , fastened on the seat part  10  by means of the adjusting armature  12 , is positioned at such an incline that a user can be seated in the seat. In this connection, on the seat frame of the seat part  10  the adjusting armature  12  comprised of two armature components  13  and  14  is fastened on each longitudinal side of the seat. With the adjusting armature component  13  the incline of the back rest  11  relative to the seat part can be adjusted and secured, for which purpose, for example, a so-called planetary armature can be used which comprises a simple planetary gear and whose armature part connected with the back rest  11  is pivoted about a first axis of rotation  15  in a self-locking way.  
         [0038]    This first armature component  13  arranged on both longitudinal sides of the seat has arranged adjacent thereto a second armature component  14  which has a bearing bracket  16  secured on the frame of the seat part  10  and a rotary bracket  17  pivotably connected thereto by a joint  18 . The lower part of the rotary bracket  17  is bent and fixedly connected to the armature part  19 , correlated with the seat part  10 , of the armature component  13  of the seat part  10 .  
         [0039]    In the position of use of the seat by a user, the armature part  19  and the rotary bracket  17  are connected by means of a stop receptacle  20  in connection with a stop bolt of a locking plate  22  and a locking bolt  21  releasably engaging it. The locking plate  22 , in turn, is fixedly connected together with the recessed fastening area  23  of the bearing bracket  16  with, for example, the frame of the seat part  10 . The joint  18  which connects the bearing bracket  16  and the rotary bracket  17  with one another has an external second axis of rotation  24  of the armature component  14  about which the rotary bracket  17 , together with the first armature component  13  remaining in its adjusted position, is pivoted together with the back rest  11  such that it can be transferred into a table function position as illustrated in FIG. 1B.  
         [0040]    In the adjusting armature illustrated in FIGS. 1 through 5, the second external rotary axis  24  in the position of use of the seat illustrated in FIG. 1A is located at a spacing above the first axis of rotation  15  of the armature component  13 , wherein this spacing is selected such that, upon movement of the back rest  11  into the table position illustrated in FIG. 1B, the upholstery of the seat part  10  and the back rest  11  will not have a negative effect on the table function position.  
         [0041]    For arresting the back rest in a position of use in which a user can sit in the seat, the rotary bracket  17  fixedly connected to the armature part  19  and the armature part  19  have a stop receptacle  20  on one side with which a stop bolt  25  secured on the locking plate  22  can be partially engaged. On the side opposite the stop receptacle, a bushing  26  is fixedly connected on the rotary bracket  17  and the armature part  19  connected thereto. The guide section  28  of the locking bolt  21  is axially moveably supported within the bushing  26 . A locking section  29  of the locking bolt  21  adjoins the guide section  28  and can engage a locking bolt receptacle  30  of the locking plate  22 . The guide section  28  of the locking bolt  21  has a hollow cylindrical recess  31  which is provided for receiving a pressure spring  32 . This pressure spring  32  is supported with one end on the bottom of the bushing  26  and loads the locking bolt  21  in the locking direction.  
         [0042]    As illustrated in FIG. 7,  8 B- 11 B and most clearly in FIG. 12, the periphery of the locking section  29  on the locking bolt  21  has a constant radius about a partial area  33  of approximately 180° which is adjoined by a circumferential area  34  of approximately 90° in which a support curve  35  extends which, starting with the constant radius, has a continuously decreasing radial spacing from the center  36  of the locking bolt  21  and has a transition into at least one planar area  37 .  
         [0043]    The support curve  35  is advantageously formed as a logarithmic spiral while the planar area  37  is comprised of two planar roof-shaped partial planes  38  and  39  abutting one another. The locking section  29  of the locking bolt  21  in the locking situation is surrounded by a locking bolt receptacle  30  which about a further circumferential area has a greater diameter than the diameter of the locking bolt  21 . This wide circular circumferential area of the locking bolt receptacle  30  is interrupted by a support surface  40  which extends as slanted plane whose normal extends at an angle of 90° at a slant to the front side of the seat part  10  and in a downward direction.  
         [0044]    In order to enable a play-free bracing of the armature component  14  relative to the seat part  10 , a readjustment of the support curve as a result of the rotation of the locking section  29  of the locking bolt  21  relative to the support surface  40  on the locking plate  22  is required. For this reason, the bushing  26  in the illustrated embodiment has two diametrically oppositely extending thread-like (spiral) sliding gates  41 , which can be seen most clearly in FIGS. 3, 10A and  11 A. The sliding gate  41  is formed by thread-like slots in the cylinder mantle area of the bushing  26 . Guide pins  43  functioning as a sliding block  42  engage this sliding gate  41  and project past it outwardly, as is clearly illustrated in FIG. 3 and FIG. 9A.  
         [0045]    The bushing  26  is engaged by a trigger sleeve  44  which also has guide grooves  45  ascending also in the axial direction. The guide pins  43  projecting from the sleeve  26  engage the guide grooves  45 . In order to ensure that, during a rotational movement of the trigger sleeve  44 , it rests always against the rotary bracket  17  as a result of the action of the pressure spring  32 , the guide grooves  45  also have an ascending course whose slant is however substantially greater than the slant of the slots of the bushing  26  forming the sliding gate  41 . The trigger sleeve  44  has at its circumference a connecting finger  47  which can be the point of contact for a pulling member, for example, in the form of a Bowden cable.  
         [0046]    In order to automatically push back the locking section  29  of the locking bolt  21  projecting from the bushing  26  and the armature part  19  upon return movement of the back rest  11  without actuating the trigger sleeve  44 , the locking plate  22  has a guide rail  48  which projects into the pivot path of the locking bolt  21  and has at its side facing the armature part  19  a slanted surface  49  by which the locking bolt  21  in the last phase of the return movement is forced into the bushing  26  against the force of the pressure spring  32 . When the armature component  14  is returned in the locked position, a stop  50  is provided below the locking bolt  21  on the locking plate  22  against which stop the underside of the rotary bracket  17  and the armature part  19  rest. This stop  50  as well as the stop bolt  25  in the locking situation receive counter forces of the locking force exerted by the locking section  29  of the locking bolt  21 ; this is illustrated in FIG. 7 by the arrows. This results in a safe play-free 3-point support in the locking situation.  
         [0047]    For explaining the locking function, FIGS. 8A and 8B will be used as a starting point. Here it is shown that the locking bolt  21  is retracted completely into the bushing  26  against the force of the pressure spring  32  loading it so that its end face does not project past the outer side of the armature part  19 . The locking bolt  21  is transferred by the trigger sleeve  44  into this position. This unlocking or release position can be seen in FIGS. 8A and 8B.  
         [0048]    When the trigger sleeve  44  is now released, by means of the pressure spring  32  the locking bolt  21  is moved into the position illustrated in FIGS. 9A and 9B where it has dropped into the locking bolt receptacle  30  of the locking plate  22 . In this connection, the locking bolt  21 has been rotated by means of its guide pins  43  with the sliding gate  41  into the position illustrated in FIG. 9B; however, in this position there is still play all-around between the locking section  29  of the locking bolt  21  and the locking bolt receptacle  30  as can be seen, in particular, in FIG. 9B. Since however the pressure spring  32  still exerts its pressure force and moves the locking bolt  21  farther axially, it rotates accordingly in a clockwise direction because of the sliding gate  41  and the guide pins  43  engaging therein so that finally the support curve  35  will rest against the support surface  40  of the locking bolt receptacle  30 , as illustrated in FIG. 10B. In this position a tensioned locking action of the armature component  14  on the locking plate  22  connected to the seat frame results.  
         [0049]    The tensioned position (bracing position) shown in the preceding FIGS. 10A and 10B is also present in FIGS. 11A and 11B in which, however, as a result of a different tolerance position of the locking bolt receptacle  30  relative to the position shown in FIG. 10B, locking bolt  21  has been moved farther.  
         [0050]    As mentioned above, the illustrated and described configuration of the present invention is to be viewed only as an exemplary embodiment.  
         [0051]    While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

Technology Classification (CPC): 1