Abstract:
In an adjuster ( 1 ) for a vehicle seat, in particular a backrest inclination adjuster for an automobile seat, having at least one detent fitting ( 5 ) with two fitting parts ( 7, 8 ) that can be pivoted relatively to one another around a central axis ( 13 ) and can be locked together, and a lever ( 6 ) which is mounted for pivoting around a pivoting axis (A), the pivoting of the lever ( 6 ) allowing to unlock the detent fitting ( 5 ), said detent fitting ( 5 ) can be unlocked via a rotatable driver ( 11 ) which is arranged around the central axis ( 13 ) and is accessible from the outside of the detent fitting ( 5 ), the lever ( 6 ) being in direct contact with the driver ( 11 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This is a continuation of PCT/EP03/10143, which was filed Sep. 12, 2003, designates the U.S., and is incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   The present invention pertains to an adjuster for a vehicle seat, in particular a backrest inclination adjuster for an automobile seat, having at least one detent fitting with two fitting parts that can be pivoted relative to one another around a central axis and can be locked together, and a lever which is mounted for pivoting around a pivoting axis, with the pivoting of the lever causing the detent fitting to unlock. 
   An adjuster of the type described in the immediately preceding paragraph is known, for example, from WO 00/44582 A1. For the adjuster of WO 00/44582 A1, the lever is mounted on a central shaft, and the detent fittings on both sides of the vehicle seat can be unlocked simultaneously by turning the shaft. 
   BRIEF SUMMARY OF SOME ASPECTS OF THE INVENTION 
   The present invention is based on the object of improving an adjuster of the type mentioned in the two immediately preceding paragraphs. According to one aspect of the present invention, an adjuster for a vehicle seat, in particular a backrest inclination adjuster for an automobile seat, has at least one detent fitting with two fitting parts that can be pivoted relative to one another around a central axis and can be locked together, and a lever which is mounted for pivoting around a pivoting axis, with the pivoting of the lever causing the detent fitting to unlock, characterized in that the detent fitting can be unlocked via a rotatable driver which is arranged around the central axis and is accessible from the outside of the detent fitting, with the lever being in direct contact with the driver. 
   Because the detent fitting can be unlocked via a rotatable driver which is arranged around the central axis and is accessible from the outside of the detent fitting, with the lever being in direct contact with the driver, a modular system is created with which, using the same driver, a centrally borne lever or an uncentrally borne lever can be arranged on the outside of the detent fitting. 
   A drive engagement between the driver and the lever causes a defined unlocking movement; the drive engagement, particularly if the lever is centrally borne, can occur via an involute gear to achieve maximum momentum transmission. Higher moments can be transmitted by using a central arrangement. By using an uncentral arrangement of the pivoting axis of the lever, one can, on the one hand, reverse the sense of direction when unlocking the fitting, this feature providing better protection from load, and, on the other hand, select a suitable transmission ratio, a feature which increases operating comfort. 
   The invention can also be used for an adjuster with gear fittings in which a step-by-step switch is mounted on one gear fitting, the step-by-step switch being activated by the driver which, in turn, is moved by the lever. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in greater detail below with reference to three exemplary embodiments which are shown in the drawings, in which: 
       FIG. 1  is a side view of the first exemplary embodiment, 
       FIG. 2  is another side view of the first exemplary embodiment, shown rotated by 90° as compared to  FIG. 1 , 
       FIG. 3  is a detail view of  FIG. 1  of a portion of the first exemplary embodiment, without the backrest compensation spring, 
       FIG. 4  is a schematic representation of a vehicle seat, 
       FIG. 5  is a detail view of the second exemplary embodiment in its initial position, 
       FIG. 6  is a detail view of the second exemplary embodiment in its final position, and 
       FIG. 7  is a cross-section through the third exemplary embodiment. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In the first exemplary embodiment, there is an adjuster  1  for adjusting the inclination of the backrest  2  of a vehicle seat  3 , particularly an automobile seat, with the optional feature in two-door automobiles of free-swinging the backrest  2 . The adjuster  1  has one detent fitting  5  on each side of the vehicle seat  3  and, on one side, a lever  6  for activating the adjuster  1 . 
   Each of the two detent fittings  5  has a lower fitting part  7  and an upper fitting part  8  which can be rotated and locked relative to the lower fitting part  7 . The lower fitting part  7  is fixed to the seat part structure of the vehicle seat  3  by means of a lower adapter  9 , whereas the upper fitting part  8  is fixed to the structure of the backrest  2 . Both fitting parts  7  and  8  enclose a construction space inside of which two latches can be radially slid. These two latches are borne and run in the lower fitting part  7 , and these two latches cooperate with the upper fitting part  8  for locking. The latches are radially moved outward by means of a spring-loaded eccentric that is rotationally fixed on a centrally arranged driver  11 , and are radially drawn inward by means of a catch disk that is arranged the same way. The structure of the detent fittings  5  is analogous to that in U.S. Pat. No. 6,454,354, which is incorporated herein by reference. 
   The two detent fittings  5  are both connected to the same driver by way of a profile shaft  13  which is rotationally fixed through a central receptacle of the drivers  11 . The shaft  13  defines the central axis of the detent fittings  5 . On that side of the adjuster  1  which is assigned to the lever  6 , a first involute gear  15  is formed onto the driver  11 , i.e. in the present case one single tooth, the lever  6  having a second involute gear  16 , also in the form of a single tooth. The lever  6  is pivotably borne on the lower fitting part  7  by means of a bearing component  17 , its pivoting axis A being arranged at a distance from the shaft  13 , and parallel to it, i.e. being arranged uncentrally. The two involute gears  15  and  16  touch at contact point K which is the distance R 1  from the central axis of the shaft  13  and a distance R 2  from the pivoting axis A of the lever  6 . During construction it is possible, by pre-selecting these distances for the initial position, to set an initial default transmission ratio for torque transmission between the lever  6  and the driver  11 . 
   In addition, a retaining bracket  18  is attached to the upper fitting part  8 , the retaining bracket supporting the inner end of a spirally coiled backrest compensation spring  21 . The outer end of the pre-loaded backrest compensation spring  21  is attached to the lower adapter  9 . The compensation spring  21  is designed to compensate, at least partially, for the weight of the backrest  2  when the inclination is being set and during free-swinging of the backrest. A pull spring  23  is attached between the lever  6  and the lower adapter  9 , for pulling the lever  6  into its initial position against a stop in the lower adapter  9 . 
   In order to activate the adjuster  1 , i.e. particularly to unlock the detent fittings  5 , the lever  6  is pulled upward, i.e. clock-wise with reference to  FIG. 1 . The second involute gear  16  then moves, with the contact point K changing its position, along the first involute gear  15 , in which process torque is transmitted and, depending on the shape of the teeth, the transmission ratio is changed. This way, the driver  11  turns in the inverse sense, i.e. counter clock-wise in  FIG. 1 . This rotation movement is transmitted to the driver  11  of the other detent fitting  5  via the shaft  13 . The driver  11  takes along the eccentric releasing the latches and the catch disk pulling the latches radially inward which are located inside the detent fitting  5 . The detent fitting  5  is thus unlocked, so that the upper fitting part  8  and, thereby, the backrest  2  can be pivoted into the desired position. 
   The second exemplary embodiment of an adjuster  101  is similar to the first exemplary embodiment, so that like components and components having like functions are given reference signs increased by 100. The only difference is in the driver  111  being in the shape of the involute gear  115  which has four teeth each staggered at a 90° angle difference from one another. One of these teeth cooperates with the second involute gear  116  of the lever  106 . The contact point K between the two curves migrates during the transition from the initial position to the end position. While rolling along the curves, the driver  111  and, thereby, the shaft  113  are rotated as before. 
   The third exemplary embodiment is in many points identical to the two other exemplary embodiments; for this reason, like components or components having like functions have reference signs increased by 200 or by 100, respectively. For example, the adjuster  1  has again a detent fitting  205  with an identical lower fitting part  207 , upper fitting part  208  and driver  211  for the shaft  213  which is only schematically represented. The inner end of a spiral-shaped backrest compensation spring  221  is supported by the upper fitting part-fixed retaining bracket  218 , the outer end of the spring being attached to a lower adapter  209  fixed to the lower fitting part. 
   The lever  206 , however, which is again pre-loaded towards the lower adapter  209  by means of a pull spring  223 , is not at a distance from the shaft  213 . Rather, the lever  206  is centrally borne, i.e. its pivoting axis A is aligned with the shaft  213 . For this purpose, the lever  206  has a receptacle positively receiving the driver  211  with its involute gear  215 , so that the lever  206  is rotationally fixed to the driver  211 . The involute gear  215  may have one tooth, as in the first exemplary embodiment, or several teeth, as in the second exemplary embodiment, the latter version allowing the transmission of higher moments. The rotational sense of the lever  206  and the driver  211  in this type of drive engagement are, of course, identical. 
   Because the same driver can be used both for the uncentrally and the centrally borne lever, a modular system is provided. This modular system will again be preferably complemented in that the bearing component  17  according to the two first exemplary embodiments will be formed similar to the driver on the side facing the lever. This way, not only the same driver, but also the same lever, can be used for both types of bearing.