Abstract:
Disclosed is a vehicle seat ( 1 ), particularly a motor vehicle seat, comprising a seat part ( 3 ), at least one fitting ( 5 ) which is provided with a first fitting part ( 7 ) and a second fitting part ( 8 ) that can be swiveled relative to the first fitting part ( 7 ) about an axis (A), and a backrest ( 4 ) which is mounted on the seat part ( 3 ) by way of the fitting ( 5 ) and can be swiveled relative to the seat part ( 3 ) about the axis (A). A sensor ( 15 ) is provided on the first fitting part ( 7 ) while a signaler ( 14 ) is provided on the second fitting part ( 8 ). The sensor ( 15 ) transmits a signal by cooperating with the signaler ( 14 ) when the second fitting part ( 8 ) swivels relative to the first fitting part ( 7 ), the signal making it possible to determine the relative angular position of the fitting parts ( 7, 8 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   The present application is a continuation of International Application PCT/EP2006/010391, which was filed Oct. 28, 2006. The entire disclosure of International Application PCT/EP2006/010391, which was filed Oct. 28, 2006, is incorporated herein by reference. 
   TECHNICAL FIELD 
   The present invention relates to a vehicle seat, particularly a motor vehicle seat, with a seat part, at least one fitting which has a first fitting part and a second fitting part which is pivotable about an axis relative to the first fitting part, and a backrest which is attached by way of the fitting to the seat part and is pivotable about the axis relative to the seat part. 
   BACKGROUND OF THE INVENTION 
   Numerous vehicle seats of the above-described type, which have a free-standing backrest with lockable fittings, or a backrest which can be locked to the vehicle structure and has fittings which can be additionally locked or designed as simple joints, are known. 
   BRIEF SUMMARY OF SOME ASPECTS OF THE INVENTION 
   An aspect of the present invention is the provision of improvements, with respect to functional diversity and reliability, to a vehicle seat of the type mentioned above. In accordance with one aspect of the present invention, a vehicle seat, in particular a motor vehicle seat, includes a seat part, a backrest and at least one fitting. The fitting includes a first fitting part and a second fitting part which is pivotable about an axis relative to the first fitting part. The backrest is attached at least by way of the fitting to the seat part, so that the backrest is pivotable about the axis relative to the seat part. The fitting further includes a signaler that is on the second fitting part, and a sensor that is on the first fitting part. The sensor is responsive to the signaler so that the sensor outputs a signal when the second fitting part pivots relative to the first fitting part, and the signal is indicative of a relative angular position between the fitting parts. 
   Because a sensor is provided on the first fitting part and a signaler is provided on the second fitting part, with the sensor being responsive to (e.g., interacting with) the signaler to output a signal when the second fitting part pivots relative to the first fitting part, the signal makes it possible to determine the relative angular position of the fitting parts. Having this relative angular position information available makes it possible to determine and control the locking capacity of the fitting, the necessity of synchronizing two fittings or the reaching of a desired inclination of the backrest. These controlling actions may be incorporated into the controlling means (e.g., a controlling device) depending on whether motorized drives are present. 
   To provide a signal which can be resolved in a meaningful manner, the signaler is preferably designed as a periodic sequence of different regions, with the periods defining the resolution. Such regions are preferably alternately magnetized and non-magnetized regions or magnetized regions with an alternating direction of magnetization. The sensor is then preferably designed as a Hall sensor. A similar solution is described in DE 102 29 369 A1 for a longitudinal adjuster of a vehicle seat. However, optical solutions are also possible. The sensor is expediently connected to a control unit which evaluates the signals of the sensor. In particular, upon each change of the region of the signaler, the control unit receives a pulse from the sensor, counts the pulses and from them determines the relative angular position of the fitting parts in relation to each other. 
   The backrest can be locked by way of locking of the fitting. The fitting is locked by way of interaction between a locking element movably mounted on the first fitting part and a mating element provided on the second fitting part. The locking element and mating element are moved away from each other when the fitting is released. The backrest can be locked cumulatively or, alternatively, can be locked to the vehicle structure by way of a lock and a mating lock element which interacts with the lock. 
   When the exemplary embodiment of the invention is used for free-standing backrests, the checking of the locking capability of the fitting, which may be part of a synchronization of two fittings, is in the foreground (e.g., is a primary operational aspect). In this checking of the locking capability, the relative position between the locking element and the mating element is determined in order to check whether they are appropriately aligned for locking to take place, i.e. whether the locking element and the mating element are aligned with each other in such a manner that, as they move towards each other, they can pass directly into their position for interaction (engagement position) so as to avoid tooth on tooth positions and therefore to ensure maximum transmission of force. In the case of the backrest which can be locked to the vehicle structure, this is important in situations in which double locking takes place by way of both a fitting of this type and a backrest lock. If appropriate, the inclination of the backrest then has to be corrected so that the fitting can be locked. However, for the backrests, it is also of interest to link the information about the current inclination of the backrest with an interrogation of the locking state of the lock in order to check that the backrest is locked correctly. 
   Other aspects and advantages of the present invention will become apparent from the following. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in more detail below with reference to an exemplary embodiment, which is illustrated in the drawings, together with modifications. In the drawings: 
       FIG. 1  shows a block circuit diagram incorporating those regions of the exemplary embodiment which are referred to by I in  FIG. 2 , with some optional parts being illustrated by dashed lines, and 
       FIG. 2  shows a schematic illustration of the exemplary embodiment. 
   

   DETAILED DESCRIPTION 
   A vehicle seat  1  of a motor vehicle has a seat part  3  and a backrest  4  which is attached to the seat part  3  by way of two fittings  5  respectively positioned at the sides of the seat part  3 , so that the backrest  4  is pivotable about an axis A relative to the seat part  3  and is preferably also adjustable with different inclinations. 
   The fitting  5  comprises a first fitting part  7 , a second fitting part  8 , which is pivotable about the axis A relative to the first fitting part  7 , and a locking element  11  which is mounted on the first fitting part  7  in a manner such that it is movable relative to the second fitting part  8 . For the locking of the fitting  5 , or, more specifically, of the two fitting parts  7  and  8 , the locking element  11  interacts with a mating element  12 . The mating element  12  is formed on the second fitting part  8 . In order to release the fitting  5 , the locking element  11  can be pulled back from the mating element  12 , i.e. the locking element  11  can be moved away from the mating element  12 . The mating element  12  is preferably a toothed ring which is formed at least over part of the circumference of the second fitting part  8 , i.e. is generally curved about the axis A. Accordingly, the locking element  11  bears a matching toothing, i.e. a toothing which interacts in a form-fitting manner. The allocation of the fitting parts  7  and  8  to the seat part  3  and backrest  4  depends on the application and on the construction space available in each case. In the relative system of the fitting parts  7  and  8 , the first fitting part  7  is arbitrarily regarded to be stationary and the second fitting part  8  to be movable in the present description. 
   The fitting  5  can be, for example, a latching fitting as described in WO 00/44582 A1, or the fitting  5  can be of the type as described in DE 102 35 141 A1. In both types, the locking element  11  and the mating element  12  take up different relative positions both for the adjustment of the inclination of the backrest  4  in different use positions and for pivoting the backrest into non-use positions and, if appropriate, for securing the backrest  4  in the latter. However, the fitting  5  may also be designed, for example, as a geared fitting with a central free-pivoting means, as described in DE 102 06 303 A1, with the associated eccentric epicyclic gear being described, for example, in DE 44 36 101 A1 for a geared fitting without a central free-pivoting means. In the case of the last-mentioned geared fitting, the central driver and the fitting part supporting it may also be considered the fitting parts which can be pivoted relative to each other within the meaning of the present invention. The entire disclosure of each of the above-mentioned documents is expressly incorporated herein by reference. 
   A signaler  14  (e.g., stimuli) is provided on the second fitting part  8 . In the exemplary embodiment, the signaler  14  is designed as a periodic sequence of strip-shaped, alternately magnetized and non-magnetized regions (or magnetized regions with an alternating direction of magnetization) that extends in the circumferential direction with respect to the axis A. The period of the magnetized regions is, as a maximum, the same size as the period of the teeth of the mating element  12 , and preferably the period of the magnetized regions is half the size of the period of the teeth of the mating element  12 . The signaler  14  is curved about the axis A and is arranged at a distance from the axis A. 
   A sensor  15  is provided on the first fitting part  7 . The sensor  15  is arranged at the same distance from the axis A as the signaler  14 . The sensor  15  interacts with the signaler  14 . In the exemplary embodiment, the sensor  15  is designed as a Hall sensor. In accordance with a modified embodiment, instead of the magnetic interaction, the signaler  14  and the sensor  15  interact optically. For example, the signaler  14  may be in the form of a sequence of strips having different reflecting characteristics, and the sensor  15  may be in the form of a combination of a light-emitting diode and a photocell. The sensor  15  is connected to a control device  17 . 
   When the fitting  5  is unlocked, i.e. the locking element  11  and the mating element are brought out of engagement, the backrest  4  can be pivoted relative to the seat part  3 . An adjustment of the inclination preferably takes place by way of a motor, with the pivoting into a non-use position preferably taking place manually. When the backrest  4  is pivoted, the fitting parts  7  and  8  also pivot relative to each other. The signaler  14  is guided past the sensor  15 . Upon each change in the magnetization, the sensor  15  outputs a signal, or, more precisely a pulse, which is counted by the control unit  17 . The current relative angular position of the fitting parts  7  and  8  in relation to each other, with reference to a defined angular position during an initial initialization, is determined in the control unit  17  from the number of pulses. 
   In accordance with the fitting  5  of the exemplary embodiment, both the relative position between the locking element  11  and mating element  12 , and the current inclination of the backrest  4  can be determined from the relative angular position of the fitting parts  7  and  8 . The information about the relative position of the locking and mating elements  11 ,  12  with respect to one another can be used to check whether the locking element  11  and the mating element  12  are appropriately aligned with each other, i.e. whether locking is basically possible. The information about the current inclination of the backrest  4  can be used to check whether the desired final position (use or non-use position) has been reached, and then the locking is activated or else continued pivoting of the backrest  4  is required, and, if appropriate, the motorized drive of the backrest  4  has to continue to be actuated. In the case of longitudinally adjustable vehicle seats, the longitudinal position of the seat can be changed, if appropriate, if the distance from the front row of seats is too small. From a combination of both sets of information, a synchronization with the fitting  5  on the opposite side of the vehicle seat can be undertaken, i.e. an angular offset between the two fittings  5  can be compensated for by different locking (in terms of time or angle) of the two fittings  5 . 
   The backrest  4  is preferably provided with a lock  20  by way of which the backrest  4  can be locked to the vehicle structure with a mating lock element  21 . The mating lock element  21  may be a clip or bolt, or the like. In the exemplary embodiment, the mating lock element  21  is movable relative to the vehicle structure, for example linearly in the direction toward the lock  20 , by way of a backrest drive unit L which can be actuated by the control unit  17 , and therefore the inclination of the backrest  4  can be adjusted by motor. When the lock  20  is released, the backrest  4  can be pivoted into a non-use position. In a modified embodiment, the positions of lock  20  and mating lock element  21  are interchanged. In a simplified embodiment, the backrest drive unit L is omitted, i.e. the mating lock element  21  (or the lock  20 ) is connected fixedly to the vehicle structure. 
   The exemplary embodiment of the invention is supplemented by a further interrogation. A lock sensor  22 , for example a microswitch, interrogates (e.g., determines) the locking state of the lock  20 , for example by way of an interrogation of the position of a latch of the lock  20 , and outputs a digital signal to the control unit  17 . An AND link with the relative angular position of the fitting parts  7  and  8  or the current inclination of the backrest  4  ensures that correct locking of the backrest  4  is only indicated when the lock  20  is locked to the mating lock element  21  and the backrest  4  is at the correct inclination. If a backrest adjustment unit L is present, the control unit  17  uses the information from the sensor  15  to actuate the backrest adjustment unit L until the backrest  4 , moved by the backrest drive unit L, is at the correct inclination for the locking of the fitting  5 , i.e. an appropriate alignment of the locking element  11  and of the mating element  12  has been reached. Errors can also be detected, for example if the lock  20  is closed but the inclination of the backrest  4  is outside the backrest inclination range, i.e. the mating lock element  21  is located outside the lock  20 . 
   It will be understood by those skilled in the art that while the present disclosure has been discussed above with reference to an exemplary embodiment and modifications, various additions, modifications and changes can be made thereto without departing from the spirit and scope of the invention as set forth in the claims.