Abstract:
A forwardly displaceable vehicle seat for vehicles in which a rear seat is accessed through a side door. A locking device ( 40 ) is assigned to the seat back joint ( 32 ) and locks the seat back joint ( 32 ) in a first locking position in a normal use position of the vehicle seat. A release ( 42 ), preferably arranged on the seat back ( 20 ), cooperates with the locking device ( 40 ), and permits displacement of the vehicle seat from the normal use position into a forwardly displaced position having the seat back ( 20 ) folded forward. A first transmission mechanism ( 54 ) sets a memory unit ( 78 ) and releases a stop unit ( 70 ) when the seat back ( 20 ) is tilted forward. The locking device ( 40 ) has a second locking position in which the seat back ( 20 ) is retained in the forwardly tilted position. A second transmission mechanism ( 56 ) actuates the locking device ( 40 ) so that it cannot adopt the second locking position within a rear portion ( 100 ) of the travel distance of the seat, and can engage the second locking position within a front portion ( 102 ) of the travel distance.

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to a forwardly displaceable vehicle seat and is more specifically intended for vehicles in which a rear seat is accessed through a side door assigned to the vehicle seat, meaning, for so-called two door vehicles. The invention relates to such a vehicle seat with a seat back, with a seat carrier, with a seat back joint arranged between seat back and seat carrier, with a locking device assigned to the seat back joint and locking said seat back joint in a first locking position adopted in a normal position of use of the vehicle seat, with a longitudinal adjusting device provided with a stop unit and with a memory unit, with a release, which is preferably arranged on the seat back and is connected to, and cooperates with, the locking device, permitting to enable displacement of the vehicle seat from the normal position of use into a forwardly displaced position, a forward displacement consisting in folding forward the seat back which allows the vehicle seat to be displaced forward in its longitudinal adjusting device, and with a first transmission means which is disposed between seat back and longitudinal adjusting device and sets the memory unit on the one side and releases the stop unit on the other side when the seat back is tilted forward. 
   Such type vehicle seats are generally known in the art and U.S. Pat. No. 5,352,019 is referred to by way of example only. 
   In the prior art vehicle seat the memory unit adopts its memory position and the stop unit of the longitudinal adjusting device is released when the seat back is tilted forward at a sufficient angle. Normally, the seat back is locked. It can be tilted forward upon actuating the release. 
   The problem with the previously known forwardly displaceable vehicle seats of this type is the following: the seat back is not retained in its forwardly tilted position. It is advantageous for a passenger accessing a rear seat with the vehicle seat being forwardly displaced when the seat back is somehow fixed in a relatively low, forwardly tilted position. Then, the space giving passengers access to the rear seats is the largest possible and mounting the vehicle is comfortable. 
   SUMMARY OF THE INVENTION 
   This is where the invention comes to bear. It is the object of the invention to further develop the forwardly displaceable vehicle seat of the type mentioned herein above in such a manner that it is more comfortable and precise to handle. The seat back of the vehicle seat that has been forwardly displaced within the longitudinal adjusting device is to be fixable in the forwardly tilted position. But it also intends to make it possible to just briefly tip the seat back forward without the seat back being locked in the forwardly tilted position for the purpose of placing an object onto the rear seats for example. 
   In view of the forwardly displaceable vehicle seat of the type mentioned herein above, the solution to this object is that the locking device is provided with a second locking position in which the seat back joint is locked in such a manner that the seat back is retained in a forwardly tilted position and that there is provided a second transmission means which is arranged between locking device and memory facility and actuates the locking device in such a manner that the locking device is not capable of adopting the second locking position within a portion of the travel distance of the seat located at the back, starting from the normal position of use, and that the locking device is allowed to engage into a second locking position within a front portion of the travel distance. 
   When the vehicle seat of the invention is displaced forward, meaning, when the seat back is tilted forward and the seat is slid forward in the longitudinal adjusting direction, the seat back is retained in the forwardly tilted position as soon as the displacement in the longitudinal adjusting direction is advanced so much that the front portion of the travel distance has been reached. Then, the seat back is locked by the seat back joint, which is in the second locking position. That is to say that it remains in its forwardly tilted position without any further assistance. 
   As a result thereof, access to a rear seat located behind the vehicle seat of concern is facilitated. It is no longer necessary, as this was usually the case in prior art, to use a hand in an effort to tilt the vehicle seat of concern as far to the front as possible and to keep it in this condition. Also, the stowage capacity is increased when bulky objects are to be transported on a rear seat. 
   The second locking position is not adopted, and, accordingly, the seat back not retained in its forwardly tilted position, until the vehicle seat has not been sufficiently displaced forward and is still in the rear portion of the travel distance. Said rear portion of the travel distance is preferably considerably shorter than the front portion. A user can just briefly tip forward the seat back of the vehicle seat of concern when he wants for example to place an object onto the rear seat located behind the vehicle seat of concern. In this case, the seat back is not yet retained in its forwardly tilted position. Accordingly, the seat back may be tilted back immediately after having been tilted forward without having to actuate the release or the like. 
   Accordingly, the seat back is only retained in its forwardly tilted position when the vehicle seat has really been sufficiently displaced forward within the longitudinal adjusting device. Without the vehicle seat being displaced forward, or when it has only been displaced a small distance, i.e., in the region of the rear portion of the travel distance, the locking device is not capable of adopting its second locking position and the seat back is not retained in the forwardly tilted position. 
   In actuating the release, the seat back is always released and the locking device always unlocked as a result thereof. This is irrespective of the fact of whether the locking device is in the first or in the second locking position. 
   If the release is actuated in the forwardly displaced position of the seat, the seat back may be tilted back to the normal upright position. Once this position is reached, the stop unit of the longitudinal adjusting device is actuated and the longitudinal adjusting device is locked into place. 
   If the user wants to bring the completely forwardly displaced vehicle seat, which, accordingly, is placed within the front portion of the travel distance, back to the normal position of use, he may either actuate the release or not do so to achieve the desired purpose. If he does not actuate the release, the seat back at first remains tilted forward while the seat is being displaced backward as long as it is caused to move within the front portion of the travel distance. However, upon reaching the rear portion of the travel distance, the locking device automatically releases the seat back and the second locking position is not used as a result thereof. Hence forward, a restoring force on the seat back not only causes the vehicle seat to be moved backward but also the seat back to be returned to its normal upright position until finally the vehicle seat is returned to its overall normal position of use. The locking device thereby automatically adopts its first locking position and the seat back is locked into the normal position of use as a result thereof as soon as the second locking position is released and the seat back has been tilted backward a large enough distance. 
   If however the release is actuated in any position of the seat within the front portion of the travel distance, the seat back may be folded up immediately and the locking device may adopt the first locking position. If the vehicle seat is located in the front portion of the travel distance and the seat back is locked into place in the second locking position of the locking device, the second locking position is always released by actuating the release. 
   The above mentioned considerations show that the vehicle seat is much more comfortable and easy to operate than a prior art vehicle seat. The additional locking of the seat back into a forwardly tilted position provides additional comfort without constituting an obstacle for the forward or backward displacement of the vehicle seat, though. 
   It has already been mentioned that it is advantageous to configure the rear portion of the travel distance to be considerably shorter than the front portion, the rear portion being more specifically configured to be at most 10%, preferably at most 5% of the overall length of the travel distance. In this way, it is possible to already lock the seat back into its forwardly tilted position after the vehicle seat has travelled but a short distance within the longitudinal adjusting device. 
   In a preferred embodiment the memory unit is provided with a catch rod which is slidably guided in a pivot member and is provided with a catch pin. The pivot member is pivotally arranged on a seat rail of the longitudinal adjusting device, is connected to the first transmission means and cooperates with the stop unit. The memory unit furthermore has a perforated bar adjacent the catch pin into which said catch pin may engage and which is connected to a bottom rail in engagement with the seat rail. The memory unit furthermore is provided with a sliding piece connected to the second transmission means. The catch rod is provided with a) a guide region for the sliding piece along which the sliding piece may slide relative to the catch rod and b) a rod catch for the sliding piece. A rail catch for the sliding piece is provided in proximity to the catch rod and is connected to the seat rail. The second transmission means is a Bowden cable that is arranged, at the one end region thereof, between sliding piece and rail catch. 
   Said memory unit is preferably suited for combination with the process of locking of the seat back into its forwardly tilted position in accordance with the invention. The actual distance the vehicle seat has travelled starting from its normal position of use is determined by the distance between the rod catch and the rail catch. The second transmission means transmits the detected distance between the two catches to the locking device. As a result thereof, said locking device is only capable of adopting the second locking position when the distance between the two catches has become small enough, provided the release was not actuated. The distance between the two catches is preferably adjusted to the length of the rear portion of the travel distance. 
   In another embodiment, the memory unit is provided with a catch cradle, a perforated bar and a lever arrangement. The catch cradle is arranged so as to be capable of travelling along the perforated bar and is provided with a catch peg which is elastically biased in a position of engagement by means of a peg spring. The perforated bar is connected to a bottom rail of the longitudinal adjusting device. The lever arrangement is disposed on a seat rail in engagement with the bottom rail. The lever arrangement is connected to the first and to the second transmission means. The lever arrangement cooperates with the stop unit and is provided with a driver lever that a) cooperates with the catch peg and actuates the same, and that takes the catch cradle along. Said memory unit constitutes an alternative embodiment to the already discussed solution with the rod, it operates with a slidable catch piece that is termed a catch cradle. It normally is connected to the stop unit of the longitudinal adjusting device and travels together therewith when the rails are slid relative to each other, that is, when the normal position of use is changed and adjusted. But if the seat back is tilted forward a large enough distance, the catch cradle is positioned onto the perforated bar so that the actual instant position of the longitudinal adjusting device is registered when the seat back is tilted forward. 
   In a preferred embodiment, the locking device of the seat back joint has a holding arm that is arranged on an arm of the seat back joint. There is provided a locking piece, which is arranged on the other arm of the seat back joint and is in engagement with the holding arm in the second locking position. The holding arm is connected to the second transmission means. Said holding arm is controlled by the distance the part of the memory unit engaging into the perforated bar, i.e., the catch cradle or the catch pin of the catch rod, is separated from the stop unit. This distance increases as the vehicle seat is being displaced further within the travel distance. As long as the vehicle seat is only displaced within the rear portion of the travel distance, holding arm and locking part are not capable of cooperating and the second locking position cannot be reached as a result thereof. The position of the respective travel distance is transferred to the locking device through the second transmission means. 
   Further advantages and characteristics of the invention will become apparent upon reading the remaining claims and the following non restrictive description of two embodiments thereof, given by way of example only with reference to the drawing. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a seat frame of a vehicle seat according to a first embodiment of the invention, 
       FIG. 2  is a perspective view in the form of an assembly drawing of a detail of  FIG. 1  in substantially the same direction of viewing, substantially showing the right longitudinal adjusting device with the parts assigned thereto, 
       FIG. 3  is a view of the joint region between seat back and seat carrier shown according to the arrow III of  FIG. 1 , 
       FIG. 4  is a view of the joint region between seat back and seat carrier on the opposite side of the seat according to arrow IV, 
       FIG. 5  is a simplified side view of the vehicle seat according to  FIG. 1 , the left couple of rails of the longitudinal adjusting device having been removed, 
       FIG. 6  is an enlarged, partially sectional, detail view of  FIG. 5  showing the right couple of rails with the accessory parts of the longitudinal adjusting device, 
       FIG. 7  is a view according to  FIG. 5  but this time with the seat back being tilted forward but not displaced within the longitudinal adjusting device, 
       FIG. 8  is a view of the seat as in  FIG. 7 , the seat being now additionally displaced forward within the longitudinal adjusting device, 
       FIG. 9  is a side view of a seat of a second exemplary embodiment of the seat; again, the left couple of rails of the longitudinal adjusting device is not illustrated, 
       FIG. 10  is a perspective view of the right couple of rails of the vehicle seat of  FIG. 9  with accessory parts, 
       FIG. 11  is a side view of the seat like in  FIG. 9  but now the seat back is tilted forward without the seat being displaced in longitudinal direction and 
       FIG. 12  is a view of the seat like in  FIG. 11  but now with the seat being displaced forward within the longitudinal adjusting device. 
   

   DETAILED DESCRIPTION 
   The first exemplary embodiment according to the  FIGS. 1-9  will be discussed first. The  FIGS. 1-6  show this seat in the normal position of use,  FIG. 8  shows the forwardly displaced position,  FIG. 7  an intermediate condition, i.e., the forwardly tilted seat back without the vehicle seat being displaced forward within its longitudinal adjusting device. The first embodiment operates with a catch cradle and will therefore be termed the cradle solution. 
   The second exemplary embodiment is shown in the  FIGS. 9-12 . Here, a catch rod is utilized; therefore, the second embodiment will also be termed the rod solution. The  FIGS. 9 and 10  show the normal position of use,  FIG. 11  the seat with the forwardly tilted seat back without forward displacement and  FIG. 12  the forwardly displaced seat. 
   The forwardly displaceable vehicle seat has a seat back  20  and a seat carrier  22  provided with a left side part  24  and with a right side part  30 . The seat back  20  is connected to the seat carrier  22  through a seat back joint  32 . A lower fitting part  34 , which is connected to the seat carrier  22  in such a manner that it is pivotal about a pivot axis  36  of the seat back, belongs to the seat back joint  32 . The angular position may be changed and fixed by way of a sector gear and additional means that have not been illustrated herein. An upper fitting part  38  is also arranged so as to be pivotal about the pivot axis of the seat back, it is durably connected to the seat back  20  or is integral part of a side frame part of the seat back  20 . A locking device  40 , which consists of several individual parts that will be discussed later, is arranged between the two fitting parts  34 ,  38 . The locking device permits to join the two fitting parts  34 ,  38  together in the normal position of use of the vehicle seat so that these two parts are like one. On releasing the locking device  40 , the seat back  20  may be tilted forward, the two fitting parts  34 ,  38  are thereby pivoted relative to each other. Finally, the seat back  20  may be locked in a forwardly tilted position by means of the locking device  40 . 
   A release  42 , which is located on a side part of the seat back in the upper region thereof, is provided on the seat back  20 , see  FIGS. 5 ,  9 ,  11  and  12 . It is connected to a release arm  46  by way of a traction means  44 , said release arm having two arms, being substantially L-shaped and pivotally hinge-linked to the upper fitting part  38 . A holding arm  48 , which is pivotally hinged to the upper fitting part  38  as well, is located in its range of movement. Said holding arm  48  cooperates with a locking part which is realized by a side  52  of a locking bight in the first exemplary embodiment. The locking part has a clamping area that contacts the side  52  preferably in the region of interlocking as the angle of the inward pivoting movement increases, this contact being shown in FIG.  3 . The pivot travel path of the upper fitting part  38  is thus locked toward the front relative to the lower fitting part  34 . To the back, the pivoting movement is locked by the holding arm  48  or its axle abutting on a second side of the locking bight, said second side substantially facing the side  52 . 
   In the normal position of use, see  FIG. 3 , the release arm  46  lies in the path of the holding arm  48  pivoting outward, it blocks the holding arm  48  in the locking position. If, however, the release arm  46  is pivoted counter-clockwise through the traction means  44  (FIG.  3 ), it strikes a release part of the holding arm  48  and causes the holding arm to pivot clockwise so that it is released from engagement with the side  52 . Now, the seat back  20  may be tilted forward. 
     FIG. 4  shows the seat back joint on the other side of the vehicle seat. The two holding arms  48  of the two seat sides are non-rotatably joined-together through a rod. Accordingly, in the normal position of use according to the  FIGS. 3 and 4 , the two sides of the seat are in the first locking position. 
   On this second seat side which, in the exemplary embodiments, is the tunnel side, the core of a first transmission means, which is configured to be a Bowden cable, is fastened on the holding arm. The sheath of the associated end region of said first transmission means, or of said first Bowden cable  54 , is fastened to an abutment which is arranged, preferably pivotally arranged, on the lower fitting part  34 . It can be surveyed therefrom that the core is pulled out of the sheath to the extent to which the upper fitting part  38  is pivoted forward from the normal position of use shown, i.e., to which the seat back  20  is pivoted forward, to the right in FIG.  4 . As soon as the distance travelled is sufficient, the vehicle seat may be displaced forward, which will be discussed later. 
   On the other side of the seat (FIG.  3 ), i.e., on the side of the door, there is provided a second transmission means  56  which is also configured to be a Bowden cable and which will be termed second Bowden cable  56  herein after. It is also arranged on, more specifically hinged to, the lower fitting part  34  on an abutment, which is built according to the same principle as the abutment already mentioned, and holds the sheath of the upper end region of said second Bowden cable  56 . The core is arranged on a locking jaw  58  which is hinged to the lower fitting part  34  in such a manner that it is pivotal about an axis  60  of the jaw. It is preferably elastically spring-biased in the clockwise direction. In the position according to  FIG. 3  it lies against the abutment of the second Bowden cable  56 . When the core is sufficiently spaced from the abutment, the locking jaw  58  may pivot upward. It reaches the position according to  FIG. 7  in which it has no effect yet. If, however, the vehicle seat is additionally displaced forward a sufficient distance, the locking jaw reaches the position according to  FIG. 8  in which it is supported at its locking bight  62  by the pivot axis of the holding arm  48 , thus locking the lower fitting part  34  relative to the upper fitting part  38 . In this condition, the seat back  20  is locked in its forwardly tilted position, said position being termed the second locking position. 
   It may be released any time by actuating the release  42 . If this happens, a third part of the holding arm  48  presses the locking jaw  58  back downward in the counter-clockwise direction so that the seat back may be tilted back again to the upright position. 
   The locking jaw  58  is configured to be a two-part buckle lever. It has an outer buckle lever part which is provided, on the free end thereof, with the locking bight  62 , and an inner buckle lever. The two are hinge-linked together by a joint. They are biased in the extended position by an elastic means (see  FIG. 3  for example). The core of this second Bowden cable  56  is attached to the joint or in proximity thereto. If, in the second locking position, i.e., in the condition shown in  FIG. 8 , the core is pulled toward the sheath, the locking jaw  58  sags and the second locking position is released. Thanks to the buckle lever configuration, this unlocking can be performed with little force. This buckle lever configuration will be claimed separately. 
   It is also possible, possibly in addition thereto, to configure the locking bight  62  in such a manner that the seat back  20  may be tilted back by a sufficiently high force on the seat back and without actuating the release  42 . 
   The pivoting forward movement of the seat back  20  is limited by a front side  64  realized on the lower fitting part  34 . In its position according to  FIG. 8 , the seat back has not yet come into contact with said front side. It is therefore still possible to tilt the seat back slightly farther toward the front. This shows that the second locking position may be positioned anywhere within the range in which the seat back  20  is tilted forward. 
   The vehicle seat furthermore has a longitudinal adjusting device provided with a left couple of rails  66  and a right couple of rails  68 . It furthermore is provided with a stop unit  70  for each couple of rails  66 ,  68 , said stop unit being configured here to be a multiple pin stop unit actuating, through a hand lever  72  attached to a pivoting tie bar  74  connecting the two couples of rails  66 ,  68 , release levers  76  of the two rail sides which are connected to said pivoting tie bar. Finally, the longitudinal adjusting device has a memory unit  78  which is only provided and arranged on one seat side. Said memory unit will be discussed in greater detail herein after. 
   The memory unit is assigned to the right couple of rails  68 , which is located on the tunnel side. Said tunnel side has a bottom rail  80  and a seat rail  82 . A perforated bar  84  of the memory unit is connected to the bottom rail. A catch cradle  86  is assigned to said perforated bar  84 , is slidable relative to the perforated bar  84  in the longitudinal sliding direction and engages in a respective one of the holes in said perforated bar  84  in the memory position. The catch cradle  86  is deposited at the respective relative position of the longitudinal adjusting device at which the normal position of use is left before longitudinal displacement within the longitudinal adjusting device takes place. 
   In the exemplary embodiment shown for example in  FIG. 6 , the catch cradle has an outer part and an inner part  88 . The inner part  88  is fastened to the outer part so as to be pivotal about an axis. The outer part is slidable along the perforated bar  84  by which it is guided. The inner part  88  has a catch peg  90  capable of engaging into a hole of the perforated bar  84 . For this purpose, the inner part is subjected to torsional load in the clockwise direction by way of a torsion spring (not shown) so that normally the catch peg  90  thereof engages into a hole of the perforated bar  84 . 
   In the normal position of use as it is shown for example in  FIG. 6  however, this engagement is prevented from taking place by a lever arrangement comprised of a stop lever  92  and a memory lever  94 . The stop lever is hinged to the seat rail  82  so as to be pivotal about an axis and is provided with an abutment for the first Bowden cable  54 . The corresponding core of the lower end of the first Bowden cable is fastened to the release lever  76  of the corresponding seat side at a distance from the pivoting tie bar  74 . 
   If the seat back  20  is tilted forward, the distance between the free end of the core and the abutment in the lower end region of the first Bowden cable  54  is reduced. The release levers  76  are pivoted as a result thereof, their respective free ends press against an unlocking lever  96  of the corresponding stop unit  70 . Said stop unit is unlocked as a result thereof. 
   A normal release of the stop unit involves the following steps: the hand lever  72  is pulled upward, causing the two release levers  76  to pivotally follow their movement, the stop units  70  of the two couples of rails  66 ,  68  are released. 
   The memory lever  94  is assigned to the stop lever  92  and is controlled by the latter. In the normal position of use, for example in  FIG. 6 , the stop lever  92  presses the memory lever  94  downward in such a manner that a dog  98  of the memory lever  94  exerts such a strong pressure onto the inner part  88  that the catch peg  90  remains out of engagement with the perforated bar  84  as a result thereof. 
   As shown in  FIG. 2 , the memory lever  94  is elastically biased by a torsion spring that rotates it in the clockwise direction. This causes the dog  98  thereof to exert a pressure onto the inner part  88  the catch peg  90  of which remains disengaged from the perforated bar  84 . 
   This applies to the normal position of use of the vehicle seat. As soon as the first Bowden cable  54  is sufficiently actuated, i.e., as soon as the seat back  20  has been tilted forward at a certain angle, one of the sides of the release lever  76  supporting the stop lever  92  has moved so much downward that the stop lever  92  is capable of pivoting counter-clockwise (FIG.  6 ). The memory lever  94  follows this pivoting movement in the clockwise direction. The dog  98  thereof is thus disengaged from the inner part  88  so that the catch peg  90  is now capable of engaging into a hole of the perforated bar  84 . The catch cradle  86  is now set. If now a longitudinal displacement occurs within the longitudinal adjusting device, the levers  92 ,  94  move increasingly away from the catch cradle  86 , as may be seen in FIG.  8 . If a forwardly displaced seat is slid back again to reach a normal position of use, the sequence of the steps described is reversed. 
   The dog  98  of the memory lever  94  has a rear oblique side. On sliding the seat back within the longitudinal adjusting device, the oblique side comes into contact with the outer part of the catch cradle  86 , which causes the memory lever  94  to pivot. Said lever slips over the outer part and reaches, through the opening thereof, a position in which it is located above the inner part  88 . The dog  98  may again reach the inner part and press it away in the downward direction into the position shown in FIG.  6 . In this condition, the stop lever  92  is pivoted as far as possible in the clockwise direction, its pivot path is no longer blocked by the memory lever  94 . As a result thereof, the release lever  76  may now also be capable of pivoting so far in the counterclockwise direction that the unlocking lever  96  is unloaded again, thus locking the stop unit. This applies to the two seat sides since they both have one release lever  76 . 
   The second locking position has not been discussed yet. This position fits into the sequences described herein above in the following manner: the overall travel distance of the seat between the normal position of use and the maximum possible forwardly displaced position is divided in a rear portion  100  and into a front portion  102 . It is detected in which portion thereof the vehicle seat is located and this information is transmitted to the locking device  40  through the second Bowden cable  56 . For this purpose, in its lower end region, the second Bowden cable  56  is supported at its core on the seat rail  82  of the couple of rails situated on the side of the tunnel, this is performed here on a part of the stop unit  70 . The corresponding sheath is fastened to an abutment realized on an upper arm of a sensing lever  104 . Said lever is pivotally arranged on the seat rail  82  and has additionally a lower arm by which it is capable of abutting the outer part of the catch cradle  86 . This abutment occurs in the normal position of use. As a result thereof, the free end of the core, in the lower end region of the second Bowden cable  56 , is positioned at the greatest possible distance from the sheath of this Bowden cable. But if, upon actuation of the release  42  and unlocking of the stop units  70  of both seat sides, the seat rail  82  is displaced forward, the distance between the free end and the sheath of the lower end region of said Bowden cable  56  is reduced. As long as this happens within the rear portion  100  of the travel distance, it has no effect. As soon however as the front portion  102  of the travel distance is reached, the locking jaw  58  is pivoted in the clockwise direction (FIG.  3 ), starting from its initial position in which it is in the normal position of use and in which it abuts on the abutment of the Bowden cable  56 , such a distance that it adopts the position shown in FIG.  8 . Then, the second locking position described is possible or reached. Said position is maintained until either the release  42  is actuated or the seat is displaced so far backward that it is located within the rear portion  100  of the travel distance. 
   A torsion spring may be allocated to the sensing lever  10 , said torsion spring biasing said lever in the counter-clockwise direction in FIG.  2 . 
   It can be surveyed therefrom that the first Bowden cable  54  and the second Bowden cable  56  are guided toward different seat sides. The design of the seat back joints is simplified as a result thereof. 
   The second exemplary embodiment will now be discussed herein after. The differences over the first embodiment will be substantially emphasized: in this second embodiment, the seat back joint on both seat sides is of a different configuration than in the embodiment discussed herein above. It is possible to combine the embodiment discussed herein above with the embodiment according to the  FIGS. 9-12 . Furthermore, the memory unit in the second embodiment is configured in another way, a catch rod  108  is substituted for the catch cradle. It moreover has several additional component parts in the region of the longitudinal adjusting device. It is possible to combine the memory unit according to the second embodiment with the seat back joints according to the first embodiment. 
   Again, the release  42  is connected to an L-shaped release arm  42  by way of a traction means  44 . Said traction means in turn cooperates with a holding arm  48  which, in the normal position of use, abuts at a head portion thereof, within the angle of interlocking, on a side  52  of a locking bight realized in the lower fitting part  34 . Said head part forms a hook that cooperates with a locking part  50  of the lower fitting part  34  in the second locking position. Said locking part  50  is here configured to be a step. 
   If, starting from the normal position of use (FIG.  9 ), the release arm  46  is pivoted in the counter-clockwise direction (FIG.  9 ), it abuts on a portion of the holding arm  48  and drives it out of the locking position in which it is. The holding arm  48  is pivoted in the clockwise direction so that its head part is removed from engagement with the side  52 , this condition being shown in FIG.  11 . The hook of the head part is then located above the locking part  50  configured to be a step (FIG.  11 ), but it is not capable of cooperating with said locking part. The second Bowden cable  56  prevents the holding arm  48  from pivoting into the second locking position. This may only happen when, on the upper end region of the second Bowden cable  56 , the core has been pushed out of the sheath to such an extent that the pivoting movement of the holding arm  48  toward the locking part  50  is enabled. Then, the position according to  FIG. 12 , in which the seat back is locked into the forwardly tilted position, is reached. 
   The memory unit according to the second exemplary embodiment will be described herein after. Again, a perforated bar  84  is connected to the bottom rail  80  of the right couple of rails on the side of the tunnel, said perforated bar covering the entire travel distance  100  plus  102 . A pivot member  106  is pivotally arranged on the seat rail  82 . On its lower portion, it has a guide for a catch rod  108 . In the normal position of use, see  FIG. 10 , the pivot member  106  is positioned in such a manner that the catch rod  108  is located outside the perforated bar  84 . 
   The first Bowden cable  54  is attached at its core to said pivot member  106 . The sheath of the corresponding lower end region of said first Bowden cable  54  is supported by the seat rail  82 . If the seat back  20  is tilted forward, the spacing between the free end of the core and the sheath decreases and the pivot member  106  is pivoted in the clockwise direction ( FIG. 10 ) as a result thereof. On its rear end, the catch rod  108  has a catch pin  110  that corresponds to the catch peg  90  of the cradle solution. In that the pivot member  106  is pivoted, which also causes the catch rod  108  to pivot, the catch pin  110  moves into engagement with the perforated bar  84 . If the seat is now displaced forward within the longitudinal adjusting device, the catch pin remains in the perforated bar. But if the release  42  is actuated and the seat back  20  is tilted backward, the pivot member  106  pivots the catch pin  110  out of engagement. The memory function is thus set. 
   In this second embodiment the following steps are carried out to know whether the vehicle seat is within the rear portion  100  of the travel distance or within the front portion  102  thereof: The lower end region of the second Bowden cable  56  detects the position of the catch rod  108 . Its sheath is supported by the seat rail  82 . The corresponding core is fastened to a sliding piece  112  capable of freely sliding along the catch rod  108 . It is made of plastic material for example. The catch rod  108  is provided with a catch  114  for the sliding piece  112  which is positioned at a distance from the catch pin. Said sliding piece is only allowed to move between said catch  114  and a front stop  116  of the catch rod  108 . Moreover, the catch rod  108  extends across an aperture  118  of a cross flange connected to the seat rail  82 . The abutment for the sheath of the second Bowden cable  56  that has been described herein above is disposed in immediate proximity to the aperture  118 . In the normal position of use (FIG.  9 ), said aperture  118  is located on the other side of the catch  114  as compared to the stop  116  described on the front side end of the catch rod  108 . It substantially is the clear distance between the aperture  118  and the surface area of the sliding piece  112  abutting on the catch that determines the length of the rear portion  100  of the travel distance. 
   The following procedure is now performed: as soon as, starting from the position in  FIG. 11 , the seat is displaced forward in its longitudinal adjusting device, the aperture  118  gets nearer to the sliding piece  112  by the same distance. In the upper end region of the second Bowden cable  56 , the core is also pulled out of the corresponding sheath by the same distance. This makes it possible for the holding arm  48  to pivot into the second locking position in the counter-clockwise direction ( FIG. 12 ) as soon as the displacement motion has reached the front portion  102 . The seat back  20  is now locked in a front position. If the seat is displaced farther forward within the longitudinal adjusting device, the sliding piece  112  slides along the portion of the catch rod  108  to which it is assigned, but the spacing between sliding piece  112  and aperture  118  is not reduced any further. The rim of the aperture  118  rather takes the sliding piece  112  along by pressing it forward. 
   On a return motion, the sliding piece  112  glides at first on the catch rod  108  until it reaches the catch  114 . On displacing the seat farther backward, the core is again pulled out relative to the sheath in the lower end region of the second Bowden cable  56 . This imperatively causes the holding arm  48  to be pulled out of the second locking position, i.e., the seat back may be brought back into the upright position. 
   The seat back  20  may be brought into the upright position any time by actuating the release  42 . Like in the first embodiment, this actuation is always given priority. 
   The rod solution and the cradle solution may be claimed independently of one another also without the combination with the second locking position, i.e., with the second Bowden cable  56  and the corresponding parts such as  46 ,  48 ,  52 ,  58 .