the foldable vehicle seat has a base structure , which , in the first exemplary embodiment according to the fig1 and 2 , is formed from a left profile member 22 and a right profile member 24 as well as from guide members 26 , 28 connected to these . the guide members 26 , 28 are provided in respective pairs on either side and have a guide slot 30 and a hole , which forms an upper hinge point 32 . longitudinal adjusting devices known per se and having each a seat rail and a floor rail , may be provided instead of the two profile members 22 , 24 . however , in another alternative , the profile members 22 , 24 may be solidly connected to an underbody 34 of a motor vehicle that has only been outlined in fig1 , or be formed from such an underbody 34 . the profile members 22 , 24 may each be connected with at least one guide member , see fig6 . the foldable vehicle seat further has a cushion support member 36 of a known construction . it has a frame and springs disposed therein . it is intended to receive a seat cushion , which is not illustrated herein for being state of the art . front support arms 38 are further provided , they are built identically or rather in a mirror - inverted fashion . they are hinged to the base structure 20 , concretely , to a respective one of the profile members 22 and 24 , at a lower hinge 40 . they are further hinged to the cushion support member 36 at an upper hinge 42 . it can be seen that the upper hinges 42 are spaced a distance of about 10 % to about 30 % of the depth ( in the x direction ) of the cushion support member 36 apart from the front edge thereof . there are further provided a left and a right carrier member 44 , which are also built identically and arranged in a mirror inverted fashion . each carrier member 44 is hinge - linked to the base structure 20 at the upper hinge point 32 . the two upper hinge points 32 of each seat side are disposed on a straight line . at a lower hinge point 46 , the carrier member 44 is hinge - linked to the cushion support member 36 , which is approximately positioned at a distance corresponding to that of the upper hinges , 42 when seen from the rear edge of the cushion member 36 . on either seat side , the base structure 20 forms , together with the front support arms 38 , the cushion support member 36 and the two carrier members 44 , a four - bar linkage . the four - bar linkage may also be described by the upper hinge point 32 , the lower hinge 40 , the upper hinge 42 and the lower hinge point 46 . the hinges described are free ; the immobilization of the four - bar linkage will be explained herein after . finally , there is provided a seat back 48 ; it has a main part 50 and two seat back arms 52 disposed thereon . one seat back arm 52 is provided on either seat side . the seat back 48 is hinge - linked to the upper hinge point 32 through the seat back arms 52 . a corresponding aperture 54 is provided for this purpose in the seat back arm 52 . the hinge itself is realized by rivets or pins that can be seen in the fig . on its seat back arms 52 , the seat back 48 also has on either side one projection 56 or a bolt that is guided in the two guide slots 30 of the guide members 26 , 28 . thus , the maximum pivot angle of the seat back 48 is imposed . the projection 56 cooperates with a control region 58 that is formed on each carrier member 44 ; however , it is sufficient to provide it on only one seat side , meaning on only one carrier member 44 . this control region 58 is defined by a front flank 60 and by a rear flank 62 . the projection is capable of coming into contact with both flanks . in the normal position of utilization as it is illustrated in the first exemplary embodiment , the projection 56 fits against the front flank 60 and is retained by an immobilization device the function of which is performed by a motor drive in the first exemplary embodiment . the motor drive has a connecting rod 64 that is rigidly connected to a respective one of the projections 56 . the connecting rod 64 is hinge - linked to a rocker arm 66 of the motor , which in turn is non - rotatably linked to an electric motor 68 . the electric motor is fixed on the base structure . in the normal position of utilization as it is shown in fig1 and fig2 as well as in fig4 , the rocker arm 66 of the motor and the connecting rod 64 are in an extended position . a load exerted onto the seat back 48 , which causes the projection 56 to exert a pressure onto the connecting rod 64 , therefore exerts a direct load onto the drive shaft of the motor , without a torque occurring . the fig3 and 5 also show the seat in the normal position of utilization , but for the manual implementation . if the electric motor is actuated , it causes the projection 56 to move away from the front flank 60 and toward the rear flank 62 . if the projection 56 reaches the rear flank 62 , the vehicle seat is folded . then , it has a structure similar to that shown in fig6 . in the second exemplary embodiment shown in fig3 , the same parts can be found as in the first exemplary embodiment , again with the following exceptions that will be discussed as follows : now , a manual stop device is provided instead of the motor drive . on each seat side , it has a front cam 70 and a rear cam 72 . the cams 70 , 72 are hinge - linked together by a kind of tooth or hinge engagement in their regions turned toward each other and they move like two meshing toothed wheels . the cams respectively have points of rotation 74 . in their end regions pointed away from each other the cams have stop members 76 . with one stop flank , they fit against the projection 56 in the respective stopped state . this cannot be seen in fig3 , but in fig6 , the reader being referred to the stop state , which is effected there by the rear cam 72 , namely by the stop member 76 and its associated stop flank . the projection 56 is fixed between this rear cam 72 and the rear flank 62 . the stop flank has a corresponding chamfer for a zero clearance fixation . an illustrated spring biases the arrangement of the two cams 70 , 72 , which can be moved together , into the stop position shown in the fig3 and 6 . it can come free from the stop position by a release mechanism . it can be seen in fig6 . for this purpose , a release lever 78 , which is connected to one of the two cams via a bowden cable 80 , is disposed on the seat back . by actuating the release lever 78 , the two cams 70 , 72 are pivoted to come free from their stop position so that the motor vehicle seat can be adjusted . the fundamental functions will now be discussed with reference to the two fig4 and 5 : in the implementations shown in the fig4 and 5 , the motor vehicle seat , which has only been illustrated very schematically , is shown in the normal position of utilization . the sequence of movements may also be seen . the two figs . show that in the normal position of utilization the front support arms are slightly inclined backward , approximately 20 to 30 degrees as compared to the z direction ; the support arms 38 are oriented approximately parallel to the seat back of which only one respective seat back arm 52 is shown . the distance between the two hinges 40 , 42 of the support arms 38 approximately corresponds to the distance between the hinge points 32 , 46 of the carrier member 44 . the carrier member 44 is inclined at an angle of about 50 ° to the support arm 38 . the hinge points of the already mentioned four - bar linkage are located so that the lower hinge 40 of the front support arm 38 , the lower hinge point 46 and the upper hinge point 32 approximately lie on a straight line . put more precisely , the lower hinge point 46 is located slightly beneath a connecting line joining the lower hinge 40 and the upper hinge point 32 . the front support arm 38 and the cushion support member 36 are approximately disposed at a right angle with respect to one another in the region of the upper hinge 42 . the carrier member 44 is substantially l - shaped , with the upper hinge point 32 lying on the bar and the lower hinge point 46 on the transverse line . the upper hinge point 32 and the two flanks 60 , 62 lie on the apexes of an isosceles , almost equilateral , triangle . upon actuation of the electric motor 68 , which can be recognized by its pinion in fig5 , the hinge of the rocker arm 66 of the motor and of the electric motor 68 moves on the dash - dotted curved line 82 and performs a movement of slightly more than 180 ° about the motor shaft . once this movement has been completed , the rocker arm 66 of the motor and the connecting rod 64 are no longer in an extended state , they rather substantially overlap . then , the projection 56 abuts the rear flank 62 . the projection 56 has traveled on a path 84 that lies on a circular arc about the upper hinge point 32 and is shown by a discontinuous line . the end position is pivoted about 110 ° with respect to the initial position . approximately 50 ° thereof account for the distance between the two flanks 60 , 62 . the last mentioned region is the first angular region . according to the remaining difference of about 60 °, the carrier member 44 is pivoted about the upper hinge point 32 , this occurring along a curve 86 about the upper hinge point 32 . it can be seen that the lower hinge point 46 now lies approximately beneath the upper hinge point 32 in the z direction . the lower hinge point 46 has been displaced a distance that approximately corresponds to the hinge distance of the support arm 38 . due to the end position described , the cushion support member 36 is substantially displaced in the negative x direction and slightly in the z direction . the definitive position in the completely folded state can be seen from fig4 . the upper hinge 42 thereby lies behind the lower hinge 40 , when substantially viewed in the negative x direction . in the completely folded state , the lower hinge 40 , the upper hinge 42 and the lower hinge point 46 are almost lying on a straight line . the upper hinge 42 pivots along a bottom line 88 about the lower hinge 40 , with the pivot angle being about 70 °. the circumstances described herein above for fig4 can also be seen in fig5 . fig5 will now be substantially described with respect to the stop device . the two cams 70 , 72 are hinge - linked to the base structure 20 and pivotal about the points of rotation 74 . they may for example be disposed on a guide member 26 , 28 . in the normal position of utilization as shown in fig5 , one stop flank of the front cam 70 fits against the projection 56 and urges it against the front flank 60 . the seat back is immobilized as a result thereof . at the same time , the four - bar linkage described is also immobilized . if the immobilization is released by actuating the release lever 78 as described , the other immobilization position , which has already been described herein above with respect to fig6 , is reached . in principle , this stop position can also be seen in fig5 . fig6 has already been mentioned . the release lever 78 is located on the rear side of the seat back 48 so that it is accessible at any time . it can be seen that the seat back is substantially horizontal . it can be brought flush with a cargo loading floor that has not been illustrated herein . as may be recognized by those skilled in the pertinent art based on the teachings herein , numerous changes and modifications may be made to the above - described foldable vehicle seat without departing from the spirit and scope of the invention as defined in the appended claims . accordingly , this detailed description is to be taken in an illustrative , as opposed to a limiting sense .