Abstract:
The fastening device consists of at least one retaining element  13  attached to the seat of the vehicle, this element holding a fastening element  14 , which can be moved between a service position and an out-of-service position (parking position). 
     So that the fastening element  14  can be moved easily into the service position and then again into the parking position without the need for any force-transferring element installed at a remote location, the fastening element  14  is connected to the retaining element  13  by means of a latching mechanism  17 , which makes it possible for the fastening element  14  to be lowered into a parking position and returned to a service position.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention pertains to a fastening device for fastening a child&#39;s seat to the seat of a vehicle by means of at least one retaining element which is attached to the vehicle seat and which holds a fastening element which can be moved between a service position and an out-of-service (“parking”) position. 
     2. Description of the Related Art 
     The usual method for attaching a child&#39;s seat to the seat of a motor vehicle is to use the available safety belt. This type of attachment, however, is unsatisfactory with respect to behavior during a crash. During a collision, deceleration occurs as the crumple zones of the vehicle undergo deformation and thus absorb energy, whereas the passengers do not begin to undergo deceleration until after the slack in their safety belts has been taken up. When a child&#39;s seat is attached to the vehicle by the same type of belt, however, the slack in this belt must be taken up first under the load of the child&#39;s seat, then the slack in the safety belt of the child&#39;s seat itself must be taken up. This means the child in the seat decelerates after the adults and thus the deceleration takes place when the crumple zone is no longer absorbing a great deal of energy, with the result that the child must endure the residual load of the deceleration process until a full stop is reached. It has already been proposed that two fastening elements on the vehicle seat in the form of yokes be permanently attached to the vehicle structure or seat. These permanent yokes, however, are a nuisance during the times when no child&#39;s seat is buckled into the vehicle seat and an adult passenger is using this seating area instead. 
     It has therefore already been proposed that fastening elements in the form of yokes be pivoted into a “parking” (stowed or out-of-service) position; these fastening elements would be adjacent to the long sides of the seats and be installed in the rear area of the seat between the back and the seat cushion. When the user wishes to attach the child&#39;s seat, the fastening elements would be swung up out of the gap between the seat cushion and the back and into the service position, where they project out over the seat cushion to allow the attachment of the child&#39;s seat. After the fastening elements are pivoted back into the parking position in the gap between the back and the seat cushion, they are held in place there by a detent pawl. This pawl is located in an inaccessible place, however, which means that the user of the seat can operate it only by pulling on a Bowden cable connected to a release lever. A comparable fastening device is described in DE 196-50,087 C1. 
     SUMMARY OF THE INVENTION 
     The task of the invention is to improve a fastening device of the type described above in such a way that the user of the seat can operate it easily without the need to actuate locking elements which must be released before-hand. This task is accomplished by means of the fastening element being connected to the retaining element by a latching mechanism, by means of which the fastening element can be lowered into a stowed position and returned to a service position. The retaining element can be easily installed by attaching it to the support structure of the seat or to the car body; it is advisable for one retaining element to be located near each long side of the seat. Because of the latching mechanism located between the fastening element and the retaining element, the fastening element effectively connected to each retaining element can be easily moved into the parking position and then again into the service position simply by pressing on it, which means that additional operating components for arriving at the two positions of the fastening element can therefore be completely omitted. 
     In a preferred embodiment of the object of the invention, the latching mechanism between the fastening element and the retaining element is designed as a two-stage mechanism, the first latching stage of which makes it possible to move the fastening element into the stowed position, whereas the second latching stage allows the fastening element to be moved into the service position. The fastening element has a base body, which is acted on by an energy storage mechanism which attempts to push the base body in the direction of the service position. A yoke is attached to the base body. The fastening device also has a control tappet, which can slide in linear fashion in a control link of the retaining element, which is mounted on the vehicle seat in such a way that it can slide transversely to the fastening element. 
     It is advantageous for the control tappet projecting from the base body of the fastening element to have a cross section in the form of an isosceles triangle, where the base which connects the two equal sides extends in the direction of the linear movement of the fastening element. It is advantageous for the control link which accepts the control tappet to consist of a guideway with both outer control surfaces and the inner control surfaces, the inner control surfaces being formed by an angled projection; these outer and inner control surfaces, furthermore, alternate in their directions, proceeding first in a linear manner in the direction in which the control tappet moves and then proceeding at a slant, in the same direction as that of one or the other of the equal sides of the triangular control tappet. 
     To secure the fastening element with its yoke in the first latching position, in which the yoke is recessed into the seat part, and also to move it reliably into the second latching position, in which the yoke projects out of the seat part, the control surface of the angled projection facing the latching stages extends over certains areas of the two control surfaces of the latching stages, the two of which both slant in the same direction, but is itself slanted in the direction opposite that of the control surfaces of the latching stages. This slanted control surface of the angled projection, furthermore, is limited by a linear control surface extending in the direction in which the control tappet moves and is pointed toward the slanted control surface of the second latching stage. The position of the yoke on the fastening element which corresponds to the second latching position, i.e., the position in which the yoke is pulled out over the top surface of the seat, is limited by an upper stop in the path of the control tappet of the fastening element, this stop being connected to the retaining element so that it remains permanently attached to it. To ensure the interference-free movement of the control tappet in the control link, the distance between the outer and inner control surfaces of the control link is made large enough to allow smooth passage of the control tappet. 
     In another embodiment of the object of the invention, a latching mechanism is used which makes it possible for the fastening element, with its yoke, to be supported pivotably on the retaining element in a plane perpendicular to the surface of the seat, where, as a result of the latching mechanism, the fastening element, i.e., its yoke, can be moved either into an upward-projecting service position or into a stowed position, folded down onto the surface of the seat. So that the user of the seat will not be disturbed by the fastening element while the element is not in use, the surface of the seat has a recess to hold the yoke of the fastening element while it is in the stowed position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention is illustrated in the drawing and explained in greater detail below on the basis of exemplary embodiments: 
     FIG. 1 shows a schematic side view of the rear seat area between the seat back and the seat part, where the retaining element attached to the seat part holds the fastening element in the pushed-in position; 
     FIG. 2 shows the latching mechanism, designed as a two-stage mechanism, by means of which the fastening element, upon which an energy storage mechanism in the form of a helical compression spring acts, can be held on the retaining element in two different latching positions, the above-cited components being shown in perspective; 
     FIG. 3 shows separate views, in perspective, of the fastening element and the retaining element as mirror images of the view of FIG. 2 together with a stop plate shown in an exploded view with respect to the retaining element; 
     FIGS. 4A-4H show a cross section of the retaining element and its control link, with a control tappet engaging in the control link in eight different positions, which mark the passage of the control tappet through the control link, the route of the control tappet being shown in dash-dot line in FIG. 4A; 
     FIG. 5 shows an additional exemplary embodiment of the object of the invention, in which the fastening element installed in the rear part of the seat can be pivoted with respect to the retaining element in a plane perpendicular to the surface of the seat part. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Attention is drawn first to the fact that the fastening device for a child&#39;s seat illustrated here and described in greater detail below is an exemplary embodiment of the object of the invention and can therefore also have a design different from that shown, as has already been suggested above. In particular, the seat, formed out of a seat part and a back part, can be designed in the standard manner, and the fittings connecting the seat part to the back can be fabricated in such a way as to allow the angle of the back part to be adjusted in the known manner. In addition, the fastening device for a child&#39;s seat is not limited to use on the front passenger seat or to the rear seats of motor vehicles; on the contrary, the fastening device can also be used on any seats suitable for carrying passengers in other forms of transportation such as buses, trains, and planes. The embodiments of fastening devices explained in the drawings here, however, are based on the example of the front passenger seat of a motor vehicle. 
     In the rear area of the seat part  10 , a retaining element  13  is installed on the seat part  10 , usually near each of the two long sides of the seat. A piece of hinge hardware  12  of the seat back  11 , the angle of which is adjustable, can be used as the attachment point, but the retaining element could also be attached to the seat back or to the car body. In the case of the exemplary embodiment shown in FIGS. 1-4H, this retaining element  13  can be moved horizontally but is held permanently in the vertical position on the seat part  10 . The fastening element  14  for the child&#39;s seat is effectively connected to the retaining element  13  so that it can be moved vertically, but it is fixed horizontally in the seat part  10 . The yoke  15  of the fastening element  14  can project out above the surface of the seat part  10 . The gap in the upholstery of the seat part  10  where the yoke  15  is held is covered by a grommet plate  16 . 
     FIG. 2 shows the effective connection between the retaining element  13  and the fastening element  14 . This effective connection is accomplished by a latching mechanism  17 , which is designed as a two-stage mechanism. The first latching stage  18  of the mechanism cooperates with a compression spring, which forms an energy storage mechanism  20  and attempts to push the fastening element  14  outward; this stage makes it possible for the fastening element  14  to be returned to the stowed position shown in FIG.  1 . By means of the second latching stage  19 , it is possible for the fastening element with its yoke  15  to be moved into the service position shown in FIG. 2 with the help of the energy storage mechanism  20 . The latching mechanism  17  consists—as is especially clear from FIG.  3 —of a control tappet  22 , projecting out from the base body  21  of the fastening element  14 ; this tappet engages a control link  23  located in the retaining element  13 . The control tappet  22  projecting out from the base body  21  has a cross section in the form of an isosceles triangle; the base  26 , which connects the two equal sides  24  and  25 , extends in the direction of linear motion of the fastening element  14 , indicated by the double arrow  27  in FIGS. 3 and 4A. The control link  23  of the retaining element  13 , which can slide horizontally in the direction of arrows  30  and  30 ′, has a guideway, which is limited by outer control surfaces  28   a - 28   i  and by inner control surfaces  29   a - 29   d . The inner control surfaces  29   a - 29   d  are components of an angled projection  31 , which projects into the interior of the control link  23 . The outer control surfaces  28   a ,  28   c ,  28   e ,  28   g , and  28   i  all extend in straight lines and are parallel to the base  26  of the triangular control tappet  22 . The outer control surfaces  28   b ,  28   d , and  28   f  proceed at an angle and are parallel to the side  25  of the control tappet  22 . The control surfaces  29   a  and  29   c  also form straight lines parallel to the base  26  of the control tappet  22 , forming part of the inside boundary of the guideway around angled projection  31 . The inner control surfaces  29   b  and  29   d  on angled projection  31  proceed at an angle, namely, parallel to the side  24  of the control tappet  22 . Finally, it can also be derived from FIG. 3 that the guideway in the retaining element  13 , which is open at the top, can be closed off by a stop plate  32 , which can be permanently connected to the retaining element  13  by screws, for example. The stop plate  32  has a projection  33 , which fits into the guideway between the control surfaces  28   a  and  28   i . The bottom side  34  of this projection is parallel to the side  24  of the control tappet  22  and thus limits the extent to which the fastening element  14  can be lifted when it is being moved into the service position. 
     The angled projection  31  in the interior of the control link  23  is designed in such a way that, when the fastening element  14  is moved from the service position into the parking position, the lower tip of the control tappet  22  first strikes the control surface  29   b  of the angled projection  31  and, as it slides farther down this surface, simultaneously causes the retaining element  13  to move transversely in the direction of arrow  30 . The route of the control tappet  22  around the guide path of the control link  23  can best be seen on the basis of the dash-dot lines of FIG. 4A-4H, which show the retaining element  13  in vertical cross section and also show how the control tappet  22  of the fastening element  14  engages the control link  23 . In the diagram of FIG. 4A, the control tappet  22  is in its upper position, which corresponds to the position of yoke  15  of fastening element  14  shown in dashdot line in FIG.  1 . In this position, the side  24  of the control tappet  22  on the fastening element  14 , which is being acted on by the pressure storage mechanism  20 , is resting against the bottom surface  34  of the projection  33  of the stop plate  32 , which is permanently connected to the retaining element  13 . When the yoke  15  is now pressed down against the force of the pressure storage mechanism  20  and thus moved out of the position shown in dash-dot line, the lower tip of the control tappet  22  first strikes the slanted control surface  29   b  of the angled projection  31  parallel to the side  24  and begins to push the retaining element  13  toward the right in the direction of arrow  30 . As the yoke  15  is pushed even farther down, the control tappet  22  also moves farther down, and the retaining element  13  is simultaneously pushed farther toward the right in the direction of arrow  30  until the lower corner of the control tappet  22  leaves the control surface  29   b . When this happens, the control tappet  22  enters the free space between the angled projection  31  and the control surface  28   g , which extends in a straight line parallel to the base  26  of the triangle. This position is shown in FIG.  4 C. Finally, the side  25  of the control tappet  22  strikes the control surface  28   f , which slants in the same direction, and slides along this into the position shown in FIG. 4D, in which the lower tip of the control tappet  22  has reached the first latching stage  18  and the retaining element  13  has moved back again somewhat in the direction of the arrow  30 ′ toward the left. In this position, the yoke  15  and thus also the control tappet  22  can no longer be pressed down any farther, with the result that the operator lets go of the yoke  15 . As soon as the spring force of the energy storage mechanism  20  is no longer being counteracted, this force is able to push the fastening element  14  back up to a certain extent; it continues pushing until the base  26  of the triangle has risen above the control surface  28   e . The side  24  then starts to slide up along control surface  29   d ; and, passing beyond the situation shown in FIG. 4E, the control tappet  22  finally reaches the latching position on the angled projection  31  shown in FIG.  4 F. In this position, shown in FIG.  4 F, the base body  21  of the fastening element  14  with the yoke  15  is in its parking position underneath the surface of the seat part  10 , as can be seen in FIG.  1 . 
     When the fastening element  14  is now to be moved out of its parking position and into the service position, the yoke  15  is pushed down again against the force being exerted by the pressure storage mechanism  20 . As this happens, the side  25  of the control tappet  22  strikes the control surface  28   d  of the control link  23  and slides down along it, thus causing the retaining element  13  to slide further in the direction of the arrow  30 ′. The tappet then breaks contact with the angled projection  31  completely. This position is shown in FIG.  4 G. As a result of the further linear displacement of the control tappet  22  in the downward direction, the lower tip of the tappet finally arrives in the second latching stage  19 , accompanied by further displacement of the retaining element  13  toward the left, so that it is now no longer possible to push the yoke  15  (and thus the control tappet  22 ) down any farther against the force of the pressure storage mechanism  20 . When the user now lets go of the yoke  15 , the pressure storage mechanism  20  pushes the base body  21  and thus also the control tappet  22  upward; the base  26  of the triangle then slides upward along the control surface  28   c , passing through the opening between the control surface  29   a  of the angled projection  31  and the control surface  28   c  of the control link  23 . Then it begins to slide between the angled projection  31  and the control surface  28   b  under simultaneous displacement of the retaining element  13  in the direction of the arrow  30 . This position is shown in FIG.  4 H. The energy storage mechanism  20 , however, continues to push the control tappet  22  straight up, which also means the retaining element  13  is pushed farther toward the right in the direction of arrow  30  until finally the position of control tappet  22  shown in FIG. 4A is reached again, with the tappet resting against the bottom surface  34  of the projection  33  of the stop plate  32 . In this position, the yoke  15  is again in its service position. 
     In the exemplary embodiment shown in FIG. 5, the fastening element  14 , which again has a yoke  15 , is connected to the retaining element  13  by a latching mechanism (not shown). This latching mechanism, however, is designed in such a way that the fastening element can pivot in a plane perpendicular to the surface of the seat and can be moved by the previously mentioned latching mechanism into a projecting service position or into a parking position, folded onto the top surface of the seat part  10 . In FIG. 5, the parking position is shown in solid line, whereas the service position of the fastening element  14  is shown in dash-dot lines. As can also be derived from FIG. 5, a recess  35 , in which the yoke  15  of the fastening element  14  can be pivoted, is advantageously provided in the upholstered surface of the seat part  10 . 
     As already mentioned, the illustrated and previously described exemplary embodiments of the object of the invention represent only examples, to which the invention is in no way limited. Additional designs and modifications of the object of the invention are also conceivable. In addition, all of the features described and illustrated in the drawings are essential to the invention, even if they are not explicitly cited in the claims. 
     List of reference numbers 
       10  seat part 
       11  seat back 
       12  hinge hardware 
       13  retaining element 
       14  fastening element 
       15  yoke 
       16  grommet plate 
       17  latching mechanism 
       18  latching stage, first 
       19  latching stage, second 
       20  energy storage mechanism 
       21  base body of  14   
       22  control tappet 
       23  control link 
       24  side of  22   
       25  side of  22   
       26  base of triangle  22   
       27  double arrow 
       28   a  control surface, linear 
       28   b  control surface, same slant as  25   
       28   c  control surface, linear 
       28   d  control surface, same slant as  25   
       28   e  control surface, linear 
       28   f  control surface, same slant as  25   
       28   g  control surface linear 
       28   h  control surface, same slant as  24   
       28   i  control surface, linear 
       29   a  control surface, linear 
       29   b  control surface, same slant as  24   
       29   c  control surface, linear 
       29   d  control surface, same slant as  24   
       30  arrow 
       30 ′ arrow 
       31  angled projection 
       32  stop plate 
       33  projection on  32   
       34  bottom surface of  33   
       35  recess