Abstract:
A drive device for a movable furniture part includes a latching element which is movable in a slotted guide track shaped as a cardioid. The slotted guide track has a closing section in which the latching element moves during the closing of the movable furniture part, a locking section with a latching trough, in which the latching element is held in the locking position, an opening section in which the latching element is movable during the opening of the movable furniture part, and a first connecting section via which the latching element is movable from the opening section into the closing section when the furniture part is open. A second connecting section, which is formed closer to the latching trough, is located between opening section and closing section.

Description:
BACKGROUND OF THE INVENTION 
     The invention concerns a drive device for a moveable furniture part comprising a latching element displaceable in a cardioid curve-like sliding track. The sliding track has a closing portion in which the latching element moves upon closing of the moveable furniture part, a locking portion having a latching recess in which the latching element is held in the locking position, an opening portion in which the latching element is displaceable upon opening of the moveable furniture part, and a first connecting portion, by way of which the latching element is moveable from the opening portion into the closing portion when the furniture part is opened. The invention also concerns an article of furniture comprising a furniture carcass, a moveable furniture part and such a drive device for the moveable furniture part. 
     Drive devices for moveable furniture parts in the form of lockable ejection devices have already been known for many years in the furniture fitting industry. In that case, unlocking of the ejection device is triggered by movement (pushing or pulling) of the moveable furniture part out of the closed position, whereby the moveable furniture part is automatically ejected or opened. 
     In that respect, locking by way of a sliding track in the form of a cardioid curve has become established as the common kind of locking action. The latching element connected to an ejection element is held in the locking portion of that sliding track, whereby the moveable furniture part is in the closed position. By pressing against the moveable furniture part, the latching element is also moved out of the locking portion and passes into an opening portion. As soon as that is reached, an ejection force storage means can be relieved of stress and ejects the moveable furniture part in the opening direction. In that respect, that opening portion is approximately as long as the ejection travel of the ejection force storage means. As soon as the ejection force storage means has been completely unloaded, therefore, the latching element is also disposed at the end of the opening portion of the sliding track. From that position, the moveable furniture part can be further opened manually in a freely running movement. 
     In a closing movement or active retraction movement by way of a retraction device, the latching element is not moved back through the opening portion again, but is deflected into a closing portion by the configuration of the sliding track. For that purpose, a transitional region is provided between the opening portion and the closing portion. That transitional region can also be referred to as a connecting portion. In commonly used drive devices, the opening portion has a length of between about 3 cm and 20 cm between the latching recess and the first connecting portion. That travel distance, however, can be individually adjusted and is dependent on the size of the moveable furniture part and other parameters. 
     In order to restore secure locking of the latching element in the latching recess, the latching element or the control projection has to be moved through the closing portion in known drive devices with a cardioid curve-like sliding track (see for example Austrian patent application A 614/2011) which is of earlier priority and which forms a prior right. If however the ejection movement is interrupted because of incorrect operation, for example by the moveable furniture part still being stopped during the ejection movement, the latching element remains in the opening portion. If now the operator wants to close the furniture part again, it is no longer possible for locking of the latching element to take place in the latching recess as the latching element cannot move from the opening portion into the locking portion by virtue of the configuration of the sliding track. Secure locking would only be possible if the operator moves the moveable furniture part in the opening direction until the latching element has reached the first connecting portion and the latching element passes into the closing portion upon the furniture part being closed again. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is therefore to provide a drive device which is improved over the state of the art. In particular, the invention seeks to provide that in the event of incorrect operation, locking of the latching element in the locking portion is possible in an easy fashion even if the ejection process is interrupted. 
     According to the invention therefore there is provided a second connecting portion, which is closer to the latching recess, between the opening portion and the closing portion. In other words, in the event of incorrect operation of the latching element, it is not necessary to travel along the entire cardioid curve-like sliding track. Instead, there is a short cut in the shape of the second connecting portion through the “heart” of the cardioid curve-like sliding track. 
     To prevent unwanted entry of the latching element from the closing portion into the second connecting portion, a deflection element which is preferably of a flap-like configuration is arranged between the second connecting portion and the closing portion. That deflection element is preferably spring-loaded, the deflection element moving only when the latching element, coming from the second connecting portion, encounters the deflection element. 
     To guarantee the deflection of the latching element into the second connecting portion, the opening portion has an inclined deflecting means by which the latching element can be deflected in the opening movement into a part of the opening portion, which part is between the first and the second connecting portion. That deflection guarantees that the latching element passes into the second connecting portion upon movement of the latching element in the closing direction in the part of the opening portion, that is between the first and the second connecting portion. 
     In a further preferred embodiment, the sliding track is provided in a housing of the drive device, wherein an ejection element which is acted upon by an ejection force storage means for the moveable furniture part is moveable relative to the housing. To allow the movement of the latching element in the sliding track, the latching element is mounted moveably, preferably pivotably, to the ejection element. 
     Protection is also claimed for an article of furniture comprising a furniture carcass, a moveable furniture part, and a drive device according to the invention for the moveable furniture part. Depending on the respective configuration of the drive device, the drive device can be arranged on the furniture carcass and in that way the moveable furniture part is actively ejected. Alternatively, the drive device can be arranged on the moveable furniture part, whereby the drive device is ejected from the furniture carcass. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further details and advantages of the present invention are described more fully hereinafter via the specific description with reference to the exemplary embodiments illustrated in the drawings, in which: 
         FIGS. 1 through 4  diagrammatically show a moveable furniture part in various positions with a drive device, 
         FIGS. 5 through 6  show exploded views of a drive device, 
         FIGS. 7 through 12  show various broken-away 3D views of the drive device, 
         FIGS. 13 through 19  show the movements involved in closing and unlocking by over-pressing, 
         FIGS. 20 through 22  show the movements involved in unlocking by pulling, 
         FIG. 23  diagrammatically shows the cardioid curve-like sliding track with various positions of the latching element, and 
         FIGS. 24 through 32  show 3D detail views of the latching element in various positions in the sliding track. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  diagrammatically shows an article of furniture  16  comprising a furniture carcass  17  and a moveable furniture part  2 , at the front side of which is mounted a front panel  21 . The moveable furniture part  2  is mounted moveably by a drawer rail  22  to a carcass rail  23 —possibly also by way of a central rail (not shown). In this diagrammatic view, the carcass rail  23  at the same time forms the housing  4  of the drive device  1 . In this  FIG. 1 , the entire drive device  1  is associated with the furniture carcass  17 , only the entrainment member  9  moves with the moveable furniture part  2 . In principle, the arrangement can also be precisely reversed so that the drive device  1  is associated with the moveable furniture part  2  while the entrainment member  9  is arranged fixed with respect to the furniture carcass. The position of the moveable furniture part  2 —especially the entrainment member  9 —is detected by a detection device  7  and passed to the locking element  5  by the transmission slide  14  which in this case is shown as a circle. The transmission slide  14  and the detection device  7  together with possible further components form the transmission device  8  for transmission of the position of the moveable part  2 , detected by the detection device  7 , to the locking element  5 . The ejection element  3  (this can also be referred to as the ejection slide  3 ) is mounted moveably on the housing  4  and is acted upon by an ejection force storage member  18  in the opening direction OR. As the movement of the ejection element  3  in the opening direction OR is blocked by the locking element  5 , the moveable furniture part  2  cannot be ejected in the opening direction OR whereby the moveable furniture part  2  is in the closed position SS. 
     If now a pressure is applied to the moveable furniture part  2  in the closing direction SR as shown in  FIG. 2 , the locking element  5  is moved by the transmission device  8  so that the ejection path for the ejection element  3  is cleared. In the event of over-pressing in the closing direction SR, the locking element  5  does not necessarily have to be moved, as in  FIGS. 1 through 4  and  FIGS. 23 through 29 . Rather, the position of the moveable furniture part  2  can be passed by the detection device  7  directly to the latching element  6  arranged on the ejection element  3  so that it is moved out of the latching recess  13  of a cardioid-shaped sliding track  12  into an opening portion  45  of the sliding track  12 , as shown in  FIGS. 5 through 22 . The over-pressed position ÜS is reached by that over-pressing action. 
     In comparison,  FIG. 3  shows a drive device  1  which is unlocked by pulling on the moveable furniture part  2  in the opening direction OR. That opening movement is also detected by the detection device  7  whereby the locking element  5  is moved relative to the housing  4  by a transmission device  8  separate from the latching element  6  and thereby clears the ejection path for the ejection element  3 . The pulling position ZS which is directly in front of the closed portion SS is reached thereby. 
     In  FIG. 4  the ejection element  3 , after unlocking thereof by pressing (as shown in  FIG. 2 ) or by pulling ( FIG. 3 ), due to the ejection force storage member  18  being relieved of stress, has ejected the moveable furniture part  2  in the opening direction OR, whereby an open position OS is reached. Upon ejection, the entrainment member  9  comes out of engagement from the detection device  7 . That can be effected by the catch lever  37  of the detection device  7  being pivoted away. 
     Exploded views of a specific embodiment by way of example of a drive device  1  are shown in  FIGS. 5 and 6 . In that case the housing base plate  24 , the housing center plate  26 , and the housing cover  25  together form the housing  4 , and the housing  4  is preferably mounted to a drawer rail  22  by the housing base plate  24 . To achieve a change in position of the moveable furniture part  2  in its closed position SS relative to the furniture carcass  17 , the housing center plate  26  can be displaced relative to the components fixed with respect to the furniture part, the housing base plate  24  and the housing cover  25 . In that case, precise setting is possible by the adjusting element  28  and the adjusting studs on the housing center plate  26 . A damping device  27  for damping the retraction movement of the moveable furniture part  2  is also connected to the housing center plate  26 . The individual components of that damping device  27  are not identified in greater detail. 
     The sliding track  12  in which the latching element  6  moves is provided in the housing center plate  26  and thus in the housing  4 . The latching element is held pivotably at one end at the mounting location  42  in the ejection element  3 . The ejection element  3  is moveable between abutments relative to the housing center plate  26 . The spring base  33  for the ejection force storage means  18  (tension spring) is provided on that ejection element  3 . The other end of the ejection force storage member  18  is held to the spring base  32 . That spring base  32  is disposed at the spring stressing element  30  fixedly connected to the housing base plate  24 . The spring stressing force can be adjusted in dependence on the location of fixing of the spring stressing element  30  to the housing base plate  24 . The spring stressing element  30  arranged on the housing base plate  24  can be moved relative to the housing base plate  24  by the second adjusting element  31  and thus the spring stressing force of the ejection force storage member  18  can be adjusted. 
     A spring base  35  for the retraction force storage member  19  (tension spring) is also disposed on the ejection element  3 , the retraction force storage member being fixed on the other hand to the spring base  34  on the retraction slide  15 . That retraction slide  15  (it can also be referred to as the retraction device  15 ) is movably mounted to the ejection slide  3  with limited movement due to abutments. At one end of the retraction slide  15  is disposed the axis of rotation  38  for the catch lever  37 . The entrainment member  9  is held by way of that catch lever  37 —which is part of the detection device  7 . The entrainment member  9  is fixedly connected to the mounting plate  36  which is mounted to the carcass rail  23  (not shown). A damping abutment  40  is also provided at the end of the retraction slide  15  so that upon contact occurring between the retraction slide  15  and the entrainment member  9 , no loud noise occurs and the components are handled gently. 
     The transmission slide  14  mounted moveably on the housing center plate  26  is provided for travel-controlled triggering of the ejection slide  3  or for travel-controlled nullification of the locking action upon pulling on the moveable furniture part. At one end, the slide  14  has the locking element  5  which in part also forms the latching recess  13  of the sliding track  12 . The inclined deflection means  43  which also forms the sliding track  12  for the over-pressing effect is also provided on that transmission slide  14 . The elastic coupling element  10  is held at the front end of the transmission slide  14 , the coupling element  10  corresponding to the connecting element  11  provided on the retraction slide  15 . Also arranged on the transmission slide  14  is the deflection element  20 , by way of which the latching element  6  can be moved back into the closed position SS in the event of the ejection movement not being complete. The slider  39  which is mounted resiliently on the housing center plate  26  ensures that the latching element  6  does not pass into an unwanted portion of the sliding track  12 , in particular when the drawer is thrown shut with too little energy and is ejected again before locking takes place. In such a movement, the slider  39  remains closed. 
       FIG. 7  shows the drive device  1  in the assembled condition, with the housing cover  25  removed. It will be seen that the damping device  27  is clamped in the housing center plate  26 . It is also possible to see the ejection force storage member  18  which is fixed on the one hand to the housing base plate  24  or to the spring stressing element  30  and on the other hand to the ejection slide  3 . The retraction slide  15  and the catch lever  37  fixed thereto can also be partly seen. The large part of the transmission slide  14  is also visible through the housing center plate  26 . 
     The housing center plate  26  is removed in  FIG. 8  in comparison with  FIG. 7 , thereby ensuring a better view of the ejection slide  3  and the retraction slide  15 . 
     It will be seen that the latching element  6  bears against an end of the retraction slide  15 —which is formed by the latching element abutment  41 . The latching element  6  cannot escape from that position as it is guided in the sliding track  12 . 
     That sliding track  12  is visible for the major part in  FIG. 9  in which, of the drive device  1 , only the housing base plate  24  is missing. The retraction force storage member  19  which is in the form of a tension spring is in this case held between the spring bases  34  and  35 . The ejection force storage member  18  is held to the spring bases  32  and  33 . The catch lever  37  is shown in the opened position, wherein the entrainment member  9  already bears against the abutment  40  of the retraction slide  15 . 
     To give a better view in relation to the latching element  6 , a part of the ejection slide  3  is removed in  FIG. 10  in contrast to  FIG. 9 . As a result, it can be seen that the latching element  6  bears against the sliding track  12  and the latching element abutment  41 . In this first coupling position K 1  of the latching element  6 , the retraction slide  15  is coupled to the ejection slide  3  as the retraction slide  15 , by virtue of the latching element abutment  41  bearing against the latching element  6 , cannot move further towards the left relative to the ejection slide  3 . As a result, the retraction force storage member  19  cannot be relieved of stress. 
     In contrast, in  FIG. 11 , the retraction force storage member  19  is relaxed as the latching element  6  has reached the second coupling position K 2  in which the path for the retraction slide  15  relative to the ejection slide  3  has been cleared. 
     In conformity therewith, the retraction slide  15  is partly removed in  FIG. 12  so that there is a clear view to the latching element  6  held in or on the latching recess  13 . 
     In  FIG. 13 , the drive device  1  and thus the moveable furniture part  2  are disposed in the open position OS. Similarly to  FIG. 10 , the latching element  6  bears against the latching element abutment  41  of the retraction slide  15  and is guided in the sliding track  12  provided in the housing center plate  26 . The entire ejection slide  3  is disposed in a first movement portion B 1  and the latching element  6  is disposed in the first coupling position K 1 . The connection to the entrainment member  9  can be seen at the other end of the retraction slide  15 , by way of the catch lever  37 . Partially concealed by the housing center plate  26  the transmission slide  14  is arranged moveably relative to the housing center plate  26 . That transmission slide  14  also forms parts of the sliding track  12 . Thus, the transmission slide for example has the locking element  5  and the inclined deflection element  43  for the latching element  6  and the inclined guide member  47  for the connecting element  11 . In addition, the coupling element  10  which can correspond to the connecting element  11  is mounted pivotably to the transmission slide  14 . 
     When the moveable furniture part  2  is further moved in the closing direction SR in  FIG. 13 , the latching element  6  moves along the sliding track  12  which is partly formed by the deflection element  20 , while retaining the first coupling position K 1 . The end of the straight closing portion of the sliding track  12  and thus the end of the first movement portion B 1  are reached in  FIG. 14 . 
     As soon as the moveable furniture part  2  is further moved from the position in  FIG. 14  into the position shown in  FIG. 15 , the latching element  6  is urged by the latching element abutment  41  of the retraction slide  15  into the latching recess of the sliding track  12 . As a result, the retraction slide  15  is uncoupled from the ejection slide  3  and at the same time the ejection slide  3  is locked to the housing  4  and the second coupling position K 2  is reached. Thus, two coupling operations are implemented by that one movement of the latching element  6 . 
     The moveable furniture part is moved or retracted from the open position OS in  FIG. 15  into the closed position SS in  FIG. 16  by stress relief of the retraction force storage element  19 . As soon as the connecting element  11  bears against the coupling element  10  of the transmission slide  14  just before the end of that retraction movement, the entire transmission slide is firstly moved towards the left to the abutment in the housing center plate  26 . After that, the connecting element  11  passes over the coupling element  10  in the closing direction SR. With that movement towards the left of the transmission slide  14 , the locking element  5  is also moved towards the left and, together with a part of the sliding track  12  provided on the housing  4  (more specifically in the housing center plate  26 ), forms the actual latching recess  13  for the latching element  6  in the housing  4 . The latching element thus remains in the second coupling position K 2 , even if slightly displaced in relation to  FIG. 15 . It can be clearly seen from  FIG. 16  that the sliding track  12  now involves a cardioid shape. 
     If pressure is applied to the moveable furniture part  2  in the closing direction SR in that closed position SS (see  FIG. 17 ) the retraction slide  15  is also further moved in the closing direction SR. As that retraction slide  15  has reached an end abutment at the ejection slide  3  in that closed position SS, the ejection slide  3  is also moved in the closing direction SR together with the latching element  6  mounted pivotably thereto. As a result, the latching element  6  moves as shown in  FIG. 17  out of the latching recess  13  until the latching element  6  bears against the inclined deflection element  43 . The over-pressed position ÜS is reached thereby. At the same time, the connection element  11  is also deflected by the inclined guide means  47 . 
     Due to deflection at the inclined deflection element  43  (see  FIG. 18 ), the latching element  6  further passes through the depression  44  provided in the transmission slide  14  and forming a part of the sliding track  12 , in the direction of the opening portion  45  of the sliding track  12 . 
     As soon as that opening portion  45  is reached the ejection element  3  is unlocked and the ejection force storage member  18  can be relieved of stress and the moveable furniture part  2  is ejected in the opening direction OR and passes into the open position OS (see  FIG. 19 ). In that ejection movement, the transmission slide  14  is moved again by the connecting element  11  by the coupling element  10  until reaching a condition of abutment a distance in the opening direction OR so that the initial position of the transmission slide  14  is restored. If the opening movement should already be interrupted shortly after the start then upon re-closing, the latching element  6  can move through the second connecting portion  48  and the latching element  6  passes into the closing portion of the sliding track  12  again, due to the deflection element  20  which is of a flap configuration being urged away. 
       FIG. 20  again shows the closed position SS in which the latching element  6  is in the second coupling position K 2 . That  FIG. 20  corresponds to the view in  FIG. 16 . 
     If now pressure is not applied to the moveable furniture part  2  from that closed position SS but a pulling force is applied to the moveable furniture part  2 , that movement is detected by the detection device  7 —which is formed by the catch lever  37  and the retraction slide  15 . As a result, the retraction slide  15  and therewith the connecting element  11  are moved towards the right until it bears against the coupling element  10  and entrains it. Due to the coupling element  10  being entrained in that way, as shown in  FIG. 21 , the entire transmission slide  14  is also moved and the locking element  5  no longer forms a part of the latching recess  13 . In that way, the path for the latching element  6  is no longed blocked by the locking element  5  and the path into the opening portion  45  of the sliding track  12  is clear. Accordingly, transmission of the pulling movement is not effected directly to the latching element  6 , but so-to-speak the latching abutment (=locking element  5 ) is drawn away from that latching element  6  and thus the locking position or the second coupling position K 2  is nullified. 
     As a further consequence, as shown in  FIG. 22 , the ejection force storage member  18  can be relieved of stress again and, by way of the ejection slide  3  and the retraction slide  15  held thereto, moves the moveable furniture part in the opening direction OR. As soon as the ejection force storage member  18  has completely relaxed, the retraction force storage member  19  is loaded with the further momentum of the moveable furniture part  2  or by actively pulling on the moveable furniture part  2  in the opening direction OR until the first coupling position K 1  between the retraction slide  15  and the ejection slide  3  is regained. Upon closure of the moveable furniture part  2 , then as a further consequence the ejection force storage member  18  is stressed before the locking position or the second coupling position K 2  is reached. That substantially corresponds to the first movement portion B 1  which is between the positions shown in  FIG. 13  and  FIG. 14 . 
       FIG. 23  diagrammatically shows a cardioid-shaped or cardioid-like sliding track  12  in which the latching element  6  moves upon opening and closing of the moveable furniture part  2 .  FIG. 23  shows ten different positions of the latching element  6 , wherein each position of the latching element  6  is identified by Roman numerals. 
     After the beginning of the closing movement or the retraction movement, accordingly, the latching element  6  is disposed at position I in the closing portion  49 . During the movement of the latching element  6  through that closing portion  49  in the closing direction SR, the ejection force storage member  18  (not shown here) is stressed as operation is in opposition to the spring force F of the ejection force storage member  18 . Shortly before the end of the closing portion  49 , the latching element  6  passes over the deflection element  20  delimiting the second connecting portion  48  and passes to the position II at the end of the opening portion  19 . In the event of an excessively fast closing movement, the latching element  6  can deflect into the first overrun track  54  which is of any desired length. 
     Either due to the configuration of the sliding track  12  or by virtue of a travel control, the latching element  6  passes into the locking portion  50  at the finishing end of the opening portion  49  (position II). If pressure is no longer applied to the moveable furniture part  2  in that portion, then the ejection force storage member  18  can be relieved of stress. As however the latching element  6  in that position II can no longer pass into the closing portion  49 , the latching element  6  is deflected by the configuration of the sliding track  12  into the latching recess  13  (see position III) and is locked there, with the ejection force storage member  18  being stressed. 
     If now pressure is applied to the moveable furniture part  2  in the closing direction SR, then the latching element  6  passes from the position III into the position IV (the starting end of the opening portion  45 ) in which it is deflected at the inclined deflection member  43  in the direction of the opening portion  45 . In the case of a strong over-pressing movement, the latching element  6  could also deflect into the second overrun track  55  which is of any desired length. If pressure is no longer applied to the moveable furniture part  2  in the closing direction SR in that position IV, then the ejection force storage member  18  can be relieved of stress and the latching element  6  moves into the opening portion  45 , in correspondence with the curve configuration. In the case of a normal—uninterrupted—ejection movement, the latching element  6  thereupon passes from the position V by way of the position VI to the position VII. In that position VII, the latching element is disposed in the first connecting portion  51  between the opening portion  45  and the closing portion  49 . In the case of a strong ejection movement, the latching element  6  can move as far as passing into the third overrun track  56 . In the closing movement, the latching element  6  then again passes into the closing portion  49  by virtue of the curve configuration and returns to the position I again. 
     If, however, because of incorrect operation the ejection movement of the moveable furniture part  2  is interrupted, then the latching element  6  firstly remains somewhere in the opening portion  45 . For example, if that happens in the position V, then the latching element  6  can no longer be moved back into the latching recess  13 . As soon as the latching element  6  has reached the front part  53  of the opening portion  45 , however, (for example position VI) by virtue of the inclined deflection member  52 , then, in the event of a closing movement of the moveable furniture part  2 , that is triggered by the operator, the latching element  6  is deflected into the second connecting portion  48  and reaches the position VIII. Due to further closing movement, the latching element  6  moves out of the position VIII through the second connecting portion  48  to the position IX in which the latching element  6  presses against the deflection element  20  in the form of the flap, and can move that deflection element  20  into the position shown by the broken line. As a result, the latching element  6  moves into the closing portion  49  again and reaches the position X. Upon further closing movement the latching element  6  passes into the position II again and as a further consequence is locked in the latching recess  13  at position III. 
       FIG. 24  shows the sliding track  12  provided in the housing  4  of an actual specific embodiment. Disposed at the end of the front part  53  of the opening portion  45  is the first connecting portion  51 , by which the opening portion  45  is connected to the closing portion  49 . In addition, it is possible to see the second connecting portion  48  which is delimited as far as the closing portion  49  by the deflection element  20 . 
       FIG. 25  additionally shows the latching element  6  which is mounted pivotably on the ejection element  3  (not shown here) and which is in the closing portion  49 . That position corresponds to the position I shown in  FIG. 23 . 
     Upon further movement in the closing direction SR, the latching element  6  moves into the position shown in  FIG. 26 . As a result, the latching element passes into the locking portion  50 . That position of the latching element  6  approximately corresponds to the position II in  FIG. 23 . 
     In  FIG. 27  the latching element  6  is in the locking position VS in the locking portion  50 . The movement in the opening direction OR is prevented by the locking element  5 . That position of the latching element  6  corresponds to the position III in  FIG. 23 . 
     After unlocking (by pressing or by pulling), the latching element  6  passes into the opening portion  45 . The position of the latching element  6  shown in  FIG. 28  approximately corresponds to the position V shown in  FIG. 23 . 
     In the event of incorrect operation or upon an interrupted ejection movement, the latching element  6  passes into the second connecting portion  48  (see  FIG. 29 ) by movement of the moveable furniture part  2  in the closing direction SR. That position of the latching element  6  approximately corresponds to the position VIII in  FIG. 23 . 
     At the end of the second connecting portion  58 , the latching element presses against the deflection element  20  (see  FIG. 30 ) and thus passes into the closing portion  49 . That position of the latching element  6  approximately corresponds to the position X in  FIG. 23 . 
     If no incorrect operation is involved, then the latching element, as shown in  FIG. 31 , passes by way of the front part  53  of the opening portion  45  and the first connecting portion  51  into the closing portion  49  again. The position in  FIG. 31  approximately corresponds to the position VI in  FIG. 23 . 
     Independently of the path adopted (first connecting portion  51  or second connecting portion  48 ) the latching element  6  passes into the locking portion  50  again at the end of the closing movement and locks in the latching recess  13  as shown in  FIG. 32 . That position of the latching element  6  in  FIG. 32  corresponds to the position III in  FIG. 23 . 
     The present invention thus provides an improved cardioid-like sliding track  12  for a drive device  1 , in which, besides the first connecting portion  51  between the opening portion  45  and the closing portion  49 , there is also a short cut in the form of the second connecting portion  48  between the opening portion  45  and the closing portion  49  in the housing  4  as part of the sliding track  12 .