Abstract:
The invention relates to a driving device for a movable furniture part, comprising retracting device for retracting device for retracting the movable furniture part out of an open position into a close position, said retracting device having a housing; a guide path which if formed in the housing and which comprises a retaining section; a retracting slide which can be moved in the guide path relative to the housing and can be locked in the retaining section; and a retracting force accumulator which urges the retracting slide. The retracting slide can be moved along the guide path between a first end position, which corresponds to the retaining section, and a second end position, which corresponds to the closed position, wherein the distance between the end positions along the guide path can be changed.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention concerns a drive device for a movable furniture part, comprising a retracting device for retracting the movable furniture part from an open position into a closed position, said retracting device having a housing, a guide path which is formed in the housing and which comprises a retaining section, a retracting slide which can be moved in the guide path relative to the housing and can be locked in the retaining section and a retracting force storage means which urges the retracting slide, wherein the retracting slide can be moved along the guide path between a first end position, which corresponds to the retaining section, and a second end position, which corresponds to the closed end position. The invention concerns further an item of furniture with such a drive device. 
         [0002]    Since many years in the field of the industry of furniture fittings there are mechanical drive devices in order to move furniture parts like for example drawers. This can be effected in this way that by pushing or by pulling on the movable furniture the ejection movement is mechanically supported or taken over completely. Also the closing movement can be effected by a so-called retracting device, so that the drawer does not have to be pushed manually till the closed position but especially the last movement section of the closing movement is taken over. 
         [0003]    Now there are since many years efforts to that effect to combine these actually contrary movements retracting and ejecting. There it has especially to be ensured that the contrarily acting forces do not hinder each other. One possibility for that exists is an appropriate arrangement of the tensioning paths of the individual force storage means. It is also possible to realize the spring forces of the individual force storage means correspondingly different. A further possibility exists therein to make the spring forces adjustable. Thus, already now miscellaneous configuration can be set with these variants. 
       SUMMARY OF THE INVENTION 
       [0004]    The object of the present invention is now to establish an alternative or better drive device compared to the prior art. 
         [0005]    This is achieved by a drive device with the features of claim  1 . According to that it is provided that the distance of the end positions from each other along the guide path can be changed. With other words, thus, the travel of the retracting slide is changed. This makes it possible to individually adapt the retracting path to the circumstances. Thus, for example a short retracting path is already sufficient when there is a relatively small drawer. Vice versa, however, it can also occur that drawers are stopped because of their weight and because of the friction already before reaching the retracting path when manually closing. This not desired stopping at a half opened drawer can be prevented by an elongation of the retracting path (distance between the end positions form each other). 
         [0006]    Basically it is possible that the distance of the end positions is adjustable by removable limit stops or by bordering elements. Preferably, however, it is provided that the housing has a base part and a slide part which is movable relative to the base part between at least a first state and a second state. In dependence of the state of the slide part also the distance between the end positions is different. 
         [0007]    According to a further preferred embodiment in can be provided that the distance between the first end position and the second end position of the retracting slide along the guide path is larger in the first state than in the second state. Concretely, the travel in the guide path is thus enlarged by the movement of the slide part into the second state. 
         [0008]    In principle, the slide part can form a limit stop for the retracting slide which is formed separately from the guide path. Preferably, however, it is provided that at least a part of the guide path is formed in the slide part. Particularly preferred the whole guide path is formed in the slide part of the housing of the retracting device. 
         [0009]    In order to enable a setting of the positions of the slide part as easy as possible, it is preferably provided that slide part can be set in a blocking position by a blocking device, the blocking position corresponding to the first state. Correspondingly it is further provided that the blocking position of the blocking device can be unset, whereby the slide part can be moved from the first state into the second state. The blocking device itself can work as a separate component between slide part and base part. Preferably it is provided that the blocking device comprises a, preferably elastically, movable latch, which is formed on the slide part, and a stop for the latch, the stop being formed on the base part. 
         [0010]    As already mentioned in the introduction, not only retracting devices are provided in modern drive devices for movable furniture parts. Much more, according to a preferred embodiment the drive device can also have an ejection device for ejecting the movable furniture part out of the closed position into an open position. This ejection device can be partly integrated in the retracting device, so that the retracting device and the ejection device form a construction unit for mounting on the furniture item or on the movable furniture part. 
         [0011]    In order to ensure a better flexibility, however, it is desired that the retracting device and the ejection device are produced as separate construction units which can be individually offered and sold. At this it is important that the individual construction units are completely functioning on their own and can also be mounted as easy as possible. 
         [0012]    If now, however, both construction units are mounted in one and the same item of furniture or movable furniture part, it is important that the individual functions to not hinder each other. This is particularly important when an ejection device is retrofitted to an existing retracting device. Till now, also the retracting device has to be exchanged when retrofitting the ejection device in order to being able to use the individual functions unlimited, because when using an ejection device the retraction device can only retract along a shorter retracting path. 
         [0013]    Now in order to prevent the exchange of the already mounted retracting device, from the outset a retracting device according to the invention with a changeable retracting path is mounted. Thus, this retracting device can be optionally retrofitted with an ejection device. When retrofitting, thus, the retracting path can be changed, in concrete can be shortened, whereby a smooth operation of the tensioning movements and of the ejection and retracting movements respectively is guaranteed. 
         [0014]    This means, when only the retracting device is mounted, another—in the concrete case a longer—travel for the retracting device is provided. If now also the ejection device is mounted, the travel of the retracting slide has to be changed—in the concrete case to be shortened. With a drive device according to the invention, this change is possible in an easy manner without exchanging the whole retracting device. 
         [0015]    For example, the distance of the end positions to each other can be easily changed prior to the mounting of the ejection device by a technician, for example by manually shifting the slide part. Particularly preferred, however, it is provided that the ejection device can be connected with the retracting device, wherein the distance of the end positions from each other along the guide path can be changed by the connecting of the ejection device with the retracting device. This means, when an ejection device is retrofitted or also mounted synchronically, the travel of the retracting slide is automatically changed by the mounting of the ejection device. This change or adjustment can be effected for example by an electric control. Preferably, however, it is provided that this is effected only in a mechanical manner, for example in that the blocking position of the blocking device can be unset by the ejection device. In the concrete case it can be provided that the ejection device comprises a triggering element by which the blocking device is movable from the blocking position, in which the latch abuts the stop, into a release position, in which the latch is released from the stop by the triggering element, when connecting the ejection device with the retracting device. The mounting movement can thus be used to change the corresponding state of the end positions. 
         [0016]    The ejection device can be for example mounted on the underside of the drawer bottom. For an easy mounting it is preferably provided that the ejection device can be, preferably positive-locking, fixed to the retracting device by a fixing device. Moreover it can be particularly preferred provided that guiding elements for the ejection device are formed on the retracting device, wherein the ejection device can be fixed at the retracting device by the fixing device by way of a sliding movement which is guided by the guiding element. Particularly preferred this sliding movement cannot only be used to reach a connection or fixation of the ejection device to the retracting device, but also thereto that the change of the distance of the end positions to each other is effected by this sliding movement also. This can be concretely effected in that the slide part of the retracting device is movable from the first state to the second state during said slide movement of the ejection device. 
         [0017]    Protection is also demanded for an item of furniture with a drive device according to the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    Further details and advantages of the present invention are described more fully hereinafter by means of the specific description with reference to the embodiments illustrated in the drawings, in which: 
           [0019]      FIG. 1  schematically shows an article of furniture with movable furniture parts in different positions, 
           [0020]      FIG. 2  schematically shows the progress of the spring forces of the retracting force storage means and of the ejection force storage means at an opening and closing movement, 
           [0021]      FIGS. 3 and 4  show exploded views of the retracting device with an ejection device and an extension guide, 
           [0022]      FIGS. 5A-7B  show the state of the retracting device relative to the extension guide during a retracting movement, 
           [0023]      FIGS. 8-10B  show the mounting progress of the ejection device on the retracting device, 
           [0024]      FIGS. 11 and 12  show details of the retracting device when changing the state of the slide part 
           [0025]      FIGS. 13 to 15  show details for the connection of the ejection device with the retracting device and 
           [0026]      FIGS. 16 to 19  show comparisons of the retracting path at different states of the slide part. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]      FIG. 1  shows an item of furniture  18  with a furniture carcass  19  and in total four movable furniture parts  2  in form of drawers. Seen from top to bottom, the both upper drawers are in an open position OS, the third drawer is in the closed position SS and the lowest drawer is in the over-pressing position ÜS. The movable furniture parts  2  each comprise the drawer container  20  and the front panels  21 . The movable furniture part  2  is connected to extension guide  24  via the drawer container  20 . This extension guide comprises the drawer rail  22 , a center rail  36  which is not shown here and the carcass rail  23 . At the drawer shown topmost an ejection device  14  is drawn schematically. This ejection device  14  mounted to the drawer rail  22  (or to the drawer bottom) via the housing  25 . The ejection entrainment member  32 —which can be coupled at least section-wise with the ejection slide  28  of the ejection device  14 —is fixed to the carcass rail  23 . This ejection slide  28  is movable relative to the housing  25 . The control lever  29  is pivotably mounted to the ejection slide  28 , wherein the control pin  30  is formed on this control lever  29 . This control pin  30  is guided in the heart curve shaped sliding guide path  26 . This sliding guide path  26  comprises the latch recess R for the control pin  30 . The control pin  30  together with the latch recess R of the sliding guide path  26  forms the locking device  27  for the ejection slide  28  at the housing  25 . The ejection slide  28  is urged by the ejection force storage means  31  (in this case a compression spring). In the shown illustration according to the topmost drawer this ejection force storage means  31  is relaxed. By this ejection device  14  the movable furniture part  2  is—as per se known—ejected from a closed position SS into opening direction OR. This is effected, starting from the topmost shown drawer, as follows: 
         [0028]    By pressing onto the movable furniture part  2  in closing direction SR, the movable furniture part  2  arrives in the open position OS according to the second drawer. During this movement the retracting slide  29  is shifted by the ejection entrainment member  32  relative to the housing  25 , whereby the ejection force storage means  31  is loaded and the control pin  30  arrives in the latch recess R. In this way the locking device  27  is in the locking position V. Then, starting from this position, the movable furniture part  2  is retracted into the closing position SS by the retracting device  3 . This movement operation is explained later in still more detail. In this way the drawer arrives in the closing position SS according to the third drawer, wherein the ejection device  14  is still in the locking position V. By over-pressing the movable furniture part  2  from this closing position SS, the movable furniture part arrives in the over-pressing position US according to the lowest drawer. Thereby, also the buffer  35 —which defines the exact position of the closed position SS—arranged between the drawer rail  22  and the carcass rail  23  is pushed in. By this over-pressing movement also the locking position V is released and the control pin  30  arrives in an ejection section of the heart curve shaped sliding guide path  26 , whereby the ejection force storage means  31  is relaxed and the movable furniture part  2  is ejected into opening direction OR. In this case the ejection device  14  is associated to the movable furniture part  2 . Of course, however, this can be also effected in a contrary manner, that is to say that the ejection device  14  is associated to the furniture carcass  19  or the carcass rail  24  and is acting onto an ejection entrainment member  32  which is associated to the movable furniture part  2 . Both of these arrangement possibilities of course apply analogous also for the retracting device  3 . 
         [0029]    Further details to this retracting device  3  can be told on behalf of both drawers in the middle of  FIG. 1 . Referring to the upper of these drawers, the retracting device  3  (which forms the drive device  1  together with the ejection device  4 ) is just at the beginning of the retracting movement. The retracting device  3  comprises a housing  4 , with which the retracting device  3  is mounted to the drawer rail  22 . Moreover, the retracting device  3  comprises a retracting slide  7  guided in the guiding path  5 . The retracting force storage means  8  (tension spring) is spanned between the retracting slide  7  and the spring base  34  arranged on the housing  4 . The retaining section  6  for the retracting slide  7  is located at an end of the guiding path  5 . Because of the movement of the movable furniture part  2  in closing direction SR, the retracting slide  7  was already released from the retaining section  6  by the retracting entrainment member  33  mounted on the carcass rail  24 , whereby the retracting force storage means  8  can relax. Thereby the movable furniture part  2  arrives in the closed position SS according to the lower drawer. This retracting movement is stopped by the buffer  35 . To that extent is also the functionality of hitherto known drive devices  1  with an ejection device  14  and with a retracting device  3 . 
         [0030]    According to the invention there is now, however, also an adjusting possibility for the travel of the retracting slide  7  in the guide path  5  of the retracting device  3 . Thereto an alternative position of the guide path  5  relative to the drawer rails  22  is illustrated with both middle drawers—each emphasized by a dashed bordering. This different position or state is enabled by a slide part  10  which is not illustrated in more detail here. As shown at the upper drawer, the retracting entrainment member  33 —which is located at the same position when there is the same open position OS of the movable furniture part  2 —does not yet abut to the retracting slide  7 . Much more, the retracting slide  7  is still in the retaining section  6  of the guide path  5 . This retaining section  6  corresponds to the first end position E 1  of the retracting slide  7  in the guide path  5 . As can be seen, in this case the retracting force storage means  8  is not loaded this strong as in the other case. This, however, does not hinder the retracting movement. Much more, the retracting movement is just started with a lower but thereby also smoother force. If now the movable furniture part  2  is manually moved further into closing direction SR, the retracting entrainment member  33  gets in contact with the retracting slide  7 , whereby this retracting slide  7  is released from the retaining section  6  of the guide path  5 . The retracting force storage means  8  can thereby relax and the retracting device  3  pulls the movable furniture part  2  into the closed position SS. This closed position SS corresponds to the second end position E 2  of the retracting slide  7  along the guide path  5 . As shown with the lower drawer, thus the distance A of the end positions E 1  and E 2  to each other is different depending on the state of the guide path  5 . This means, the length of the travel of the retracting slide  7  along the guide path  5  is different. 
         [0031]    In  FIG. 2  the progress of the spring forces of the force storage means  8  and  31  along the movement path of the movable furniture part  2  is illustrated schematically. In this case the spring forces are illustrated as straight lines, in the concrete case the spring force progress is of course more curved. In the diagram according to  FIG. 2  the spring forces F( 31 ) of the ejection force storage means  31  and F( 8 ) of the retracting force storage means  8  are compared. The spring force of the force storage means  31  is higher than the spring force of the retracting force storage means  8 . Fully left the movable furniture part  2  is located in the closed position SS. Thereby the ejection force storage means  31  is fully tensioned and loaded. The retracting force storage means  8  is relaxed. By moving the movable furniture part  2  in closing direction SR, the movable furniture part  2  reaches the over-pressing position ÜS. At that the ejection force storage means  31  is further loaded, while the retracting force storage means  8  relaxes. By releasing the movable furniture part  2  the ejection force storage means  31  can then relax, whereby the movable furniture part  2  is ejected in opening direction OR and reaches the open position OS 1 . Simultaneous with this ejection movement also the retracting force storage means  8  is tensioned. If the slide part  10  at that is in the first state S 1 , the retracting force storage means  8  is tensioned to a higher spring force F( 8 ) than if the slide part  10  is in the second state S 2 . 
         [0032]    If now the movable furniture part  2 , starting from a free run, is moved again into closing direction SR, the movable furniture part  2  first arrives in the open position OS 2 . From this position the ejection force storage means  31  is again loaded by the manual pushing till the open position OS 1  is reached. In this movement section the spring force F( 8 ) of the retracting force storage means  8  remains unchanged. With a further closing movement the retracting slide  8  is then, however, released from its retaining section  6 , this means the retracting slide  7  leaves its first end position E 1 . The concrete position of this first end position E 1  depends on the state S 1  or S 2  of the slide part  10 . If the slide part  10  is in the state S 1 , the subsequent retracting path EW 1  is longer than if the slide part  10  is in the second state S 2  (retracting path EW 2 ). At the end of this retracting movement the retracting slide  7  arrives in the second end position E 2  which corresponds to the closed position SS of the movable furniture part  2 . The distance A between the end positions E 1  and E 2  is therefore—depending on the state of the slide part  10 —differently long. 
         [0033]      FIGS. 3 and 4  show important components of a drive device  1  in exploded views. Moreover, the extension guide  24  with the carcass rail  23 , the drawer rail  22  and the central rail  36  is illustrated. As a base component the retracting device  3  comprises a housing  4 . This housing  4  consists of a base part  9  and the slide part  10  slidable relative to the base part  9 . The base part  9  again consists of the base plate  37  and the base cover  38 . The housing  4  is attachable to the drawer rail  22  via screws  45 . In the housing  4  the retracting slide  7  is movably supported along the guide path  5 . The retracting slide  7  comprises the slide base  41  and the catch lever  40  pivotably supported on the slide base  41 . A dampening device  44  for damping or braking the retracting movement is arranged on the slide base  41 . The dampening device  44  comprises the dampening cylinder  42  and the dampening piston  43 . Further, a transmission element  39  is arranged in the area of the retracting slide  7 . Moreover, the retracting force storage means  8  formed as a tensioning spring is spanned between the retracting slide  7  and the housing  4 . For its function the retracting device  3  furthermore needs the retracting entrainment member  33 . This retracting entrainment member  33  is arranged on the holding plate  53  which again is mounted to the carcass rail  23 . 
         [0034]    Furthermore, the drive device  1  also comprises an ejection device  14 , whose function is per se known, which is why it is not shown in an exploded view. However, details of the ejection device  14  can be found in  FIG. 1 . The ejection device  14  comprises a housing  25  or a mounting plate, via which the ejection device  14  can be connected with the retracting device  3 . In the concrete case the triggering element  15  and the locking catch  47  are formed at the housing  25 . Together with the locking stop  48  formed at the base cover  38  the locking catch  47  forms a part of the fixing device  17 . Further, the fixing device  17  is formed by the locking projection  49  formed at the base cover  38  and by the locking recess  50  formed in the housing  25 . Moreover, several guiding elements  16  for guiding the sliding movement S of the ejection device  14  at the retracting device  3  are formed at the base cover  38  of the base part  9  of the housing  4 . It can also be recognized from the exploded views that the retaining section  6  of the guide path  5  is formed in the slide part  10 . Furthermore, the latch  12  of the blocking device  11  is arranged on the slide part  10 . The blocking device  11  is formed by the latch  12  together with the stop  13 . For its function the ejection device  14  also needs the ejection entrainment member  32  which is fixed to the carcass rail  23  via the holding plate  52 . 
         [0035]    The basic retracting function is explained in more detail in  FIGS. 5A-7B . In  FIG. 5A  the drawer rail  22  is still located in an open position OS relative to the carcass rail  23 . As is shown in  FIG. 5B , the catch lever  40  is still pivoted about the pivot axis  51  and is latched or held in the retaining section  6  of the guide path  5 . The retracting entrainment member  33  is not yet in contact with the retracting slide  7  and with its catch lever  40 , respectively. 
         [0036]    If now starting from  FIG. 5A  the movable furniture part  2  and the drawer rail  22  are moved in closing direction SR, the retracting entrainment member  33  gets into contact with the catch lever  40  as can be seen in  FIGS. 6A and 6B . The catch lever  40  and thus the retracting slide  7  are still, however, in its retaining section  6 , which corresponds to the first end position E 1 . 
         [0037]    However, as soon as by the closing movement the catch lever  40  is released from the retaining section  6  because of the force effected from the retracting entrainment member  33 , the retracting force storage means  8  can relax and pulls the movable furniture part  2  with the drawer rail  22  into the closed position SS, as can be seen in  FIGS. 7A and 7B . At that also the catch lever  40  is re-pivoted about the pivot axis  51  and is located in the second end position E 2 . 
         [0038]    By means of the  FIGS. 8A to 15  the mounting of the ejection device  14  on the retracting device  3  and as a consequence thereof the adjusting of the slide part  10  form the state S 1  to the state S 2  is described in more detail: 
         [0039]    In  FIG. 8A  the retracting device  3  is illustrated in a state mounted to the drawer rail  23 . At that the slide part  10  is located in the first state S 1 . Therefore, the travel or the retracting path EW 1  of the retracting slide  7  is long. This first state S 1  of the slide part  10  is reached or fixed by the blocking device  11 , because the resilient latch  12  formed on the slide part  10  abuts the stop  13  formed on the base cover  38  (see  FIG. 8B ). 
         [0040]    If now the ejecting device  14 , as illustrated in  FIGS. 9A and 9B , is pressed to the retracting device  3 , the latch  12  is pushed in by the triggering element  15  formed on the housing  25 . Thereby the blocking device  13  is not anymore in the blocking position B but in the release position L. The latch  12  does not anymore abut the stop  13 . 
         [0041]    Originating from this position according to  FIG. 9A or 9B , the ejection device  14  is the fixed to the retracting device  3 . This fixation is amongst others effected thereby that the locking catch  47  is moved into the locking stop  48 . These both components  47  and  48  together build a part of the fixing device  17 . Simultaneous with this sliding movement S also the slide part  10  is moved with the limit stop  54  formed on the housing, so that the slide part  10  gets from the first state S 1  to the second state S 2 . During this slide movement S also the blocking device  11  remains in its releasing position L (see  FIG. 10B ). 
         [0042]    For a better illustration the ejection device  14  and the base cover  38  of the base part  9  are hidden in  FIGS. 11 and 12 , whereby a better view onto the slide part  10  and onto its position relative to the base plate  37  of the base part  9  is possible. In  FIG. 11  the slide part  10  is still in its first state S 1 . Also the latch  12  is still not pushed in. In contrast, the latch  12  is pushed in in  FIG. 12  and the slide part  10  is already slid. Thereby, also the retaining section  6  of the guide path  5  closer to the retracting force storage means  8 . 
         [0043]    The retracting device  3  mounted to the drawer rail  22  and the not yet mounted ejection device  14  are shown in  FIG. 13 . The guiding elements  16  as well as the locking stop  48  and the locking projection  19 , which are all together formed on the base cover  38 , are well visible in this  FIG. 13 . Corresponding to these components of the retracting device  3 —as can be seen in  FIG. 14 —the locking recess  50 , the triggering element  15 , the guiding recesses  55  as well as the locking catch  47  are formed on the ejection device  14  or on its housing  25  and fixation plate, respectively. With the sliding movement S already described, the fixation of the ejection device  14  to the retracting device  3  is then carried out. Thereby the position according to  FIG. 15  is reached, in which the locking catch  47  is fixed at the locking stop  48  and the locking projection  49  is fixed in the locking recess  50 . 
         [0044]    In  FIGS. 16 to 19  the basic thoughts of the invention are again illustrated. According to  FIG. 16  the movable furniture part  2  is in an open position OS, wherein the retracting entrainment member  33  already contacts the catch lever  40  of the retracting slide  7 . This retracting slide  7 , however, is still in the first end position E 1  which corresponds to the retaining section  6  of the guide path  5 . The slide part  10  is in its first state  51 . From this position according to  FIG. 16  the first retracting path EW 1  starts and ends in the closed position SS according to  FIG. 17 , in which the retracting slide  7  is in its second end position E 2 . To this it has to be mentioned that the retracting slide  7  could of course be moved further in closing direction. Basically this second end position E 2 , however, corresponds to the position where the movable furniture part  2  is located in the closed position SS. 
         [0045]    In  FIG. 18  it can be recognized that the position of the slide part  10  relative to the drawer rail  22  was changed. Therefore, the slide part  10  is in the second state S 2 . Although the drawer rail  22  has already been moved further in closing direction SR compared with  FIG. 16 , the retracting entrainment member  33  is still at the beginning of the releasing movement of the catch lever  40  from the retaining section  6 . Thus, the retracting slide  7  is still in the first end position E 1 . Originating from this position the shortened retracting path EW 2  starts, in which the retracting force storage means  8  relaxes and the movable furniture part  2  moves in closing direction SR into the closed position SS according to  FIG. 19 . Thereby the retracting slide  7  is again in its second end position E 2 . Particularly in a comparison of  FIGS. 19 and 17  it can thus be seen how according to the invention the distance A of the end positions E 1  and E 2  can be changed from each other along the guide path  5 .