Abstract:
A drive device includes an ejection element, a housing, and a locking element for the ejection element. The locking element is disposed in or on the housing and is movable relative thereto, and a detent element, which is connected to the ejection element and, in the closed position, abuts the locking element. In the locking position, the locking element can block the path of the detent element in the opening direction. The ejection element can be released both when a movable piece of furniture is subjected to increased pressure from a closed position in the closure direction and when the movable piece of furniture is pulled from the closure position in the opening direction. A detection system detects the position of the movable piece of furniture, and a transmission device transmits the position of the movable piece of furniture detected by the detection system to the locking element.

Description:
BACKGROUND OF THE INVENTION 
     The invention concerns a drive device for a moveable furniture part, comprising an ejection element which acts on the moveable furniture part in the opening direction, a housing, a locking element for the ejection element, which is arranged in or on the housing and is moveable relative to the housing, and a latching element which is connected to the ejection element and which in the closed position bears against the locking element. The path of the latching element in the opening direction can be blocked by the locking element at least in the closed position of the moveable furniture part, and the ejection element can be released both upon over-pressing of the moveable furniture part from a closed position in the closing direction and also upon pulling of the moveable furniture part from the closed position in the opening direction. The drive device also includes a detection device for detecting the position of the moveable furniture part. The invention further concerns an article of furniture having such a drive device. 
     Various drive devices with lockable ejection devices have already been known for many years in the furniture fitting industry, in which unlocking is effected by pressing or by pulling on the moveable furniture part (drawer, flap, door or the like). By virtue of that unlocking action, the ejection element is free and can eject the moveable furniture part in the opening direction. 
     An example of this is to be found in Austrian patent application A 1891/2011 to the present applicant, which is published after the relevant date and which forms a prior right. 
     EP 2 294 944 A1 discloses a latching system in which a switching element is latched in a loop-shaped portion of a switching curve. That switching curve has a latching recess, wherein the latching recess is at least partly moveable in order to cause unlocking of the switching element when a force acts on the switching element in the opening direction. Upon unlocking of a switching element of a latching fitment, the force of at least two force storage means causes unlocking of the switching element of a second latching fitment. 
     Both specifications therefore disclose force-controlled triggering of the latching element or switching element. Upon movement of the moveable furniture part from the closed position in the opening direction (therefore by pulling), by way of the latching element or the switching element itself, respectively, a part of the locking element or the latching recess itself is moved against a spring force whereby the ejection element is unlocked. A disadvantage in that respect is that, in particular for unlocking by pulling, pulling has to be effected against the force of a separate force storage means. 
     SUMMARY OF THE INVENTION 
     Therefore the object of the present invention is to provide a drive device which is an alternative to the state of the art or which is improved over the state of the art. 
     In accordance with the invention, there is provided a transmission device which is separate from the latching element for transmission of the position of the moveable furniture part, that is detected by the detection device, to the locking portion. Upon pulling of the moveable furniture part from the closed position in the opening direction, the locking element is moveable by the transmission device. Thus at least when a pulling force is applied it is no longer the latching element itself that serves to transmit the pulling movement involving the moveable furniture part. Rather, there is provided a transmission device which is separate from the latching element and which upon pulling—depending on the respective design configuration involved, in addition upon over-pressing—unlocks the ejection element. 
     According to a preferred embodiment of the present invention, the detection device can be coupled to the moveable furniture part by way of an entrainment member at least in a part of the path of movement of the moveable furniture part. That coupling action should occur in particular in the path of movement of the moveable furniture part immediately prior to the closed position. 
     To guarantee exact detection and transmission of the position of the moveable furniture part to the locking element, the transmission device has a moveable, preferably pivotable, coupling element. Upon movement of the detection device from the closed position in the opening direction, the transmission device can be coupled to a connecting element of the detection device by way of the coupling element. If only the movement of the moveable furniture part in the opening direction is intended to have an effect on the transmission device, then preferably the coupling element should be overridable upon movement of the detection device in the closing direction by the connecting element of the detection device. 
     In itself locking of the latching element can be implemented by way of a frictionally locking and/or positively locking action between the latching element and the locking element. Preferably, in the housing at least partly is a preferably cardioid curve-shaped sliding track for engaging the latching element which is mounted preferably pivotably to the ejection element, wherein the locking element forms at least a part of a latching recess of the sliding track. 
     For a simple structural configuration, the transmission device has a transmission slide mounted moveably in or on the housing, wherein preferably the locking element is in one piece with the transmission slide. Thus, the transmission slide serves on the one hand for transmission of the movement of the moveable furniture part to the locking element, and at the same time forms a part of the latching recess of the sliding track. 
     In principle, besides a lockable ejection device the drive device can also have a retraction device for retraction of the moveable furniture part from an open position into the closed position. Preferably in that case, the retraction device forms a part of the detection device, in particular when the entrainment member is arranged on the retraction device. The retraction device can additionally also be damped by a damping device. 
     An article of furniture can include a furniture carcass, a moveable furniture part, and a drive device according to the invention for the moveable furniture part. Preferably the major part—therefore except for the entrainment member—of the drive device is associated with the moveable furniture part and engages the entrainment member which is fixed with respect to the furniture carcass by way of catch lever. However, in the reverse arrangement, the lockable ejection device can be arranged on the furniture carcass and the entrainment member can also be moveable with the moveable furniture part. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further details and advantages of the present invention are described more fully hereinafter by the specific description with reference to the embodiments by way of example 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  are exploded views of a drive device, 
         FIGS. 7 through 12  are 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, and 
         FIGS. 23 through 29  show a second embodiment of a drive device with travel-controlled triggering. 
     
    
    
     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 way of 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 way of 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 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 ejection element  6  arranged on the ejection element  3  so that it is moved out of the latching recess  13  of a cardioid curve-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 US 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  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 member  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 member  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 way of the 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 mounted to the ejection slide  3  moveably limitedly by 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 member  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  serves to provide 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 member  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  then 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 member  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  its 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 has 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 bears against the inclined deflection member  43 . The over-pressed position US is reached thereby. At the same time the connection element  11  is also deflected by the inclined guide member  47 . 
     Due to deflection at the inclined deflection member  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 way of 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 deflection passage  48  and the latching element  6  passes into the closing portion of the sliding track  12  again, due to the deflection element  20  having 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 . 
       FIGS. 23 through 29  show a second embodiment of the travel-controlled triggering or unlocking of the latching element  6 . In that case, on the housing  4  the ejection slide  3  is acted upon in the opening direction by an ejection force storage member  18  (not shown). At the end of the ejection slide  3 , the latching element  6  is formed by a widened portion. The detection device  7  which bears directly or indirectly against the moveable furniture part  2 , with the transmission slide  14  in the form of a rotary element, forms the transmission device  8 . The rotary element bears against the locking element  5  which is acted upon by the locking spring  46 . 
       FIG. 25  shows that drive device  1  in the closed position SS, and the locking element  5  bears against the point, closest to the axis of rotation, of the rotary element. Thus the spring  46  is substantially relieved of stress and the locking element  5  holds the ejection slide  3  by way of the latching element  6  in frictionally locking or positively locking relationship. 
     If as shown in  FIG. 26  a pressing force is applied to the detection device  7  in the closing direction SR, then the rotary element is rotated in the clockwise direction by way of the eccentric point of engagement on the rotary element. Thus, the locking element  5  is pivoted in the counter-clockwise direction and against the spring force of the locking spring  46 . The latching element  6  is released as a result. 
       FIG. 27  shows pulling on the moveable furniture part  2  and thus a movement of the detection device  7  in the opening direction OR. As a result, the rotary element moves in the counter-clockwise direction. At the same time, however, the locking element  5  is again moved in the counter-clockwise direction, with release of the latching element  6 . 
     By virtue of that release effect, the ejection force storage member  18  (not shown) can be relieved of stress and moves the ejection element  3  in the opening direction OR, so that the moveable furniture part reaches the open position OS shown in  FIG. 28 . 
     In the closing movement as shown in  FIG. 29 , the latching element  6  moves with its inclined deflection member over the locking element  5  and passes again into the closed position SS in which the ejection element  3  is locked. 
     In contrast to the first embodiment, this second embodiment provides that the locking element  5  is moved relative to the housing not only when a pulling force is applied but also in the event of over-pressing, while the latching element  6  respectively remains passive and is only released. 
     Therefore, that travel-controlled triggering of the latching element  6  provides a possible option, as an alternative to force-controlled triggering, for unlocking the latching element  6  at least when pulling on the moveable furniture part  2  in the opening direction OR.