Patent Publication Number: US-9903145-B2

Title: Adjusting drive for furniture flaps

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an actuating drive for moving a movable furniture part, including an actuating arm pivotally mounted about a pivoting axis for moving the movable furniture part, a spring device for applying a force onto the actuating arm, and a transmission mechanism for transmitting a force of the spring device onto the actuating arm. The transmission mechanism includes an actuating portion movement-coupled to the actuating arm, a setting contour, and a pressure portion pressurized by the spring device. The pressure portion is in the form of a rotatably mounted pressure roller which can run along the setting contour upon a movement of the actuating arm, and the setting contour is arranged between the actuating portion and the pressure roller. 
     The invention further relates to an arrangement having a movable furniture part and an actuating drive of the kind to be described. 
     Such an actuating drive is shown, for example, in DE 10 2006 014 493 A1. Here, a pivotally mounted actuating arm is rotatably mounted by a setting contour arranged on the actuating arm and a pressure portion in the form of a pressure roller abutting the setting contour. The setting contour of the actuating arm is formed by the material thickness of the actuating arm and additionally by disc portions arranged on both sides of the actuating arm (disc portions 30, 31 in FIG. 4). As a result of this three-part construction, the contact surface for the pressure roller is enlarged and thus the arising forces can be distributed over an enlarged area. 
     Usually, the setting contours of such actuating drives are produced by precision blanking or fine blanking, respectively. In other words, the setting contours are produced by a manufacturing process in which during a working operation, workpieces can be produced having a precise contour with smooth and rectangular cutting edges. An advantage of this technology in comparison with a usual punch technique is that by way of the achieved clean cut, a high surface quality can be attained so that a laborious post-treatment of the setting contours (for example polishing) can be omitted. A smooth surface of the setting contour is namely a necessary requirement because possible irregularities are negatively noticed by a user when opening and closing the movable furniture part. A disadvantage of the precision blanking is, however, the fact that this manufacturing process is relatively costly and only a low number of cutting cycles are permitted in serial production. 
     A further disadvantage of the known designs of setting contours is the fact that the running surface provided for the contact with the pressure roller is determined by the material thickness of the setting contour. Accordingly, relatively high material thicknesses must be provided in order for a sufficient stable abutting surface, which is partially pressurized by the spring device with very high pre-stressing forces, for the pressure roller to be obtained. 
     WO 2004/104339 A1 shows an actuating mechanism for furniture flaps, in which a pivotally mounted actuating arm on the end forming the setting contour has a surface which runs perpendicularly to the pivoting axis of the actuating arm. With relation to the pivoting axis, a bulge axially protrudes from this surface, and the bulge extends along the setting contour. Moreover, a guide shoe with a groove is provided which accommodates the bulge and which is guided along the bulge. Thus, the guide shoe flatly abuts against the bulge in order to avoid punctual contacts or line contacts with high surface pressure. However, the surface quality of the bulge does practically not matter at all, because possible irregularities of the bulge are compensated for by the flat contact of the guide shoe and do not have any influence on the movement behavior of the actuating arm. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to propose an actuating drive of the kind mentioned in the introductory part of this specification, in which the manufacture of such a setting contour can be facilitated. 
     According to the invention, the setting contour is arranged on a contour portion which is separate from the actuating portion. The contour portion includes a fastening section configured to rest against the actuating portion and a limb extending transversely from the fastening section, and the setting contour is formed by a curved outer surface of the limb. 
     In other words, a contour portion is separate from the actuating portion, and the contour portion has a setting contour which serves in fact as an intermediate piece between the pressure roller and the actuating portion. Upon a movement of the actuating arm, the pressure roller does not run along a contour of the actuating portion which is movement-coupled to the actuating arm, but rather along a curved formed outer surface of the contour portion separate from the actuating portion. 
     According to an embodiment, the actuating portion which is movement-coupled to the actuating arm is pivotally mounted about a pivoting axis. The actuating portion, on the end region facing towards the pivoting axis, has a peripheral surface which is radially spaced in relation to the pivoting axis. The radially spaced peripheral surface is at least partially covered by the setting contour of the contour portion. Preferably, the setting contour forms a contact surface for the rotatably mounted pressure roller, and the contact surface runs parallel in relation to the pivoting axis of the actuating portion. 
     A particular advantage of the invention lies in the fact that the contour portion with the setting contour and also the actuating portion itself can be formed as a bending portion or as a deep-drawing portion, respectively. The deep-drawing is a known technique of sheet metal forming in which a flat metal portion is reshaped into a hollow body, without substantially changing the metal thickness. Thus, by way of relatively thin material thicknesses, contour portions and actuating portions with large and smooth surfaces can be produced which form the setting contour for the pressure portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further details and advantages of the present invention result from the embodiments shown in the Figures, in which: 
         FIG. 1 a , 1 b    show an item of furniture with an upwardly moving flap in a closed position and in an open position, 
         FIG. 2  shows a possible embodiment of an actuating drive in a perspective cross-section, 
         FIG. 3  shows a detail view of the actuating drive in a perspective cross-section, 
         FIGS. 4 a , 4 b    show two different variants of the arrangement of contour portions onto the actuating portion, 
         FIGS. 5 a , 5 b    show an embodiment of a multi-part contour portion, and 
         FIG. 6 a -6 d    show an embodiment with a pressure roller in the form of a double-tapered roller. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1 a    shows a side view of an item of furniture  1  having a furniture carcass  2  and a movable furniture part  3  in the form of a flap  4  which is upwardly movable relative to the furniture carcass  2 .  FIG. 1 b    shows the item of furniture  1  with the flap  4  in an open position, wherein the flap  4  is pivotally mounted by way of hinges  22  relative to a cabinet top  23  of the furniture carcass  2 . For moving the flap  4 , an actuating drive  5  with a housing  6  is provided, the housing  6  is pivotally supported on the furniture carcass  2  on a bearing axis  21 . The actuating drive  5  further includes an actuating arm  9  which, in the mounting position, is pivotally mounted about a horizontal extending pivoting axis  10 . By way of the actuating drive  5 , the flap  4  can be moved between a vertical closed position ( FIG. 1 a   ) and a swiveled-up open position which enables access to the furniture carcass  2  ( FIG. 1 b   ). The free end region of the actuating arm  9  is to be connected to the flap  4  by way of a hinge axis  24 . 
       FIG. 2  shows the actuating drive  5  in a perspective cross-section, wherein the actuating arm  9  is pivotally mounted about a horizontally extending axis  10  in the mounting position. The actuating drive  5  includes a housing  6 , in which a spring device  11  is accommodated, to be fastened to the furniture carcass  2 . In the shown embodiment, the spring device  11  includes at least one coil spring in the form of a pressure spring. However, it is also possible to provide two or more—preferably arranged in parallel—coil springs. The spring device  11  is supported with an end onto a counter bearing in the form of an adjustable screw nut  12  which is in thread engagement with an adjusting screw  16 . By way of an adjusting device  13 , the torque acting on the actuating arm  9  can be adjusted. The adjusting device  13  includes an adjusting wheel  14  with an adapter  15  for receiving an actuating tool, wherein the adjusting wheel  14  interacts via a transmission, preferably a bevel gear, with the head of the adjusting screw  16 . Upon a rotation of the adapter  15  by the actuating tool, the adjusting screw  16  can be rotated, whereby the screw nut  12  can be adjusted along the thread  17  of the adjusting screw  16 . In this way, the spring device  11  can be variably compressed and thus the force of the spring device  11  acting on the actuating arm  9  can be variably adjusted. In the shown Figure, the screw nut  12  is in a position in which the spring device  11  is minimally pre-stressed, i.e. that the torque acting onto the actuating arm  9  is at its lowest. 
     For transmitting a force of the spring device  11  onto the actuating arm  9 , a transmission mechanism  25  includes an actuating portion  29  which is movement-coupled to the actuating arm  9 , and the actuating portion  29  is in the form of a cam section. The transmission mechanism  25  further includes a setting contour  20  and a pressure portion  7  in the form of a rotatably mounted pressure roller  19  which is pressurized by the spring device  11 . The pressure roller  19 , upon a movement of the actuating arm  9 , can run (i.e. roll off) along the setting contour  20 . The pressure roller  19  is supported on a slider  18  which is movable, preferably linearly displaceable, relative to the housing  6 . In the shown embodiment, the actuating portion  29  together with the actuating arm  9  has a one-piece configuration, so that the pivoting axis  10  of the actuating portion  29  also forms the pivoting axis  10  of the actuating arm  9 . Naturally, it is also possible to arrange the actuating portion  29  separate from the actuating arm  9 , for example in the form of a pivotally mounted lever (not shown here) of the transmission mechanism  25  which is connected in a movement-coupled manner to the actuating arm  9 . Thus, it is certainly possible to arrange the actuating portion  29  on a different position along the acting force-transmission path between the spring device  11  and the actuating arm  9 . 
     As clearly visible in  FIG. 2 , the actuating portion  29  which is pivotable about the pivoting axis  10  includes a peripheral surface  26  which is radially spaced from the pivoting axis  10 . Thus, the pressure portion  7  in the form of the pressure roller  19  does not directly rest against the peripheral surface  26  of the actuating portion  29 , but rather against a setting contour  20  in the form of a curved outer surface  34  which is arranged on a contour portion  8  being separate from the actuating portion  29 . The setting contour  20  of the contour portion  8  is arranged so as to at least partially cover the peripheral surface  26  of the actuating portion  29  which is radially spaced from the pivoting axis  10 . The contour portion  8  can be formed as a bent metal portion or a deep-drawing portion which is inexpensive and easy to manufacture. The contour portion  8  forms, relative to the pivoting axis  10  of the actuating portion  29 , an eccentric setting contour  20  affecting the movement behavior of the movable furniture part  3  in terms of force. The contour portion  8  is movement-coupled to the actuating arm  9 , wherein upon a movement of the actuating arm  9 , the contour portion  8  also pivots therewith. The setting contour  20  of the contour portion  8  forms a differing radial spacing relative to the pivoting axis  10  of the actuating portion  29 . The setting contour  20  of the contour portion  8  is configured such that the actuating arm  9 , at the end of the closing movement, is being pressed by the force of the spring device  11  into the final closed position. Upon an opening movement of the actuating arm  9 , the pressure portion  7  in the form of the pressure roller  19  reaches an apex-position (that is to say the region of the setting contour  20  with the largest radial spacing in relation to the pivoting axis  10 ) so that the spring device  11 , after passing a dead-center position, applies a torque onto the actuating arm  9  in the opening direction. For damping the closing- and/or opening movement of the actuating arm  9 , a damper, in particular a fluid damper (not shown here), can also be provided. 
       FIG. 3  shows a detail view of the transmission mechanism  25  of the actuating drive  5 . The actuating portion  29  being movement-coupled to the actuating arm  9  includes fastener(s)  27  which interact with corresponding fastening locations  30  ( FIG. 4 b   ) of the contour portion  8 . The contour portion  8  has a fastening section  28  for laterally resting against the actuating portion  29  and a limb  31  protruding transversely from the fastening section  28 , in which the setting contour  20  is formed by a curved radially outer surface  34  of the limb  31 . The width B of the limb  31  which forms the setting contour  20  corresponds substantially to the width B 1  of the pressure portion  7 , and thus substantially corresponds to the width of the pressure roller  19 . The spring device  11  presses against the slider  18  which is, together with the pressure portion  7  arranged thereon, linearly displaceable relative to the housing  6 . 
       FIG. 4 a    and  FIG. 4 b    show two different variants of the arrangement of contour portions  8  onto the actuating portion  29 . The actuating portion  29  is pivotally mounted about the pivoting axis  10  and has a peripheral surface  26  which is radially spaced from the pivoting axis  10 . In  FIG. 4 a   , a contour portion  8  is fixed to only one side of the actuating portion  29 . The contour portion  8  has a flat-shaped fastening section  28  which, in the mounted position, is configured to rest against a corresponding flat-shaped side surface of the actuating portion  29 . The contour portion  8  further includes a limb  31  protruding laterally from the fastening section  28 , wherein the setting contour  20  for the pressure portion  7  is formed by a curved outer surface  34  of the limb  31 . By way of the setting contour  20  of the contour portion  8 , the peripheral surface  26  of the actuating portion  8  is covered which does not necessarily mean that the inner side of the limb  31  facing towards the peripheral surface  26  needs to directly rest against the peripheral surface  26  of the actuating portion  29 . It is preferable that the inner side and the outer side of the limb  31  each form a contour running parallel to the pivoting axis  10 . The actuating portion  29  includes fastener(s)  27  which, in the mounted condition, interact with fastening locations  30  ( FIG. 4 b   ) of the contour portion  8 . At least one or more fastening locations  30  of the contour portion  8  are eccentrically arranged in relation to the pivoting axis  10  of the actuating portion  29  so that the contour portion  8  is non-rotatably secured to the actuating portion  29  (i.e., the contour portion  8  cannot rotate relative to the actuating portion  29 ). The wall thickness of the at least one contour portion  8  is thereby configured to be substantially constant. 
       FIG. 4 b    shows a variant in which contour portions  8  with a curved outer surface  34  are arranged on both sides of the actuating portion  29 . Thus, a first contour portion  8  is fixed to a first side of the actuating portion  29  and a second contour portion  8  is fixed to a second side of the actuating portion  29 , and the setting contour  20  of the first contour portion  8  and the setting contour  20  of the second contour portion  8  (i.e. the edge regions of the limbs  31  of both contour portions  8 ) rest against each other and thereby cover at least partially the peripheral surface  26  of the actuating portion  29 . 
       FIG. 5 a    shows a further embodiment of a multi-part contour portion  8 , wherein the fastening section  28  and the limb  31  forming the setting contour  20  with the curved outer surface  34  are configured as separate components. In a first mounting step, both fastening sections  28  are fixed to the left and to the right onto the actuating portion  29 , and so both fastening sections  28  accommodate the actuating portion  29  in their middle. The convex-bulged limb  31  includes several fastening locations  32  in the form of tabs which are configured to be fixed to both fastening sections  28 . 
       FIG. 5 b    shows the embodiment according to  FIG. 5 a    in the mounted condition. The fastening locations  32  of the contour portion  8  are provided with openings which serve for the passage of bolts, screws or the like. It is, however, also possible that the actuating portion  29  includes a bearing location into which the limb  31  with the setting contour  20  can be inserted. Furthermore, a latching device can be spaced from the bearing location so that, due to the latching device, the limb  31  with the setting contour  20 , after having been pivoted towards the actuating portion  29 , can be latched, preferably releasable, therewith. 
       FIGS. 6 a -6 d    show an embodiment with a pressure roller  19  in the form of a double-tapered roller. As shown in  FIG. 6 a   , the disc-shaped actuating portion  29  which is movement-coupled to the actuating arm  9  includes on both sides a contour portion  8  with a fastening section  28 , and the limbs  31  each protrude transversely from the fastening sections  28  at an angle differing from 90°. The pressure roller  19  in the form of the double-tapered roller, which is rotatably mounted about the hinge axis  33 , runs thereby along the curved outer surfaces  34  of the limbs  31 . 
       FIG. 6 b    shows a frontside view of the actuating arm  9  which is pivotally mounted about the pivoting axis  10 , while  FIG. 6 c    shows this construction in a perspective view.  FIG. 6 d    shows the framed region of  FIG. 6 c    in an enlarged view, and the pressure roller  19  in the form of the double-tapered roller is clearly visible. The double-tapered roller includes two, preferably identically shaped, truncated cones  19   a ,  19   b  which are connected to each other by their smaller bases. Thereby, the truncated cones  19   a ,  19   b  roll along the, in relation to the pivoting axis  10 , curved outer surface  34  of the limbs  31 . In this way, optimal centering of the pressure roller  19 , a uniform distribution of pressure forces of the spring device  11  acting on the pressure roller  19  and a smooth running of the pressure roller  19  for the line contact with the smooth, curved outer surfaces  34  of the limbs  31  can be provided.