Patent Publication Number: US-2007101539-A1

Title: Device for moving a movable furniture part

Description:
The present invention relates to a device for moving a movable furniture part, in particular a drawer or a door, which is arranged in or on a furniture body, with a closing device to retract the movable furniture part into a closed, final position in or on the body of furniture, wherein the closing device has a catch to carry the movable furniture part and an energy-storing device, in particular at least one spring, to act upon the catch.  
      Devices with such closing devices have long been known in the art. These involve the catch of the closing device grasping the movable furniture part, which moves freely over the majority of the distance between the closed final position in or on the body of furniture and the fully open final position, in the rear retraction area and reliably drawing it into the closed final position.  
      It is object of the present invention to improve the ease of use of generic devices.  
      This is achieved according to the invention in that the device comprises an electromotor to drive the catch.  
      This makes it possible to reduce or even to eliminate the expenditure of energy applied by a user in order to overcome the closing device in generic devices during the opening procedure of a movable furniture part.  
      Since the closing device, in order to retract the movable furniture part, only in fact has to engage with the movable furniture part over a part of the total path on the approach to the closed end position, it is preferable to make provision that the catch is detachably coupleable with the movable furniture part. For example, provision can be made that a pin member moving with the movable furniture part is detachably lockable into an indentation disposed on the catch.  
      In an advantageous embodiment of the invention, provision is made that the catch is disposed on a movable slide. The slide can thereby be arranged so as to be linearly displaceable with respect to a housing. Thus the motion of the slide and thereby the movement of the catch can be stabilized.  
      In this connection, provision can be made that the catch is rigidly connected with the catch and is preferably made in one piece with the slide. Alternatively, provision may be made that the catch is movably, preferably tiltably, connected with the slide. For this purpose, for example, the catch can be arranged via a pin on the slide. This allows the catch to pivot away into a parking position, out of which it can be moved by the movable furniture part during its closing process.  
      The provided energy-storing device for retracting the movable furniture part into the closed final position can, for example, comprise a spring. For example the spring can be anchored on an anchoring member and engage either on the slide or directly on the catch.  
      The movable furniture part can, as known in the art, be retracted by contacting a pin member which moves with the moveable furniture part with the catch of the closing device into the parking position thereof.  
      In an advantageous embodiment of the invention, provision is made that the device has a ram acted upon the electromotor to actuate the catch or the slide. This allows the opening force to be exerted with precision on the slide or on the catch.  
      In a further advantageous embodiment of the invention, provision is made that the ram is linked with the catch or the slide, preferably pivotably thereto. This allows the electromotor to remain engaged over the entire movement path of the catch or the slide with these latter. This allows the retraction movement of the movable furniture part to be supported by the electromotor.  
      Alternatively, provision can be made that the ram loosely abuts against the catch or on the slide. In this case, the ram can be retracted into its initial position as soon as the opening procedure ends.  
      Unlike generic devices in which the energy-storing devices provided to act upon the closing device are charged manually by the user, in the device according to the invention, the energy-storing device can be charged by the electromotor.  
      It is especially preferable to make provision that the electromotor provided in the device according to the invention is not a general device for converting electrical into mechanical energy, but an electromotor in the narrow sense, which comprises a stator, whereby the stator preferably comprises an electromagnet. Furthermore the electromotor also comprises a rotor which rotates in relation to the stator, said rotor preferably comprising at least one permanent magnet.  
      Electromotors of this type are commercially available at low cost in space-saving constructions.  
      In a further embodiment, provision is made that the electromotor is in the form of a linear motor.  
      Linear motors of this type have the advantage that no gears are necessary to convert the rotation of the motor for the desired linear exertion of force.  
      It is thereby especially advantageous to provide a linear motor having a stator, wherein for preference the stator comprises at least one electromagnet. Preferably the stator comprises at least two coils separate from each other, which are arranged in a sleeve bearing. Provision may also be made that the linear motor includes a runner linearly displaceable in relation to the stator (direct linear motor). This can incorporate at least one permanent magnet.  
      The linear motor can either abut loosely against the movable furniture part or on a closing device for the movable furniture part or be rigidly connected thereto. If the linear motor is rigidly connected with the movable furniture part it can take over the functions of the closing device, which can then be omitted.  
      In an advantageous embodiment of the invention, provision is made that the device has a ram acted upon the linear motor to act upon the movable furniture part. Naturally, as an alternative, as already described, provision can be made that the ram acts upon the catch or the slide of the closing device.  
      It is especially preferable for the ram to be disposed on the runner of the linear motor and preferably formed integrally thereto. This allows an especially compact construction.  
      In one especially preferred embodiment of the invention, provision is also made that the device includes a path-measuring device, which is preferably integrated into the electromotor. The path-measuring device can thereby be used to determine the position and/or the distance covered by the movable furniture part, by the catch of the closing device or by the slide of the closing device.  
      It is especially preferable for the path-measuring device to comprise an inductive or capacitive sensor.  
      Especially when the electromotor is in the form of a linear motor, inductive or capacitive sensors have the advantage that the path-measuring device can be realised without additional components and in a compact construction.  
      For example, a capacitive path-measuring device can be realised as follows:  
      The stator of the linear motor comprises two coils separated from each other arranged on a sleeve bearing. The runner of the linear motor, which comprises a permanent magnet, is displaceable in the coils and can be moved out from the first coil. This changes the capacity of the first coil, which allows the position of the runner of the linear motor to be determined. To determine a reference value, provision can be made for electrical contacting of one the two sleeve bearings with a condenser of known capacity. The electrical interconnection of the path-measuring device in an equivalent circuit diagram acts as a series circuit of the capacities of the two coils with the condenser, thus as a series circuit of three capacities, where the capacity of the first coil depends on how far the runner of the linear motor is moved out of it. This allows the position of the runner to be determined.  
      An inductive path-measuring device can be realised, for example, as follows:  
      The stator of the linear motor comprises two coils separated from each other on a sleeve bearing. The runner of the linear motor, which comprises a permanent magnet, is displaceable in the coils and can be moved out from the first coil. To measure the path, a sinusoidal AC measurement voltage is overlaid on the motor voltage. The low-frequency driving current is thus superimposed by a high-frequency AC measurement voltage (for example approx. 20 kHz). Due to the inertia of the motor, the AC measurement voltage, which can for example be in the range of between 1 and 5% of the motor voltage, has no effect whatsoever on the motion behaviour of the motor. If one now measures off the AC measurement voltage separately via both coils, the measured voltage amplitude is a function of the impedance of the respective coil, thus a function of the position of the runner. To measure off the two coils separately, a centre tap is also lead through on the connection of the two coils from the linear motor. The measured AC voltages are electronically filtered, amplified and divided in order to remove any DC field interference. The measurement signal obtained after division of the two partial AC measurement voltages is proportional to the position of the runner.  
      Another aspect of the invention relates to an extension guide for a movable furniture part, especially a drawer or a door, arranged in or on a body of furniture, with an extension rail attachable onto the movable furniture part and a mounting rail attachable onto the body of furniture, whereby the extension guide has a device according to the invention of the aforementioned type.  
      In order to fully pull out the movable furniture part, provision may also be made that a central rail is arranged between the extension rail and the mounting rail.  
      For example, both the electromotor and the closing device can be disposed on the mounting rail of the extension guide. For preference, a pin member may disposed on the extension rail. The pin member can, for example, be acted upon the electromotor. However, provision may also be made that the pin member is—preferably detachably—coupleable with the catch of the closing device.  
      Another aspect of the invention relates to a piece of furniture with at least one movable furniture part, especially a drawer or a door, characterised in having an inventive device of the type described above, wherein the device is preferably disposed in an extension guide of the type described above.  
      For preference, provision is made that the movable furniture part can be retracted by the closing device at least over a part of the total opening path leading up to the closed final position of the movable furniture part.  
      A further aspect of the invention relates to a method for moving a movable furniture part arranged in or on a body of furniture of a piece of furniture according to the invention, wherein the movable furniture part is pushed out of its closed final position in or on the body of furniture by the electromotor.  
      Alternatively, provision can be made that the movable furniture part is moved back by the closing device into its closed final position or that the movable furniture part is moved back by the electromotor into its closed final position.  
      In each case, provision can be made for the closure movement of the movable furniture part or the catch of the closing device to be damped by the electromotor.  
      Of course, in addition or alternatively, a damping device separate from the electromotor can be provided to damp the closing motion.  
      The electromotor can be started, for example, by manual actuation of a switch. If a path-measuring device is provided, this can also be used to start the electromotor. For example the motor can be started when the path-measuring device determines that the catch has only been moved a pre-determinable or pre-determined distance. 
    
    
      Further advantages and details of the invention will be apparent with the aid of the following description of the figures which show:  
       FIG. 1  the exploded view of an embodiment of a closing device known in the art,  
       FIG. 2   a ,  2   b  a first embodiment of the inventive device in perspective general view and detailed view,  
       FIG. 3   a ,  3   b  the embodiment shown in  FIG. 2   a ,  2   b  with the catch moved outwards,  
       FIG. 4   a ,  4   b , 4   c  the top view of the embodiment shown in  FIGS. 2 and 3  in different positions of the catch,  
       FIG. 5 a  further embodiment of a closing device known in the art,  
       FIG. 6   a ,  6   b  a further embodiment of an inventive device in perspective view and detailed view,  
       FIG. 7   a ,  7   b  the embodiment shown in  FIG. 6   a ,  6   b  with the catch moved outwards,  
       FIG. 8   a ,  8   b ,  8   c  this embodiment in top view in different positions of the catch,  
       FIG. 9   a ,  9   b ,  9   c  a further embodiment of an inventive device in perspective view, detailed view and in sectional view,  
       FIG. 10   a ,  10   b ,  10   c  a linear motor in top view, perspective view and sectional view,  
       FIG. 11   a ,  11   b  an embodiment of an inventive extension guide in perspective view and in sectional view,  
       FIG. 12 a  further embodiment of an inventive device in perspective view,  
       FIG. 13   a ,  13   b ,  13   c  a further embodiment of an inventive device in perspective view and in detailed views, and  
       FIG. 14   a ,  14   b  a piece of furniture with an inventive device in perspective view and detailed view. 
    
    
       FIG. 1  shows a closing device  2  known in the art with a housing  7  which can for example be anchored on a horizontal web of a mounting rail  19 , not shown in  FIG. 1 , of an extension guide  18 .  
      A slide  8  is disposed so as to be linearly displaceable within a housing  7 , whereby a catch  12  is tiltably arranged on the slide  8 . The catch  12  is arranged via a lug  13  on the slide  8 , said catch  12  having a projection, not shown in  FIG. 1 , by means of which it is guided into a guideway  29  of the housing  7 . Furthermore the slide  8  has a stop  25  for an electromotor  3 , not shown in  FIG. 1 .  
      Two springs  14  are provided to exert force on the slide  8  in the closing direction, and these are anchored on an anchoring element  15 . The anchoring element  15  is distanced from the housing  7  in the assembled position. The distance of the anchoring element  15  from the housing  7  determines the stress of the springs  14 .  
       FIG. 2   a  shows an inventive device  1  with an electromotor  3  designed as a linear motor. The ram  9  of the electromotor  3  abuts loosely on the stop  25  of the slide  8  of the closing device  2 . In the situation shown in  FIG. 2   a  slide  8  and ram  9  are near to their rear final position. In  FIG. 2   b  the catch  12  is partly shown in detail.  
      In  FIGS. 3   a  and  3   b  the device  1  is shown with the ram  9  moved out of the housing of the electromotor  3 . By moving the ram  9  out, the slide  8  and thus the carrier  12  of the closing device  2  disposed thereon has been brought along the housing  7  of the closing device  2  into the outer final position of the closing device  2  (parking position of the catch  12 ). Also shown is a pin member  22  disposed on a movable furniture part  6 , not shown, or on an extension rail  20  of an extension guide  18 , also not shown, which is locked into place in the indentation  16  of the catch  12 .  
       FIGS. 4   a ,  4   b  and  4   c  show a top view of the inventive device  1  at various stages of the opening motion of a movable furniture part  6 , not shown.  
      In  FIG. 4   a  the movable furniture part  6 , not shown, is in its closed final position in or on the body of furniture. The pin member  22  abuts on the catch  12  of the closing device  2 . The ram  9  of the electromotor  3  abuts loosely on the stop  25  of the slide  8  of the closing device  2 . In the situation shown in  FIG. 4   b , the ram  9  of the electromotor  3  has forced the slide  8  and thus the catch  12  and the pin member  22  outwards, as the result of which the movable furniture part  6  has been moved out of its closed final position in or on the body of furniture. The catch  12  which is tiltably arranged on the slide  8  has thereby been moved into its parking position. The pin member  22  has not yet separated from the catch  12 . In  FIG. 4   c  the pin member  22  has separated from the catch  12  and the movable furniture part  6  has moved further in the direction of its fully-open final position.  
      In  FIG. 5 a  further embodiment of a closing device  2  known in the art is shown, which only differs from the closing device  2  shown in  FIG. 1  in that the projection  25  disposed on the slide  8  in  FIG. 1  is now directly arranged on the catch  12 .  
      As can be seen in  FIGS. 6   a ,  6   a  and  7   a ,  7   b  and  8   a  to  8   c , in this embodiment the catch  12  is directly acted upon the ram  9 . Here the ram  9  abuts with its free end in the situation shown in  FIG. 8   a  on the projection  25 , while the catch  12  and thus the projection  25  in the situations shown in  FIGS. 8   b  and  8   c  have been moved away by the ram  9 .  
      It is common to both embodiments that during the closing movement of the movable furniture part  6 , the pin member  22  locks into place in the indentation  16  of the catch  12  and rotates the catch  12  out of its parking position, as shown in  FIGS. 4   c  and  8   c . As soon as the projection  25  of the catch  12  is in the guideway  29  of the housing  7 , the springs  14  draw the slide  8  together with the catch  12  backwards, as a result of which the movable furniture part  6  is brought into its closed final position. The ram  9  had thereby been retracted just a short time after the situation shown in  FIGS. 4   c  and  8   c  respectively into the housing of the electromotor  3 .  
      The embodiment of an inventive device  1  shown in FIGS.  2  to  4  differs from the embodiment of an inventive device  1  shown in  FIGS. 9   a ,  9   b  and  9   c  only in that the ram  9  of the electromotor  3  is rigidly connected with the slide  8  of the closing device  2  by a clamp  23 , instead of abutting loosely. In  FIG. 9   c , for example, the arrangement of the device  1  in an extension guide  18  is shown.  FIGS. 13   a ,  13   b  and  13   c  show an equally advantageous embodiment which only differs from the embodiment shown in FIGS.  6  to  8  in that the ram  9  of the electromotor  3  is rigidly connected by a joint  26  with the stop  25  of the catch  12  of the closing device  2 , instead of loosely abutting. Both alternative embodiments allow the closing motion of the movable furniture part  6  to be supported, as soon as the pin member  22  locks into place in the indentation  16  of the catch  12 .  
      In  FIGS. 10   a ,  10   b  and  10   c , for example, an electromotor  3  is shown in the form of a linear motor. In particular,  FIG. 10   c  shows the runner  17 , the stator  10  and the ram  9 , whereby the ram  9  is integrated into the runner  17 .  
      In  FIGS. 10   a  and  10   b , it can be seen that the ram  9  of the electromotor  3 , which takes the form of a linear motor, as an alternative to the aforementioned embodiments, abuts loosely on an angle bracket  24  which can be disposed on an extension rail  20 , not shown, or on a movable furniture part  6 , not shown.  
       FIG. 11   a  shows in perspective view the arrangement of the electromotor  3  shown in  FIGS. 10   a  to  10   c  on an extension guide  18 , which has a mounting rail  19  to be disposed on the body of furniture, an extension rail  20  to be disposed on the movable furniture part  6  and a centre rail  21  ( FIG. 11   b ). Not shown here are carriages and similar disposed between the rails. In  FIG. 11   b  in particular the pin member  22  disposed on the extension rail  20  can be seen.  
      In  FIG. 11   a  it can be seen that in this embodiment the ram  9  acts directly upon the pin member  22 .  
       FIG. 12  shows another embodiment of an inventive device  1  with a pinion  26  driven by an electromotor  3 , not shown. The electromotor  3  drives the slide  8  and with it the catch  12  via a toothed profile  27  formed on the slide  8  of the closing device  2 .  
      In  FIG. 14   a , a piece of furniture  5  with several movable furniture parts  6  is shown, where the inventive device  1  in this embodiment is disposed in the area of the lowest movable furniture part  6  (see detail view,  FIG. 14   b ).