Abstract:
An ejection device for a movable furniture component disposed in or against a furniture body includes an electric motor, a lever having a free end for ejecting the movable furniture component, and a gear mechanism for transmitting force from the electric motor to the lever. The gear mechanism has a slipping clutch which includes a spring washer and driving dogs. The spring washer extends upon overload and slips over the driving dogs. The ejection device may also include a path measuring device which activates the ejection device. The path measuring device can be a potentiometer directly coupled to the lever such that slipping of the slipping clutch does not change a position of the potentiometer relative to the lever.

Description:
This application is a divisional of U.S. application Ser. No. 13/218,821, filed Aug. 26, 2011, now U.S. Pat. No. 8,360,537, which is a divisional of U.S. application Ser. No. 11/705,416, filed Feb. 13, 2007, now U.S. Pat. No. 8,029,078, which is a continuation of International Application No. PCT/AT2005/000227, filed Jun. 24, 2005, the entireties of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates in a first variant to an ejection device for a furniture component moveably housed in or against a furniture body, with a swivellably housed lever, wherein a first castor is attached to the free end of the lever. 
     2. Description of the Related Art 
     U.S. Pat. No. 6,669,250 B1 discloses an ejection device for a furniture component (door or drawer) moveably housed in or against a furniture body, with a swivellably housed lever, wherein a castor is attached to the free end of the lever. 
     EP 1 314 842 A1 discloses an ejection device for a furniture component (door or drawer) moveably housed in or against a furniture body, with a swivellably housed lever, wherein a castor is attached to the free end of the lever. 
     EP 1 374 732 A1 discloses an ejection device for a furniture component (drawer) moveably housed in or against a furniture body, with an electric drive unit, a control or regulation apparatus to control or regulate the drive unit, and a gear mechanism to transmit power from the drive unit to an ejector. 
     DE 29 24 145 A1 discloses an ejection device for an oven carriage moveably housed in a domestic oven, with a swivellably housed lever (transport lever) and an electric drive unit (electric motor). 
     U.S. Pat. No. 4,720,154 A discloses an example embodiment of an ejection device for a drawer moveably housed in a furniture body (cash dispenser), with a swivellably housed lever and an electric drive unit (electric motor) (See  FIG. 10 ). 
     WO 2004/100718 A1 discloses an ejection device for a furniture component (door or drawer) moveably housed in or against a furniture body, with a swivellably housed lever, an electric drive unit, and a control or regulation apparatus to control or regulate the drive unit. 
     The problem with the above-described ejection devices is that in most cases the initial acceleration of the movable furniture component to which the force of the lever has been applied is extremely sluggish. In order to counter this problem, the drive unit provided for the lever is frequently overdimensioned in order to have the capacity to achieve a rapid initial acceleration of the movable furniture component via the lever. After the initial acceleration of the movable furniture component, a much smaller drive capacity would be sufficient. 
     SUMMARY OF THE INVENTION 
     The object of the invention is to create an ejection device which does not have the above-described problem. 
     This is achieved by a second castor which is attached to the lever at a distance from the free end of the lever. 
     Uniform loading of the drive unit for driving the lever over the entire ejection distance is achieved by this feature of the invention. The swivellably housed lever first comes into contact with the movable furniture component via the second castor attached to the lever at a distance from the free end of the lever, whereby the torque exerted on the movable furniture component is less than the torque exerted when the castor attached to the free end of the lever first contacts the furniture component. The drive unit, which may comprise an electric motor, is thereby subjected to a smaller torque during the initial acceleration of the movable furniture component. The result of this is a more favorable starting behavior, which is perceived by the user as more responsive initial acceleration of the movable furniture component. 
     After the initial acceleration of the movable furniture component, the lever comes into contact with the movable furniture component via the first castor attached to the free end of the lever and can thus exert a greater force on the movable furniture component via the greater torque (due to the longer lever arm). As the inertia of the movable furniture component has been overcome, the drive unit is now, in spite of the greater torque, loaded to approximately the same extent as during the initial acceleration phase. Therefore, the overall result is an equal distribution of the load of the drive unit over the entire ejection distance of the movable furniture component. 
     In a particularly preferred embodiment of the invention, the second castor is attached to the lever at approximately half way between the free end and the other end of the lever. The result is a satisfactory distribution of the load forces acting on the drive unit. 
     A further, second variant of the invention is an ejection device for a furniture component moveably housed in or against a furniture body, with a swivellably housed lever and a drive unit, in particular electric, to drive the lever. 
     Typically, the operation of such ejection devices generates unpleasant noise. In addition to the initial sound of the impact when the swivellably housed lever comes into contact with the movable furniture component, further operation of the ejection device also generates unpleasant noise. 
     The object of this variant of the invention is to create a generic ejection device which is characterized by the generation of less noise. 
     This is achieved by a lever having at least a first lever part and a second lever part, wherein the first lever part can be brought into contact with the movable furniture component and the second lever part can be driven by the drive unit. The first lever part is coupled, movable to a limited extent, to the second lever part, and an energy accumulator acts between the first lever part and the second lever part such that the first lever part is pre-loaded relative to the second lever part. 
     The two-part design of the lever results in interaction between the first and the second lever part. By pre-loading the first lever part relative to the second lever part, the first lever part is pressed against the movable furniture component. The second lever part is forced away from the first lever part by the force of the energy accumulator. As a result, the parts of the drive unit in contact with the second lever part are also subjected to stress. Surprisingly, this leads to a reduction of the operating noise of the ejection device. 
     In an advantageous embodiment of this variant of the invention, the first lever part is pre-loaded relative to the second lever part by a spring. This represents a particularly simple structural realization of this variant of the invention. 
     A further, third variant of the invention is an ejection device for a furniture component moveably housed in or against a furniture body, with a swivellably housed lever to eject the movable furniture component, a drive unit, in particular electric, to drive the lever, and a control or regulation apparatus to control or regulate the drive unit. 
     With such ejection devices the problem arises of how the user can best actuate the ejector. In this regard, it is advantageous if the ejection device can be operated as intuitively as possible. 
     The object of this variant is, therefore, to create an ejection device which can be actuated intuitively. 
     This is achieved by a switch for the actuation of the ejection device. The switch is attached to, or in the lever, such that the signals from the switch can be fed at least to the control or regulation apparatus. 
     This feature of the invention permits the ejection device to be actuated by pressing the front panel of the movable furniture component into the furniture body. For this, sufficient interaction must of course remain when the movable furniture component is in closed position. As soon as the movable furniture component comes into contact with the switch attached to the lever, the switch sends the actuation signal to the control or regulation apparatus of the ejection device. 
     A particular advantage results when this variant is combined with the second variant of the invention. If the lever has at least a first and a second lever part, the switch can have at least two contacts, wherein the first contact is attached to the first lever part and the second contact is attached to the second lever part. 
     By pressing the movable furniture component into the furniture body, the first lever part resting against the movable furniture component is pushed in the direction of the second lever part, whereby the two contacts touch and close the circuit. 
     An energy accumulator is preferably arranged between the two lever parts to generate an initial stress. 
     Alternatively, the switch may comprise a push switch which is preferably attached to the free end of the lever. A two-part design of the lever can be dispensed with in this embodiment. 
     A further, fourth variant of the invention is an ejection device for a furniture component moveably housed in or against a furniture body, with an ejector to eject the movable furniture component, a drive unit, electric in particular, a gear mechanism to transmit power from the drive unit to the ejector, and a control or regulation apparatus to control or regulate the drive unit. 
     In such ejection devices it is frequently desirable to know the position of the ejector, in order to, for example, be able to configure the ejection profile according to the position. Accordingly, actuation of the ejection device can occur during an initial displacement caused by a user of the movable furniture component and the ejector. 
     It is therefore the object of this variant of the invention to create an ejection device in which the position of the ejector can be established. 
     This is achieved by providing the ejection device with a potentiometer, wherein the signals from the potentiometer can be fed at least to the control or regulation apparatus, and the actuator of the potentiometer is coupled to the gear mechanism. 
     Compared with other path-measuring devices, all potentiometers have the advantage that they measure the position of the ejector in absolute terms, hence there is no need to initialize the path-measuring device. 
     If the ejector comprises a lever, it is particularly advantageous if the drive of the gear mechanism is formed in one piece with the lever. 
     In this case, the actuator of the potentiometer can be directly coupled with the lever. This has among other things the advantage that, if the gear mechanism comprises a slipping clutch, the position of the lever can be correctly determined in spite of the lever slipping through. 
     In particular, in the case of a swivellably housed lever, in order to avoid a change of movement, it is particularly advantageous if the potentiometer is a rotary potentiometer. 
     A further, fifth variant of the invention is an ejection device for a furniture component moveably housed in or against a furniture body, with an ejector to eject the movable furniture component, an electric drive unit, and a gear mechanism to transmit power from the drive unit to the ejector. 
     Such ejection devices are problematic because the gear mechanism is frequently damaged as a result of misuse of the ejection device. For example, a user wishing to close an ejected movable furniture component often pushes the movable furniture component with considerable force, in the direction of the furniture body. If the movable furniture component strikes the ejector of the ejection device, this force is transmitted to the gear mechanism of the ejection device, which can lead to destruction of the gear mechanism in the worst case. 
     The object of the invention is therefore to create an ejection device which does not have the above-described problem. 
     This is achieved by providing the gear mechanism with a slipping clutch. 
     If the force transmitted by the ejector onto the gear mechanism exceeds a limit value governed by the structure of the slipping clutch, the gear mechanism coupled to the slipping clutch will slip through, which prevents damage to the gear mechanism. 
     The present invention also relates to an item of furniture with a movable furniture component, in particular drawer or door, with an ejection device according to one of the previously mentioned variants of the invention. 
     A path-measuring device can be attached to or in the item of furniture to actuate the ejection device. 
     In order to allow the simplest possible incorporation into an item of furniture according to the invention, it is particularly advantageous if the path-measuring device is attached to or in the ejection device. 
     However, the path-measuring device can also be attached to or in the furniture body. 
     A possible embodiment of the invention which is characterized by its simplicity includes a path-measuring device comprising a pusher to which pressure can be applied by the movable furniture component. 
     If the ejection device is to be actuated by a pulling force applied to the movable furniture component by the user, it can be advantageous to provide the path-measuring device with a drive carrier which can be coupled with the movable furniture component. 
     The path-measuring device can be formed both as an absolute measuring device and as an incremental measuring device. 
     In the first case, the path-measuring device can, for example, comprise a potentiometer. In the second case, the path-measuring device can, for example, comprise an encoder. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the invention will be seen from the following description and the accompanying figures, in which: 
         FIGS. 1   a  to  1   b ,  2   a  to  2   b  and  3   a  to  3   b  to  3  show a first embodiment of the invention in top view and in perspective view, for different positions of the lever of the ejection device; 
         FIGS. 4   a  to  4   b  and  5   a  to  5   d  show a second embodiment of the invention, in various views; 
         FIGS. 6   a  to  6   d  show a third embodiment the invention, in various views; 
         FIGS. 7   a  to  7   d  show a further variant of the third embodiment of the invention; 
         FIGS. 8   a  to  8   c  and  9   a  to  9   c  show a fourth embodiment of the invention, in different views; 
         FIGS. 10   a  to  10   i  and to  11   a  to  11   b  show a fifth embodiment of the invention, in different views; 
         FIG. 12  is a perspective view of a further embodiment of an ejection device according to the invention; 
         FIG. 13  is an exploded view of the ejection device shown in  FIG. 12 ; 
         FIG. 14  is an exploded, perspective view of some components of the ejection device illustrated in  FIG. 13 ; 
         FIGS. 15   a  to  15   c  are cross-sections of a further embodiment of an ejection device according to the invention; 
         FIG. 16  is an exploded view of the ejection device illustrated in  FIG. 15 ; 
         FIG. 17  is an exploded view of a further embodiment of an ejection device according to the invention; 
         FIGS. 18   a  to  18   d  show an embodiment of an item of furniture according to the invention; 
         FIGS. 19   a  to  19   c  show an embodiment of a path-measuring device in two perspective views and in exploded view; 
         FIGS. 20   a  to  20   c  are perspective views of a further embodiment of an ejection device according to the invention; and 
         FIGS. 21   a  to  21   c  are top views of the ejection device illustrated in  FIGS. 20   a  to  20   c.    
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1   a  is a top view of a first embodiment of an ejection device  8  according to the invention which is attached to a furniture body  3  via a bearing rail  19 . The ejection device  8  has a swivellably housed lever  4 , wherein a first castor  10  is attached to the free end of the lever  9  (“free lever end”), and a second castor  11  (i.e. roller) is attached approximately half-way between the articulation point of the lever  4  and the free lever end  9 . In the position represented in  FIG. 1   a , the movable furniture component  2 , of which only the rear panel is represented here, is in its closed position in the furniture body  3 , as a result of which the lever  4  lies with the second castor  11  against the movable furniture component  2 . 
       FIG. 1   b  shows a perspective view of the ejection device  8 , whereinto the movable furniture component  2  has not been illustrated for greater clarity. 
     In  FIG. 2   a , the movable furniture component has already been moved by the lever  4  so far from its closed position in the furniture body  3  that now the first castor  10  attached to the free lever end  9  also comes into contact with the movable furniture component  2 . 
       FIG. 2   b  is a perspective view of the ejection device  8  in this position. 
       FIGS. 3   a  and  3   b  show the situation shortly before the movable furniture component  2  moves completely away from the lever  4 . Lever  4  is now in contact with the movable furniture component  2  via the first castor  10  attached to the free lever end  9 , while the second castor  11  is no longer in contact with the movable furniture component  2 . 
       FIGS. 4   a  and  4   b  show a lever  4  according to the invention which consists of a first lever part  20  and a second lever part  21 . The second lever part  21  is formed in one piece with the drive  17  of a gear mechanism  13 , not illustrated in  FIG. 4 . A first castor  10  for applying a load on a movable furniture component  2 , not illustrated in  FIG. 4 , is provided at the free lever end  9  against the first lever part  20 . Furthermore, the second castor  11  is arranged approximately in the middle of the lever  4 . Arranged between the first lever part  20  and the second lever part  21  is a spring  18  which rests with one end  36  against the second lever part  21  and with its other end  37  against the first lever part  20 . The first lever part  20  is thereby pre-loaded in relation to the second lever part  21 . In this example embodiment, a drive wheel  22  is formed against the first lever part  20  for a potentiometer  15 , not illustrated in  FIG. 4 , for determining the position of the lever  4 . 
       FIG. 5   c  shows the respective positions of the first lever part  20  and the second lever part  21  when the movable furniture component  2 , not illustrated in  FIG. 5 , is in its closed position. The castor  10  lies against the rear panel of the movable furniture component  2 . In  FIG. 5   a , the second lever part  21  is driven via the drive  22  of a gear mechanism  13  not illustrated in  FIG. 5  in order to eject the movable furniture component  2 . The first lever part  20  thereby lies against the second lever part  21 . The spring  18  supports the ejection process of the movable furniture component  2 .  FIGS. 5   b  and  5   d  are perspective views of  FIGS. 5   a  and  5   c.    
       FIGS. 6   a  to  6   d  show a first embodiment of the third variant of the invention which includes a switch  7  attached to the lever  4 . As in the aforementioned embodiment, the lever  4  has a first lever part  20  for the application of force to a movable furniture component  2  not illustrated in  FIG. 6 , and a second lever part  21  which is connected to a drive unit  5 , likewise not represented. A spring  25  is arranged between the two lever parts  20 ,  21 . A castor  10  is attached to the first lever part  20 . The switch  7  comprises a first contact  27  attached to the first lever part  20  and a second contact  26  attached to the second lever part  21 . In the positions illustrated in  FIGS. 6   c  and  6   d , the two contacts  26 ,  27  are separated. This corresponds to the inactive position of the switch  7 . A user, not illustrated, moves the furniture component  2 , also not illustrated, in the direction of closure, i.e. into the furniture body  3 , also not illustrated. The first lever part  20  is thereby moved against the application of force of the spring  25 . The two contacts  26 ,  27  thereby come into contact, which completes an electrical circuit, which is not illustrated in detail, for clarity, whereby an actuation signal is relayed to the drive unit  5  over the lines  24 . 
       FIGS. 7   a  to  7   d  show a second embodiment of the third variant of the invention, in which the lever  4  is formed in one piece. In this embodiment, the switch  7  is formed as a push switch attached to the free lever end  9 . 
       FIGS. 8   a  to  8   c  show different embodiments of the fourth variant of the invention. A gear mechanism  13  which serves to transmit power from the electric motor  29  to the second lever part  21  is shown. Power is transmitted, via a spindle  35 , which cannot be seen in  FIG. 8  (but can be seen in  FIGS. 9   a  and  9   b ), the toothed wheel  31 , the further toothed wheel  33 , and the drive  17  of the gear mechanism, which in this embodiment is formed in one piece with the second lever part  21 . According to the invention, in each of  FIGS. 8   a  to  8   c , a potentiometer  15  (here, a rotary potentiometer) is connected to the gear mechanism  13 . The potentiometer  15  has three contacts  30  for connecting or tapping electrical current. In the embodiment shown in  FIG. 8   a , the potentiometer  15  is connected to the middle stage of the gear mechanism  13  via a common axle. In the embodiment shown in  FIG. 8   b , the potentiometer  15  is connected to the toothed wheel  31 . In the particularly preferred embodiment of  FIG. 8   c , the potentiometer  15  is connected to the second lever part  21 . 
       FIGS. 9   a  to  9   c  show alternative views of the embodiments illustrated in  FIGS. 8   a  to  8   c.    
       FIGS. 10   a  to  10   f  show an embodiment of the fifth variant of the invention.  FIG. 10   a  is a side view of a part of a gear mechanism  13  which comprises a slipping clutch  14 . In this embodiment, the slipping clutch  14  consists of a spring washer  41  which broadens when disproportionately loaded and slides over the driving dogs  42 . This process is illustrated in  FIGS. 10   d  to  10   f .  FIGS. 10   g  to  10   i  show this process in detail.  FIG. 10   b  is a perspective view of part of gear mechanism  13 . 
     The structure of the of the gear mechanism  13  shown in  FIGS. 10   a  to  10   i  can be seen more clearly in the exploded view of  FIG. 11   b . The toothed wheel  33 , the further toothed wheel  32 , which is connected in rotation-resistant manner to the spring washer  40 , and the driving dogs  42  are arranged on a common pin  23 . The driving dogs  42  are fitted conjugately onto the part of the toothed wheel  33  formed as a bolt  43 .  FIG. 11   a  is a perspective view of the complete gear mechanism  13 , which is driven by an electric motor  29  and in turn drives the second lever part  21 . 
       FIG. 12  shows the ejection device  8  illustrated in  FIGS. 11   a - 11   b  attached to a bearing rail  19 . The first lever part  20  and a portion of the casing are shown. 
       FIG. 13  is a further exploded representation of the ejection device  8  illustrated in  FIGS. 11   a  and  12 , wherein all of the casing of the ejection device  8  can be seen. Furthermore, the arrangement of the potentiometer  15  directly on a plate  44 , which houses all the circuits of the ejection device  8 , can be seen in  FIG. 13 . The potentiometer  15  is connected to the gear mechanism  13  via the drive  22  and measures the position of the lever  4 .  FIG. 14  is a further exploded representation of the drive mechanism of the ejection device  8 . 
     A further embodiment of an ejection device  8  according to the invention is illustrated in  FIGS. 15   a  to  15   c . This embodiment is characterized in particular by a path-measuring device  38 . The path-measuring device  38  has a spring-loaded pusher  39  which can be subjected to pressure by a movable furniture component  2 , not shown. In  FIG. 15   a , the pusher  39  has been pushed into the housing of the ejection device  8  by the movable furniture component  2 , which triggers the ejection process. The structure of this ejection device is more clearly shown in  FIG. 16 , which is an exploded view. 
       FIG. 17  is an exploded view of a further embodiment of an ejection device  8  according to the invention, which differs from the embodiment illustrated in  FIG. 13  only in that one fewer gear mechanism stage is provided. 
     An item of furniture  1  is shown in  FIGS. 18   a  to  18   d . The item of furniture includes a movable furniture component  2  formed as a drawer. A path-measuring device  38  attached to the furniture body  3  which comprises an encoder  45  can be seen. Force can be applied to a pusher  39  by the back of the movable furniture component  2 . In the position illustrated in  FIG. 18   a , the pusher  39  is pushed in by the movable furniture component  2  which is in its closed position. When a user moves the movable furniture component  2  slightly out of its closed position, the spring-impacted pusher  39  moves outward, and the movement is recorded by the encoder  45 . The path-measuring device  38  then issues to an ejection device  8 , not illustrated in  FIG. 18 , a command to eject the movable furniture component  2 . 
     The path-measuring device  38  shown in  FIGS. 18   a - 18   d  is shown in detail in  FIGS. 19   a  to  19   c . As shown, the pusher  39  is formed as a toothed rack  46 , which engages a pinion  48  connected to the disk  47  of the encoder  45 . A spring-loaded stop  49  which enables path measurement when the movable furniture component  2  is in its closed position, and pressed in the direction of the furniture body  3  by the user for actuation. 
     A further embodiment of an ejection device according to the invention  8  is illustrated in  FIGS. 20   a  to  20   c . This embodiment is characterized by a potentiometer  15  attached to the furniture body  3 . The actuator  16  of the potentiometer  15  is connected to the back of a movable furniture component  2  via a drive carrier  28 . The movement of the movable furniture component  2  out of its closed position drives the actuator  26  of the potentiometer  15  via the drive carriers  28 , whereupon the potentiometer  15  orders the ejection of the movable furniture component  2  by the ejection device  8 . This process is illustrated in  FIGS. 21   a  to  21   c  in a top view.