Abstract:
A piece of furniture including a body and at least one flap that can be upwardly displaced by means of at least one actuating arm which is joined to the flap in an articulated manner and can preferably be pivoted about a horizontal axis. At least one actuating arm is subjected to the action of a spring device, and at least one electric drive acts on at least one actuating arm. A coupling device acts between the electric drive and the actuating arm, said coupling device having a free wheel for freely displacing the actuating arm into an open position and/or a closed position, in at least one rotary direction over a defined angular region.

Description:
This is a Continuation Application of International Application Number PCT/AT2006/000117, filed on Mar. 20, 2006. 
    
    
     BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention relates to an item of furniture having a furniture body and at least one flap being upwardly movable by means of an actuating arm which is connected to the flap and acted upon by a spring device, wherein the actuating arm is preferably pivotable about a horizontal axis and wherein further an electric drive device is provided which can act upon the actuating arm. 
     (2) Description of Related Art 
     According to the prior art, various designs of items of furniture are known which have a setting device for moving a flap upwardly. DE 102 23 026 describes a cover setting device for a cupboard, whereby a flap can be swung parallel to the front side of the item of furniture and also across thereto. In order to retain the flap in any desired open position, a spring device is provided which has an adjustable sliding member in order to act upon the actuating arm. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an item of furniture of the type referred to above which improves the intuitive operability of the movable flap. 
     In the present invention, this object is achieved by providing a coupling device which can operate between the electric drive device and the actuating arm, wherein the coupling device allows the actuating arm to move freely across a limited pivoting range in an open position and/or in a closed position in at least one direction of rotation. 
     By means of the arrangement or effect of the electric drive device referred to above, the movement of the flap which opens upwards can be at least partially supported by the electrical drive device, and in the case of heavy flaps with a large surface area, the operability can be facilitated. A flap which is in a fully open position in a spatially high location can often only be reached with difficulty and the manipulation of this flap is significantly facilitated by the electric drive device. Advantageously, it is provided that the electric drive device acts on the same actuating arm or lever which is also acted upon by the spring device. 
     The arrangement of the pressurised actuating arm with the electric drive device may also be provided on both sides of the flap or on both furniture side walls of the cabinet. It might, however, also be sufficient to fit an electric drive device to only one side of the flap or of the item of furniture. 
     By arranging the coupling device in the manner described above, a motorised movement of the actuating arm can be achieved, wherein the electric drive device preferably only operates across a partial range of the pivotal distance of the actuating arm. This can, for example, allow the motor to supply a starting impulse which will provide the actuating arm a sufficient torque via the coupling device so that the flap can be moved into the respective end positions without any additional motorised support, only by means of the force of the spring device which acts upon the actuating arm. 
     A preferred embodiment of the invention provides for the spring device to pressurise the actuating arm such that the flap is basically retained in any pivoting position against the force of gravity. The spring device serves to compensate the weight of the flap so that the flap is essentially self-supporting. To achieve this, all measures and arrangements according to the prior art may be applied here, including the actions and layouts, whether in terms of distances between axes as, for example, described in DE 101 45 856, by suitable actuating arm pivot points with reference to the flap, by spring mechanisms with varying ratios of transmission, by adjustable sliding valves, control cams with control contours or by similar means. It is, however, provided that the spring device can be adjustable in order for the torque applied on the actuating arm can be varied. 
     In connection with this invention, “spring devices” should be understood to refer not only to spring mechanisms with mechanical spring components but also to all other known power stores such as gas pressure stores or the like. It is also possible to provide power from an external energy source, for example, that of the electric drive, to form at least part of the spring device. 
     In designing the electric drive device it may be useful if the torque which is to be supplied to the adjustable arm by the electric drive in order to open the flap is essentially equal to the moment of inertia of the flap multiplied by the angular acceleration of the flap which is to be obtained. For a flap which has been ideally put in balance, this means that the electric drive has only to provide minimal power. A minimally structured electric motor can therefore be designed which shall guarantee operation without any problems while using little power. 
     A further embodiment of the invention provides that an actuating device may be arranged in order to move the flap, wherein the actuating device comprises a base structure adapted to be fitted to the body of furniture. The actuating arm is on the one hand pivotably mounted to the base structure and on the other hand articulated to the flap. There a numerous known designs of these actuating devices in the prior art which can be advantageously combined with the scope of the present invention. The base structure (core) is normally fitted to a lateral wall of the item of furniture. A spring device pressurises the actuating arm connected to the base structure by means of setting devices. Advantageously, the flap can be moved by the actuating device from the fully closed position to an open position or in the opposite direction. One embodiment of the invention provides for the actuating arm to be arranged on the basic structure on a bearing axis. In this connection it is convenient if the electric drive device is arranged substantially coaxially to the bearing axis of the actuating arm. This can enable a central pivot point which will, in addition, require few construction components, so permitting the actuating device to be simply realised as a structural feature. 
     One embodiment of the invention provides that the electric drive device can be connected—at least temporarily—to the actuating arm. For this purpose, a transmission may be arranged which can be equipped—in the event that structural conditions are required—with a gear or a gear reduction. Also a coupling mechanism may be provided which includes gear teeth, friction linings or the like. Due to the minimally required torque of the electric drive and the small structural size resulting from this, it can usefully be fitted inside a casing or in or onto said base structure of the actuating device. 
     A further embodiment of the invention provides that a second flap may be provided which is articulated about a horizontal axis with respect to the first flap. This type of arrangement is known as bi-fold lids which can be used for cover elements of upper cupboards in kitchens. The actuating arm is advantageously articulated to the lower second flap for easier mobility and for more stable guidance of the flap. 
     In accordance with the state of art, there are flaps which are known as so-called swivel flaps, where the connected furniture flap can be swung backwards across beyond the furniture body. Also known are so-called lift flaps, where the furniture flap can be moved substantially parallel to the front face of the furniture body across the entire opening and closing movement path. It is also within the scope of invention to combine above-mentioned flaps with the concept of the present invention. 
     Advantageously the flap can be moved from an open to a fully closed position over at least a part of the movement path by means of the electric drive. It can also be advantageous if the flap can be moved to a fully open position over at least a part of the movement path by the electric drive. This enables the flap to be brought into the respective end position, wherein this movement can be damped. For this purpose the electrical drive itself can be provided to achieve a dampened motion of the flap. 
     A number of design features are conceivable and possible in order to activate the electric drive. The electric drive can, for example, be activated by a switch device, preferably a push-button switch. It may be practical that the switch device is arranged on or in the item of furniture or spatially outside thereof. This type of switch device significantly facilitates the process since the weight of the flap can often be more than 20 kg. The switch device can also activate the electric drive by wireless transmission means. 
     Alternatively or as an addition, it can be useful if the electric drive can be activated by a manual movement of the flap, in which the electric drive can be activated by pulling or pushing the flap. These types of functions are known as touch-latch functions, where the flap can be moved into the fully open as well as the fully closed position by being pulled or pushed. Accordingly, it is not necessary to provide handles or holding components on the flap. 
     Alternatively or as an addition to the aforementioned possible forms of activation, it may be an advantage for the electric drive to be activated by a sensor device, preferably a contactless sensor device. A further design feature provides for the electric drive to be verbally activated by a speech recognition device. Activation of the electric drive may also be performed by an optical detecting device, preferably a camera. 
     Advantageously the electric drive comprises an electric motor, preferably a direct current motor, and a transmission gear. The direct current motor may also be designed as a linear motor. 
     With regard to the energy supply, it is an advantage if the electric drive is supplied with power by a power store, preferably a battery. An external power supply can also be provided by the normal domestic power grid. 
     For a smooth and regular process of movement it can be an advantage if at least one damper device is provided in order to dampen the movement of the flap. For this purpose, bumpers, linear or rotation dampers or the like may be used. A useful design feature is, however, provided so that the damper device is at least partly formed from the electric drive while the damping action can also fully be effected by the motor. In order to reduce the loud noise of closing and any mechanical overstraining of the system components, it may be an advantage if the damper device at least dampens the movement of the flap over the last opening section and/or at least over the last closing section of the flap. 
     Further details and advantages of this invention will be explained in greater detail by the description given in the following figures and by reference to the drawings. 
    
    
     
       DETAILED DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic representation of an embodiment of the invention with an upwardly movable flap, 
         FIGS. 2   a ,  2   b  is a side view and a top plan view of the embodiment shown in  FIG. 1 , 
         FIG. 3  is an exploded representation of the embodiment shown in  FIG. 1  and  FIG. 2 , 
         FIGS. 4   a ,  4   b  is an embodiment of the actuating device with an adjustable spring device for moving the flap, 
         FIG. 5  is a further embodiment of the invention with a motorised actuating device for moving a bi-fold flap, 
         FIG. 6  is a side view of the embodiment shown in  FIG. 5 , 
         FIG. 7  is an example of a block circuit diagram of the possible forms of activation, 
         FIG. 8   a - 8   c  is various possible methods of activation of the electric drive, 
         FIG. 9   a - 9   e  is an exemplary embodiment of a coupling device for connecting the electrical drive with the actuating arm, 
         FIG. 10  is a graphic representation of the opening motion of the actuating arm and of the pivotal motion of the electric drive as a function of time, and 
         FIG. 11  is a representation of the operative angle ranges of the electric drive and of the spring device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a schematic perspective view of a side wall  1  of an item of furniture. To the side wall  1  an assembly plate  7  with a spring device  4  is attached, wherein the spring device  4  acts upon at least one actuating arm  3  with a torque. In  FIG. 1 , the spring device  4  is only represented diagrammatically and can operate on actuating arm  3  such that the flap  2  which is connected by a fitting  6  is essentially retained in any pivotal position against the force of gravity. In order to fully balance the flap  2  according to its size and weight, spring device  4  is adjustable in order for the force applied to the actuating arm  3  to be varied. In order to control the movement of the flap  6 , another actuating arm  3 ′ is provided which is connected on one side to assembly plate  7  and to fitting  6  of flap  2  on the other side. In order to support the movement process of flap  2  at least partially, electric drive  5  is provided which is connected to bearing axis  8 . A preferred embodiment provides for bearing axis  8  to be directly connected to the bearing axis of actuating arm  3  or to be at least temporarily able to be connected to the latter by a transmission gear which is not shown. This has the advantage that the force required to move the flap can be reduced to a minimum due to being well balanced by spring device  4 . This means that minimal sizes of electric drives  5  can be used which also can be arranged within the casing of an actuating device. 
       FIG. 2   a  shows the embodiment shown in  FIG. 1  in a side view,  FIG. 2   b  shows a top plan view of this arrangement. For the sake of clarity, spring device  4  which is shown in  FIG. 1  is not depicted.  FIG. 2   a  shows the flap  2  connected to actuating arms  3 ,  3 ′ in its function as a swivel flap, where it can be swung backwards across the furniture body. It can be seen from  FIG. 2   b  that a control cam  10  is connected or formed onto one end of actuating arms  3 ,  3 ′, said control cam  10  being pivotably arranged on a bearing axis  9  on assembly plate  7 . In the embodiment shown, bearing axis  9  of actuating arm  3  corresponds to bearing axis  8  of electric drive  5 . 
       FIG. 3  shows an exploded view of the embodiment shown in  FIG. 1  and  FIG. 2 . Assembly plate  7  is firmly screwed to side wall  2  of an item of furniture. Both actuating arms  3 ,  3 ′ are connected to assembly plate  7  in an articulated manner, where actuating arm  3  is coupled to its end with control cam  10 . Control cam  10  comprises a control contour  11  which can run along a pressure roller (not shown) which is again directly or indirectly pressurised by a spring device  4 . 
       FIG. 4   a  shows a schematic embodiment of an adjustable actuating device  16  in side view,  FIG. 4   b  shows the detail B from  FIG. 4   a . For reasons of clarity, electric drive  5  which operates on actuating arm  3  is not shown. Flap  2  which can be pivoted about a horizontal axis is in a closed position. Actuating device  16  comprises a base structure  18  on which actuating arm  3  is pivotally located on bearing axis  9 . Second actuating arm  3 ′ is coupled to side wall  1  of the furniture body. Spring device  4  is located on pivoting axis  17  and comprises a compression spring package which includes at least one or more compression springs—preferably parallel switched. Spring device  4  pressurises a displaceable setting part  15  with a force, wherein working point  13  is moved corresponding to the pressure of spring device  4 . Adjusting device  20  converts the (linear) motion of setting part  15  into a pivotal motion of intermediate lever  14 . Intermediate lever  14  comprises a guide path  21  along which working point  13  can be adjustably located. By adjusting working point  13  in this way, the force of pressure roller  12  on control contour  11  of control cam  10  can be set. Electric drive  5  may be connected directly or indirectly to bearing axis  9  of control cam  10 . Actuating device  16  as shown is only represented as an example and in principle it can comprise all the other known solutions in accordance with the state of the art. 
       FIG. 5  shows a perspective view of an item of furniture on side wall  1  of which is connected actuating device  16 . Electric drive  5  is arranged so that it acts upon actuating arm  3 . Flap  2  can be pivoted about a horizontal axis with respect to the furniture body. A second flap  2 ′ is pivotally located about a horizontal axis on flap  2 . In the figure shown, actuating arm  3  is connected to lower flap  2 ′. 
       FIG. 6  shows a side elevation of the embodiment shown in  FIG. 5 . Actuating device  16 , which is supported by motorised electric drive  5 , is provided in order to move a bi-fold flap having part flap  2  and part flap  2 ′. Upper part flap  2  is pivoted about a horizontal axis in relation to the furniture body. For this, at least two hinges  22  are provided which are attached on the one hand to the lower section of cupboard cover  23  and on the other hand to flap  2 . Lower part flap  2 ′ is connected to the lower section of upper part flap  2  by means of a two- or multi-dimensional hinge  22 ′. Actuating arm  3  is connected to lower part flap  2 ′ by fitting  6  for easy movement of flaps  2  and  2 ′. Motorised drive  5  can support the movement of part flaps  2  and  2 ′ from the fully closed position to the fully open position or vice-versa for at least part of this movement path. As an advantage, electric drive  5  can also be used as a device to dampen the motion of flaps  2  and  2 ′. 
       FIG. 7  shows a schematic block circuit diagram of various ways for activating electric drive  5 . As examples, switch device  30  (e.g. a push button switch), an optical detecting device  31  (e.g. a camera), a speech recognition device  32  (e.g. a microphone), a sensor device  33  (e.g. distance sensors) and a Touch-Latch device  34  are provided which can be arranged either individually or in any possible combination with each other. Touch-Latch device  34  operates together with flap  2  by control lead  37 , wherein Touch-Latch device  34  can be activated by pulling or pressing flap  2 . An activation device  35  assesses the signals of devices  30 - 34  referred to above and directs these to a control and regulating device  36  which in turn can control electric drive  5  and also flap  2  in accordance with a selectable operating mode. 
       FIG. 8   a - 8   c  show various embodiments of activation of electric drive  5 . Each of the representations shows views onto side wall  1  of an item of furniture with a bi-fold flap being upwardly movable, said bi fold flap comprises two part flaps  2  and  2 ′.  FIG. 8   a  shows an activation with a switching Touch-Latch device  34  between lower part flap  2 ′ and cupboard base  24 , whereby electric drive  5  is activated by manual pressure on lower part flap  2 ′.  FIG. 8   b  shows an alternative form where activation takes place upon operating switch device  30 .  FIG. 8   c  shows sensor device  33  which registers the operation of a handle component  25  and so activates electric drive  5 . 
       FIG. 9   a - 9   e  show an exemplary embodiment of coupling the electric drive  5  and actuating arm  3 . A coupling device  40  comprises of two substantially disc-shaped coupling elements  41  and  42  which are arranged coaxially relative to one another and which permit at least a temporary connection between electric drive  5  and actuating arm  3 . The first coupling element  41  can be connected with the electric drive  5 , while the second coupling element  42  is connected with actuating arm  3 . The first coupling element  41  has a circular sector shaped opening  43  with a stop  45  and a counter-stop  46 . The second coupling element  42  comprises a lug  44  which can engage into opening  43 , provided that the coupling elements  41 ,  42  are in a coupled position. Lug  44  is freely movable between stop  45  and counter-stop  46 .  FIG. 9   b  shows a vertical cross section through both coupling elements  41  and  42 . The opening  43  has an opening angle α which substantially corresponds to the angular movement of actuating arm  3 , so that flap  2  can be moved from the closed position to the fully open position thereof. Said opening angle α also corresponds to the angular movement of electric drive  5 . This figure shows that wedge-shaped lug  44  can be moved between stop  45  and counter-stop  46  of first coupling element  41 . 
       FIG. 9   c - 9   e  each show perspective views of both coupling elements  41  and  42 , where lug  45  in opening  43  can be guided between stop  45  and counter-stop  46 . First coupling element  41  is connected to electric drive  5  while second coupling element  42  is connected to actuating arm  3  of flap  2 .  FIG. 9   c  corresponds to the closed position of flap  2  where lug  44  abuts to stop  45 . When electric drive  5  is now activated, coupling element  41  is turned in an anti-clockwise direction. If the weight of flap  2  is ideally fully compensated by the spring device  4  as described in  FIGS. 4   a ,  4   b , a slight (turning) movement of first coupling element  41  across a partial range of opening angle α is sufficient for the second coupling element  42  and its lug  44  to be released from stop  45  and then to move freely in the direction of counter-stop  46 .  FIG. 9   d  shows lug  44  released from stop  45  which is now located about half-way within opening angle α (corresponding to the half open position of flap  2 ). Electric drive  5  then returns coupling element  41  back to its initial position and lug  44  abuts to counter-stop  46  as shown in  FIG. 9   e .  FIG. 9   e  therefore corresponds to the fully open position of flap  2 . The closing process can be analogously deduced in the sequence of  FIG. 9   e ,  FIG. 9   d  and  FIG. 9   c . When the weight of flap  2  is ideally compensated, a clockwise turning impulse of electric drive  5  is sufficient to release lug  44  from counter-stop  46  and to move it freely in the direction of stop  45 . In order to avoid lug  44  from striking hard against stop  45  or counter-stop  46 , these stops  45 ,  46  can be fitted with attenuating shock absorbing supports (for example soft rubber pads) so that any banging noises which arise can be reduced. 
       FIG. 10  shows a diagram of opening angle α of actuating arm  3  (characteristic curve S) and the turning motion of electric drive  5  (characteristic curve M) as a function of time. Electric drive  5  initially turns together with lug  45  (identical path of characteristic curves M and S), however, after a slight turning movement across a partial section of opening angle α, electric drive  5  returns to its initial starting position, flap  2  though is automatically moved to the fully open position or vice-versa due to the balance-compensation of weight attained by spring device  4 . 
       FIG. 11  shows the operative angle ranges of electric drive  5  and spring device  4  during the pivotal movement of actuating arm  3 . The vertical line corresponds to the closing position of actuating arm  3 , while the line which points obliquely upwards identifies the fully open position of actuating arm  3  or of flap  2 . Actuating arm  3  is pressurised by spring device  4  radiant from a neutral position N lying between these two end positions of flap  2  on one side in a first pivoting range S 2  towards the external end position and is likewise pressurised by spring device  4  radiant from this neutral position N in a second pivoting range S 1  to the internal end position. If flap  2  is transferred from the closed position towards the open position, neutral position N shall be exceeded so that from this time actuating arm  3  is pressed towards the fully open position by spring device  4 . Moreover, actuating arm  3  is pressed vice-versa from the fully open position of adjustable arm  3  into the closed position once neutral position N has been passed. In addition, provision is made for electric drive  5  to be active in the opening process of flap  2 , radiant from the fully closed position of flap  2  across an angle range M 1  of maximum 50°, preferably of maximum 30°, towards the open position. With the aid of electric drive  5 , actuating arm  3  is moved beyond neutral position N, where from this time electric drive  5  is preferably no longer active and actuating arm  3  or flap  2  can be moved on its own into the fully open position by spring device  4 . Vice-versa, in the closing process of flap  2 , electric drive  5  is active radiant from the fully open position of flap  2  across a angle range M 2  of maximum 100°, preferably of maximum 80°, towards the closed position. Electric drive  5  supports the closing process of flap  2  beyond neutral position N so that actuating arm  3  is moved freely into the closed position, without further aid of electric drive  5 , but by being pressurised by spring device  4 . 
     Coupling device  40  is advantageously designed such that the maximum opening angle of actuating arm  3  or of flap  2  can be adjusted. The position of coupling device  40  shown in  FIG. 9   a  to  9   e  with coupling elements  41  and  42  can be detected by an electronic measuring device, the signals of which can be directed to control and regulation device  36 . 
     The present invention is not limited to the embodiments shown, but includes or extends to all variants and technical equivalents which can fall within the scope of the following claims. The positional details which have been selected in the description (such as top, bottom, lateral or the like) refer to the usual installation position or to the figure directly described and illustrated and in the event of a change of position may be correspondingly transferred to the new position. Actuating arm  3  can, for example, also be designed as a gear rack which meshes with a pinion on electric drive  5 . The invention is identified by a simple and smooth fitting system which by the use of the free-wheel coupling device described and in conjunction with an ideal weight compensation of flap  2  requires a minimum degree of power from electric drive  5 , since a turning impulse of electric drive  5  will suffice to transfer the necessary torque for the opening or closing movement. The electrical performance of the motor can, for example, be determined at 20 W to 40 W, where an impulse time of 0.5 to 1.0 seconds has been shown to be favourable. If the electric drive  5  is active across the entire pivotal path of actuating arm  3  or of flap  2 , the performance dimensions of the motor shall be correspondingly less, for example from 4 W to 5 W. The performance data of electric drive  5  are, however, dependent on the friction values of the complete system, in particular on the selective setting of spring device  4 . In addition to control and regulation device  36  (which can be designed as hardware and/or software), a start-up coupling device and an overload connection device, for example a coil spring device which operates on coupling device  40 , can be supplied.