Abstract:
A coupling is provided for detachably connecting a mobile part of a piece of furniture to a drive. The coupling includes a coupling element that can be moved between the mobile part of the piece of furniture and the drive in a limited manner in at least one direction, in order to compensate for position tolerances in relation to the at least one direction.

Description:
This application is a Continuation of International application No. PCT/AT2008/000064, filed Feb. 27, 2009, the entire disclosure incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention concerns a coupling for releasably connecting a movable furniture part to a drive, wherein the coupling has a coupling portion. Couplings of this kind suffer from the problem that, due to positional tolerances of the movable furniture part relative to the drive, it may be difficult to make the connection between the movable furniture part and the drive. The positional tolerances may involve, for example, installation tolerances. They are to be attributed to the fact that neither the drive nor the movable furniture part is mounted exactly at the same location on a body or carcass of an article of furniture, in each mounting operation. 
     A further example of positional tolerances are operating tolerances which are therefore not to be attributed to inaccurate fitment of the drive or the furniture part in the furniture body or carcass, but which inevitably occur in operation of the movable furniture part. It is known, for example, that a movable furniture part which is in the form of a drawer can rise or fall by some millimeters, depending on the respective loading condition. 
     SUMMARY OF THE INVENTION 
     The object of the invention is to provide a coupling of the general kind set forth, which is suitable for overcoming the above-discussed problems. According to the invention that is attained by a coupling having the features described herein. 
     The provision of a limited mobility of the coupling portion in the direction to be compensated means that positional tolerances are of no consequence either in the form of installation tolerances or in the form of operating tolerances. 
     The concept according to the invention is admittedly not limited to a given kind of drive. A particularly preferred embodiment however is one in which it is provided that the drive has a pulling means which can be wound onto a roller drivable by an electric motor. In that case, the limited mobility of the coupling portion at least along the line of action of the drive (that is to say in or in opposite relationship to the extension direction of the movable furniture part) can be implemented by the pulling means or the roller having a certain play. In other words, even when the drive is not activated, the pulling means because of the play can be unwound from or wound onto the roller. 
     With this embodiment it can further be provided that the drive has a housing. Provided in the unwinding region of the roller is a window for the exit of the pulling means, and the window is substantially larger than the diameter of the pulling means. That also affords a compensation option for directions which extend in orthogonal relationship to the line of action of the drive. For example, the pulling means will generally be of a diameter of between 0.5 mm and 1 mm. In that case, it is sufficient if the window is of a dimension in the region of about 5 mm (for example in the case of a square configuration, for each side). 
     A further advantageous embodiment is afforded if it is provided that the coupling portion is a magnet connected to the pulling means. Movable furniture parts normally have a metallic rear wall (for example a metallic drawer body frame). In that case, the magnet can couple at any position delimited only by the pulling means anywhere on the rear side of the movable furniture part. 
     In another embodiment of the invention, the coupling portion has a first part for mounting to the movable furniture part and a second part for mounting to the drive. 
     In that case it can be provided that the second part is mounted on a slide displaceable in two mutually orthogonal directions which extend in orthogonal relationship with the line of action of the drive. That affords a compensating option in relation to positional tolerances in orthogonal relationship with the line of action of the drive. 
     Alternatively or additionally, the second part is mounted limitedly movably along the line of action of the drive, thereby affording a compensating option along the line of action of the drive. 
     Further alternatively or additionally, the second part is mounted pivotably relative to a housing of the drive. A pivotable mounting arrangement also affords compensating options both in the line of action of the drive and also in orthogonal relationship with that line of action. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages and details of the invention will be apparent from the Figures and the related specific description. Therein,  FIGS. 1 through 5  each show a separate embodiment of the invention in a perspective view ( FIGS. 1   a ,  2   a ,  3   a ,  4   a , and  5   a ), a partial exploded view ( FIGS. 1   b ,  2   b ,  3   b ,  4   b , and  5   b ), sectional views ( FIGS. 1   c ,  1   d ,  2   c ,  2   d ,  3   c ,  3   d ,  4   c ,  4   d ,  5   c  and  5   d ), and a schematic diagram ( FIG. 1   e ). 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Each of the Figures shows a drive  5  which is releasably fixed to a profiled rail  6  and has an ejection lever  7  and a pull-in retraction device having a pulling member  4 . As shown in the schematic diagram of  FIG. 1   e , the pulling member  4  is wound on roller  23  of drive  5 , and roller  23  is driven by motor  25 . The notional line of action  21  is orthogonal to the axis of rotation  24  of the roller  23 . The embodiments differ in the configuration of the coupling  1 . Thus, components having the same configuration in each embodiment are identified with the same reference numbers. 
     Thus  FIGS. 1   a  through  1   d  show an embodiment of the coupling  1 , in which the coupling  1  has two parts  2 ,  3 . The first part  2  is provided for mounting to the movable furniture part  8 , and the second part  3  is provided for mounting to a free end  26  of the pulling member  4  of the drive  5 . 
     The pulling member  4  is passed out of the housing  22  of the drive  5  by way of (adjustably guided by) deflection rollers  19  (not shown in  FIG. 1   b , but see  FIG. 1   d ) and a window  9 . The deflection rollers  19  compensate for positional tolerances in directions which extend orthogonally with respect to the line of action  21  of the drive  5  (in all the Figures, the direction of movement of the pulling member  4  outside the housing). As shown in  FIG. 1   b , the window  9  is larger than a cross-section of the pulling member  4  so as to allow the second coupling part  3  to have limited movement in a direction orthogonal to the notional line of action  21  of the drive  5  (see also the schematic diagram of  FIG. 1   e ). To compensate for positional tolerances in the direction of the line of action of the drive  5 , the second part  3  has a grooved pin  10  (i.e., the pin  10  has circumferential grooves  20 ), the first part  2  being of such a configuration that the pin  10  can be locked with any individual groove  20  of pin  10  in the first part  2 , more specifically by way of clamping jaws  11  (see the sectional view in  FIG. 1   d ). 
     In all embodiments, the movable furniture part  8  is in the form of a drawer. 
     The coupling  1   a  also has a two-part structure in the embodiment of  FIGS. 2   a  through  2   d . In this case, once again the second part  3   a  has a grooved pin  10   a  which can provide for compensation in the direction of the line of action of the drive  5 . 
     To provide for compensation in respect of positional tolerances in a direction orthogonal to the line of action of the drive  5 , the first coupling portion  2   a  has a capture part  13  which is mounted on a slide  12  and which has of a funnel-shaped configuration. 
     In this case, the slide  12  is mounted limitedly displaceable along two orthogonal directions. 
     In the embodiment of  FIGS. 3   a  through  3   d  the coupling  1   b  has a one-part configuration and has a coupling portion in the form of a magnet  14 . In this case the magnet  14  is connected to the free end of the pulling means  4 . The mobility of the pulling means  4  and the fact that in principle the magnet  14  can cling to any location on the metallic furniture part  8  provide a compensating option for positional tolerances both in the line of action of the drive  5  and orthogonally thereto. 
     The embodiment of  FIGS. 4   a  through  4   d  again has a two-part coupling  1   c . This corresponds to the coupling  1  shown in  FIGS. 1   a  through  1   d , with the differences that the second coupling portion  3   c  is mounted pivotably relative to the housing of the drive  5  (the part  15  is mounted pivotably by way of the joint  16  to the housing of the drive  5 ). The pulling means  4  is passed out of the housing of the drive  5  in the rear-wall region of the portion  15  and connected with the free end to the second part  3   c  of the coupling  1   c.    
     In the embodiment of  FIGS. 5   a  through  5   d  the second part  3   d  of the coupling  1   d  is mounted on a slide  12   d  (corresponding to  FIG. 2   a ). The second part  3   d  again has a grooved pin  10   d . The slide  12   d  is mounted limitedly movably along two mutually orthogonal directions. Provided for centering the pin  10   d , there are two centering pins  17  engaging into corresponding openings  18  on the first part  2   d  of the coupling  1   d . The first part  2   d  is again arranged at the rear wall of a movable furniture part  8  (not shown in  FIGS. 5   a  through  5   d ).