Abstract:
A hinge for furniture comprises a fastening box designed to be received with a central portion thereof into a hole in a piece of furniture. The box comprises two axially rotatable pins designed to be fitted into the hole together with the central portion of the box. Each pin has at least one laterally projecting tab. Working levers enable the pins to be rotated to lead the tabs to project outwardly of the box so as to interfere with the wall of the receiving hole and prevent the box from being drawn out of the hole.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a hinge for furniture provided with an improved box-fastening arrangement.  
         [0003]     2. State of the Prior Art  
         [0004]     The ironmongery market for furniture has always been sensitive to innovations enabling a quicker and steadier fastening of the ironmongery elements to the wooden panels. In particular in the case of furniture intended for the “do-it-yourself” market, the so-called “tool less” systems have been increasingly more appreciated, by means of which a safe fastening is ensured without resorting to any type of implement such as a screwdriver or a hammer.  
         [0005]     Different technical solutions are known as well as different patents describing this type of fastening; in particular U.S. Pat. No. 6,279,200 shows a particularly cheap and efficient solution for fastening the movable part of a hinge (the box) to the door of a piece of furniture. In this embodiment, expansion of a fastening anchor is obtained by manual rotation of a flat lever partly overlapping the box flange. The embodiment shown in such a patent however has a limit, i.e. in addition to the central hole for housing the box, two side holes are required for introduction of the screw anchors and for this reason the manufacturer is obliged to carry out a type of drilling that is slightly more expensive than the most standardized drilling systems, but above all of difficult interchangeability with them.  
         [0006]     Fastening solutions are also known in which fitting directly takes place on the walls of the central hole receiving the hinge box, this arrangement being substantially standardized and practically common to all types of hinges presently on the market.  
         [0007]     These solutions however suffer from a relative complexity, and usually need kinematic mechanisms and/or cams producing the outwards thrust of locking jaws on the wood, in an attempt to someway exploit the idea of the screw anchor. These fastening arrangements therefore are not satisfactory.  
         [0008]     A further aspect of the problem resides in that often known mechanisms for locking the box in the hole have only one thrust component that is radial to the hole, while an additional axial component would be advantageous to enable the box to be drawn inwardly of the hole and better adhere to the furniture surface.  
         [0009]     It is a general aim of the present invention to obviate the above mentioned drawbacks by providing a furniture hinge provided with a fastening mechanism directly acting inside the box hole in a simple and efficient manner and, if desired, with an axial pulling component.  
       SUMMARY OF THE INVENTION  
       [0010]     In view of the above aim, in accordance with the invention, a hinge for furniture has been devised which comprises a fastening box designed to be received with a central portion thereof into a hole in a piece of furniture and adapted to bear hinging, the box being provided with maneuverable members for fastening into the hole of the piece of furniture, characterized in that the fastening members comprise two axially rotatable pins disposed parallel to the fitting axis of the box in the hole and designed to be fitted into the hole together with said central portion of the box and at substantially diametrically opposite positions of the hole, each pin having at least one tab laterally projecting therefrom and an upper working lever enabling the pin to be rotated between a non-operating position of introduction and extraction of the box into and from the hole and a fastening operating position in which the tabs project outwardly of the box so as to interfere with the wall of the receiving hole and prevent the box from being drawn out of the hole itself. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     For better explaining the innovative principles of the present invention and the advantages it offers over the known art, a possible embodiment applying said principles will be described hereinafter by way of example, with the aid of the accompanying drawings. In the drawings:  
         [0012]      FIG. 1  is a partial diagrammatic plan view of a hinge made in accordance with the principles of the invention;  
         [0013]      FIG. 2  is a bottom view of the hinge seen in  FIG. 1 ;  
         [0014]      FIG. 3  shows an elevation side view of the hinge in  FIG. 1 ;  
         [0015]      FIGS. 4 and 5  show a bottom view and an elevation side view respectively, similar to those seen in  FIGS. 2 and 3  but with a different hinge embodiment, applying the principles of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     With reference to the drawings, an articulated hinge for furniture is diagrammatically shown in  FIG. 1  and generally denoted at  10 ; it comprises a box  11  for fastening to a door and a wing or flange  12  for fastening to a shoulder or side of a piece of furniture by means of known elements, herein not shown. The box and wing are hinged with each other by means of an articulation  13 . The articulation too, a four-bar linkage for example or the like, is of known type and will not be further described or shown, as it can be easily conceived by a person skilled in the art. Advantageously, the box is formed from drawn metal plate.  
         [0017]     Disposed on the box are two working levers  14 ,  15  pivotally mounted at  16  and  17  respectively, on either side of the drawn central hollow  21  receiving the articulation when the hinge is in a closed position. The central portion  21  formed of the drawn plate is designed to be received in a suitable hole in the piece of furniture. The levers advantageously have an L-shaped configuration comprising mirror images of each other to match the shape of the box around the central hollow and can rotate (through an angle of approximately 90°, for example) from the rest position (shown in the figure for the right lever) to a fastening position (shown in the figure for the left lever) in which they overlap side tabs of the box.  
         [0018]     As clearly shown in  FIGS. 2 and 3 , the pivot pins  16 ,  17  of the levers extend on the lower side of the box at either side of the drawn plate  21  so as to be disposed between the side wall of the drawn plate and the side wall of the hole (diagrammatically shown in chain line at  18  in  FIG. 2 ), generally a blind hole, which receives the box in the piece of furniture. Advantageously, the pins bears against the side wall of the drawn plate so that said wall constitutes a reaction surface to the radial fitting thrusts to which the pins will be submitted during use.  
         [0019]     The pins laterally have radial tabs  19 ,  20  that, when the corresponding lever is in the fastening position, project in the direction of the box-receiving hole  18 , as shown for pin  16  in  FIGS. 2 and 3 , so as to interfere with the hole walls. When the lever is in the rest position (shown for pin  17 ) the tabs are on the contrary within the circumference inscribing the box portion that is fitted into the hole in the piece of furniture, so that they do not interfere with the walls of said hole and enable insertion or extraction of the box.  
         [0020]     As clearly shown in  FIG. 3  (where the articulation has been removed for clarity), tabs  19 ,  20  can consist of a group of tabs distributed along the axial extension of the respective pin, so as to furnish several fitting points in the hole wall and improve gripping. The pin is substantially as long as the height of the box that is embedded into the hole in the piece of furniture.  
         [0021]     Advantageously, the tabs can be inclined to the pin axis in the circumferential direction of the pin (as clearly shown in  FIG. 3  for tabs  20 ), to produce, upon rotation of the pin to the fitting position, a force with an axial component in a direction towards the hole bottom, thereby improving adhesion of the box to the surface of the piece of furniture. In other words, the tabs are advantageously helically inclined like the parts of a thread.  
         [0022]     At this point it is apparent that the purposes of the invention are achieved. By rotating levers  14 ,  15 , the radial tabs  19 ,  20  penetrate into the hole walls and fasten the box without requiring other intermediate gripping means. If the lamellar sectors forming the tabs are suitably inclined, an important pulling force is also obtained which makes fastening of the box to the furniture door still steadier.  
         [0023]     To make fastening still safer the end portions of levers  14 ,  15  and the central upper surface of the box flange have been suitably designed so as to create a clip-like snap when the levers are in the closed position. For instance, as viewed from  FIG. 3 , the levers can have a flap  22  stepping over a relief  23  on the box and being snap-fitted thereon.  
         [0024]     To make fastening still steadier and prevent the box from rotating around the axis of hole  18 , ridges  25 ,  26  can be provided that project from under the box wings to be fitted into corresponding hollows in the wood.  
         [0025]     A variant is shown in  FIGS. 4 and 5  and generally identified by reference numeral  110 , said variant being suitable for fastening to thin walls. This embodiment is in particular useful for doors having a sandwich construction whose structure consists of two panels of relatively stiff and thin material (masonite, for example) spaced apart from each other by honeycomb-folded paperboard. The door of the above type externally appears like a normal door made of particle board, but practically it is internally hollow and all ironmongery such as handles and hinges must be fastened to the external thin panel (typically of a thickness of about 3 mm).  
         [0026]     For the sake of clarity, elements similar to those of the preceding embodiment are allocated the same reference numerals increased by 100. Therefore there is a hinge  110  comprising a box  111  and a wing  112  that are hinged on each other by an articulation  113 . Disposed on the box are two working levers  114 ,  115  integral with pins  116  and  117  on the two sides of the drawn central hollow  121  of the box.  
         [0027]     In the figures, lever  115  is shown in a rest position and lever  114 , rotated through about 90°, is shown in a fitted position.  
         [0028]     Pins  116 ,  117  extend on the lower side of the box on either side of the drawn plate  121  (advantageously laterally bearing against the drawn wall) to enter hole  118  receiving the box.  
         [0029]     As pins  16 ,  17  of the preceding embodiment, pins  116 ,  117  too have laterally projecting tabs for fitting into the hole. However, due to the small thickness of the wall of hole  118 , the tabs are positioned under the abutment surface of the box on the wall to a distance substantially corresponding to the wall thickness so that, when rotated to an operating position, they bear on the inner face of the hole wall (instead of bearing on the side wall of the hole), as clearly shown in  FIG. 5 . The tab length is also sufficient to enable a steady support extending away from the hole edge to a degree sufficient to avoid yielding of the relatively thin wall.  
         [0030]     The elongated tabs are advantageously of curved conformation (in mirror image relationship) so that in the non-operating position (shown for tab  120 ) they are contained within the circumference of the hole  118 , this enabling insertion or extraction of the box into or from the hole. These tabs are curved in mirror image relationship, in an opposite way relative to the rotation direction towards the fastening position, so as to enable gradual insertion against the fastening wall, thereby facilitating manual rotation of the levers.  
         [0031]     In this case therefore, fastening does not take place by interference on the inner side walls of the hole, but through clamping of the wall thickness between the fastening members  119 ,  120  and the bearing flange of the box.  
         [0032]     To facilitate rotation of the levers to the fitting position and improve fastening (also advantageously providing pulling of the box to the inside of the hole), it is suitable for the upper surfaces of tabs  119  and  120  to be slightly inclined in the rotation direction, on the face turned towards the inner face of the holed wall, as shown in  FIG. 5  for tab  120 .  
         [0033]     In the same manner as for the preceding embodiment, for snap-locking of the levers, flaps  122  can be provided at the lever ends for fitting on a relief  123  on the box. To make fastening still steadier and prevent the box from rotating, ridges  125 ,  126  can be provided that project from under the box wings to be fitted into corresponding hollows in the wood.  
         [0034]     Obviously, the above description of an embodiment applying the innovative principles of the present invention is taken by way of example only and therefore must not be considered as a limitation of the patent rights herein claimed. For instance, the exact shape of the box, wing and hinging, as well as the related sizes can vary depending on particular requirements. In addition, the hinge can be provided with any known arrangement for adjustment of position and inclination.