Patent Publication Number: US-7905524-B2

Title: Door with a pressure opening

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a door, in particular for furniture, of the type provided with a pressure opening system. 
     2. State of the Prior Art 
     Applications are known in which use of doors without a handle is preferred. In this case often suitable ratchets are mounted that are known as “pull-push” devices and that, by pushing the door against the ledge, alternatively retain the door in a closed position or release it to enable opening of same. 
     Selection of these mechanisms can be suggested both for aesthetic reasons (possibility of making doors without handles) and for practical reasons such as the possibility of opening the door by mere pressure without needing to have the hands free, for example. The last mentioned feature is for example convenient when heavy articles lifting of which must be made with both hands are to be stowed in a piece of furniture; should a traditional closing system be used, it would be necessary to lay the object down in order to open the door, lift the object again and put it into the piece of furniture; on the contrary, if the door is provided with a pull-push mechanism it is sufficient to exert pressure on the door, with an elbow for example, to enable release of the opening mechanism. Unfortunately, in traditional doors provided with pull-push mechanisms the release spring with which the mechanism is provided moves the door only few millimeters from the closed position and full opening is not at all ensured. In addition, if traditional furniture hinges are used that are provided with a spring which, over at least one given angle, acts to keep the door closed, the hinge and the opening spring of the pull-push mechanism produce opposite forces and opening of the door must always be completed through manual pulling of the door itself. Particularly in the case of doors with an edge that is substantially flush with the ledge, displacement of few millimeters towards the open condition which is caused by release of the pull-push device can also be insufficient to show the door edge to such an extent that gripping of same with one hand and full opening of the door is enabled. 
     In addition to the disadvantage of not succeeding in fully opening the door, there is also the opposite disadvantage consisting in that release of the pull-push mechanism may pass unnoticed and the door may remain only set ajar and not closed. 
     It is a general aim of the present invention to obviate the above mentioned drawbacks by providing a door having a pull-push mechanism of cheap and strong manufacture and with a reliable opening movement. 
     SUMMARY OF THE INVENTION 
     In view of the above aim, in accordance with the invention a door with a pressure opening has been conceived which comprises articulated hinges for hinging to the piece of furniture and a “pull-push” closing device to be released by manual thrust of the door towards the inside, characterized in that at least one articulated hinge comprises a spring acting for its movement from the closed position to the open position, in the way of pushing the door to the open position against the retaining action in the closed position performed by the pull-push device in order to help in opening the door upon release of the pull-push device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1  is a top view of a door made in accordance with the invention; 
         FIG. 2  is a more detailed side view of a particular of the door in  FIG. 1 ; 
         FIG. 3  is a sectional view of a particular of the hinge for the door in accordance with the invention; 
         FIG. 4  is a possible alternative embodiment of the hinge in  FIG. 3 ; 
         FIG. 5  is a sectional view of the hinge of  FIG. 3  in a closed position; 
         FIG. 6  is a sectional view of the hinge of  FIG. 4  in a closed position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the drawings, shown in  FIG. 1  is a door for furniture, generally denoted at  10 , with a pressure opening. The door is hinged to the piece of furniture to be movable between a closed position and an open position by means of articulated hinges  12  and is also provided with a “pull-push” closing device  13  of known type, with release by manual thrust of the door towards the inside. As better shown in  FIG. 2 , the device  13  comprises one portion that is fixed to the piece of furniture and is provided with a coupling element  14  to be fitted into a complementary hooking element  15  fastened to the door. According to known operation of these mechanisms, by pushing the door towards the furniture ledge, alternatively the mechanism hooks and unhooks the coupling element  14  to and from the hooking element  15  (in  FIG. 2  the hooked position is shown in chain line). This mechanism, usually provided with a release spring  16 , is well known to a person skilled in the art and will not be further described or shown, as it can be easily imagined. 
     As shown still in  FIG. 1 , hinges  12  are advantageously of the quadrilateral type comprising a wing  17  for fastening to the piece of furniture and a bowl  18  for fastening to the inside of the door. 
     As viewed from  FIGS. 3 and 5 , the quadrilateral hinge comprises an outer connecting rod  19  and a more internal connecting rod  20  the ends  21 ,  22 , and  23 ,  24  of which are pivotally mounted to the wing and the bowl, respectively. 
     At least one of the hinges  12  comprises a spring  25  acting for its movement from the closed position to the open position in the way of pushing the door to the open position against the retaining action in the closed position performed by the pull-push device. In this manner, upon release of the pull-push device the hinge helps in opening the door in a substantial manner. 
     In the preferred embodiment described, the internal connecting rod  20  has an extension  26  on which an arm  27  of the spring exerts pressure starting from the closed position, so as to rotate the connecting rod in the opening direction of the hinge. The spring has a second feedback arm  28  exerting pressure on the inside of the wing. 
     Advantageously, the spring is spiral wound around a pin (that can be the articulation pin of the connecting rod  19  on the wing) and has an arm  27  (that can be a U-bent central region of the double-spiral spring) exerting pressure on the projection starting from the closed position to at least an important stretch of the opening stroke. 
     In the embodiment in  FIG. 3 , towards the end of the opening stroke the spring does no longer exert pressure on the extension  26  and the hinge becomes neutral. This is apparent from  FIG. 3  itself. 
     Still advantageously, the extension of the internal connecting rod on which the spring exerts pressure is formed with a tab that is cut out and bent outwards relative to the portion  29  of the connecting rod  20  that is wound up around its pivoting point  22  on the wing. 
     Shown in  FIGS. 4 and 6  is an alternative embodiment according to which the opening thrust substantially goes on until the end of the opening stroke of the hinge. In order to enable the spring to go on bearing against the extension  26 , the connecting-rod portion  29  that is wound around the pivoting point on the wing comprises a cut-away region  30  so that it does not interfere with the spring itself. The cut-away region is advantageously obtained from the same cut-out forming the extension  26 . The spring is also wound on a pin  31  that is located more towards the back of the wing relative to pin  21 . This technique promotes the action of the spring towards the position close to complete opening of the hinge. 
     At this point it is apparent that the intended purposes have been achieved. Opening of the door in accordance with the invention takes place always and in any case upon release of the pull-push device by virtue of the opening thrust of the hinge. The door costs are not however increased, since separated thrust devices are not used. 
     Obviously, the above description of an embodiment applying the innovative principles of the present invention is given by way of example only and therefore must not be considered as a limitation of the scope of the patent rights herein claimed.