Abstract:
The present invention refers to a support frame ( 2 ) for wall-mounting at least one electrical apparatus, the frame ( 2 ) comprising:—a frame body ( 7 ) fixable to the wall and developing about a window ( 9 ) defining a mounting seat adapted for receiving and holding said at least one electrical apparatus; and—fixing means ( 12 ) for removably fixing a cover plate ( 3 ) to the support frame ( 2 ). The support frame ( 2 ) is characterised in that the fixing means includes at least one fixing channel ( 12 ) exhibiting an end jointed to an opening ( 13 ) obtained in the frame body ( 7 ), the fixing channel ( 12 ) being such as to be capable of receiving, through the opening ( 13 ), a corresponding fixing tongue ( 4 ), provided in the cover plate ( 3 ), the fixing channel ( 12 ) including therein relief means ( 14 ) that can face a surface ( 31 ) of the tongue ( 4 ) and pushing means ( 20, 21 ) adapted for acting on the fixing tongue ( 4 ) for engaging pressure-wise said surface ( 31 ) of the tongue against said relief means ( 14 ) of the channel ( 12 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a national filing in the U.S. Patent &amp; Trademark Office of PCT/IT2006/000216 filed Apr. 3, 2006, and claims priority of Italy Patent Application No. RM2005A000162 filed Apr. 7, 2005, both of which applications are incorporated herein in their entireties by this reference. 
     FIELD OF THE INVENTION 
     The present invention relates to the technical field of electrical systems for homes and offices, and more in particular, it relates to a support frame and a composite structure, or group of parts, including such frame, for wall-mounting one or more electrical apparatuses. 
     BACKGROUND OF THE INVENTION 
     For the purposes of the present description, by electrical apparatus we mean, in general, any means or  electrical device generally being part of electrical installations in civil buildings and the like and usually intended to be mounted, for example built in, onto walls of such buildings. 
     This definition therefore includes, not limitingly, switches, electrical power sockets, sockets for data networks, TV sockets, telephone sockets, buttons, commutators, deviators, electrical adjustment devices in general, connectors, thermostats, timers, fuse holders, alarms/buzzers, emergency lights, for example removable, signalling lights, for example step markers, displays, for example LCD and the like. 
     As known, many of the aforementioned electrical apparatuses are usually installed on a wall using composite mounting structures, or groups of parts, generally including:
         a box intended to be built into the wall;   an apparatus-carrying mounting frame (or support frame) fixable to the box and comprising a frame body developing about an opening defining a mounting seat suitable for receiving and holding one or more electrical apparatuses; and   a cover plate that can be removably fixed to the frame and provided with an opening for allowing a user to gain access, visually or manually, the electrical apparatuses installed on the support frame.       

     In the prior art, several systems are known for removably fixing a cover plate to a support frame. For example, screw fixing systems are known, which despite being sturdy are almost outdated since they are unaesthetic. 
     Several snap-wise fixing systems between plate and frame also belong to the prior art. For example, it is known to provide a plurality of tongues on an edge portion of the plate intended for facing the support frame, adapted for engaging snap-wise with respective protruding edges provided on the external perimeter of the support frame. 
     The snap-wise fixing systems of the prior art, despite being highly used, in some cases exhibit a problem of fragility of the snap-wise fixing elements, in other cases are not such as to prevent an accidental detachment of the plate from the support frame. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a support frame which should be provided with an innovative fixing system to a cover plate and which should allow overcoming the disadvantages described above with reference to the prior art. 
     Such object is achieved by a support frame as defined in the annexed first claim in the most general form thereof and in the dependent claims in some particular embodiments. 
     The object of the present invention also is a group of parts as defined in the annexed claim  10 . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention shall be better understood from the following detailed description of a particularly preferred embodiment thereof, made by way of a non-limiting example with reference to the annexed drawings, wherein: 
         FIG. 1  shows a side view of a particularly preferred embodiment of a plate-frame group according to the present invention; 
         FIG. 2  shows a front plane view of the support frame belonging to the plate-frame group shown in  FIG. 1 ; 
         FIG. 3  shows an axonometric section view of the support frame of  FIG. 2 ; 
         FIG. 4  shows an axonometric view of a sheet element associable to the support frame of  FIG. 2 ; 
         FIGS. 5   a  and  5   b  show a partial section view of the plate-frame group of  FIG. 1  in two different operating positions between the covering plate and the support frame; and 
         FIG. 6  shows an enlarged detail of the cover plate of the plate-frame group of  FIG. 1 . 
     
    
    
     In the figures, like or similar elements shall be indicated by the same reference numerals. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows a side view of a particularly preferred embodiment of a plate-frame group of parts, globally indicated with reference numeral  1 , according to the present invention. 
     The plate-frame group of parts includes a support frame  2  and a cover plate  3  removably fixable to the support frame  2 . For fixing to the support frame  2 , fixing elements shaped as tongues  4  are provided on face  5  of the cover plate  2  facing the support frame  3 . Preferably, the cover plate  3  includes four fixing tongues  4 , of which only two are visible in  FIG. 1 . 
     As is known to the man skilled in the art, the role of such a cover plate  3  is both that of ensuring a minimal protection for the electrical apparatuses, for example from dust, and of that preventing dangerous access (for example, through pointed objects) to the electrically conducting parts of the electrical apparatuses. Another fundamental task assigned to the cover plates, moreover, is that of hiding any imperfections produced for example by the presence of the mounting frame and box which, rather than having an aesthetic value, have a functional value that is difficult to combine with aesthetic requirements or standards. 
     The cover plate  3  is substantially shaped as a frame and is provided with a central opening, not visible in  FIG. 1 , for allowing a user to access, visually or manually, the electrical apparatuses installed on the support frame  2 . 
     The support frame  2  is in turn fixable to the wall, for example by a pair of screws  6  adapted for holding the support frame  2  anchored to a box flush mounted in the wall, not shown in the figures. 
     As is better seen in the plan view shown in  FIG. 2 , the support frame  2  includes a frame body  7 , preferably made of an insulating material and approximately having the shape of a substantially plate-shaped frame, as a non-limiting example, with quadrangular plan with rounded corners. By way of an example only, the frame body of frame  7  is shown with a substantially rectangular shape. 
     In the example, a pair of through holes  8 , preferably slotted, is provided in the frame body  7  of frame  2 . The through holes  8  are such as to be crossed by respective screws  6  in order to fix the support frame  2  to the box flush mounted in the wall. 
     The frame body  7  of the support frame  2  develops about a mounting window  9 , defining a mounting seat adapted for receiving or holding one or more electrical apparatuses, not shown in the figures. Two opposed walls  10  of the support frame  2  face the mounting window  9 , each including a plurality of hooking elements  11  that project from walls  10  towards the mounting window  9 . These hooking elements  11  are such as to cooperate with corresponding hooking elements provided on two opposite sides of the electrical apparatuses to be hooked to the support frame  2 . Preferably, such hooking elements  11  allow obtaining a joint-wise and a snap-wise hooking of the electrical apparatuses to the support frame  2 . 
     The support frame  2  further includes fixing means  12  for removably fixing the cover plate  3  to the support frame. 
     Advantageously, such fixing means  12  comprises fixing channels  12  adapted for receiving respective fixing tongues  4  of the cover plate  3 . Preferably but non-limiting, the number of fixing channels  12  provided in the support frame  2  is equal to four. 
     A fixing channel  12  is better visible in  FIG. 3 , which shows a section view along axes x-x and y-y of the support frame  2  of  FIG. 2 . In particular, a sectioned fixing channel  12  is visible in such figure. 
     The fixing channel  12  exhibits an end  13  jointed to an opening  13  obtained in the frame body  7  of the support frame  2 , so as to receive therein, through opening  13 , a fixing tongue  4  of the cover plate  3 . Preferably, as shown in  FIG. 3 , the edge of the frame body  7  delimiting such opening  13  is chamfered so as to favour the introduction of the fixing tongue  4  into the fixing channel  12 . 
     Advantageously, the fixing channel  12  includes relief means  14  therein. Preferably, such relief means includes at least one protruding edge  14 , for example with triangular profile, projecting from a wall  15  of the channel inwards of channel  12 . 
     Advantageously, the fixing channel  12  further includes pushing means  20  opposite the relief means  14 . In  FIG. 3 , for clarity, the pushing means  20  is shown separate from the fixing channel  12 . Such pushing means  20 ,  21  is such as to exert a pressure against the fixing tongue  4  of the cover plate  3 , so that a surface of such fixing tongue  4  engages pressure-wise against the protruding edge  14  when the cover plate  3  is fixed to the support frame  2 . 
     In a particularly advantageous embodiment, the pushing means  20 ,  21  includes a tooth  21  flexible and inclined relative to the direction of extension of the fixing channel  12 . Such tooth has an end  22  protruding inwards of channel  12  and an opposite end  23  constrained to the wall of channel  16  opposite the wall of channel  15  including the relief means  14 . Preferably, end  22  of tooth  21  protruding inwards of channel  12  is a curved end. 
     In a particularly preferred embodiment, the flexible tooth  21  is a metal tooth being part of a sheet element  20  insertable, preferably joint-wise and snap-wise, in a notch  25  adjacent the fixing channel  12 . 
     The sheet element  20  is shown in a partial view in  FIG. 3  and in an overall and more detailed view in  FIG. 4 . Such sheet element  20  preferably is a metal sheet including a frame base portion  20   a ,  20   b ,  20   c ,  20   d  intended for being inserted in notch  25 . The frame base portion  20   a ,  20   b ,  20   c ,  20   d  consists of four walls substantially parallel by twos. One of such walls, that is, wall  20   a , is jointed to the flexible tooth  22 . Wall  20   c  opposite wall  20   a , in the introduction of sheet  20  into notch  25 , is intended for passing over a projecting element  26  which protrudes from the wall of channel  16 , for locking snap-wise sheet  20  to the support frame  2 . Preferably, wall  20   c  of sheet  20  exhibits a wall portion  27  slightly inclined relative to the plane on which the base portion  20   a ,  20   b ,  20   c ,  20   d  of sheet  20  lays, in order to allow the projecting element  26  to be passed over by wall  20   c  in the snap-wise introduction of sheet  20  into notch  25 . 
     Preferably, the other two walls  20   b ,  20   d  of the sheet element  20  exhibit a notched outside edge advantageously adapted for allowing the forced and irreversible mounting of sheet  20  into notch  25 . 
       FIGS. 5   a  and  5   b  show two partial views of the cover plate  3  and of the support frame  2  in two different operating positions. In such figures, the cover plate  3  advantageously includes a fixing tongue  4 , provided with a first surface  31  at least partly shaped as a saw tooth and a second surface  30  substantially smooth and opposite the first shaped surface  31 . 
     The first surface  31 , thanks to the pushing action exerted by tooth  21  is such as to engage pressure-wise against the protruding edge  14  provided in the fixing channel  12  for holding the cover plate  3  constrained to the support frame  2 . 
     The second surface  30 , during the introduction of the fixing tongue  4  in the fixing channel  12  is such as to interfere by sliding against the flexible tooth  21 . After the introduction, the flexible tooth  21  is such as to exert a pushing action on such surface  30  which determines a slight bending of the fixing tongue  4 . Thanks to such bending, not visible in the figures, the shaped surface  31  of the fixing tongue  4  is held pressure-wise against the protruding edge  14  provided inside the fixing channel  12 . 
     In a particularly preferred embodiment, as shown in  FIG. 6 , the fixing tongue  4  has a substantially plate-like shape and is provided with relief thickening elements  32 ,  33  obtained on the surface of tongue  30  intended for cooperating with the flexible tooth  21 . In the practice, the flexible tooth  21  is such as to apply a pushing force on such elements  32 ,  33 , thus allowing a constant pressure to be maintained on the fixing tongue  4 , in order to advantageously maintain the disconnection force of the cover plate  3  from the support frame  2  constant over time, irrespective of the number of manoeuvres carried out. 
     In the particularly preferred embodiment of  FIG. 6 , the fixing tongue is further provided with a chamfered end portion  34  in order to facilitate the centring and the introduction of the fixing tongue  4  into the fixing channel  12  of the support frame  2 . 
     Based on the description above, it is therefore possible to understand how a support frame  2  according to the present invention allows making the application of a cover plate  3  thereto particularly easy. 
     It should be noted that the provision of pushing means into the fixing channel allows obtaining a reliable fixing of the cover plate  3  to the support frame  2  without imposing an excessive stress of the structural parts that ensure the fixing of the cover plate  3  to the support frame  2 . 
     Advantageously, the provision on the fixing tongue  4  of a surface  31  shaped as a saw tooth and adapted for cooperating with a relief element  14  provided in the fixing channel  12  allows aligning the cover plate  3  parallel to the fixing wall also when, for example due a non-prefect installation of the flush mounted box into the wall, the frame body  7  of the support frame  2  is not perfectly aligned with such fixing wall. 
     Moreover, it should be noted that, advantageously, the provision of a pushing tooth against a curved surface allows such tooth not to jib against the fixing tongue  4  during the removal of the cover plate  3  from the support frame  4 . 
     Of course, the man skilled in the art can mane numerous modifications and variations to the support frame described above, in order to satisfy contingent and specific requirements, all of which are in any case covered by the scope of protection of the invention as defined by the following claims.