Patent Publication Number: US-8117794-B2

Title: Two part grille with interlocking connections for assembly in doors or the like

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 12/068,984, filed Feb. 14, 2008, now pending. The patent application identified above is incorporated by reference in its entirety to provide continuity of disclosure. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to a two part grille with interlocking connections on a backside of the parts for assembling a grille in an opening in a door or the like with the benefit of no screws or the like necessary. 
     2. Description of Prior Art 
     Natural ventilation generally means that sufficient fresh air may be channeled into indoor room to reach the purpose of dissipating the heat accumulated in the building or diluting and dispelling the harmful or bad material from the air. 
     For this purpose of ventilation mentioned above, metal and wood grilles for openings in doors and windows are well known. However metal grilles do not have good weathering qualities, being subject to rusting and pealing paint. Likewise wooden grilles need periodic painting and are often subject to warping of its components when exposed to moisture. 
     BRIEF SUMMARY OF THE INVENTION 
     The current invention relates to a two part plastic grille made of opaque plastics which include preformed mortise and tenon connectors on a backside of parts to lock them together when they are assembled on opposite sides of an opening in a door or wall. 
     This invention is directed to a grill provided with one or more screens or air filters supported within the grille for allowing natural ventilation through doors and or walls, composed of two parts, with these parts provided with interlocking connections allowing the parts to be fitted on opposite sides of an opening in a wall or door and interlocked by engagement of the mortise and tenon elements on a backside of the two parts, to interlock the parts together so that no screws are necessary. 
     This grill includes two parts, each having a frame defining a perimeter of each grille part, each part having a series of parallel, horizontal vanes evenly spaced between lateral uprights of its frame with a plurality of cooperation mortise and tenon elements disposed on the back side of each frame whereby two parts are interlocked together by a mortise and tenon joint when these elements are engaged. Further spaces, having a mortise element on one end and tenon element on the other, can be provided between the interlocking mortise and tenon elements to accommodate walls or doors of differing thicknesses. 
     The design of the two part plastic grille is very convenient in retrofitting openings in doors or walls with a grille to provide natural circulation through the door or wall to improve the air quality in a space, such as a room, by enabling the ingress of fresh air, to, for example, dissipate heat or dilute harmful vapors in such a room. 
     Because of its simple construction, economical price and ease of installation, the grille of the current invention provides a grating for openings made in doors or walls to facilitate natural air circulation that limits the ingress of insects, birds and the like from passing through the opening. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view showing the grille of the present invention fitted into an opening in a wall as grating for ventilation; 
         FIG. 2  is another schematic view showing the grille of the present invention fitted into an opening in a door as grating for ventilation; 
         FIG. 3  is an exploded view of the first embodiment of the two parts of the grille of the present invention illustrating the backside of one of the parts having tenon elements and mortise elements thereon; in addition,  FIG. 3  further shows a spacer that can be used to extent the tenon elements and mortise elements to accommodated differing thicknesses in walls or doors; 
         FIG. 4  is a partial assembling view of the first embodiment shown in  FIG. 3 ; in addition,  FIG. 4  further has an expanded view cut from the partial assembling view to illustrate the backside of one of the parts having protruding poles formed thereon and a screen or air filter supported on one of the parts through the corresponding meshes of the screen or air filter are properly sleeved on the protruding poles of said part; 
         FIG. 5  is a sectional view of an opening in a door having the novel grille assembled therein; 
         FIG. 6  is a sectional view of a wall opening having the novel grille assembled therein and showing the use of spacers to accommodate the increased thickness of the wall; 
         FIG. 7  is an exploded view of the second embodiment of the two parts of the grille of the present invention; 
         FIG. 8  is a partial assembling view of the second embodiment shown in  FIG. 7 ; in addition,  FIG. 8  further has an expanded view cut from the partial assembling view to illustrate a screen or air filter having a reinforced sealing-edge arranged about the periphery and supported on one of the parts through the reinforced sealing-edge of the screen or filter tightly in contact with the protruding poles of said part; 
         FIG. 9  is an exploded view of the third embodiment of the two parts of the grille of the present invention illustrating the backside of one of the parts having a guide channel formed thereon for matching with a looped packing securely inserted therein; and 
         FIG. 10  is a partially expanded sectional view of the third embodiment of the present invention to illustrate a screen or air filter supported on one of the parts through the periphery of the screen or filter tightly pressed into the guide channel of one of the parts with the looped packing shown in  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIGS. 1 to 6 , the present invention is disclosed as a two part grille  10  having a configuration which not only allows its parts to be fitted on opposite sides of an opening in a wall  80  or a door  90  locked together by a mortise and tenon joint so that no screws are necessary, but also allows one or more screens or air filters  20  to be supported within the grille  10 . 
     The two parts of the novel grille  10  of the present invention are constructed of a molded opaque plastic composition, chosen for its superior weather resistance and distortion resistance. Each part includes a frame  11  defining a perimeter of that part of the grille  10 , with a series of parallel, horizontal vanes  12  evenly spaced between lateral uprights of its frame  11  which forms a grating. 
     On a back side  13  of each frame  11  of the grille  10  has a plurality of tenon elements  15  and mortise elements  17 . It is preferred that these elements alternate between tenon elements  15  and mortise elements  17  on back side  13  of each frame  11 . 
     Further these elements  15  or  17  of each frame  11  are arranged so that the tenon elements  15  will be in registry with the mortise elements  17  and vise verse so that when the back side  13  of each frame  11  is placed on opposite sides of an opening in a wall  80  or a door  90  and these elements  15  or  17  are mutually engaged, the tenon elements  15  (or the mortise elements  17 ) on each frame  11  will interlock with the mortise elements  17  (or the tenon elements  15 ) on the other frame  11 . 
     For installation of the screen(s) or air filter(s)  20  supported between the two opposite frame  11  of the grille  10 , on the back side  13  of each frame  11  of the grille  10 , in addition to tenon elements  15  and mortise elements  17  formed thereon, further has a plurality of protruding poles  19  as shown in  FIG. 3  or  FIG. 7  for positioning the screen(s) or air filter(s)  20  in proper location, or, alternatively, has a guide channel  14  formed around the back side  13  of the frame  11  as shown in  FIG. 9  for matching with a looped packing  40  to be inserted into the guide channel  14  to position and fasten the screen(s) or air filter(s)  20  in proper location. 
     As shown in  FIG. 7 , the screen or air filter  20  may selectively have a reinforced sealing-edge  27  arranged about its periphery. As shown in  FIGS. 7 and 8 , this kind of screen or air filter  20  may be positioned and installed on each frame  11  of the grille  10 , after the whole reinforced sealing-edge  27  of the screen or air filter  20  has been tightly in contact with the whole protruding poles  19  of the frame  11 . As illustrated in  FIG. 5  or  FIG. 6 , the result is that this kind of screen or air filter  20  may be supported within the grille  10 . 
     As shown in  FIGS. 3 and 4 , if the screen or air filter  20  does not provide with a reinforced sealing-edge  27  arranged about its periphery, this kind of screen or air filter  20  may be still positioned and installed on each frame  11  of the grille  10 , after by having the corresponding meshes  21  of the screen or air filter  20  properly sleeved on each protruding poles  19  of said frame  11 . As illustrated in  FIG. 5  or  FIG. 6 , the result is that this kind of screen or air filter  20  may be supported within the grille  10 . 
     As shown in  FIGS. 9 and 10 , if the frame  11  is provided with a guide channel  14  on the back side  13  and the screen or air filter  20  is not provided with a reinforced sealing-edge  27  arranged about its periphery, this kind of screen or air filter  20  may be still positioned and installed on the frame  11  of the grille  10  after the periphery of the screen or filter  20  is tightly pressed into the guide channel  14  of the frame  11  due to a looped packing  40  securely inserted into the guide channel  14  of said frame  11 . As illustrated in  FIG. 6 , the result is that this kind of screen or air filter  20  may be supported within the grille  10 . 
     Normally, the perimeter of said frame  11  for each part of grille  10  of the present invention is square or rectangular. However these frames can be have circular, elliptic, or semi-circular shapes or other kinds of geometric shapes without departing from the spirit of the invention. 
     In  FIGS. 3 and 6 , an intermediate spacer  30  is illustrated with a first tenon element  35  at one end and a second tenon element  37  at the other end. It can be appreciated that the spacers  30  can be used between a tenon element  15  (or a mortise elements  17 ) on one part of said frame  11  and a mortise elements  17  (or a tenon elements  15 ) on the other of said frame  11 , as illustrated in  FIGS. 3 and 6 . 
     Accordingly, the spacer  30  is an auxiliary component selectively used to accommodate differing thickness of a wall  80  or the like which has a greater thickness than a door  90 . Further using spacers  30  of differing lengths expands the adaptability of the novel invention. 
     In  FIGS. 2 and 5 , the grille  10  having one or more screens or air filters  20  supported inside if fitted into an opening in a door  90  where it can be seen the frames  11  of each part of the grille  10  forms a flange around the opening the door  90 . Like the installation shown for the wall  80 , the two parts of the grille  10  are locked together by the tenon elements  15  and the mortise elements  17  which are formed so that the tenon elements  15  lock into the mortise element  17  when they come together. Sometimes such cooperating tenon elements  15  and mortise elements  17  that lock when they engage are referred to as snap-on connections. 
     As can be seen in  FIG. 5  the spacers  30  are not necessary to assemble the grille on a door  90  because the thickness of the door  90  does not require them, compared to the use of these spacers  30  for the installation in the wall  80  as showing  FIG. 6 . 
     In this invention it should be appreciated that the tenon elements  15  and the mortise elements  17  are specially designed so that the tenon elements  15  on one part of said frame  11 , regardless of the degree the tenon elements  15  moves into the mortise element  17 , will interlock with the mortise elements  17  on the other of said frame  11 . As a result depending on the length of the tenon element  15 , the novel grille  10  can easily accommodate openings of differing thicknesses because of this incremental locking feature as the two parts move toward one another with these elements engaged. Further, longer tenon elements  15  on one part of said frame  11  may be used to accommodate differing thicknesses in the openings.