Abstract:
A low cost prefabricated wall panel comprised by an internal metallic grid structure incorporating a plurality of sandwiched cardboard strips, two cardboard sheet covers, a fire proof substance applied to both cardboard sheet covers and to the wall panel edges and means for linking other panels. The internal cardboard core acts as a sound and thermal insulator, which helps to lower the energy consumption used for cooling and heating inside the construction.

Description:
A. FIELD OF THE INVENTION  
       [0001]     The present invention is related to prefabricated walls and more particularly to a prefabricated wall panel comprised by sandwiched cardboard supported by an iron structure.  
       B. DESCRIPTION OF THE RELATED ART  
       [0002]     There are well known the prefabricated walls comprised by a plurality of superposed flat panels.  
         [0003]     Many of the panels forming the prefabricated walls are made of wood or a combination of other materials such as polyurethane, plastic, etc. for providing a number of desirable characteristics such as convenient sound and/or temperature insulation properties. Furthermore, a fire proof or water proof covering may be included in order to comply with local regulations.  
         [0004]     A space divider is disclosed in the U.S. Pat. No. 4,706,422 which comprises two perforated walls with two opposite edges inturned to mate to form cavities to hold acoustic bats therebetween and including intersecting stiffeners and means to hold a pull-over fabric cover and including apertures in end closures to engage forming and locating means for the panels and for attaching shelving.  
         [0005]     The space divider disclosed by the Pat. No. 4,706 422, as well as many of the wall panels currently in the market, have a relatively complex internal structure which use expensive materials and need qualified workmanship for its assembly, which raises the total cost of the wall panel.  
         [0006]     Such kinds of wall panels, given its high cost, are more suited for residential and commercial use, and its acquisition by low resources individuals or entities is very difficult.  
         [0007]     In countries under development or undeveloped, it is very usual that in zones having high poverty rates, the houses are built of inadequate, unsuitable and dangerous materials, such as cardboard, iron sheets and waste material. Therefore, if it weren&#39;t for its high cost the use of prefabricated wall panels for building or modifying low resources homes would be ideal since they are very durable, resistant and are economically and easily installed.  
         [0008]     Therefore, it would be highly desirable to have a low cost prefabricated wall panel which may be acquired by low resources families in order to build or modify their houses or used by low budget constructions.  
         [0009]     In view of the above referred need, applicant developed a fire proof prefabricated wall panel comprised by sandwiched cardboard supported by an iron structure only.  
         [0010]     The prefabricated wall panel is specifically comprised by an internal metallic grid structure incorporating a plurality of sandwiched cardboard strips, two cardboard sheet covers, a fire proof substance applied to both cardboard sheet covers and to the wall panel edges and means for linking other panels.  
         [0011]     Thanks to the use of the above described materials, applicant&#39;s prefabricated wall panel is fire proof, very light, has a high resistance and a very low cost, ideal for build or modify low resources homes or budget constructions.  
         [0012]     Furthermore, the internal cardboard core acts as a sound and thermal insulator, which helps to lower the energy consumption used for cooling and heating inside the construction.  
         [0013]     Finally, the external fire proof covering provides security in its use and weather or humidity resistance, thus prolonging the useful life of the wall panel.  
       SUMMARY OF THE INVENTION  
       [0014]     It is therefore a main object of the present invention to provide a low cost prefabricated wall panel.  
         [0015]     It is also a main object of the present invention to provide a prefabricated wall panel having the above disclosed nature comprising an internal metallic grid structure incorporating a plurality of sandwiched cardboard strips, two cardboard sheet covers, a fire proof substance applied to both cardboard sheet covers and to the wall panel edges and means for linking other panels.  
         [0016]     It is still another main object of the present invention to provide a prefabricated wall panel having the above disclosed nature, which is fire proof, very light, has a high resistance and a very low cost, ideal for build or modify low resources homes or budget constructions.  
         [0017]     It is another object of the present invention to provide a prefabricated wall panel having the above disclosed nature in which, the internal cardboard core acts as a sound and thermal insulator, which helps to lower the energy consumption used for cooling and heating inside the construction.  
         [0018]     It is a further object of the present invention to provide a prefabricated wall panel having the above disclosed nature in which the external fire proof covering provides security in its use and weather or humidity resistance, thus prolonging the useful life of the wall panel.  
         [0019]     These and other objects and advantages of the prefabricated wall panel of the present invention will become apparent to those persons having an ordinary skill in the art, from the following detailed description of the embodiments of the invention which will be made with reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1  is a perspective frontal view of a portion of the prefabricated wall panel in accordance with the present invention having one of its cardboard sheets covers removed showing its internal structure.  
         [0021]      FIG. 2  is a view of a lateral cut of the prefabricated wall panel in accordance with the present invention showing its internal structure. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     The prefabricated wall panel will now be described making reference to a preferred embodiment thereof, which is shown in the accompanying drawings wherein the same signs and numbers refer to the same parts of the shown figure, wherein the prefabricated wall panel of the present invention comprising: 
        an internal metallic grid structure having: 
            a plurality of metallic galvanized horizontal rods  1 ,  1 ′ having a square shaped cross section and a size of ½″× 1/2 ″;     a plurality of metallic galvanized vertical rods  2 ,  2 ′ having a square shaped cross section and a size of ½″×½″, intersecting the plurality of horizontal rods  1 ,  1 ′ and joined thereof by welding at the intersecting points  3 , forming a grid having a plurality of quadrangular cells  4 ;    
            a solid cardboard quadrangular body core formed by a plurality of sandwiched cardboard strips, all joined by means of an adherent substance, said quadrangular body core having a first  5  and a second  6  longitudinal edges, a first and a second lateral edge (not shown), and a superior and an inferior edge  7 ,  8  and composed by: 
            a plurality of quadrangular sections  9 , each one lodged inside a cell  4 ; and     a first  10  and a second  11  layer surrounding the plurality of quadrangular sections  9  and the metallic structure;     a first “F” and a second “S” external quadrangular cardboard cover, covering the first  10  and second  11  layer respectively and joined thereof by means of an adherent substance, each external quadrangular cardboard cover “F”, “S”formed by a plurality of sandwiched cardboard sheets joined together by means of an adherent substance;    
            a fire proof and water resistant layer surrounding the entire wall panel having a textured finish.        
 
         [0031]     In a preferred embodiment, the panel width is 2″ and its total area is 0.90×1.25 mts., furthermore, in said preferred embodiment, there are two vertical  13  and horizontal  14  rods, forming nine cells per panel.  
         [0032]     The ends of each vertical  13  and horizontal  14  rod project out of the wall panel and serve as means for linking the wall panel to other wall panels or directly to other structure such as a headframe by means of anchors or welding for example.  
         [0033]     The fire proof and water resistant layer  12  provides additional rigidity to the panel and at the same time gives a pleasant texture at the touch and finish to the panel.  
         [0034]     Normally, the panels are installed between headframes having vertical rodding in such way that the ends of the vertical rods  14  projecting out of the panel, are linked to the headframe vertical rodding.  
         [0035]     Once the panels are linked to the headframes, a cover of gypsum or another substance may be applied to the panels, headframes and in between the panels and headframes in order to give the appearance of a continuous wall to all the linked panels and finally a cover of painting may be applied in order to improve the appearance of the linked panels and headframes which appear to be a continuous wall.  
         [0036]     As previously described, the horizontal  1 ,  1 ′ rods intersect vertical  2 ,  2 ′ rods and are welded at the intersecting points  3 . In a preferred embodiment, each horizontal rod is located over each vertical rod and welded at the intersecting points  3  or vice versa, however in other embodiments, the metallic structure may be constructed in one piece, and in such embodiment, the horizontal and vertical rods intersect to each other at the same plane.  
         [0037]     Although it was described that the horizontal  1 ,  1 ′ and vertical  2 ,  2 ′ rods project out of the wall panel and serve as means for linking the wall panel to other wall panels or structures, it may be possible that the horizontal  1 ,  1 ′ and vertical  2 ,  2 ′ rods remain inside the wall panel, and in such way, the linking means may comprise a clamp system, rails or any other suitable linking means which may result adequate for the characteristics of the construction in which the wall panels will be installed. Also, depending of such specific needs, the core body of the wall panel may be made of paper, corrugated cardboard or any other suitable package material.  
         [0038]     Furthermore, although it was described that the prefabricated wall panel of the present invention may be used mainly for the assembly of wall structures, it may be possible to use it for assembling roof structures such as roof subframes.  
         [0039]     The following are test examples that show the resistance of the prefabricated wall panel of the present invention under stress.  
       EXAMPLE 1  
       [0040]     A prefabricated wall panel in accordance with the present invention having a size of 35.4″×47.24″×1.96″and a metallic grid including four horizontal rods and  3  vertical rods each having a size of ½″×½″ forming six quadrangular cells, was submitted to a test for determining its charge capacity when applying a flexing force.  
         [0041]     The test was carried out by placing the wall panel over four metallic perimetric supports each having a width of  5 ″. The force was evenly applied to each cell by means of two iron plates longitudinally placed over the wall panel so each plate contacted a row of three quadrangular cells, each plate having a size of 9.84″×9.84″×1″. A downward force was applied to both plates by means of a pair of two elongated metallic members connected to a hydraulic cylinder and perpendicularly oriented with respect of the iron plates.  
         [0042]     The force was quantified by means of a charge cell having a resolution of 11.02 lbs and a special gauge was used to evaluate the vertical displacement at the center of the panel. The force was applied until the panel failed thus obtaining a maximum endurance force of 6,779.21 lbs and a maximum vertical displacement of approximately 2.36″.  
         [0043]     The following graphic show the values of force versus vertical displacement until half of the maximum endurance force, showing a lineal performance. 
         
 
       EXAMPLE 2  
       [0044]     A prefabricated wall panel in accordance with the present invention having a size of 15.74″×19.68″×1.96″ and a metallic grid including two horizontal rods and two vertical rods each having a size of ½″×½″ forming one complete quadrangular cells, was submitted to a test for determining its charge capacity when applying an axial force.  
         [0045]     The test was carried out by placing the wall panel over one of its longitudinal sides. The force was evenly applied over the total length of the panel by means of a horizontal elongated metallic member connected to a hydraulic cylinder.  
         [0046]     The force was quantified by means of a charge cell having a resolution of 11.02 lbs and a special gauge was used to evaluate the vertical deformation of the panel. The force was applied until the panel failed thus obtaining a maximum endurance force of 8,126.23 lbs and a maximum vertical deformation of 0.095″ 
         [0047]     The following graphic show the values of force versus vertical deformation until half of the maximum endurance force. 
         
 
         [0048]     Finally it must be understood that the prefabricated wall panel, of the present invention, is not limited exclusively to the embodiments above described and illustrated and that the persons having ordinary skill in the art can, with the teaching provided by the invention, to make modifications to the prefabricated wall panel of the present invention, which will clearly be within of the true inventive concept and of the scope of the invention which is claimed in the following claims.