Abstract:
Lightweight structural panel units for construction of space enclosing structures each of which is formed from a blank of flat, suitably rigid, yet foldable sheet of material, which are profiled and pre-creased with a unique configuration. Upon folding, the blanks form a substantially hollow three dimensional polygonal beam-like unit having a shape and configuration which positively aligns and interlocks when conjoined with a plurality of similar folded beam-like units to form a substantially hollow 3-dimensional “structural panel unit” having symmetrical cross bracing inside and sufficient rigidity to enable sufficiently large areas to be produced for the construction of space enclosing structures. Each structural panel unit has a configuration and profile that positively aligns and interlocks when engaged with similar structural panel units to complete a desired space-enclosing structure which has an exterior facing surface and an interior facing surface separated by a substantially hollow void.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of Provisional Patent Application Ser. No. 60/313,984 filed 2001, Aug. 20. 

   FEDERALLY SPONSORED RESEARCH 
   Not Applicable 
   SEQUENCE LISTING OR PROGRAM 
   Not applicable 
   BACKGROUND 
   My invention relates to a method for constructing lightweight structural panel units suitable for use in constructing space enclosing structures. 
   Building construction members, particularly triangular shaped structural panels utilized in the construction of geodesic, or dome like space enclosing structures are known. 
   The most common means for constructing such structural panels will generally consist of some type of space framework composed of wood or metal struts and various attachment hardware combined to produce a polygonal form unit, usually triangular in shape, which will then have a covering material of some type, or structural panels which are fabricated from a formed, or molded and then hardened matter or composite material. 
   The manufacturing process for the common types of structural panels is frequently complicated, time-consuming and costly, and the resulting structural panels are not generally portable, or easily assembled into larger space enclosing structures without specialized machinery, skilled labor, and tools. 
   U.S. Pat. No. 2,881,717, Buckminster Fuller—entitled “Building Construction”, discloses a method of folding cardboard or other flat sheet material to form a “building member” suitable for constructing geodesic dome structure. 
   The benefits achieved by utilizing folded, flat sheets of material to fabricate structural panel units are many, and include: lower cost of materials, lower cost of fabrication, lighter weight, and easier onsite assembly relative to most common means for fabricating structural panels. 
   Beyond early experimental work in the 1950&#39;s and 1960&#39;s with folding cardboard geodesic domes, Fuller&#39;s approach has failed to find any significant commercial application due to a variety of weaknesses in the method. 
   In the prior art, the approach was to take a single flat sheet of relatively heavy material and fold it into itself to form a relatively small structural panel. A panel so formed had no integrated means for allowing itself to be attached or conjoined to additional, like panels during the construction of a space enclosing structure. That approach also severely limited the scale and utility of the structural panel so formed, and made the construction of space enclosing structures a complicated and tedious process prone to errors in panel alignment. 
   Prior art examples have also generally had no integrated provision for allowing natural light to pass into the space enclosing structure formed from such structural panels, unless the panels were only intended to produce a space frame, wherein such a space frame had no utility as a weather proof shelter without additional material or parts. 
   Objects and Advantages 
   The current invention asserts significant and unique improvements over, and differs substantially from the prior art, in the number of, and manner in which, flat sheets of material are profiled, folded, and conjoined to form a structural panel, and further how said structural panels are conjoined to form a space enclosing structure. 
   The current invention utilizes a plurality of similarly profiled flat sheets of material which are folded and conjoined to form a single Structural Panel Unit. This approach allows very large structural panel units to be formed from standard material blanks which have been produced with standard fabrication equipment. 
   Additionally, the folding method presently described, provides a significant amount of symmetrical cross bracing within a formed structural panel, and provides flaps or flanges without, which will serve to overlap similar adjacent structural panels being conjoined to form a space enclosing structure. This overlapping action provides a simple means for ensuring structural panel alignment and attachment, making the construction of a useful space enclosing structure far easier to accomplish than with a panel type described in the prior art. 
   The current invention is structurally superior to, and allows the use of a much less substantial material than that required in the prior art while still providing suitable strength for the construction of a useful space enclosing structure. 
   The current invention provides a method for constructing space enclosing structures wherein all parts may be fabricated on standard flat material conversion equipment available worldwide, be produced from readily available commodity materials, and wherein said space enclosing structures may be constructed and utilized by unskilled labor following simple pictographic instructions. 
   Objectives 
   
       
       (1)—To define and establish a unique method for making structural panel units suitable for use in constructing space enclosing structures. 
       (2)—To provide a panelized structural sub-assembly which employs an integrated structural skin approach with cooperating integrated internal bracing, which utilizes both tension and compression force, and which allows structural load to be distributed evenly making additional framing material unnecessary in the forming of a greater space enclosing structure. 
       (3)—To provide a structural panel unit which has an overlapping configuration when conjoined with similar such structural panels, and wherein said conjoined structural panel units are automatically forced to behave structurally together in unison eliminating the possibility of misalignment in all directions—toward the center, away from the center, and along the surface. 
       (4)—To provide a substantially hollow structural panel unit, wherein a plurality of said panel units are utilized to form a space enclosing structure having an effective concentric shell configuration, wherein said shell configuration encloses a substantially hollow void between an outer facing and an inner facing shell surface, and whereby airflow may pass in between said surfaces freely moving in all directions which run in parallel to said surfaces by convective or other means. 
       (3)—To provide a structural panel unit which possesses remarkable strength relative to its composite material mass. 
       (2)—To utilize a commonly available method for profiling blank, flat sheet material, which allows for simple and inexpensive part production. 
       (9)—To provide a structural panel unit configuration which facilitates convenient final onsite assembly. 
       (11)—To provide a structural panel unit wherein useful accessories, or structural details such as a doorway, windows, or a ground to structure interface assembly, may be added or modified simply by utilizing the same method of folding flat sheets of material which have been profiled for engagement with said structural panels. 
     
  
   SUMMARY OF THE INVENTION 
   This invention is directed to a unique method for constructing prefabricated, self-supporting, integrated, hollow structural panel units which are made from a plurality of flat sheets of suitably rigid, foldable material, wherein said sheets of foldable material have been profiled for engagement, folded, and conjoined together to provide a structural panel unit of the desired size and rigidity required to construct a space enclosing structure. 
   Space enclosing structures which are resulting from the conjoining of a plurality of said structural panel units are conceived of as temporary, or semi permanent structures of nearly any size, and which are suitable for shelter or amusement. 

   
     DRAWINGS 
     Certain embodiments of the invention are described by way of illustration, without limitation thereto other than as set forth in the accompanying claims, reference being made to the accompanying drawings, wherein: 
     DRAWING FIGURES 
       FIG. 1A  Flat view of profiled foldable sheet of material with reference numerals. 
       FIG. 1B  Flat view of profiled foldable sheet of material. 
       FIG. 2A  Inside perspective of folded polygonal beam like unit partially complete 
       FIG. 2B  Inside perspective of folded polygonal beam like unit complete 
       FIG. 3A  Outside perspective of folded polygonal beam like unit partially complete 
       FIG. 3B  Outside perspective of folded polygonal beam like unit 
       FIG. 4A  Interior perspective of three folded polygonal beam like units 
       FIG. 4B  Shows conjoining polygonal beam like units 
       FIG. 4C  Interior perspective of a structural panel unit 
       FIG. 5A  Exterior perspective of three folded polygonal beam like units 
       FIG. 5B  Shows conjoining polygonal beam like units 
       FIG. 5C  Exterior perspective of a structural panel unit 
       FIG. 6  Optional “window” parts 
       FIG. 7A  Interior perspective of structural panel with window parts 
       FIG. 7B  Interior perspective of structural panel with window parts partially 
       FIG. 7C  Interior perspective of a structural panel unit, window parts conjoined 
       FIG. 7D  Exterior perspective of a structural panel unit, window parts conjoined 
       FIG. 8  Shows conjoining structural panel units 
       FIG. 9A  One configuration of 2 conjoined structural panel units 
       FIG. 9B  Another configuration of 2 conjoined structural panel units 
       FIG. 10  Exterior perspective of a fifteen faceted, partial icosahedron 
       FIG. 11  A space enclosing structure utilizing 40 structural panel units 
       FIG. 12  A space enclosing structure utilizing 30 structural panel units 
       FIG. 13  Another space enclosing structure utilizing 30 structural panel units 
   

   REFERENCE NUMERALS IN DRAWINGS 
   
       
         10  Crease line 
         20  Vent hole (edge) 
         21  Vent hole (window) 
         22  Vent hole (box end) 
         50  Tabs (panel beam) 
         51  Slots (panel beam) 
         52  Tab (box end) 
         53  Slot (box end) 
         54  Box end flaps 
         55  Closed end of beam 
         56  Open beam end 
         60  Tab (panel beam inside tri) 
         61  Slot a (panel beam inside tri) 
         62  Tab c (panel beam inside tri) 
         63  Slot c (panel beam inside tri) 
         70  Tab a (system panel unit edge) 
         71  Slot a (system panel unit edge) 
         72  Tab b(system panel unit edge) 
         73  Slot b(system panel unit edge) 
         74  Tab a (outside face) 
         75  Slot a (outside face) 
         76  Tab b (outside face) 
         77  Slot b (outside face) 
         30  Bayonet Tab 
         31  Slot Bayonet 
         89  Inner window mounting slots 
         90  Inner window part 
         91  Outer window part 
         92  Outer window seam flap 
         94  Outer window corner flap 
         95  Outer window v edge 
         96  Window opening saddle edge 
         97  Outer window tabs 
         98  Inner window tabs 
         99  Large triangle flange 
     
  
   DETAILED DESCRIPTION 
   One Embodiment 
   In the presently described embodiment, a substantially hollow, triangular shaped Structural Panel Unit ( FIG. 4C ,  5 C) suitable for the construction of space enclosing structures is formed from the conjunction of three similar beam like units ( FIG. 4A ,  5 A) wherein said beam like units ( FIG. 2B ,  3 B) have been each formed by folding a flat sheet of material ( FIG. 1B ) and wherein a plurality of said structural panel units are conjoined to form a desired space enclosing structure ( FIGS. 10 through 13 ). 
   Fold a Beam 
   Referring to  FIG. 1A , a view of a flat, profiled sheet of material, utilized in one embodiment of the present invention is shown. 
   Wherein, said profiled sheet of material is to be folded along crease lines  10  ( FIG. 1B ), and tabs  50  mate with slots  51  ( FIG. 2A ), and tab  52  is inserted into slot  53  ( FIG. 2B ) and flaps  54  are folded so that said flaps form a closed box like end  55  ( FIG. 2B ), thereby forming a hollow three dimensional beam like unit ( FIG. 2B ) having a polygonal cross section. Adhesive means, or other mechanical fastener means may easily be substituted for the tabs and slots. 
   Wherein said beam is closed or boxed on one end  55 , and substantially open on the opposite end  56  ( FIG. 2B ), wherein said closed end  55  is profiled for under-lapping and said open end  56  is profiled for overlapping. 
   Wherein said beam has a substantial flap  99  which extends sideways from the outside edge of the exterior facing plane of said beam ( FIG. 2B ). 
   Wherein said beam has a vent hole  22  ( FIG. 7D ) which will enable airflow to pass into or out of said hollow beam when said beam is conjoined with similar beams. 
   Note:  FIGS. 2A ,  2 B,  2 C illustrate the preceding steps from an interior facing plane view and  FIGS. 3A ,  3 B,  3 C illustrate the same steps from an exterior facing plane view. 
   Form a Structural Panel 
   Referring to  FIG. 4A , an interior facing plane view showing three beam like units arranged and ready to be conjoined and interlocked to form a structural panel unit is shown. 
   By sliding the boxed end  55  of a first beam into the open end  56  of second similar beam, and aligning bayonet  30  of said second beam into slot  31  of said first beam, said beam units become interlocked together ( FIG. 4B ), wherein said interlocking action serves to align and secure said beam like units together. 
   Referring to  FIG. 4B , said two conjoined beams are arranged for conjoining and interlocking with a third beam. 
   By sliding said boxed end  55  of said second beam into the open end  56  of said third beam and inserting box end  55  of said third beam into said open end of said first beam, and aligning bayonet  30  of said third beam into slot  31  of said second beam, and aligning bayonet  30  of said first beam into slot  31  of said third beam, all three said beam units become interlocked together ( FIG. 4B ) forming a structural panel unit ( FIG. 4C ) suitable for use in the construction of space enclosing structures. 
   Referring to  FIG. 4C , an interior facing plane view of said structural panel unit wherein triangular flaps  99  extend sideways from the outside edge of the exterior facing plane of said conjoined beams forming said structural panel unit is shown. 
   Note:  FIGS. 4A ,  4 B,  4 C illustrate the preceding steps from an interior facing plane view and  FIGS. 5A ,  5 B,  5 C illustrate the same steps from an exterior facing plane view. 
   Window Parts 
   In the present invention, the parts so named by including the word “window” in said names, are actually structural elements, wherein opaque material may be chosen in the fabrication of said parts in order to limit the transmission of light, or conversely, all structures referred to herein, may be fabricated from translucent material creating in effect a greenhouse type configuration. The designation of “window” is therefore arbitrary but shall serve as a common designation in this description. 
   Referring to  FIG. 6A , the triangular part  90  is an interior window panel, and the profiled shape  91  will be folded to form a generally tetrahedron shaped exterior facing window part. 
   Referring to  FIG. 6B , said tetrahedron shaped window part  91  is shown folded, wherein flaps  92  have been secured together to the inside of said tetra window part, and corner tabs  94  have been secured to window edge  95  on the outside of said tetra window part. 
   Referring to  FIG. 7A , the interior facing plane view of a structural panel is shown, wherein said window panel  90  and said folded tetrahedron window part  91  are ready to be conjoined to said structural panel. 
   Wherein said folded tetrahedron window  91  has “v” edges  95  which were formed as a result of folding said tetrahedron window part  91 . 
   Whereby said tetrahedron window  91  is conjoined with said structural panel ( FIG. 7B ) by mating said “v” edges  95  with said saddle edges  96  ( FIG. 7A ), and by mating tabs  97  on said tetrahedron window part  91  with slots  51  on said structural panel unit. 
   Wherein the conjoining of said tetrahedron window  91  and said structural panel creates a compression force along the juncture between said “v” edges  95  and said saddle edges  96 , wherein said compression force serves to lock said window part  91  into place with said structural panel thereby increasing structural strength to both said window part  91  and said structural panel. 
   Referring to  FIG. 7B , said tetrahedron window  91  has been conjoined with said structural panel unit, and said interior window panel  90  is arranged and ready to be conjoined to said structural panel unit. 
   Wherein inner window  90  is conjoined to said structural panel by mating inner window panel tabs  98  to the inner window mounting slots  89  on said structural panel unit ( FIG. 7B ). 
   Referring to  FIG. 7C , an interior facing plane view of said structural panel unit with said window parts  90  and  91  installed is shown. 
   Airflow 
   One important benefit of constructing a space enclosing structure from substantially hollow structural panels is that the said space enclosing structure will effectively have a concentric shell configuration. That is, an inner, and an outer shell having a substantial void formed between. A concentric shell configuration allows the utilization of any convective airflow within said void to be harnessed for practical ends. 
   Air is allowed to flow throughout each substantially hollow structural panel, and in between any conjoined structural panels which are forming a space enclosing structure by means of vents  20 ,  21 ,  22 . 
   Referring to  FIG. 7D  an exterior facing plane view of said structural panel unit with said window parts  90  and  91  installed is shown. 
   Wherein a hollow void is formed between said installed tetrahedron window part  91  and said inner window part  90 . 
   Wherein said void formed between said window parts is connected with said hollow space inside said structural panel by means of vent holes  21  thereby allowing airflow to pass between said window void and said hollow panel space. 
   Wherein said airflow may flow into, or out of said hollow panel space by means of vents  20 . 
   Wherein said airflow may circulate throughout said space enclosing structure by means of the combined function of said vents  20 ,  21 ,  22 . 
   Conjoining Structural Panels 
   In order to construct a useful space enclosing structure, a plurality of structural panel units must be conjoined. 
   Referring to  FIG. 8 , two structural panels are aligned and ready for conjoining. Flaps  99 , and additionally a tab and slot means are provided with each structural panel to produce an automatic alignment and locking action when said structural panels are conjoined. 
   One characteristic of a space enclosing structure formed from a plurality of said substantially hollow structural panels is the aforementioned concentric shell configuration, wherein said shell configuration consists an outer shell or skin, and an inner shell separated by a substantially hollow void. When flaps  99  are overlapping on said conjoining structural panels, a tension is produced across said skin of said space enclosing structure and a compression force is created between the edges said conjoined structural panels. 
   Wherein tabs  70  and  72  are inserted into slots  71  and  73 , and flaps  99  overlap the exterior faces of each adjoining structural panel, and tab  76  is inserted into slots  77  and  78 , thereby automatically placing into alignment and physically interlocked in all directions the two said structural panels. 
   Another novel characteristic granted by the present invention is the ability for conjoined structural panel units to be varied in their respective orientation across the longitudinal axis formed at the conjunction of said panels outer facing plane through an arc of at approximately 60 degrees without significantly affecting the combined structural strength of said conjoined panels. 
   This variability in said angle across said panels outer facing planes allows both pentagonal and hexagonal assemblies to be formed from said conjoined structural panels wherein said hexagonal and pentagonal assemblies may be utilized in the construction of space enclosing structures without necessitating additionally sized or shaped discreet structural panels or panel parts. 
   Referring to  FIG. 9A , two conjoined structural panels configured to form an angle of 180 degrees across the contiguous exterior facing planes are shown. 
   Referring to  FIG. 9B , two conjoined structural panels configured to form an angle of 138.19 degrees across the contiguous exterior facing planes is shown. 
   Space Enclosing Structure 
   A novel characteristic of the present invention is the ability to construct a variety of differently shaped space enclosing structures utilizing only one structural panel type. 
   Whereby altering the quantity of similar structural panel units being conjoined together, and varying the angle across the exterior facing planes of said panels, a space enclosing structure of a desired shape may be achieved. 
   Referring to  FIG. 10 , an exterior perspective of a space enclosing structure shaped in the manner of a partial 1 frequency icosahedron utilizing fifteen conjoined structural panels is shown. 
   Referring to  FIG. 11 , an exterior perspective of a space enclosing structure utilizing forty conjoined structural panels is shown. 
   Referring to  FIG. 12 , an exterior perspective of a space enclosing structure utilizing thirty conjoined structural panels is shown. 
   Referring to  FIG. 13 , an exterior perspective of a space enclosing structure utilizing thirty conjoined structural panels is shown. 
   While in the foregoing specification detailed descriptions of specific embodiments of the invention have been set forth for the purpose of illustration, it is to be understood that many of the details herein given may be varied considerably by those skilled in the art without departing from the spirit and scope of the invention.