AU685941B2 - Building module made from foldable sheet material for use in constructing geodesic domes and like structures - Google Patents

Description

Building Module made from Foldable Sheet Material for Use In Constructing Geodesic Domes and Like Structuree.

The invention is a method by which a building module, comprising both the construction members and external surface, can be made from a single sheet of foldable sheet material, such as corrugated/fluted polypropylene plastic or fibreboard, which when joined together with similar modules form a complete and fully enclosed geodesic dome or like structure, Compared to traditional building designs, geodesic structures achieve a high degree of structural strength without the need for construction members capable of withstanding high compression loadings.

This allows lightweight, Inexpensive materials, such as corrugated/fluted plastic S. or fibreboard sheeting, which would normally buckle under traditional construction loadings, to be used in geodesic structures, resulting In lower costs and easier prefabrication, transport and erection, The use of corrugated/fluted fibreboard as construction members in geodesic

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structures has been patented. That invention, however, concentrated on the use of corrugated/fluted fibreboard as a construction member to make a structural framework. It requires an external surface be applied to or draped over the framework to make the structure weatherproof. There are also disadvantages in it's method of joining the component parts together and achieving the correct angular relationship between them, resulting In a less rigid, less strong and more difficult to waterproof structure.

Corrugated/fluted fibreboard sheets have also been used in the past as an external cladding material over or in a structural framework, not necessarily geodesic, However, It's purpose was only as a weather shield with little or no structural role.

These deficiencies are overcome by the present Invention. This invention combines both the construction member and the external surface of the structure into a one-piece building module, with which, when joined together with other similar modules, it is possible to construct a fully enclosed geodesic structure, not merely a framework.

This is an improvement for several reasons there is no necessity for additional cladding or covering of the framework, Sstructural strength is greater because the external surface acts as additional bracing to the construction members, by correct dimensioning, the edges of the building module can be accurately angled to achieve the correct angular relationship between different modules, allowing easy joining of the individual building panels and quick and accurate S" construction of the desired geodesic structure.

S by incorporating a seamless external surface together with the construction members, water leakage points are minimised and sealing made much easier, Once assembled and satisfactorily sealed, the structure can be used as temporary shelter storage units, or become the formwork for a permanent structure by applying external coatings (e.g ferro-concrete, adobe, S.i polyurethane).

The building module consists of two main parts: a large plane area, which will form part of the external surface of the structure; and the protruding edges or 'wings' which will be folded and glued, or otherwise affixed, to create the construction members, which give rigidity and structural strength to the plane surface and provide the angled edge surfaces for joining together with other panels.

The shape of the plane area will usually be triangular, this being the basis of most geodesic structures, however, other polygonal shapes, e,g. trapezoid, rectangle, occur in some geodesic structures.

I jLn 3 The size of the plane area will depend on the desired size of the completed dome, but will be practically limited by the maximum size of the sheet material manufactured and the cutting capability of the available machinery.

The precise dimensions of the plane area will depend on the type and size of geodesic structure one wants to construct and determined in accordance with geodesic principles.

The foldable edges or 'wings' are designed to form a hollow reinforcing, construction member of triangular cross-section along each side of the plane area.

a. The first part of each 'wing', that nearest the plane area, needs to be of common width in every module that goes to make up any given g. desic structure. This S will be the surface that abuts and Joins with that of other modules, Heles will be cut into this first part of the 'wing' to allow connecting bolts or S specialised fasteners to connect with the next module or if the edge rests on the ground, these holes will be used by anchoring bolts or pegs, The widths of the second and third parts of each 'wing', together with the first part, define the angle of the module edge so accurate dimensioning of the 'wing' parts is very important to achieve perfect interfitting and abutment between the building modules, Because the edge angles may vary on different sides of the same module, as well as between different modules, it follows that the widths of the second and third parts of each 'wing' will not be common but must be derived in accordance with the rules of trigonometry to make the required edge angle.

Holes of sufficient size to allow easy access for the insertion and fastening of bolts or specialised fasteners through the first part of the 'wing', should be made in the second part of the 'wing'.

In another variation of the invention, the material forming these holes is not completely removed but remains attached, effectively forming a hinged flap.

After they have been used to connect the modules together, the access holes can be 'filled' by closing the flap, allowing the injection of viscous or foam materials which upon subsequent solidifying could impart additional structural and/or insulation properties.

The ends of the 'wings' are cut so as to allow a mitred join with the 'wings' on adjacent edges of the same module when folded. The precise shape will be determined by the geometry of the particular plane area and 'wings'.

Whilst the dimensions of each of the three parts of each 'wing' must be in the correct ratio to make the correct edge angle, their size is independent of the dimensions of the plane surface and will be determined in accordance with structural strength, material usage and material sheet size.

S In another variation of the invention, a substantial part of the plane area is cut 5" away and folded back to leave a largely empty frame. A sheet of some other material, e.g, transparent polycarbonate, cut slightly larger than the 'hole' in the plane area, can be inserted, before folding, to perform a specialised function, e.g. a window, In this variant, the second and third parts of the 'wings' on this module would need to be re-dimensioned to maintain the correct edge angle, given the extra thicknesses of material on the plane area.

The method of module construction has been designed to be extremely simple.

The foldable sheet material is cut to the required shapes. Fold lines are scored In accordance with the broken lines In the drawings.

Adhesive Is then applied to the underside of the third part of a 'wing' and the 'wing' is folded over to form a hollow box, triangular in cross-section. In doing so the glued surface of the 'wing' abuts the plane area and can be stuck in place, Care must be taken to ensure the edge of the third part of the 'wing' butts up against the surface of the first part of the 'wing' when folded, if the correct edge angle is to be formed.

The folding and gluing process is repeated for each wing of all modules In the geodesic structure.

Although other methods, e.g, stapling, are possible, adhesive (glue or tape) is the preferred method of forming the modules, as it does not puncture what will be the external surface and so create possible leakage points.

The geodesic structure can be simply assembled by joining the modules together.

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Fixing holes were made in the first part of each 'wing', now folded to form the l edges of the building modules, These will align with similar fixing holes In other S: building modules.

It is recommended that the fixing holes in each side be positioned so as to align only with the fixing holes in the sides of other modules to which they should be joined. This will help prevent modules being joined incorrectly during assembly.

A simple nut, bolt and two washers are sufficient to join at each fixing hole.

However, a specialised, plastic fastener would be preferable.

The pattern of module assembly will vary with the design of the underlying geodesic structure and does not form part of this invention. However, it is usual for the triangular modules to be joined together in sub-assemblies of five or six to form pentagonal or hexagonal units. These sub-assemblies are then joined together to form the generally dome-like, geodesic structure. If necessary, modules of other shapes, e.g, trapezoid, rectangular, generally fit between the hexagonal pentagonal sub-assemblies, usually above access openings.

In the drawings, broken I dash lines denote fold lines, full lines are out lines, FIG. 1 Is a plan view of a triangular module of foldable sheet material before being folded, The module consists of plane surface I and foldable 'wings' 2,3 and 4. Each wing consists of three foldable parts 5,6 and 7. Connection holes 8 have been made in the first part of each wing 5 which will enable joining with other modules to assemble the geodesic structure. Access holes 9 have been made in the second part of each wing 6 to allow access to the connection holes once the 'wing' 2 has been folded. Folding will form a hollow 'box' of triangular cross-section along each side of the plane surface, Adhesive would be applied to the underside of the third part 7 of a 'wing' 2 which, when folded, will lie flat against plane surface 1, making sure that the edge of the 'wing' part 1 0 butts up against the surface of the first 'wing' part 2, In this way, the edge of the construction member, 2, will make the correct angle to the plane surface 1,.

FIG. 2 is a plan view of the triangular module shown in Fig.1 after folding.

Connection holes 8 are on the now external edge 5 of the module. Access holes 9 are on the internal edge 6.

FIG. 3 is an enlarged cross-sectional view along the line A-A. The single sheet of material has been folded to form sides 5, 6 and 7 of the hollow construction member. The third side 7 of the triangular construction member lies flush with and is adhered to the plane area 1, 20 FIG. 4 is a plan view of a variant to a standard triangular module, where the majority of plane surface 1 the cross hatched area has been cut away to allow the insertion of a flat panel of some other material, e.g. transparent polycarbonate if a window is required. The parts and details are largely the same as in Fig,1 except that surfaces 11 would fold back to lie flat against and be adhered to the remains of surface 1, 'wing' parts 6 7 would need to be redimensioned to make the correct edge angle and 'wing' part 7 would now adhere to the inserted panel of polycarbonate, or some other material.

FIG. 5 is a plan view of another polygonal shaped module (a trapezoid) of foldable sheet material before being folded. The parts and details of other polygonal shapes are essentially the same as for Fig.l.

Claims (4)

1. A building module for use In constructing geodesic domes and like structures, made from a single sheet of foldable sheet material, such as corrugated/fluted plastic or fibreboard, which incorporates both: the external surface, being a flat, plane area, usually triangular in shape but Including other polygonal shapes; and construction members, being hollow boxes of triangular cross-section formed by folding the sheet material along the edges of the plane surface.

2. A building module according to claim 1 wherein the central, plane surface is largely removed or folded back to create a hole over which a sheet of some other material or having other physical characteristics can be inserted and fixed in position to perform a specialised function.

3. A building panel according to claim 1 wherein the material otherwise completely cut out and discarded to form an access hole in the side of the hollow construction member of triangular cross-section, is not completely cut out but remains attached along a portion of it's circumference effectively creating a hinged flap which, after using the access holes to join the individual modules together, can be hinged back to close the access hole and allow the injection of viscous or foam materials into the construction member cavities which upon subsequent solidifying impart additional structural and/or Insulation properties, 9 20

4. A building module substantially as herein described with reference to the I accompanying drawings. :f Name of Applicant: SOLWEIG BIRGITTA PRYKE Date 20th SEPTEMBER 1997 p ~"slar~sl*- 1 ABSTRACT A building module for use in constructing geodesic domes and like structures, is disclosed. This one-piece building module is made from a single sheet of foldable sheet material, such as corrugated/fluted plastic or fibreboard, and incorporates both: the external surface being a flat, plane area, usually triangular in shape but including other polygonal shapes; and construction members being hollow boxes of triangular cross-section formed by folding the sheet material along the edges of the plane surface. When correctly dimensioned, in accord with established geodesic principles and the rules of trigonometry, and correctly joined with similarly formed building modules a fully enclosed geodesic structure can be constructed. *o *00 o *4 o *ft