GB2148971A - Polygonal components for domes - Google Patents

Abstract

A polygonal component of a lattice-work structure consists of a peripheral frame (15) formed of straight struts (16) and strengthening members (18) which extend from each corner of the frame and are secured together at or adjacent the centre of the frame. The structure can be clad with cloth, plastic sheet or wire netting. <IMAGE>

Description

SPECIFICATION Dome like structures FIELD OF THE INVENTION This invention relates to structures that are assembled from prefabricated components.

BACKGROUND OF THE INVENTION For the sake of convenience, the invention will be described in relation to the application of the invention to a garden "dome", but, it is to be understood that the invention is not limited thereto. The term "dome" as used in this specification is not restricted to hemispherical shapes produced by rotating an arch on its vertical axis but embraces shapes of approximately hemispherical form as well as shapes the general outline of which may be circumscribed by a hemisphere. Furthermore, the shape may be larger than or smaller than a hemisphere.

Domes of non-spherical form that are constructed from a lattice-work of polygons are known as geodesic domes and with such domes the load is shared evenly through the structure. Hitherto, each polygonal component of a geodesic dome has been constructed as a self-sufficient substructure whose strength resided in the peripheral framework and/or the covering or cladding on the framework and/or a combination of both.

SUMMARY OF THE INVENTION According to the invention there is provided an improved structure formed from a latticework of polygonal components characterised in that each polygonal component consists of a peripheral frame having strengthening members extending from each corner of the frame and being secured together at or near the centre of the polygon to provide bracing for the component.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more readily understood and put into practical effect reference will now be made to the accompanying drawings in which: Figure 1 is a front elevational view of domelike structure according to one embodiment of the invention, Figure 2 is a plan view of the structure shown in Fig. 1, Figure 3 is a plan view of a hexagonal component of the dome shown in Figs. 1 and 2, Figure 4 is a plan view of a pentagonal component of the dome shown in Figs. 1 and 2, Figure 5 is a plan view of a trapezoidal component of the dome shown in Figs. 1 and 2, Figure 6 is a plan view of a hexagonal component of the dome shown in Figs. 1 and 2 which incorporates a door opening, Figure 7 is an enlarged view showing the manner in which the strengthening members are secured together at the centre of a hexagonal component, Figure 8 is a plan view of an attachment plate for the strengthening members, Figure 9 is an enlarged, broken-away, plan view of a corner of a hexagonal component, Figure 10 is an enlarged, broken away, plan view of three components joined together by three plates, Figure 11 is an enlarged, broken away, plan view of three components joined together by a single plate, Figure 12 is a view similar to Fig. 9 but with the braces tensioned by twisting, and, Figure 13 is a view similar to Fig. 9 showing an alternative form of brace tensioned by crimping.

DESCRIPTION OF THE PREFERRED EMBODI MENT The dome-like structure 10 shown in Figs.

1 and 2 is, in essence, a truncated icosahedron constructed from a plurality of polygonal components 11, hexagonal components 1 2, trapezoidal fill components 1 3 and a door component 14.

A hexagonal component 1 2 is shown in Fig. 3 and it consists of a peripheral framework 1 5 formed from six straight struts 1 6 joined at their corners 1 7 as will be hereinafter described. Wire Braces 1 8 which extend from each corner 1 7 to the centre of the hexagon act as strengthening or tensioning members.

The stuts 1 6 which may be solid or hollow are constructed of any convenient material such as timber (treated if necessary), metal, plastic or composites thereof. The wire braces 1 8 may be replaced by braces made of strip material.

A pentagon component 11 is shown in Fig.

4 and it consists of a peripheal framework 1 8 formed from five straight strusts 1 9 joined at their corners 21. Wire Braces 20 which extend from each corner 21 to the centre of the pentagon act as strengthening or tensioning members.

The trapezoidal fill component 1 3 shown in Fig. 5 is constructed in a similar manner to the other components but because it is but half of a hexagonal component it has two cross struts 25 a base strut 26 as well as peripheral struts 27. The door component in Fig. 6 has peripheral struts 28 and vertical struts 29 which are braced by cross strut 30.

The braces of each polygonal component are joined together at the centre of the polygon as is shown in Fig. 7 in respect of a hexagonal component. In this instance, there is an annular member or washer 31 at the centre of the hexagon around which each Ushaped wire brace 1 8 passes. The free ends of each brace are connected to an anchorage which in this instance is in the form of a brace attachment plate 22 which is shown in Fig. 8.

Each brace attachment plate 22 has attachment holes 23 and brace receiving holes 24.

As indicated in Fig. 9, the brace attachment plate 22 is located at the corner 1 7 formed by the junction of the struts 16. Dowels 33 pass through the attachment holes 23 and are received in appropriate dowel holes in the studs 16. The corner joint is completed by a nail strap 34.

The free end of the brace attachment plate 22 extends inwardly from the interior of corner 1 7 so that its brace receiving holes 24 are freely accessible. The free ends of each brace wire 1 8 are passed through the respective holes 24 and bent as indicated in Fig. 7 to provide a firm anchorage. After all the braces are located the framework is tensioned by twisting the arms of the U-shaped wire braces together as is shown in Fig. 1 2.

Fig. 1 3 shows a alternative brace arrangement in which a single brace 42 is secured to the plate by a sleeve 43. In this arrangement, the framework is tensioned by crimping the brace 42, The various components of the dome-like structure are connected together by plates which are screwed to the peripheral framework of the components as is shown in Figs.

10 and 11.

In Fig. 10, the components are joined togather by three plates 40 secured to abutting struts of adjacent components. In Fig. 11, the components are joined together by a single plate 41 that is secured to each of the struts.

When constructed of hollow struts, the components can be joined together by suitably angled corner-joining members which are inserted into the hollow ends of the struts. Such corner-joining members would, of course, incorporate an attachment plate for the braces.

The components may be clad with any convenient material such as shade cloth, translucent plastic sheet, wire netting and the like.

A complete structure may be used for a wide variety of purposes including fernaries, bush houses, aviaries, spar enclosures and outdoor insect-proof rooms.

Various modifications may be made in details of design and construction without departing from the scope and ambit of the invention.

Claims (9)

1. A structure formed from a lattice-work of polygonal components characterised in that each polygonal component consists of a peripheral frame having strengthening members extending from each corner of the frame and being secured together at or near the centre of the polygon to provide bracing for the component.

3. A structure as claimed in claim 1 wherein each peripheral frame is constructed from a plurality of struts and wherein at each strut joint there is an inwardly directed anchorage for the respective strengthening member.

3. A structure as claimed in claim 2 wherein each anchorage is in the form of a plate that is securely joined to the struts at the joint and which extends inwardly of the interior corner of the joint and wherein the projecting end of the plate has means to which the strengthened member is attached.

4. A structure as claimed in claim 2 wherein the strengthening members are wires which are looped around an annular member at or near the centre of the component.

5. A structure according to claim 4 wherein the ends of each wire are secured to the anchorage at the strut joing and each framework is tensioned by twisting the runs of each wire around each other.

6. A structure as claimed in claim 2 wherein the strengthened members are made of strip material with one end being secured to an annular member at or near the centre of the component, and the other end being secured by a clamp to the anchorage.

7. A structure according to claim 6 wherein the framework is tensioned by crimping the strip material.

8. A structure according to any one of the preceding claims wherein the lattice-work is covered.

9. A structure formed from a lattice-work of polygonal components, substantially as herein described, with reference to the accompanying drawings.