GB2315286A - Structure - Google Patents

Abstract

A structure for use in tent assemblies, space frames and panel constructions. The structure has at least six mutually inclined planar faces, with adjacent faces intersecting along lines which all intersect at a common apex. Alternative lines of intersection are inclined at a greater angle than lines of intersection therebetween.

Description

STRUCTURE This invention relates to a structure for use in tent assemblies, space frames and panel constructions.

Space frames are commonly used to support the roofs of large, open plan buildings such as factories, warehouses or spectator stands. These space frames typically consist of girders which span the length and width of the building and support struts which are fixed to the girders. The girders are arranged in two planar arrays, the lower of which is supported by columns or walls. The upper array is spaced from and supported on the lower array by the struts which are angled to form groups of pyramid like structures. The struts are positioned to define a number of inclined sequential planar faces intersecting at the upper and lower arrays.

In accordance with the present invention, there is provided a structure having at least six mutually inclined planar faces, with adjacent faces intersecting along lines which all intersect at a common apex, the lines of intersection being inclined to a central axis of the support structure which passes through the apex, with alternate lines of intersect ion inclined at a greater angle than lines of intersection therebetween.

The invention is based on the concept of FOLDING IN MULTI-DIRECTIONS to create integrable modules from flat surfaces.

If a regular flat surface is folded in multi-directions, with fóld lines passing through a common centre, a certain space shape shall be formed. By the proper selection of the initial flat surface shape, the direction of folding, and the angles between fold lines, the resulting modules can be integrated. The multi-folded surface gives the module more rigidity than one which has only one direction of folding such as corrugated steel sheet. The greater rigidity removes the need for a complex arrangement of girders and support struts in space frame structures. The modules created by multi-folding may be either foldable structures or rigid structures.

Preferred features of the invention are defined in the dependent claims to which reference should now be made.

Embodiments of the invention include four main modules.

Each one of the main modules has different characteristics depending on starting shape and fold angle. As explained hereinafter, the modules have integration ability in many ways according to their characteristics. Integration in a horizontal plane around plan angles is termed angle integration; integration in a horizontal plane along a side is termed side integration; integration in a plane along a module face encompassing two sides is termed face integration; and integration of modules above each other is termed vertical integration. Different types of integration can be combined at the same time. The modules have advantageous application in structural frame systems of space frames, tents and in panel construction. Many examples of integrable module types are described. The proper module for a particular application would be selected according to its intended function and cost considerations.

Various embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: FIGURES la,lb,lc and ld show a first module embodying the invention; FIGURES 2a,2b,2c and 2d show a second module embodying the invention; FIGURES 3a,3b,3c and 3d show a third module embodying the invention; FIGURES 4a, 4b,4c and 4d show a fourth module embodying the invention; FIGURES Sa, 5b and Sc illustrate a tent frame based on the second module; FIGURES 6a, 6b, 6c and 6d show the upper part of a frame construction for the tent of Figures 5a, 5b and 5c; FIGURES 7a, 7b and 7c illustrate schematically the complete folding of the tent of figures 5a, Sb and 5c.

FIGURES 8a, 8b and Sc illustrate the 3-dimensional appearance of the tent of figures 5a, Sb and 5c; FIGURES 9a, 9b and 9c illustrate the arrangement of modules in three different integrated structures; FIGURES 10a and 10b illustrate an integrated tent structure supported with ropes; FIGURE 11 illustrates the centre portion of the frame of a shade umbrella based on the second module; FIGURES 12a, 12b, 12c and 12d show the frame construction of the shade umbrella of figure 11; FIGURES 13a, 13b and 13c illustrate a space frame formed from nine units, each based on the second module; FIGURES 14a, 14b and 14c show schematically the frame work of the space module of figures 13a, 13b and 13c; FIGURE 15 is a perspective view of the framework of the space module of figures 13a, 13b and 13c; FIGURES 16a and 16b illustrate a space frame formed from fifty-four units, each based on the fourth module; FIGURES 17a, 17b and 17c illustrate a space frame formed from twenty-one units, each based on the fourth module; FIGURES 18a and 18b illustrate a space frame formed from eighteen units, each based on the first module; FIGURES 19a, 19b and 19c illustrate an arched vault formed from thirty-two units, each based on the second module; FIGURES 20a, 20b and 20c illustrate the construction of a column formed from units based on the second module; FIGURES 21a and 21b illustrate a column formed from units based on the fourth module; FIGURE 22 shows an arrangement of integrated modules forming a roof structure for covering the spectator area at a stadium; FIGURES 23a and 23b show a universal node joint for joining units together; FIGURES 24a and 24b illustrate the integration of modules; and CHARTS 1 to 13 show the relationship between various parameters described with reference to Figures 1 to 4.

Figures 1 to 4 illustrate four modules which exemplify the present invention. The characteristics of each module will be described in turn, starting with details of the flat surfaces from which each module is formed.

FIRST MODULE Fig la, lb, lc and ld represent the first module which has fold lines in four directions. Fig la indicates the initial shape of the flat surface before folding, which is rectangular, with a and b representing the half-side lengths, and P representing the half-diagonal length.

The rectangular shape is folded along the diagonal lines (BB) and along the cross lines (AA and A'A') in between the diagonals. All fold lines pass through the centre 0 of the rectangular shape. The direction of folding is alternated so that the lines (OB) are aligned along "furrows" and the lines (OA and OA') are aligned along "ridges" in the resulting space shape of the first module.

Fig Ib is the front elevation of the space shape; fig lc is a plan view of the space shape, and fig ld is perspective view of the space shape. By proper selection of the half-side lengths (a and b) and folding angle (6), the desired corner angles in the plan projection (Fig lc) can be achieved. If corner angles (PLA) or (PLB) equal 90 or 120 degrees in the horizontal plane, then respectively either four or three identical modules can be integrated around the corner angle, (angle integration). If the half-side lengths (a and b) are equal such that the value of angles (PLA) and (PLB) are equal, the plan projection of the space shape would be square if (PLA) or (PLB) are 900. Such square shapes are fully integrable in all directions, (angle, side and face integration).

The relationship between module angle (6) and angles (PLA) & (PLB) for various b/a ratios is shown Chart 1 over a practical application range. The relationship between the three angles marked in fig lc is as follows: (ABQ) = 2700 - 0.S(PLA) 0.S(PLB).

The modules have potential for side integration along any half-side (AB) or half-side (A'B) to form a circular group.

The angles (RSA) and (RSB) are the unit angles which determine the degree of side integration. The relation between (RSA) and (PLA) is (RSA) = 1800 - (PLA), and between (RSB) and (PLB) is (RSB) = 1800 - (PLB) . Alternatively, face integration is possible through the plane containing either sides (BA' and A'B) or (BA and AB). So long as one of the angles between pairs of planes containing sides (BA and AB) [angle (RANB)] or (BA' and AB) [angle (RANA)] is more than zero, face integration modules can be used to form an arched vault. The relationship between module angle (6) and (RANA) & (RANB) for various b/a ratios is shown in Chart 2.

SECOND MODULE Fig 2a,.2b, 2c and 2d indicate the second module which has fold lines in four directions. Fig 2a indicates the initial shape of the flat surface before folding, which is octagonal with sides of length a, diagonal lines BB of half length ss which intersect at right angles at the center 0, and cross lines AA of half length b which also intersect at right angles at the center O. The diagonal lines divide the module to four sub modules. The cross lines bisect the angles between the diagonals.

The octagonal shape is folded along the diagonals and along the cross lines. The direction of folding is alternated so that the diagonals are aligned along furrows and the cross lines are aligned on ridges in the resulting space shape of the second module. Fig 2b is the front elevation of space shape; fig 2c is a plan view of the space shape; and fig 2d is a perspective view of the space shape. The hatched area of fig 2c represents one of the sub modules. The relationship between folding angle ( 5) and angle (KPKP) for different (buzz values is shown in Chart 3 over a practical application range.

From geometrical analysis of the second module, for any case: (KPKP) + (LDKP) = 2700 If angle (KPKP) = 90 degrees, the plan projection of the second module will be square, which has full integration potential in the horizontal plane (angle, side, and face integration). Angles (RB) and (RL) are the unit angles for side integration to form circular group. The angle (RL) = 180 - (LDKP), also the angle (RB) = 1800 - (KBKB). The angle (RAN) is the unit angle for face integration and is a measure of the angle of inclination between the opposing faces of the module which are each parallel to two sides AB and BA. If angle (RAN) is more than zero (i.e. the opposing faces are non-parallel), face integration of modules can be used to create an arched vault, as in fig 19a.

By combining face integration in two directions it is possible to create a domed vault. The relationship between folding angle (6) and angle (RAN) for various b/Q ratios is shown in Chart 4.

THIRD MODULE The third module is a modification of the second module in which the corner regions have additional folds. Fig 3a, 3b, 3c and 3d indicate this module which has fold lines in four directions. Fig 3a indicates the initial flat shape of the flat surface before folding. The long diagonal lines BB are mutually perpendicular, as are the shorter cross lines AA. The diagonal lines BB and the cross lines AA all intersect at the centre point 0, with the angle between adjacent diagonal and cross lines (BOA) being 450. The corner regions (CDBD) are square with sides (CD) being parallel to one or other of the cross lines AA. The length (OA) can be varied independently of the length (OB); and the location of point (C) on (OB) is also variable.

The surface is folded along the diagonal lines BB and along the cross lines AA. The resulting space shape is similar to that of the second module. The portion (CD) of each half diagonal is folded so the space shape is raised up on the four corner regions. Fig 3b is the front elevation; fig 3c is a plan view of the module when angles (YVY) and (YOB?) equal 180 degrees; and fig 3d is a perspective view of the module.

The angles (wry), (YBY) and (B?V) define the geometrical plan shape. The module folding angle is (AOG), which is between line (OA) and an imaginary vertical line passing through the module center 0. The module can be divided into four sub-modules. Changing the value of the folding angle (AOG) or (CB/BO) ratio or length of line (OA), can have an effect on the values of the plan angles. The angle (YOB?) is not affected by the (CB/BO) ratio or the (OA) line length; it only changes with module folding angle (AOG). The relation between plan angle (YOB?) and module folding angle (AOG) is shown in Chart 5. If (CB/BO) = 1, then (CD) = (OA) and the module reverts to the second module, with the angle (WY) becoming angle (LDKP). If (CB/BO) = 0, then the module again reverts to the second module and the angle (YVY) will replaced by (KPKP). Thus the second module may be considered as special case of the third module. The relation between angle (YVY) and module folding angle (AOG) is shown at different (CB/BO) ratios in Charts 6, 7, 8, 9, 10, 11, and 12. From geometrical analysis of fig 3c, the relation between three plan angles is (BYV) = 3150 - 0.S(WY) - 0.S(YB?) - The third module may be capable of angle, side and face integration. Face integration may only be suitable for modules having a plan angle (YVY) or (YOB?) equal to 180 degrees, as in fig 3c, where the integration would be in a horizontal plane.

FOURTH MODULE The fourth module is in geometrical terms the simplest module; it has a good ability for integration. It is created from folding a regular flat surface along three independent directions which all intersect at point 0. The figures 4a, 4b, 4c and 4d illustrate this module. Figure 4a shows the initial shape of the flat surface before folding, which is a polygon with six equal sides of length (b). The polygon has three crosslines (AB) of length (Q+a) which intersect at the centre 0. The length (a) is variable; if (Q) = (a), the polygon will be a regular hexagon; if (Q) = 2 (a), the polygon shall be reduced to an equilateral triangle. The angle between (OA) and (OB) is always equal to 60 degrees.

The polygonal shape is folded along the crosslines AB, with the direction of fold being alternated such that lines OA are aligned along furrows and lines OB are aligned on ridges. Figure 4b is a front elevation of the space shape; fig 4c a plan view of the space shape; and fig 4d is a perspective view of the space shape. The ratio (a/B) and folding angle (X) are selected to get the desired module shape. The angles (PS) and (LP) define the shape of the module plan projection. The relation between angle (PS) and module folding angle (X) at various values of (a/Q) is shown in Chart 13. From geometrical analysis of the module plan projection, at any module folding angle (X), the angles (PS) and (LP) add up to 240 degrees. Thus, if angle (PS) = angle (LP) then the module plan projection is a hexagon; if either angle (PS) or angle (LP) is equal to 60 degrees, the module plan projection is an equilateral triangle.

The angle (RSA) is the unit angle for side integration to form a circular group. The relation between the three angles is (RSA) = PS - 120 Or (ESM) = LP - 1200 for positive values of (RSA). Face integration is simple for modules which have angle (PS) or angle (PL) equal to 60 degrees, where the integration will be in a horizontal plane. However, the face integration of modules having other values would be more complicated.

The last four modules have a wide range of applications; they can facilitate frame construction design and they can be used as construction panels.

TENTS Tents have been known and used for many hundreds of years. They are still used all around the world in numerous fields. Most of them have one or more central poles, which support the tent canvas. The construction of tent frames is a clear application of the present invention, where the space shape of each module can be considered a sort of tent. The tent poles or frame members can be arranged along fold lines in the modules and can be connected by suitable hinges. Since all the modules are created by folding a flat surface, the tent canvas is not limited to any one fold angle, which means that the same canvas can be used for the tent regardless of the desired adjusting angles. Providing the tent poles can support the weight of the tent, there is no need for a central pole, thus increasing the usable area under the tent.

FOLDABLE INTEGRABLE TENT FRAME This is a most glorious application of the invention.

A tent frame can be completely folded and can be fully integrated with similar frames to form a compound of tents. Fig Sa up to fig 9c indicate the design concept of this tent frame. The second module is used to explain the design concept. The frame members are connected together by suitable hinges which would be made of metal or rubber to give free member movement. Fig Sa, Sb and Sc indicate the plan and two side views of the erected frame. The frame members consist of three types, transverse members [20], lower members [4], and upper members [7]. The upper and lower members are connected together through frame head [1]. The lateral or transverse members [20] and upper members [7] are connected together with upper hinges [22]; lateral members [20] and lower members [4] are connected together with lower hinges [21]. The hinges are designed to give members free movement in folding directions. The members and hinged connections (nodes) move symmetrically relative to the frame head [1]. Since each member is coupled to the frame head [1] and two other members, none of the members are free to move independently. The hinges could be made of rubber for small, lightweight frames, or they could be made of metal for large and heavy duty frames. The frame has eight, identical, triangular sides, each bounded by the three types of members. These triangles have a fixed shape and move as one part during partial folding. A folding hinge [23] is added to each upper member [7] to facilitate the complete folding of the frame. Once the frame is fully extended, the folding hinges are locked to keep the upper members [7] straight.

The detail of the head frame [1] is shown in figures 6a, 6b, and 6c. The head frame [1] consists of a housing to which all the upper and lower members are hinged. The housing has eight slots; four slots [11] for the lower members [4] and four slots [18] for the upper members [7]. The upper ends [5,8] of the upper and lower members pivot in the slots about hinges [6] and [19] respectively. The upper ends [8] of the lower members extend inside the housing and have curved tips which engage spring seat [3] which is biased by spring [2]. The curved tips press against the bias of the spring at all times, and are shaped to give an over-centring type action to lock the members in position when the tent is folded away.

Figure 6d shows the sequence of folding and the force transmitting contact between curved tips [8] and bottom of the seat [3] before and after folding. As the members [4] are folded together, the seat [3] rises up to the topmost position thereby increasing the downward spring force, at that position the members [4] are nearly vertical and the reaction force pass through centre of pivot [19], so the members [4] and seat shall be in equillibrium. As the members [4] move slightly inside toward the centre, the seat [3] moves slightly down creating a reaction force passing outside of pivot [19] which keeps members [4] in folded position and prevents unwanted unfolding of the tent frame.

Four link rods or struts [13] for adjusting and locking the frame in certain positions are connected to the lower members [4] with hinges [17].

The lower ends of the link rods [13] are connected to a sliding plate [14] with hinges [24]. The plate [14] slides along a threaded bar [10]. The upper and lower nuts [12] and [15] are used for locking the sliding plate in position relative to the bar [10] The threaded bar [10] is fixed rigidly to the bottom [9] of the frame head [1]. The threaded bar [10] is calibrated for easy and accurate determination of the tent angle. By moving the sliding plate [14] up or down, the tent angle increases or decreases accordingly. After reaching the desired angle, the sliding plate [14] is locked in position by upper and lower nuts.

The tent covering remains taut, and is not affected by adjusting the tent angle.

Fig 7a, 7b and 7c indicate the sequential steps for complete folding of the tent frame which is completed in two steps. In the first step, the lower locking nut [15] is released and the lower members [4] are forced against the spring bias towards the bar [10]. In order to clear the radially outermost edges from the ground, it may be necessary to slightly up the frame.

Once the members are held in the folded position by the over-centring action previously described, upper locking nut [12] is lowered to lock the sliding plate [14] in its new position.

In the second step, the locking hinge [23] is released to allow the folding of the upper members [7]. The four folding hinges [23] are pushed towards the bar [10] so that, each of the four upper members [7] starts to fold back on itself. This pulls the lateral members [20] towards a vertical position. Finally, all members are pressed together and held tightly, nearly in vertical alignment. Fig 7a indicates the frame before folding, fig 7b indicates the frame at the end of the first step; and fig 7c indicates the frame nearing the end of the second step. Opening the frame is completed by reversing the sequence of steps.

The figures 8a and 8b shows the plan and perspective views for a tent which uses the frame of Figures Sa, 5b and 5c.

Fig 8c shows the tent with closed side faces [30];, these side faces [30] are fabricated according to the desired tent angle.

The figures 9a, 9b and 9c show examples of integration arrangements using tent units, which have the same (a/l) ratio, but different folding angles, as per Chart 3. The figure 9a illustrates side integration when angle (KPKP) = 1350. The interior area has square plan shape which may be used for ventilation and lighting. The Figure 9b shows side integration when angle (KPKP) = 1200; the central area is diamond shaped in this case. The Figure 9c shows full integration when (KPKP) = 900. The tent unit plan shape is square, and capable of all types of integration (side, angle and face) in all directions, forming rectangular or square integration arrangements or compounds. The complete folding and unfolding of a compound of integrated tent frames at one time as one construction is possible, and Figures 10a and 10b indicate the principal of this idea. The upper members of the tent frames are substituted by ropes which permits complete folding of the compound.

The weight of the tent is supported by the lower members which rest on the ground. When the compound is erected, the ropes are in tension and work as rigid members. (Figure 10b shows schematically the force lines "F" in the compound). For stability, the outer frames are tethered by guys [40]. The camp is completely folded up by moving the four sides towered the center or by moving the two sides towards the far corner. The idea of using tension ropes is applicable for unitary tents, in which case, when completed unfolded, the frame should be tethered from the four sides. This idea would be particularly suitable for large unitary tent frames.

POWERED INTEGRABLE FOLDABLE SHADE UMBRELLA The shade umbrella can be considered as a special overhang tent. The design concept of foldable tent, which is described in fig 5a to 7c, is similar and can be applied with some modifications. For example, if the tent module is installed upside-down with the frame head 1 mounted on a pillar, a shade umbrella will be formed. The shade umbrellas can be integrated together to create a vast shaded area. The design principal of the foldable tent can be modified to create a Powered Integrable Foldable Shading Umbrella. An electric motor ,24] installed in the frame head, powers the folding motion, and all upper and lowered members are provided with links for stability and moving the members.

Fig 11, 12a, 12b, 12c and 12d indicate the design concept of powered integrable foldable shade umbrella. Fig 11 shows a perspective view of the members [4 and 7] and links [13 and 26]. The threaded bar [10] is rotatably driven by the motor in the head [1]. Rotation of the bar [10] moves the internally threaded disk [14] along the bar. One end of each link [13, 26] is hinged to the disk and the other end is hinged to one of the members [4, 7]. The Fig 12a shows the front view for the opened umbrella; figure 12b shows the umbrella partly folded; and figure 12d shows an enlarged view of the head indicating the electric motor [24] and the base on which the frame head is rested to which it is fixed. Figure 12c is a plan view indicating the distribution of the members around the head frame. The head frame plate cover is bolted to the head frame by eight bolts [25].

The folding sequence begins when the electric motor [24] starts to rotate the threaded bar [10], the threaded bar being either directly connected to the motor shaft or connected to it through reduction gearing to increase the resultant torque.

The rotation of the threaded bar [10] drives the disk [14] threaded thereon away from the frame head drawing all the members towards the vertical. The members [7] are divided by the hinges [23] into two parts [7L and 7U]. In the fully open position, the two parts of the member [7] are in a straight line. During folding, the lower part member [7L] rotates about a pivot point fixed in the head frame. The upper part member [7U] rotates in the opposite direction around hinge [23], helping the frame to fold compactly. The hinge [22] which is initially higher than the hinge [23] moves downwards relative to the hinge [23]. The member [20] moves laterally and rotates simultaneously; it moves towards the threaded bar [10] and rotates into a substantially vertical orientation. The further the disk [14] moves from the frame head [1] , the closer the members become to adopting a vertical position. Movements of the members are controlled by the electric motor [24]; when the motor stops, the members are immobile. The length of links [13 and 26] and their connection to the members are selected to facilitate the desired motion. The shade umbrella is opened by rotating the motor in the reverse direction, thereby reversing the folding sequence.

SPACE FRAMES Space frames is another important application of the present invention in the field of steel construction. The space frames are mainly constructed from members connected together at nodes Using modules according to the present invention offers high flexibility in the design of the space frame. More over, only one kind of module would need to be used to construct a complete space frame.

Fig 13a, 13b and 13c indicate the arrangement of nine of the second- modules each having angle (KPKP) = 90 degrees. The modules are fully integrated to form a square space frame. Fig 13a is a plan view of the arrangement. The modules which are indicated as a folded surfaces fully integrated with each other.

The hatched area is one module unit. Fig 13b and 13c are side views.

The space frame shown in fig 14a, 14b and 14c is the same as that shown in the previous figures except that the folded surfaces are replaced by bar-like members and node joints. The members are aligned along the fold lines of folded surfaces. The node joints are used to connect the members. Fig 15 is a perspective view of the structure of fig 14a which shows the arrangement of the members of the space frame in three dimensions.

Fig 16a, 16b indicate an arrangement of fifty-four of the fourth- modules, each having angle (PS) = 60 degrees, so the module plan projection is an equilateral triangle. The modules are integrated to form a hexagonal space frame. The Figure 16a is the plan view and fig 16b is the front view, with the shaded area representing one of the modules.

Figures 17a, 17b and 17c indicate an arrangement of twenty-one of the fourth-modules, each having angles (PS) = (LP) = 120 degrees, so the module plan projection is hexagonal. The modules are integrated to form a triangular space frame. Figure 17a is the arrangement plan view and figure 17b and 17c are the front and side views; the shaded are represents one is module unit.

Figures 18a and 18b indicate an arrangement of eighteen of the first- modules, each having angle (PLA) or (PLB) = 120 degrees. The modules are integrated to form a circular space frame with a star-shaped opening at the centre. Figure 18a is a plan view and figure 18b is the front view. The shaded are represents one of the module units.

In each of the previous examples, only typical modules are used to form the space frames. All previous examples are also applicable to tent frames. The third module has the same integration potential as the other module types. The previous examples are not the only integration possibilities between the modules.

ARCHED VAULT The construction of a curved space frame represents a big challenge. Nearly all known designs use more than one module type to form the curvature. Fig l9a, 19b and 19c indicate the principle of constructing the arched vault space frame using only one module type of one size. A non-symmetrical second module is used for face integration in two directions. As mentioned in the description of the second module, the module is divided into four sub-modules. The left and right sub-modules, in the X direction in fig l9b, have the same size ratio (b/l) forming inclined faces with a curvature angle. The other two sub-modules, in the Y direction, have a different (b/l) ratio which form parallel sides faces with (RAN) angle equal to zero. The integration in X direction will form the arch; the integration in the Y direction defines the axial length of the vault. Fig l9a is the side elevation of eight modules which are face integrated to form an arched vault. Fig l9b is the plan view of four arched vault units integrated together to form complete curved space frame. The hatched area represents one of the module units. Figure 19c is the perspective view of the curved space frame SPACE FRAME COLUMN The columns are important part of any comprehensive construction. Some modules of the present invention can be used to construct the columns. Fig 20a, 20b, and 20c illustrate the use of vertical integration to form a space frame column. Only completely symmetrical modules can be vertically integrated.

Figure 20a is a form of the second module with angles (KPKP) and (LDKP) equal to 135. Figure 20b is the same module rotated through 45 degrees. These two modules can integrate when one is stacked immediately above the other. Fig 20c shows the sequence for stacking the modules vertically to form a column. The points a,b,c,d and e are the integration points, the upper modules shall integrate by the same manner. Since the pre-described module can be integrated in a plane as in fig 9a, the space frame column module can also be side integrated.

Fig 21a and 21b illustrates a space frame integrated both horizontally and vertically. Figure 21a shows three units of the fourth module, each having angles (LP) = (PS) = 120 degrees.

The three units are fully integrated in the horizontal plane.

Also each one of the three modules is integrated in the vertical direction with other modules; vertically adjacent modules being angularly offset by 60 degrees, as in figure 21b. The result is a single column composed of three interengaging columns.

If the modules of a space frame column are rotated into registration the column can collapse in a vertical direction to minimize the volume for storage or transportation. It is possible to integrate between space frame columns and horizontal space frames which employ the same module. The upper module of the column also forms part of the horizontal space frame. Thus, only one module would need to be used to construct a complete integrated frame construction, including a multi-story construction, giving great opportunities for lowering the costs and facilitating construction.

CONSTRUCTION APPLICATION Fig 22 indicates a application example for using modules to cover the spectator area of a stadium with integrated frames. Two different module units each according to the fourth module are used, the two units having different size ratio (a/l).

Nine of the first unit modules, are integrated each having (RSA) angle equal to 20 degrees, to form each one of the two semicircles. Eleven of the second unit modules, each having (RSA) angle equal to zero, are used to connect the semi-circles, with four modules side integrated in a straight line on either side of the stadium. The remaining three modules are added to one side of the stadium in order to increase the covered area. The two different modules which have different size ratio are side integrated; the length and the upper end height of the common side member for each module should be equal.

UNIVERSAL NODE JOINT The joints represent an important part of space frame constructions. They connect the ends of the members together, and also they should direct forces through the members avoiding bending stresses on the members. The threaded node joint connection is well known and has radial pre-threaded holes into which the members are screwed and hence rigidly fixed with respect to each other. The threaded nodes are manufactured for certain angles which correspond to the main module member angles. The threaded joint nodes are relatively costly and there is limited choice to when changing the angles between the members. Thus, their usability for space frame module integration is very limited. The universal node which is a part of this invention has been developed to give complete freedom for module angles over a wide practical range. It can be used with space frames or tent frames. The universal node can be used as joint connection for most present other modules.

Fig 23a and 23b, illustrate the universal node idea; fig 23a being a cross-sectional view and fig 23b being a plan view. The main idea depends on using the partially spherical body [50] as a central guide for keeping the members in position. The members have concave end surfaces having a radius of curvature mirroring that of the hemispherical body [50] which ensure that the members adopt radial positions and facilitate easy adjustment of members around the hemispherical body [50]. The members can have frustoconical end portions, as illustrated with member [54], to minimize the size of the spherical body [50]. Alternatively, the members can have cylindrical end portions, as illustrated with members [53], to minimise preparation costs and increase the contact area between the members and the hemispherical body [50].

When using frustoconical members [54] it is advisable to use a curved bar having a raised shoulder [62] to increase the usable angle range. All members are pressed tightly against the hemispherical body [50] by curved tie bars [52] and are held at the required angle. Each member has a curved slot [61] through which a curved bar [52] passes. The upper and lower ends of the curved bars [52] are held together by frustoconical collars [55] and [56]. The collars [55, 56] are located at opposite ends of a tightening bolt [58] which extends through the centre of the spherical body [50]. Nuts [70, 71] are threaded on the tightening bolt [58] outside the collars [55, 56] such that, when screwed towards each other, they push the collars towards the hemispherical body [50]. The ends [59] of the curved bars are urged towards each other by the tapered wall of the dollar [55] as the nuts [70] are moved towards the hemispherical body [50].

At the same time, the straight portions [60] of the curved bars slide toward each other on the top surface of the hemispherical body and the members are pressed towards the centre point [4]. The end [59] of each curved bar is slightly chamfered to ensure better end contact with adjacent curved bars to prevent the bars from rotating relative to each other even when no members are engaged in the node. The curvature of the curved bars offers a slight spring action which assists the locking action of the node joint.

The lower part of each curved bar [52] slides on seat [57] which has a profile to match the curvature of the curved bars at the points of contact.

The members are rigidly held against the spherical body after complete tightening of the nuts [70, 71]. If one of the members is under compression, the force is transmitted directly to the spherical body. If one of the members is under tension, the force is transmitted through the curved bars to the upper and lower collars. In either case, the load bearing component must withstand the load. The overall force on the node must balance in order to keep the node in position.

The universal node design concept can accommodate different types of members over a wide range of angles; there is no need to make independent adjustments to fit each member. If the module members and nodes are correctly sized, the modules shall be self positioned and integrated in the correct place on tightening the nodes.

PANEL CONSTRUCTIONS The constructions using prefabricated panels is another application of the present invention, and uses include skylight panels, roofing, walling, ceiling tiles and storage tank constructions. The panels are formed to take the shape of a preselected integrable module. The panel materials may be metal, plastic, fiber glass or any similar material. The panels can be easily formed by pressing the initial flat surface of the module to the desired angle. The panels can be integrated to form horizontal, vertical or curved surfaces as showed in figures 13c, 16a, 17a, 18a and l9c.

SKYLIGHT PANELS Most types of sky light constructions use flat panels of glass with special space frames to carry the panels. In this system, the glass is cut to size to fit the frames and mounted so that each panel is bounded by framework. The system disadvantageously needs a large number of interlocking frames, and also the panels may not all be of similar shape, especially for curved constructions. Another type of skylight construction uses pre-molded acrylic panels which have the advantage of reducing the number of interlocking frames. Furthermore, owing to the fact that acrylic is less dense than glass, the required framework can be lighter and simpler. However, the main problems of acrylic panels are the high cost of the molding process and the module shapes which have limited integration potential. Applying the invention to skylight construction could help to decrease panel cost and give rise to a new range of module shapes. The shaping of the acrylic module panels does not require the casting of molten material into purpose built moulds. Instead, the module panels are formed from flat acrylic sheets using heat to soften the material and a press to force the material into the required shape. This method of manufacturing is easier and more economical than moulding molten material.

CONSTRUCTION PANELS FOR WALLS OR ROOFS Integrable module panels for walls or roof construction can be formed in the same way as the skylight panels. The type and size of the modules is obviously governed by the intended application. The panels can even be constructed with double skins with heat insulation in between to improve thermal insulation performance. The method of assembly and fixation varies from application to another.

CONSTRUCTION PANELS FOR STORAGE TANKS Tanks fabricated from panels are used in many applications; these tanks have the advantage of assembly in situ.

CEILING TILES Using modules according to the invention as ceiling tiles has a potential sound attenuation effect. The multi-inclined surfaces of the modules may diffuse the sound.

As shown in Figures 24a and 24b portions of the modules described above can be integrated where the portions are each able to rest on at least three points. Figure 24a shows a plan view of four modules of the type of Figure 9c. Integrating the adjacent halves (shown hatched) of the four modules forms a space which is usable either on its own or in continuation with similar space shapes. Figure 24b is a perspective view of the shape of Figure 24a and illustrates how each module half is resting on three points.

Claims (21)

1. A structure having at least six mutually inclined planar faces, with adjacent faces intersecting along lines which all intersect at a common apex, the lines of intersection being inclined to a central axis of the support structure which passes through the apex, with alternate lines of intersection inclined at a greater angle than lines of intersection therebetween.

2. A structure according to claim 1 further comprising support arms aligned along each of the lines of intersection, the support arms being connected to a housing at the apex.

3. A structure according to claim 2 in which the connections between the support arms and the housing are pivotal, the arms being pivotable towards the central axis, and further comprising means for locking the arms in position relative to the central axis.

4. A structure according to claim 3 in which the angles between the support arms and the central axis are variable.

5. A structure according to claim 3 or 4 further comprising biasing means for urging the support arms to pivot in a direction away from the central axis.

6. A structure according to claim 3, 4 or 5 further comprising support members which pivotally connect together the support arms, the support members being spaced from the housing.

7. A structure according to claim 6 in which the support arms inclined at the greater angle to the central axis have hinge joints enabling the ends of the said support arms spaced from the housing to fold towards the housing whilst the other support arms pivot towards the central axis.

8. A structure according to any of claims 3 to 7 further comprising an axial support along which the locking means is moveable, and struts which extend between the locking means and alternate support arms.

9. A structure according to any preceding claim further comprising transverse arms connecting adjacent support arms.

10. A structure according to claim 2 in which at least one of the support arms inclined at the greater angle to the central axis is a rope which, in use, is maintained in tension.

11. A structure according to claim 1 formed from a planar sheet of material.

12. A structure according to any preceding claim having eight planar faces.

13. An assembly comprising a plurality of structures, each in accordance with any of the preceding claims, the structures being joined together such that the outer edge of one face of one structure contacts the outer edge of one face of another structure along a line parallel to both faces.

14. An assembly comprising at least two structures each in accordance with any of claims 2 to 9, the structures being joined together, with one support arm of each structure coupled to a connecting means which urges the said support arms into radial positions around a common centre.

15. An assembly according to claim 14 in which the connecting means comprises a substantially hemispherical body, against which the ends of the said support arms abut.

16. An assembly according to claim 15 in which the connecting means further comprises guide rails which engage the said support arms and, in use, bias the ends of the support arms against the substantially hemispherical body.

17. An assembly according to claim 16 in which the ends of the said support arms are moveable over the periphery of the hemispherical body in the absence of any bias therebetween.

18. A column comprising a plurality of structures, each in accordance with any of the preceding claims, the structures being stacked in axial alignment, with adjacent structures angularly offset such that lines of intersection at a greater angle of inclination of one structure are registered with lines of intersection at a lesser angle of inclination of an adjacent structure.

19. A structure substantially as hereinbefore described with reference to the accompanying drawings.

20. An assembly of structures substantially as hereinbefore described with reference to figures 9, 10, 13 to 19, and 22.

21. A column substantially as hereinbefore described with reference to figures 20 and 21.