WO2007137343A1

WO2007137343A1 - Construction shelter

Info

Publication number: WO2007137343A1
Application number: PCT/AU2007/000737
Authority: WO
Inventors: Bruce Charles Turner
Original assignee: Bruce Charles Turner
Priority date: 2006-05-26
Filing date: 2007-05-28
Publication date: 2007-12-06

Abstract

A roof framing system (20) adapted to be supported above the roof (12) of a damaged building (10). A membrane, usually canvas tarpaulins or the like may be supported on the framing to protect and shield the existing roof from the weather and particularly rain or other precipitation. The components of the system may be connected together to accommodate different roof pitches, as well as different widths and lengths.

Description

Construction Shelter

Field of Invention

This invention relates to temporary shelters and more particularly to structures that provide shelter to damaged buildings whilst undergoing repair.

Background

When working on a roof structure, for safety reasons, workers are not or should not be allowed to work when it is raining or when the work areas are wet. This is due to the increased risk of workers slipping or falling and injuring themselves or others. When the local climate has many rainy days or frequent showers, this can cause significant delays and increased cost in completing repairs.

Extreme weather conditions, such as cyclones, tornadoes and hurricanes can cause significant damage to large numbers of buildings. Typically the roof structure is damaged. Until the building is repaired to be weatherproof, any internal damage cannot be repaired. Thus providing a structure or system that is usable on different sized and configured roof structures to provide weather protection will enable roof repairs to be completed more quickly that otherwise and enable the buildings to be repaired at less cost.

Summary of the Invention

The present invention provides a roof framing system adapted to be supported above the roof of a damaged building. A membrane, usually canvas tarpaulins or the like may be supported on the framing to protect and shield the existing roof from the weather and particularly rain or other precipitation. The components of the system may be connected together to accommodate different roof pitches, as well as different widths and lengths.

In preferred embodiments the roof framing system is mounted on conventional scaffolding and is sized to provide sufficient clearance between the frame and the existing roof such that workers may easily work on the existing roof.

In one broad form the invention provides an adjustable structure, for mounting above a damaged roof, the adjustable structure including: at least one first elongate member; at least one second elongate member, spaced from the at least one first elongate member, said first and second elongate members for extending over or adjacent the roof with at least a portion of the roof underneath and between said members; at least one third elongate member extending at least between and mounted to first and second elongate members, said at least one third elongate member connected to said first and second elongate members via respective connectors , at least one of said connectors allowing freedom of positioning of the third elongate member about the axis of the respective first or second elongate member.

The third elongate member may extend over at least one of the first or second elongate members.

At least one of the connectors may include at least two J shaped retaining devices that extend over a one of the elongate members from opposite sides of the one elongate member and sandwich the one elongate member against at least one retaining surface.

At least one of the connectors may include a first pair of J shaped retaining devices that extend over one of the elongate members from opposite sides of the one elongate member and a second pair of J shaped retaining devices that extend over the other elongate member from opposite sides of the other elongate member.

The J- shaped retaining members are preferably J-shaped bolts, with an arcuate retaining portion that extends over an elongate member to be retained and a generally straight portion that extends along side the elongate member transverse to the axis of the elongate member.

The connectors may be separate components or may be integrated into an elongate member. In the preferred embodiments the connectors are separate components. One of the connectors is adapted to engage the end of an elongate member and the wall of the second elongate member. Another of the connectors engages the walls of both elongate members to be connected together.

In the preferred embodiment the elongate members connected by a connector extend substantially perpendicular to each other. Different positions of one elongate members about the about the axis of the other are achievable by rotating the connector about the axis of the other elongate member. It is within the scope of the invention for the connector itself to provide this adjustability, with a first part connected to one elongate member and a second par connected to a second elongate member, the first and second parts capable of being fixed in more than one position relative to each other. The connectors may also provide for the two elongate members connected together to extend other than perpendicularly to each other. This may be at fixed angles of may be at variable angles. Again a connector may have two parts movable relative to each other to provide this adjustability. In the preferred embodiment one of the connectors is adapted to be engaged in or on the end of an elongate member. The connector includes an adaptor plate that has at least one mounting surface complementary to the shape of the elongate member to be connected to. In the preferred embodiment the elongate members are cylindrical tubes and the or each mounting surface has an arcuate shape. J shaped bolts extend adjacent the mounting surfaces and sandwich the other elongate member between themselves and the mounting surface.

Another connector has at least one mounting surface and at least one pair of complementary J - shaped bolts for connecting to an elongate member and at least another pair of J - shaped bolts for connecting to the other elongate member.

In another broad form the invention provides a connector for attachment to an elongate member, the connector adapted to engage the outer surface of the elongate member, the connector including an engagement surface that engages the outer surface of the elongate member and at least two retaining members for sandwiching the elongate member between themselves and the engagement surface, the retaining members extending from adjacent the engagement surface on opposite transverse sides of the elongate member and toward each other. Preferably, when viewed along the axis of the elongate member secured with the retainers, the retainers overlap.

When the elongate member has a cylindrical outer surface the retaining members preferably have curved portions that engage the cylindrical outer surface. In the preferred embodiment the retaining members are J-shaped bolts.

In other forms of the invention the or each third member may be connected to the first member via a hook like first connector member that engages a portion of the first member.

The first member may include a rod or tube like member that extends longitudinally to which the hook member engages and is movable along.

The third member may have a substantially straight first portion and a second portion, the first portion extending between the first and second members and the second portion extending beyond the second member. - A -

The second portion may include a first section that extends substantially coaxially with the first portion and a second section that extends downwards relative to the first portion.

The second portion may include a third section intermediate the first and second sections, the third section providing a curved transition between the first and second sections.

The adjustable structure may include tarpaulin retaining means mounted on or extending from the upper surface of the third member, to which a tarpaulin may be attached. This is preferably via a clip or the like but may be by way of rope or elastic tension members.

The tarpaulin retaining means may include an elongate member that extends substantially parallel to the first member. The tarpaulin retaining means preferably extends across at least two third members.

The tarpaulin retaining means may bear against hook members on the third member that each have a first portion extending upwards from the upper surface of the third member and a second portion that depends from the free end of the first portion and extends toward the first member substantially parallel to the upper surface.

The or each third member may rest on top of the second member and may be secured thereto by a second connector member.

The second connector member may include a hook portion that extends over and engages the third member and a clamp portion that engages the second member. The clamp portion preferably defines an aperture through which the second member extends. The adjustable structure may include a rod or tube extending substantially parallel to the second member and connected to the free ends of at least two third members. The free ends of each third member preferably include a tube extending substantially parallel to the second member.

Brief Description of the Drawings

Figure 1 is a schematic perspective view of a building with the roof structure according to an embodiment of the invention mounted on a support structure.

Figure 2 is an end view of the arrangement of figure 1.

Figure 3 is a schematic perspective view of a building with the roof structure according to an embodiment of the invention with the support structure omitted for clarity. Figure 4 is a side view of a first component of the roof structure of figure 1. Figure 5 is an end view of the component of figure 4. Figure 6 is a side view of a component of the roof structure of figure 1. Figure 7 is another side view of the component of figure 6. Figure 8 is a perspective view of the component of figure 6. Figure 9 is a plan view of part of the component of figure 6.

Figure 10 is a perspective view of another component of the roof structure of figure 1.

Figure 11 is a side view of another component of the roof structure of figure 1.

Figure 12 is an end view of the component of figure 11.

Figure 13 is a plan view of part of the component of figure 6.

Figure 14 is a perspective view of the component of figure 6.

Figure 15 is a side view another component of the roof structure of figure 1. Figure 16 is a perspective view of an end plug for the roof structure of figure 1.

Figure 17 is a perspective view of a ridge beam component. Figure 18 is a perspective view of an alternate roof tube assembly. Figure 19 is a side view of the end of the roof tube assembly of figure 18. Figure 20 is a perspective view of the hook component of the roof tube assembly of figure 18.

Figure 21 is a side view of a clamp component.

Figure 22 is an end view of the clamp component of figure 21.

Figure 23 is a perspective view of the clamp component of figure 21. Figure 24 and 24a are perspective views of the beam component and a detail view of its end.

Figure 25 is a side view of the end of the beam component of figure 24. Figure 26 is an end view of the roof structure showing how the components of figures 17 to 25 are assembled.

Figure 27 is a plan view of the roof structure of figure 26.

Detailed Description of Preferred and other Embodiments

Referring to figures 1 to 3 there is shown a damaged building 10 with a damaged roof 12. For clarity the damage is not shown.

A conventional scaffolding structure 14 is build around the perimeter of the building 10. For clarity the scaffolding 14 is only shown extending along the sides of the building 10 and not across the ends. The scaffolding 14 preferably surrounds the building 10 so as to provide a self supporting structure that will resist tipping over. However, this is not essential.

The roof 12 of the building 10 has two sloping faces 16, 18 that extend away and downwards from a longitudinally extending ridge line 20. The invention is not limited to roofs having only two faces and is applicable to other roofs, such as pyramid type roofs having four faces.

Mounted on the scaffolding 14 is an adjustable roof framing system 22 according to an embodiment of the invention. The system 22 includes outer supports 24, which are mounted on the conventional scaffolding structure 14 on either side of the roof 12 and central supports 26, mounted on the ridge board of the existing roof 12.

In the preferred embodiment the conventional scaffolding is built to approximately roof height and the adjustable roof framing system 22 is mounted on the scaffolding.

A ridge tube assembly 38 is mounted on the central supports 26 and extends generally parallel and above the ridge line 20. An outer tube assembly 42 is mounted on the outer supports 24 and extends generally parallel to the edge of the roof 12. Roof tube assemblies 44 extend from the ridge tube assembly, over and preferably beyond the outer tube assemblies 42 and support edge tube assemblies 52 at their free ends. The roof pitch of buildings varies. Accordingly, the angle of the roof tube assemblies 44 to the horizontally extending ridge tube and outer tube assemblies 38, 42 varies. Accordingly, the mounting of the roof tube assemblies 44 needs to allow for variable angles. Similarly, the length of the various assemblies needs to be variable. As seen in figures 4 and 5, each of the central supports 26 is telescopic, having two tubes, with one 28 received within the other 30. The lower tube 30 has a U- shaped bracket 32 mounted at its lower end that is attached to the ridge board (not shown) of the existing roof with the lower tube extending substantially upwards. Other brackets may be used to secure the support to the roof structure. Attachment to the ridge board is via screws or bolts passing into or through the ridge board. This may require removal of part of the existing roof covering top provide access to the ridge board. The second, upper, tube 28 has a series of apertures 34 into which a bolt or pin (not shown) may be inserted to limit movement of the second tube into the first tube. If desired, the outer, lower, tube 30 may be provided with one or more apertures through which the bolt(s) may pass, so as to lock the two tubes together. The upper end of the upper tube has a first connector 36 for attaching to a tube extending perpendicularly to the central support 26. The configuration of the first connector will be explained later. As seen in figures 1 and 3, a ridge tube assembly 38 is mounted on the central supports 26. This is via the connector 36. The assembly 38 extends along the ridge line. The ridge line need not be horizontal and may extend at an angle to the horizontal. Preferably the ridge tube assembly also extends at a substantially constant height above the ridge line, although this is not essential. This is so as to provide a substantially constant working clearance between the ridge tube assembly and the existing roof. The outer supports 24 extend substantially vertically and are secured to the conventional scaffolding tubes using conventional clamps. The upper end of the tube has a connector 40 similar to the first connector 36 on the end of the central supports 26. The connector 40 is for connecting to a tube extending perpendicularly to itself. As seen in figures 1 and 3, an outer tube assembly 42 is mounted on the outer supports 24 via connector 40 and extends generally parallel to the edge of the roof. For a conventional rectangular building this will be substantially parallel to the ridge line. However, the invention is not limited to rectangular roofs and the edge of the roof need not be parallel to the ridge line. In addition, the roof edge need not be straight. For example, a conical roof with a curved periphery may be protected by suitably modified versions of the invention.

Extending between the ridge tube assembly 38 and the outer tube assembly 42 are a number of roof tube assemblies 44. These roof tube assemblies 44 are preferably spaced substantially parallel to each other with a substantially constant spacing, preferably about 1 meter apart. The spacing is not critical and may be made larger or smaller.

The upper end of each roof tube assembly 44 is attached to the ridge tube assembly 38 via a connector 46. The connector 46 is substantially the same as the connectors 36 and 40 and allows the roof tube assembly 44 to be rotated about the axis of the ridge tube assembly 38. Accordingly, the roof tube assembly 44 may extend at any angle to the horizontal. In the preferred embodiments the roof tube assembly 44 extends generally parallel to the existing roof and extends over and beyond the outer tube assembly 42. A second connector 48 (see figures 11 to 14) connects the roof tube assembly 44 to the outer tube assembly 42. As with the connectors 36, 40 and 46, the connector 48 may accommodate different angles about the axis of the outer tube assembly 42. In the preferred embodiment the connectors require the roof tube assembly 44 to extend generally perpendicular to the ridge and outer type assemblies 38 and 42. However, it is within the scope of the invention that the connectors allow the roof tube assembly 44 to extend at an angle to the local axes of one or both of the ridge tube and outer tube assemblies 38 and 42. The roof tube assemblies 44 preferably extend by about 600 to 900 mm horizontally beyond the outer tube assembly 42 and the ends are preferably provided with connectors 50 (see figure 15), for holding an edge tube assembly 52. The edge tube assemblies 52 preferably extend generally parallel to the outer tube assemblies 42. Referring to figures 6 to 8, the first connector 36 is shown. This connector is essentially the same as the connectors 40 and 46. The connector 36 includes a cylindrical portion 54 that is received within the hollow end of a tube assembly. The cylindrical portion 54 is secured in position by a bolt, not shown, that passes through apertures in the wall of the relevant tube and apertures 56c in the cylindrical portion.

Located on the free end of the cylindrical portion 54 is a retainer 58 adapted to be secured around a tube of another assembly. The retainer 58 includes a base 60 having one or more connector surfaces 62 complementary to the surface of the tube being held. In the preferred embodiments all the tubes and poles are hollow and circular in cross section and, accordingly, the mounting surfaces 62 are circular, with a radius corresponding to outer radius of the relevant tubes.

Two J-shaped retaining bolts 64 pass through apertures 65 in the base 60, one on either side of the tube and extend up and over the tube. As seen in figures 7 and 8 the curved portions 66 of the two bolts overlap. Each bolt is preferably located adjacent one of the mounting surfaces 62. The other, straight, end 68 of each of the bolts 64 is threaded and a nut 70 is mounted on a threaded portion 72. Tightening the nut 70 draws the curved portion 66 tightly against the tube and sandwiches it between the mounting surface 62 and the curved portion 66.

The mounting surfaces 62 and curved surfaces 66 of the J - bolts allow the connector to be rotated about the axis of the tube being secured. Accordingly, the roof tube assembly may be secured to the ridge tube at any angle to the horizontal. In the preferred embodiment the base 60 and the mounting surfaces are formed of metal plate or sheet cut and bent appropriately. Figure 9 shows the plate before bending. A cast base may be used, in which case a single, longitudinally extending surface may be provided to receive the ridge tube.

The use of two J- bolts has significant advantages. The nuts on the bolts may be loosened to allow the bolts to be drawn up from the base and rotated so the curved portions do not overly the region where a tube will be placed. The tube can be placed between the two bolts 64 and the bolts then rotated so the curved sections overlay the tube. The nuts 70 are then tightened to secure the tube to the connector. This configuration means that all the components are always secured to the connector - it is not necessary to remove the nuts or the bolts from the connector. Since the nuts and bolts do not need to be removed from the base, the loss of these components during assembly is substantially reduced, if not totally eliminated.

The ridge, roof and outer tube assemblies are preferably constructed of lengths of pipe or tube joined end open end. Adjacent lengths are joined using a joiner 72, shown in figure 10. The joiner 72 has a central, cylindrical, section 74, and two outer, smaller diameter, cylindrical sections 76 that extend from each end of the central section 74. The diameter of the outer sections 76 allows them to be snugly inserted into the ends of the tubes. The diameter of the central section is greater than the inside diameters of the tubes, preferably the same as the outside diameter, and the free ends of the tubes bear against the ends of the central section. Each of the outer sections is preferably provided with at least one retaining mechanism 79 for retaining the outer section within the corresponding pipe or tube. In the preferred embodiment the outer sections have a bore extending diametrically through the section, and a bolt extends through and out of the bore and is retained by a nut on its free end. Alternatively there may be a threaded bore into which a bolt is screwed.

The connector 48, for attaching the roof tube assemblies to the outer tube assemblies, is shown in figures 11 to 14. The connector 48 has engagement surfaces 78, 80 for engaging the surfaces of the two tubes. In the preferred embodiment the connector is similar to the connector 36 and has a folded metal plate 82 having a central section 84 and two upturned ends 86 forming spaced apart curved engagement surfaces 78. The centre section 84 of the metal plate has two pairs of diagonally arranges holes 87, 88, through each of which a J- bolt passes. One diagonally opposite pair of bolts 90 extend in one direction and the other pair 92 extends in the opposite direction. The first pair 90 serves to retain one of the tubes against the curved retaining surfaces 78 whilst the other pair 92 serves to retain the other tube against the rear surface 80 of the central section 84. As with the connector 36, each J-bolt of a pair is located on opposite sides of the tube being retained and the curved portions of the bolts overlap. Th e configuration of the pairs of holes and bolts is that the two tubes are held substantially perpendicular to each other. However, when the connector is not fully tightened, the two tubes but may be rotated around the axis of the other. The connector 100, which is used to mount the edge tube assemblies to the free ends of the roof tube assemblies, is shown at figure 15. The connector 100 includes a cylindrical part 102 adapted to be partially inserted in the free end of a roof tube. The outer portion 104 is of greater diameter than the inner portion 106 to limit insertion into the tube. A bolt 108 passes through an aperture in the roof tube and engages an appropriately threaded bore 110 in the inner portion 106. Attached to the outer portion 104 is a U- shaped clamp 112, sized to receive an edge tube between its two legs 114. The edge tube is secured by a bolt 116 extending between the two legs 1114. The bolt 116 is retained by a nut 118. In the preferred embodiment the U-shaped clamp is a separate component that is attached or mounted on the cylindrical portion, preferably by welding. However, this is not essential and the connector may be formed integrally. The nut and bolt arrangement may be replaced with a spring-loaded pin, which is biased to a closed position. Withdrawing the pin allows the tube to be inserted and when the pin is released it automatically closes the opening, retaining the tube.

An end cap 120, shown in figure 16 is provided for any tube ends that are not closed with an appropriate connector. The end cap 120 includes a cylindrical portion 122 sized to be received in a tube and an end portion 124 that bears against the end of the tube. The cap is retained in the tube by a bolt, not shown, that passes through an aperture in the tube and is screwed into a threaded bore 126 in the inner portion

Once the system has been assembled, preferably a series of tarpaulins are laid on the framework and secured thereto. Preferably separate tarpaulins are used for each roof face and these are laid to extend upwards from the edge tube assemblies to the ridge line. The tarpaulins then overlap at the ridge line. Preferably the tarpaulins extend beyond the edge tube assemblies and hang down, more preferably to the level of the conventional scaffolding 14. This prevents rain or other precipitation falling or being blown onto the working area and so repairs can continue under the protective cover when it is raining. The tarpaulins may remain on the frame work in wind speeds up to about 20 km/hr - at speeds above that they should be removed or rolled up. When the tarpaulins are removed the framework of the embodiment described generates little uplift.

Referring to figures 17 to 27 there are shown variations of the invention to provide better strength, durability and weather proofing for the structure made according to the invention. Figure 17 shows a ridge beam 130 comprising parallel spaced apart tubular members 132 and 134 with cross bracing 136 extending between the tubular members. The ridge beam 130 extends alone and above the ridge of the building to be repaired and is supported via centre beam supports 26. Alternatively the beam 130 may be self supporting between the transverse ends of the structure.

Figures 18 and 19 show a modified roof tube assembly 140 that is intended as a replacement for the roof tube assembly 44 previously described. The assembly 140 comprises two lengths of tubing, having a straight section 143 and has a bent portion tubular 142 at its lower, outer end 144. There is a hook 146 at its upper, ridge end 148. In use the hook 146 engages the upper tubular member 132 of ridge beam 130. Adjacent hook 146 is angle 150 that extends toward the hook. The hook may be permanently affixed to the straight section 143 or may be an end piece 145, as shown in figure 20 that is inserted in the end of the tube 143 and secured using bolt 147

The lower end 144 is bent at about 45 degrees and includes a section of tubing 152 that extends perpendicular to the tubular 142.

In use the roof tube assembly 140 extends from the ridge beam 130 and over the outer tube assembly 42. The weight of the roof tube assembly 140 and tarpaulin supported keep the hook secured to the ridge beam and it is not essential that it be bolted in place. However, this may be done if desired. A clamp 160, shown in figures 20 to 22 secures the tube assembly 140 to the outer tube assembly 42. The clamp 160 has a hook portion 162 that is hooked over the tube assembly 140. A securing member 164, pivotably mounted to hook member 162 about axis 166 perpendicular to tube assembly 140 defines an opening 168 through which the outer tube assembly 42 passes. A threaded bolt assembly 170 allows the clamp to be tightened to the outer tube assembly 42.

A tarpaulin connection beam 180 is mounted on the roof tube assembly 140 adjacent the ridge beam 140. The tarpaulin connection beam 180 extends parallel to the ridge beam and extends over a series of the roof tube assemblies 140.

The tarpaulin connection beam 180 comprises a length of square section tubing 182 and a parallel length of rod 184 or the like that is spaced from the tubing 182. The rod 182 is attached periodically to the tubing 182 by spacer members 186. Clips 188 are mounted on the rod 184 and are free to slide along the rod 184 between the spacers 186.

As seen in figures 26 St 27, the beam 180 is mounted on top of the tube assembly 140 with the square section tube 182 underneath and ridge side of the angle bracket 150 with the rod 184 located away from the ridge. The tube assembly 140 extends over the outer tube assembly 42 with the bent section 142 extending outwards and downwards. A tarpaulin 190 extends over the structure and the bent end 142 of the tube assembly 140. The top edge 193 of the tarpaulin is attached to the tarpaulin connection beam 180 by double ended carabina clips 192. The lower edge 194 is pulled toward the ground by a series of elastic members 196 and so is placed under tension between the clips 192 and the ground or the structure. The elastic members 196 are designed to break under extreme loads and typically have a breaking strain of about 200 kg. Straps 199 extend over the tarpaulin and prevent the tarpaulin escaping if the elastic members 196 break, such as under high wind loads. Straps 199 are attached to the ground or the structure.

A tube 198 extends between or through the tubing 152 located at the end of the tube assembly 140. This aids in keeping the tarpaulin even and straight and allows the tension applied to the tarpaulin to be evened out and the tarpaulin easily tensioned. The bent end portion 142 enables a continuous section of tarpaulin to extend from adjacent the ridge line over all of the roof and down the sides of the structure and to be easily tensioned without damage due to sharp edges or the like. This improves weatherproofing and durability.

Unless the context clearly requires otherwise, throughout the description and the claims the words 'comprise', 'comprising', and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

It will be apparent to those skilled in the art that many obvious modifications and variations may be made to the embodiments described herein without departing from the spirit or scope of the invention.

Claims

The claims defining the invention are as follows:

1. An adjustable structure, for mounting above a damaged roof, the adjustable structure including: at least one first elongate member; at least one second elongate member, spaced from the at least one first elongate member, said first and second elongate members for extending over or adjacent the roof with at least a portion of the roof underneath and between said members; at least one third elongate member extending at least between and mounted to first and second elongate members, said at least one third elongate member mounted to said first and second elongate members via respective connectors, at least one of said connectors allowing freedom of positioning of the third elongate member about the axis of the respective first or second elongate member.

2. The adjustable structure of claim 1 wherein the third elongate member extends over at least one of the first or second elongate members.

3. The adjustable structure of any one of the preceding claims wherein the or each third member is connected to the first member via a hook like first connector member that engages a portion of the first member.

4. The adjustable structure of claim 4 wherein the first member includes a rod or tube like member that extends longitudinally to which the hook member engages and is movable along.

5. The adjustable structure of any one of the preceding claims wherein the third member has a substantially straight first portion and a second portion, the first portion extending between the first and second members and the second portion extending beyond the second member.

6. The adjustable structure of claim 5 wherein the second portion includes a first section that extends substantially coaxially with the first portion and a second section that extends downwards relative to the first portion.

7. The adjustable structure of claim 5 or claim 6 including a third section intermediate the first and second sections, the third section providing a curved transition between the first and second sections.

8. The adjustable structure of any one of the preceding claims including tarpaulin retaining means mounted on or extending from the upper surface of the third member, to which a tarpaulin may be attached.

9. The adjustable structure of claim 8 wherein the tarpaulin retaining means includes an elongate member that extends substantially parallel to the first member.

10. The adjustable structure of claim 8 or claim 9 wherein the tarpaulin retaining means extends across at least two third members.

11. The adjustable structure of any one of claims 8 to 10 wherein the tarpaulin retaining means bears against hook members on the third member that each have a first portion extending upwards from the upper surface of the third member and a second portion that depends from the free end of the first portion and extends toward the first member substantially parallel to the upper surface.

12. The adjustable structure of any one of the preceding claims wherein the or each third member rests on top of the second member and is secured thereto by a second connector member.

13. The adjustable structure of claim 12 wherein the second connector member includes a hook portion that extends over and engages the third member and a clamp portion that engages the second member.

14. The adjustable structure of claim 13 wherein the clamp portion defines an aperture through which the second member extends.

15. The adjustable structure of any one of the preceding claims including a rod or tube extending substantially parallel to the second member and connected to the free ends of at least two third members.

16. The adjustable structure of claim 15 wherein the free ends of each third member includes a tube extending substantially parallel to the second member.

17. The adjustable structure of any one of the preceding claims wherein said at least one connector includes at least two J shaped retaining devices that extend over a one of the elongate members from opposite sides of the one elongate member and sandwich the one elongate member against at least one retaining surface.

18. The adjustable structure of any one of the preceding claims wherein at least one connector includes a first pair of J shaped retaining devices that extend over one of the elongate members from opposite sides of the one elongate member and a second pair of J shaped retaining devices that extend over the other elongate member from opposite sides of the other elongate member.

19. A connector for attachment to an elongate member, the connector adapted to engage the outer surface of the elongate member, the connector including an engagement surface that engages the outer surface of the elongate member and at least two retaining members for sandwiching the elongate member between themselves and the engagement surface, the retaining members extending from adjacent the engagement surface on opposite transverse sides of the elongate member and toward each other.

20. An adjustable structure, substantially as herein described with reference to the drawings.

21. A connector for attachment to an elongate member, substantially as herein described with reference to the drawings.