WO2008068493A2

WO2008068493A2 - Inflatable canopy structures

Info

Publication number: WO2008068493A2
Application number: PCT/GB2007/004671
Authority: WO
Inventors: Andrew Cunningham; Dipesh Patel; Andrew Robertson; Hitoshi Yonamine
Original assignee: Arup Group Limited
Priority date: 2006-12-06
Filing date: 2007-12-06
Publication date: 2008-06-12
Also published as: WO2008068493A3; GB0624437D0

Abstract

An inflatable canopy structure comprises first and second inflatable beams, and an inflatable panel secured between, and supported by, said beams. The beams are supported by rings at the front and rear.

Description

INFLATABLE CANOPY STRUCTURES

The present invention relates to canopy structures, and in particular to inflatable canopy structures .

Sporting and other venues, such as concert venues, frequently have seating areas which are not covered. However, it is desirable in many instance to provide covered seating areas in order to protect spectators from the weather, be it from rain or from sun.

Moreover, there are certain sporting or other venues where temporary covered seating areas are required.

Erecting a canopy over any significant area is time consuming and expensive. Moreover, the structure necessary to support the canopy may provide a substantial obstacle for spectators.

The present invention seeks to provide a canopy structure which may facilitate the provision of covered seating areas either on a permanent basis or more preferably on a temporary basis.

According to a first aspect of the invention, there is provided an inflatable canopy structure comprising first and second inflatable beams, and an inflatable panel secured between, and supported by, said beams. In accordance with the invention therefore, an inflatable structure has beams which provide support for one or more panels arranged between the beams . Such an arrangement is advantageous in that it allows for a simple and effective support for the panels which will in most cases at least form the main area of the canopy.

The canopy structure may comprise any number of beams and panels arranged in an alternating fashion to cover a desired area.

From a further aspect therefore, the invention provides an inflatable canopy structure comprising a plurality of inflatable beams and inflatable panels arranged in an alternating fashion, said panels being secured- between, and supported by, adjacent beams.

The beams are preferably elongate in shape, and of a tubular, circular cross section construction. The panels are generally planar, providing a significant area of coverage between the beams .

Preferably the beams taper, most preferably from front to rear. The infill panels may then be appropriately shaped to engage with the beams . For example, they may have parallel or non-parallel edges.

IrL one embodiment, if the canopy is to cover a generally semicircular, inwardly facing space, the edges of the infill panels converge from front to rear. A straight canopy could be obtained simply by using panels whose edges converge less .

Preferably the beam shape is the same throughout any installation and any changes in canopy shape are achieved by varying the shape of the infill panels.

The panels should be sufficiently strong to resist gravitational and wind loads acting on the panels. However, as the main structural strength of the structure lies in the beams, they may be relatively thin, for example having a width to thickness ratio of between 4 and 8. Preferably the panels are inflated to a higher pressure than the beams .

The beams are intended to support the panels and transfer loads, primarily gravitational and wind loads, acting on both the beams and the panels into an appropriate support. To this end, each beam preferably comprises respective supports arranged at spaced apart locations along the length of the beam.

Preferably, a first structural support is provided at the rear of the beam and a second structural support provided at a location towards the front of the beam. The first, rear structural support is constructed so as to act as the main structural support, in particular preferably resisting both vertical and horizontal loads. The advantage of providing such a structural support at the rear of the tube is that while it may be quite substantial it will not obstruct spectators' vision.

Moreover, by having the main support resist horizontal loads, the second support may not need to resist horizontal loads and need only resist primarily vertical loads. This means that the second support need not be as strong as the first support and may therefore be significantly smaller in terms of diameter or cross- section, thereby providing a smaller obstruction to spectators' vision.

This in itself is a novel arrangement for an inflatable structure so from a further aspect the invention provides an inflatable canopy structure comprising a first support arranged at the rear of the canopy structure for resisting acting substantially vertical and horizontal loads and a second support arranged towards the front of the structure for resisting only substantially vertical loads . . Of course, not all such second supports provided in a structure need be designed to support only vertical loads. Some supports, for example those at an end of a structure may be designed so as also to resist horizontal loading. In certain embodiments of the invention, the rear support may be formed as a frame structure so as to transmit the main canopy loads effectively into the ground or other support, e.g. a stand structure. The forward support may be formed as a relatively slender column which provides minimal visual obstruction to spectators .

From a yet further aspect the invention provides an inflatable canopy structure comprising a first support arranged at the rear of the canopy structure and a. second support arranged towards the front of the structure, said second support being relatively slender compared to said first support. As the forward support may in certain embodiments only resist vertical loading, it may be secured to a support surface or structure using a pin type joint which provides no resistance to bending of the front support .

In the preferred embodiment, the rear support structure comprises a connector which engages over the rear end of the inflatable beam.

In one embodiment the connector comprises a plurality of fingers which engage over the rear end of the beam and are suitably attached thereto. Such an arrangement will transmit shear and torsion into the rear support structure.

Preferably the rear end of the inflatable beam is curved and the fingers are curved so as to match the curvature of the beam.

Preferably the fingers are circumferentially equispaced around the end of the beam in order to transmit forces more evenly into the support. Preferably there are at least eight, more preferably at least twelve fingers.

The fingers need not be rigidly attached to the beam, but may be secured thereto by a plurality of loops of material attached to the beam. This will allow forces to be transmitted from the beam to the fingers in an adequate manner.

This arrangement of connecting an inflatable beam to a support is in itself a novel arrangement so from a further aspect the invention provides a support for a tubular inflatable beam, said support comprising a connector for engaging an end of the beam, said connector comprising a plurality of circumferentially spaced fingers engaging around the end of the beam.

The connector may further comprise a connector plate which also engages the end of the beam. Most preferably the plate is secured to the inflatable beam, for example by bolts. Such connections should, of course, be air-tight to avoid air escaping from the beam.

Preferably the fingers are mounted to the plate, most preferably through a tubular ring attached around the periphery of the plate.

Most preferably the plate is coupled to a pivotal coupling which allows the beam and^' plate to pivot relative to the rear support about a horizontal axis. This will reduce bending forces being transmitted into the rear support due particularly to wind induced movement of the inflatable beam in use.

Most preferably the connector plate is formed with a window which aligns with a transparent or translucent portion of the inflatable beam such that the inside of the beam may be illuminated by suitable lighting means mounted to the connector .

The rear support may be arranged under the rear of the beam in order to provide a more compact arrangement or to meet with the constraints of the installation site. In some embodiments of the invention, therefore, the upper portion of the rear support is cranked with respect to' the lower portion of the support .

In an alternative embodiment, the^{^}rear support comprises a ring which circumscribes a rear section of the beam.

This may be advantageous over the finger arrangement described above, as it may reduce the stresses in the rear of the beam, and may more evenly distribute loads around the beam. From a further aspect, therefore, the invention provides a structure comprising an inflatable tubular beam and a support ring circumscribing and supporting a rear section of the beam.

The ring is advantageously supported atop a support column positioned under the beam. The ring is preferably vertically aligned with the support column.. This is considerably simpler than the cantilevered support discussed above.

The ring may be attached to the beam by means of lacing the ring to flaps provided on the beam structure. Preferably successive flaps are provided on opposite sides of the ring, with eyelets or other openings for receiving a rope or the like. The ring may have also locating eyes through which the rope may pass, preferably provided at spaced apart intervals on its outside diameter.

The ring may be made in more than one arcuate segment, with suitable connections between the segments. Where the beam is to be illuminated, lighting means may be suitably mounted to the rear of the beam, for example using a plate having a transparent port.

In both embodiments described above, the rear support may be attached directly to the ground or may be attached to another structure, for example, a seating ^' stand. In a preferred embodiment, the support is stabilised by props attached to an appropriate support structure. In the preferred embodiment, props extend both generally parallel to and laterally with respect to the axis of the inflatable beam, so as to react forces acting on the support in those directions . Returning now to the forward support, as mentioned above, this is preferably constructed relatively slender in order to minimise any obstruction to spectators. The support beam will act primarily to counteract a proportion of the weight and wind loads acting on the canopy structure and as these can be quite significant, if the connection between the forward support and the inflatable beam is not properly designed it could lead potentially to the column piercing the beam structure, particularly under downward wind loading. Accordingly, in certain embodiments of the invention, the beam is provided with reinforcement in the region of the attachment of the forward support to the beam. In one embodiment, the beam comprises one or more reinforcing tubes aligned with the support and inflated to a higher pressure than the remainder of the beam. Such an arrangement provides a relative rigid section of beam which will resist the tendency of the beam to deform in this area. It also allows the beam to resist downward wind loads which may act on the structure in that area, thereby avoiding the possibility that the forward support may pierce the beam. This arrangement for providing reinforcement in an inflatable structure is in itself novel, so from a further aspect the invention provides an inflatable tubular structure comprising a tubular reinforcement arranged at a predetermined position along the length of the structure and inflated to a higher pressure than the inflated tubular structure.

The tubular reinforcement is preferably annular, so as to provide a central opening. This will allow light to pass through the reinforcement from the rearward to the forward part of the canopy.

Whilst a single annular reinforcement may be provided, in order to provide sufficient strength and stiffness with such an arrangement the central opening in the reinforcement would have to be relatively small ; This is not- optimal for light transmission etc. to the forward part of the beam. Accordingly, in a preferred embodiment, the reinforcement comprises a double annular tube construction. This will allow a larger opening to be provided through the centre of the reinforcement while at the same time providing the requisite strength. A double annular tube arrangement will also allow the forward column loads to be received by the inflatable beam over a larger area.

Although the annular tubes may be completely separate, they are preferably joined together along a common web, with air hol'es being provided through the ^■ web to allow inflation of both tubes from a single source.

Preferably the forward support structure is connected to the reinforcement over an area so as to distribute loads acting on the reinforcement and the support to further reduce the possibility of the support piercing the structure. In a preferred embodiment, therefore, the front support is provided with a cradle which engages the beam around the reinforcement . Preferably the cradle comprises a ring whose curvature matches that of the reinforcement and which is connected to the support by a plurality of angled support arms .

The ring may be generally elliptical- in plan view and it may be provided with one or more mountings which engages the reinforcement and which are secured thereto for example by a plates arranged on the other- side of the skin of the reinforcement or tube.

Preferably the ring is arranged such that in the axial direction of the beam, its axial extremities align with the centre lines of the respective tubes in a- double tube arrangement.

The tubes may be enveloped by a common fabric skin ^■ and the upper part of the support may be attached thereto in a similar manner to that described above.

In an alternative embodiment,, the front support may be attached to the beam by a ring externally circumscribing a front portion of the beam. This is advantageous in terms of simplicity and also in terms of better distributing stresses around the forward part of the beam.

From a further aspect, therefore, the invention provides an inflatable tubular structure comprising a support ring externally circumscribing a front portion of the tubular structure.

The front support ring may be suitably mounted atop a support column. As discussed above, in the preferred einbodiment the support column is relatively slender, and the front support ring may simply be attached to it by a clevis type connection, which will counteract vertically applied forces and will avoid or reduce bending stresses in the ring.

One or more tension cables may be provided extending between the front ring and front support column for additional rigidity.

As the front support may be relatively slender, a problem which may arise is that the column may be susceptible to buckling. To mitigate this problem, a lateral support is preferably provided at an intermediate position along the length of the column. Most simply this may comprise one or more lateral support surfaces on a stand structure through which the front support . column passes. The column may be provided with a bracket or the like to engage the support surface (s) .

Where the front support also has to resist • horizontal loadings (for example at the end of a structure) , the front ring or the upper part of the front support column may be braced e.g. by bracing cables.

The front ring may be attached to the beam in the same manner as the rear ring described above, and also ^• be constructed from joined segments, as with the rear ring.

In addition to the forward and rear supports discussed above, it will be understood that in use the inflatable canopy structure will be subjected not only to downward loadings due to weight and wind, but may also experience upward loading due to wind. In fact uplift loadings may be very high and indeed significantly larger than the downward loadings on the structure. The forward and rear supports will in the preferred embodiment counteract such loadings, but as there may be some considerable spacing between the rear and forward structure supports, in the preferred embodiments of the invention further structure for resisting uplift forces is arranged between the rear and forward supports. Such a structure does not have to resist downward forces acting on the canopy as^' these are taken through the forward and rear supports . It acts to reduce the effective span of the beam under uplift loadings . . .

This in itself is a novel arrangement, so from a further aspect, the invention provides an inflatable canopy structure comprising forward and rear supports for counteracting forces acting on or due to the canopy and a further support intermediate the forward and rearward supports for counteracting uplift forces acting on the structure.

Since the intermediate structure does not have to counteract downwardly acting forces, it can be constructed purely as a tension member, for example in the form of a flexible tie down member, for example a tie-down cable or a tie-down strap.

In one embodiment, a saddle is formed around the appropriate part of the inflatable beam and the tie-down member attached to the respective ends of that saddle. The saddle acts to distribute the uplift forces more evenly into the beam.

The saddle may be of fabric and may be welded or otherwise secured to the beam. The respective ends of the saddle and the end of the tie-down member may be provided with suitable connectors. In a simple embodiment, the connectors comprise respective plates which are joined in use by cables.

The saddle may be generally rectangular in projection, but in a preferred embodiment, the respective sides of the saddle taper towards the bottom of the beam.

This provides a more aesthetic appearance and facilitates connection to the tie down member. In another embodiment, however, the intermediate support may be formed as a ring circumscribing the beam. This may facilitate the attachment of the tie down member to the intermediate support, e.g. via suitable lugs on -the ring.

The intermediate support ring may be constructed and attached to the beam in the same manner as for the aforementioned front and rear rings .

In the preferred embodiment, therefore the beam is supported by external rings at its front and rear and at an intermediate location. From a further broad aspect, therefore, the invention provides an inflatable canopy structure comprising an inflatable tubular support beam, said support beam being supported by rings circumscribing the beam at a rear location, a front location and a location intermediate said front and rear locations .

In broader terms still, the invention provides an inflatable canopy structure comprising an inflatable tubular support- beam, said support beam being supported by rings circumscribing the beam at a rear location, and a front location.

The rings and their supporting structure may have the features discussed above. As mentioned above, generally the inflatable beams will be generally tubular in form and the panel arranged between the beams will be generally planar in construction. The connection between a beam and panel must be able to transmit the forces acting on the panels, for example gravity and wind loading, into the beams so that these forces can be suitably reacted by the beam supports .

From a further aspect the invention provides a connection between an inflatable support tube and an inflatable panel, said connection comprising a first connection for transmitting shear between the panel and the tube and a second connection for resisting rotation of the panel relative to the tube.

The first connection may comprise a shear key arranged between the tube and the panel. This may, for example, comprise a clevis type coupling.

In one embodiment, however, the first connection comprises one or more tension members, preferably straps, connected between the beam and the panel. In one embodiment, a first tension member is attached between an upper part of one of the two parts and a lower part of the other component. A second tension member is then attached between an upper part of the other component to a lower part of the first component. This double strap arrangement provides a mechanism to transfer the shear loads from one component to the other.

From a further aspect, the invention provides a connection between an inflatable support tube and an inflatable panel, said connection comprising a first tension member attached between an upper part of one of the two parts and a lower part of the other component and a second tension member attached between an upper part of the other component to a lower part of the first component . • The second connection means may comprise respective flaps joining respective upper parts of the two i components and respective lower parts of the two components . A tie member may extend between the two flaps which can be pretensioned in order to draw the two components together .

A plurality of connections may be provided along the interface of the beam and panel .

The upper flap may be continuous so as to act as a gutter for the canopy. In other embodiments, however, a simpler construction may suffice. In a further embodiment, therefore, the connection may simply comprise upper and lower laced connections between the beam and panel.

Preferably each connection comprises respective upper and lower pairs of flaps attached to the beam and the panel respectively, suitably laced together. The flaps provided on the panel may advantageously be formed from the same piece of material.

Preferably the panel comprises a plurality of transversely extending sections or compartments, suitably joined together, and a connection is provided at each panel section.

In a preferred embodiment therefore, the panel is formed with a plurality of transversely extending compartments . The upper surfaces of each compartment are preferably curved so as to give a ribbed appearance to the panel. Respective transversely extending troughs are formed between the compartments which will allow water to accumulate and to be conducted to a gutter at the edge of the panel. In one embodiment, the central- section of the panel is deeper than its transverse edges, such that the troughs are naturally inclined towards the transverse edges of the panel to provide the requisite drainage.

However, this may be difficult to manufacture, and in an alternative construction, the panel is of substantially constant depth. This means that the troughs between adjacent ribs will be generally horizontal and thus unable to drain the water from the centre region of the panel . ' To overcome this problem, a drainage sheet is preferably attached across each trough between adjacent ribs . The drainage sheet is attached between a relatively high point on a central portion of each rib and a relatively low point on an edge portion of each rib such that the drainage sheet slopes downwardly towards the edge of the panel so that water can drain down the drainage sheet towards the edge of the panel . This is an inventive construction in its own right and may have general application to_, all manner of ribbed structures. From a further aspect, therefore, the invention provides a structure having a plurality of transversely extending ribs separated by respective troughs, and a drainage surface formed across a said trough between adjacent ribs, said drainage surface extending between a relatively high point on adjacent ribs to a relatively low point on adjacent ribs, thereby creating an inclined drainage surface.

Preferably the ribs are formed in an inflatable structure with generally parallel upper and lower surfaces as described above.

Preferably also the drainage surfaces are formed by panels or sheets which are suitably attached, for example welded, between the ribs of the structure.

Most simply, the drainage surface can be formed from an appropriately shaped sheet of fabric.

In assembling the construction, sections of structure may be preassembled before being installed in situ. For example, a section comprising two beams and a panel may be preassembled and installed. A further such unit may then be installed spaced from the first unit and a further infill panel then located between the two units in situ.

From a further broad aspect the invention provides a method of installing an inflatable canopy unit comprising first and second beams with a panel arranged between the two beams, comprising joining the beams ■ and panels together prior to installation.

From a further broad aspect the invention also provides an inflatable canopy unit comprising first and second inflatable beams, and an inflatable panel secured between, and supported by, said beams. Some preferred embodiments of the invention will now be described by way of example only, with reference to the accompanying , drawings in which: Figure 1 shows an inflatable canopy structure in accordance with the invention in situ;

Figure 2 shows a plan view of a structure in accordance with the invention; Figure 3 shows a detail 3 of the canopy of Figure 2;

Figure 4 shows a front view of a section of the canopy structure of Figure 1;

Figure 5 shows a more detailed view of an inflatable beam of the canopy of Figure 1;

Figure 6 shows a greater detailed view of the in fill panel of the canopy of Figure 1 ;

Figure 7 shows detail of the connection of the beam of the canopy of Figure 1 to its rear support; Figure 8 shows a view along line 8 - 8 of Figure 7; Figure 9 shows a partial view along the line 9 - 9 of Figure 7;

Figure 10 shows an underneath view of a beam of a canopy of Figure 1 showing the joining of the forward support to the beam structure;

Figure 11 is a sectional view along the line 11 - 11 of Figure 10.

Figure 12 is a detail of area 12 marked on Figure

11; Figure 13 is a detail of area 13 marked on Figure 12;

Figure 14 is a side view of Figure 12; Figure 15 is a detail of the. area marked C on Figure 14; Figure 16 shows a section through the inflatable beam of the canopy of Figure 1 in the area of the tie down saddle;

Figure 17 is a detail of area 17 of Figure 16; Figure 18 is a top view of the saddle arrangement; Figure 19 is a view in the direction of arrow E of Figure 18 showing attachment of the saddle to a tie down cable; Figure 20 shows a perspective view of a preferred arrangement for joining a beam to an infill panel;

Figure 21 ^"is a section through Figure 20;

Figure 22 shows detail 22 of Figure 21; Figures 23 to 26 illustrate a sequence of erecting the canopy structure of Figure 1;

Figure 27 shows a second canopy structure embodying the invention;

Figure 28 shows a second embodiment of an inflatable canopy structure in accordance with the invention;

Figure 29 shows a double panel canopy structure similar to that shown in Figure 28;

Figure 30 shows a front view of a section of the canopy structure of Figure 28;

Figure 31 shows a side view of a canopy structure as shown in Figure 28;

Figure 32 shows a detail of the connection of the beam of the canopy of Figure 28 to its rear support; Figure 33 is a front view of the detail of Figure 32;

Figure 33a is a perspective view of the detail of Figure 32;

Figure 34 is a detail of the attachment of the support ring of Figure 33 to the inflatable beam;

Figure 35 shows a front view of the attachment of the front support ring to the inflatable beam;

Figures 35a and 35b details of Figure 35;

Figure 36 shows a front view of the attachment of the intermediate ring to the inflatable beam;

Figure 37 shows a connection of the inflatable beam to an infill panel;

Figure 38 shows a sectional view through such a connection; Figure 39 shows a sectional view through a beam and infill panel;

Figure 40 shows a plan view of Figure 39. Figure 41 shows a straight multibay structure in accordance with the invention; and

Figure 42 shows a curved multibay structure in accordance with the invention. Referring firstly to Figure 1, a canopy structure 2 in accordance with the invention is shown mounted over a stand 4 having an upper seating tier 6 and a lower seating tier 8. The stand 4 may be for a permanent structure or more preferably it is a temporary structure installed in a desired location, for example at a sporting venue.

The canopy structure 2 comprises a plurality of elongate inflatable beams 10 joined together by a plurality of inflatable in fill panels 12. Each inflatable beam 10 is supported by a rear support 14 and a forward support 16. Intermediate the rear and forward supports 14, 16 is a tie down member 18. Further details of this support system will be described below. With references to Figures 2 and 3, it will be seen that each inflatable beam 10 is elongate, having curved forward and rearward ends 20, 22. In this particular embodiment, the canopy 2 is intended to extend over a arcuate area so each inflatable tube 10 tapers in diameter from its forward end 20 to its rearward end 22. The inflatable beam 10 is formed from any suitable, sufficiently- strong air tight fabric which will allow the beam to resist environmental factors such as rain, sunlight and impact damage. Such materials are well- known in the art and include for example a type 3 PVC coated polyester.

As shown in Figures 2 and 3, the centre lines 24 of the respective inflatable beams 10 converge to a common centre radius such that the facing regions 26 of adjacent tubes 10 diverge from one another towards the rear of the canopy 2. This diverging space is filled by the infill panel 12 which has a generally trapezoidal shape, with the leading edge 28 of each panel 12 being shorter than the trailing end 30 of each panel 12. Again the infill panel 12 is made from any suitable airtight weather resistant material or fabric such as type 3 PVC coated polyester. In practice a material may not be completely airtight, but have a low leakage rate.

As can be seen from Figures 1 and 6 more particularly, the infill panel 12 is formed with a series of ribs 32 extending transversely on each panel. As can be seen from the cross-sectional view in Figure 6, the panel 12 is formed from an outer fabric skin 34 having a series of webs 36 extending between the upper and lower surfaces 38, 40 of the fabric skin 34. As shown further in Figure 20, each web 36 is provided with a number of holes 42, so as to allow air to pass through the infill panel 12. In addition to the above, a series of vertical ties 44 are provided between adjacent webs 36 extending in a longitudinal direction of the panel 12. Again these are connected to the upper and lower surfaces 38, 40 of the panel. This form of construction allows the panel to maintain its shape and to distribute forces within the structure in use.

Returning to the beam structure 10, Figures 4 and 5 give further details of the construction and support of the beam 10. From Figure 5 it is apparent that the rear support 14 is more substantial that the forward support 16. The rear support 14, which will be described in further detail below, is designed to be the primary structural support for the beam 10 which means that the ^• forward support 16 need not be as substantial. This is apparent from Figures 4 and 5 where the front support 16 is very slender both in longitudinal and transverse cross section. This is important in that it does not significantly impede the view of the spectators seated in the upper tier 6 of the stand 4. The rear support 14 comprises a rectangular truss structure 50 having a cranked upper end 52 which is joined to a connector 54 at its upper end. The truss column 50 is supported on a pin joint 56 at its lower end on a foundation 58 of the stand structure 4.

The truss column 50 is stabilised longitudinally of the beam 10 by bracing frames 60, 62. Main bracing frame 60 is joined at one end to the truss column 50 and its other end to the foundation structure 58. Similarly, as shown in Figure 4, the truss column 50 is braced transversely of the inflatable beam 10 by bracing frames 64, 66. Again, the main bracing frames 64 are attached at one end to the truss column 50 and at the other end to the foundation structure 58.

Turning now to Figures 7 to 9, these show the connector 54 in greater detail . The cranked upper end 52 of the truss column 50 is provided with a pin joint 68 comprising first and second plates 70, 72 extending upwardly from a base plate 74. The side plates 70, 72 are reinforced by rib plates 76 extending between the side plates 70, 72 and the base plate 74. The base plate 74 is mounted to the top of the cranked section 52 by further plates 78 extending over and around the elements of the section 52.

The side plates 70, 72 receive a pin 80 which also extends through a plate 82 formed on the beam engaging part 84 of the• connector 54. This part 84 comprises a annular plate 86 connected to the mounting plate 82 through a plurality of webs 88 and a circular plate 90

The webs 88 leave a free space 92 within the connector part 84 which can accommodate a lamp 94 for illuminating the internal space of the beam 10. To this end, a glass or perspex plate 96 is provided centrally of the annular, plate 86.

The annular plate 86 is fastened to the fabric of the beam 10 in an airtight manner by a plurality of bolts 98. A tubular ring 100 is joined, e.g. welded to the outer periphery of the mounting plate 86. Extending from the ring 90 are twelve circumferentially eguispaced fingers 102. The curvature of the fingers 102 is designed to complement the curvature of the rear of the beam 10. The fingers 102 are connected to the beam 10 by a plurality of fabric loops 104 suitably secured to the skin of the beam 10. The fingers 102 are rigidly attached to the ring 100 so as to transmit forces thereto .

In addition, the rear support 14 supplies air to the beam 10 through pipes 106, 108. These pass through airtight couplings 110 in the beam. Although the beam 10 will normally be inflated prior to installation, it is envisaged that air may be added to or removed from the beam 10 in use so as to control the pressure within the beam in response to, for example, changes in wind. speed and so on. Accordingly, a suitable air supply should be provided for that purpose. Similarly, the second air supply 108 is provided for supplying or removing air to a further part of the tube construction to be described further below in similar circumstances. A further air supply (not shown) may be provided for the infill panel 12. Vents may also be provided to allow pressure to be reduced within the beam 10 etc..

The connector 54 accommodates rotation of the beam 10 about a horizontal axis by virtue of the pin joint 68. It also resists shearing and horizontal rotation of the beam by virtue of the mounting plate 86 and the fingers 102.

Turning now to Figures 10 to 15, the construction of the forward support 14 will be described in more detail. Whilst the internal pressure of the beam 10 will provide the beam with rigidity, the area at which forward support 16 is provided must be reinforced in order to prevent significant deformation or even puncture of the beam 10 in that region by the front support 16.

The front support 16 comprises a column or post 120 which is joined to the beam 10 at its upper end 122 and is mounted to the foundation construction of the stand 4 at its lower end 124 (see Figure 5) . Typically the column 120 will be circular in cross section and since lateral loading on the structure is intended to be taken by the rear support 14, it need not resist such loading and as such may be relatively slender. For example, in one embodiment that diameter of the post 120 may be in region of 170 millimetres. This, it will be recognised, will provide only a minimal obstruction to spectators seated in the upper tier 6 of the stand 4.

The upper end 122 of the post 120 tapers, the top 126 of the tapering portion 122 being attached to the beam structure 10. However, the connection to the beam 10 also includes a cradle structure 128 which is mounted to the top of the post 120. The cradle structure comprises 12 angled members, e.g. tubular members, 130 which are connected to the post 120 at their lower ends 132 through a pin joint structure 140. The pin joint structure 140 is shown in greater detail in Figure 13 and comprises respective pin joints 134. Post 120 is provided at its upper end with a flange 136 which mounts a flange 138 of the pin joint structure 140. The pin joint structure further comprises a number of plates 142 each having a pin joint 134 at its outer extremity. The tapering region 122 of the post 120 is also joined to the flange plate 138 and is separate from the rest of the post 120. The cradle structure 128 is formed separately from the post 120 to facilitate installation as will be described further below. At their upper ends, the members 130 are connected to a elliptical, concave ring 144 again by respective pin joints 146. Bracing elements (one 148 of which is shown in Figure 14) extend in the plane of the ring 146 between the front and rear of the ring 146 and between its sides along the axes A and B shown in Figure 10. The ring 146 is curved transversely to match the curvature of the dome and is generally straight in the longitudinal direction.

The ring 146 is attached to the skin 150 of the beam 10 by a plurality of clamps 152. Each clamp 152 comprises a rib plate 154 attached to the ring 146 and having a transverse clamping plate 156 formed on its upper end extending on either side of the rib plate 154. A further plate 158 is provided inside the beam 10 and a plurality of bolts 160 extend through both plates 156, 158 in order to attach the ring 146 to the beam 10, typically at 200mm spacing.

The ring 146 is connected to the upper end 126_, of the post 122 by a T-section bracing member 148. The upper end of the tapering section 126 of the post 122 is then attached to the beam 10 in a similar manner to the attachment of the ring 146 to the beam 10. In particular, the upper end 126 is provided with a T- shaped connector 162 having bolting flanges 164 extending on either side with a clamping plate 166 being provided on the other side of the fabric skin 150.

Bolts 168 connect the flanges 164 and clamping plate 166 together .

As mentioned above, it is necessary to reinforce the beam structure 10 in the region of forward support 16 so as to avoid damage to the beam 10 in that region. In the embodiment described, the reinforcement is . provided by a inflated tubular construction 170. The inflated tyre structure 170 comprises two annular "inner" tubes 172 which are joined by a web 174. An air hole 176 is provided in the web 174 at a number of circumferential locations in order to allow air to pass from one tube 172 to the other. The tubes 172 are inflated to a higher pressure than that of the beam 10 so as to provide the necessary additional strength in this area.

As discussed above in the case of inflation of the beam 10, the pressure within the tubes 172 may also need to be varied during use and to this end the air supply tube 108 shown in Figure 7 may extend to the tube structure.

The central hole 176 in the tubular structure 170 will allow light to pass from the rear of the beam 10 to the front of the beam 10 for illumination purposes .

It will be appreciated from the above that the rear and front supports 14, 16 will both counteract generally vertically acting forces i.e. gravity and upward and downward wind loading. However, since upward wind loading are potentially much greater than downwardly acting forces, a further structure 18 is provided between intermediate the rear and forward supports 14, 16 specifically to deal with such upwardly acting forces. The further structure 18 is shown in further detail in Figures 5 and 16 to 19.

As can be seen from Figure 5, the intermediate structure 18 comprises a fabric reinforcement saddle 180 which is welded or otherwise attached over the surface of the beam 10,. As can be seen from Figure 5, the sides 182 of the saddle 180 taper in the downward direction. The respective ends 184 of the saddle 180 are connected to a tie down cable 186 which is anchored at its lower end 188 to the foundation structure 56 of the stand 4. The respective ends 184 of this saddle 180 are provided with a plate 188 suitable secured e.g. bolted ϋ to the saddle end 184. The tie down cable 186 is provided with a braced, generally Y-shaped coupler 190 at its upper end which receives the other end of a plurality of cables 192 extending from the ends of the saddle 184. The coupler 190. is mounted to the tie down cable 186 by a pin joint 194. Each connecting cable 192 is provided with a turnbuckle 196 which allows the length of the cable and thus the tension in each cable 192 to be adjusted as required. The cables 192 preferably lie at an angle of 90° to one another, with the end portion 184 of the saddle 184 also making an angle of 90° to the centre line of the beam 10.

From the above it will be seen that the beam 10 is supported with respect to both downwardly acting gravitational loads and also to upwardly and downwardly acting wind forces. Moreover, axial forces acting on the beam 10 are absorbed by the rear support 14.

The beams 10 provide the main structural strength of the canopy 2 and support the infill panels 12 connected between them. The connection between the beam 10 and the infill panels 12 is an important one as it must be able to accommodate both shear loads applied between the two components and also rotation or bending movements. Figures 20 to 22 show an embodiment of connection between the two parts..

In this embodiment, upper and lower fabric flaps 200, 202 are welded or otherwise attached to the beam 10. The other end of each flap 200, 202 is welded to an infill panel 12. The flaps 200, 202 need not extend ^' along the complete length of the beam 10 and infill panel 12 and a plurality of sets of flaps may be_. provided at spaced apart locations along the length of the beam 10 and panel 12 if so required. Alternatively, at least the upper flap 200 may be continuous so as to act as a gutter for rainwater draining off the infill panel 12 and beam 10. Alternatively a separate flap may be provided for that purpose.

A pre-stressed tie member 204 is connected between the flaps ^'200, 202 •. By tensioning the tie member 204, e.g. by a suitable ratchet mechanism, the infill panel 12 and beam 10 are drawn closely into contact. Moreover, this connection will counteract any tendency of the beam 10 and panel 12 to rotate one relative to the other. In particular, it will be seen that the lower flap 202 will counteract any clockwise rotation of the panel 12 relative to the beam 10 while the upper flap 200 will tend to counteract any clockwise rotation. In addition to such movements, the connection should also be able to resist shear loading between the two parts. To this end, a pair of straps 206, 208 are connected between the beam 10 and infill panel 12. The first strap 206 is suitably joined to an upper part of the beam 10 and passes to the underside of the infill panel 12 where it is secured to the panel 12. The second strap 208 extends from the lower part of the beam 10 to the upper surface of the infill panel 12 where it is secured. As will be apparent from Figure 22, the strap 208 will counteract any uploads acting on the infill panel 12 whilst strap 206 will counteract any downloads. This arrangement is preferred in that it avoids a mechanical joint at the interface between the r beam 10 and in fill panel 12 which could damage either component in that region.

Turning now to Figures 23 to 26 a typical erection , sequence for the canopy 2 will be described. As shown in Figure 23, the basic stand structure 4 is first ' installed, together with the rear support 14 and front support 16. A modular unit 300 consisting of two inflated support beams 10 joined to an inflated infill panel 12 is lifted into position by a crane 302 and mounted to the supports 14, 16. The unit 300 is made by laying out uninflated beams 10 and an infill 12 adjacent one another and connecting them together using the strap system described above. The rear connector part 84 and the front cradle structure 128 may then be attached to the uninflated beam 10 and the assembly then inflated.

The module can then be attached to the rear support 14 by the rear connector part 84 and to the front support by the cradle structure 128. The intermediate tie down structure 18 can be connected at that time also.

A second module 300 is then constructed, inflated . and raised into position spaced from the first module 300 by crane 302. This module 300 is then also fitted to its respective supports 14, 16. A further infill panel 12 is then prepared at ground level and lifted into position using the crane 302. That infill panel 12 must then be connected to the modules on either side in situ. This sequence can be repeated for other modules.

It is of course not necessary to preassembly modules ^'for erection. For example, individual beams 10 can be constructed, inflated and installed with infill panels 12 then being secured between adjacent beams 10. After the canopy has been positioned, seating may be installed in the stand structure.

To remove the stand structure including the canopy after it has been used the above sequence is essentially reversed.

In use, the air pressure within the various components of the structure may be controlled to give an appropriate rigidity and strength. This is heavily dependent upon wind speed. For example in relatively light winds (up to 19.4 m/s) the pressure within beam 10 may be 4 kPa, the pressure within the reinforcement structure 170 may be 24 kPa and the pressure within the infill panel 12 be 9 kPa. At higher speeds however e.g. up to 25 m/s these figures may be increased to 8 kPa, 48 kPa and 15 kPa respectively. The pressure within the elements may be measured and adjusted by adding or removing air in response to wind speed measured by one or more air speed sensors .

It will thus be seen that the present invention provides a versatile, relatively lightweight canopy which can be installed in a chosen location with great ease and flexibility and which provides minimal obstruction for spectators.

The canopy described above is particularly suited to temporary installation, for example at sporting fixtures. It is possible, however, that users may wish to use the canopy as a permanent fixture. Moreover, although the canopy described above is actuate, a straight canopy, (or indeed any other shape of canopy) can be achieved using the same support beams 10 merely by. changing the degree of convergence of the edges of the infill panels 12. This is illustrated in Figure 27 which shows a straight canopy structure incorporating the invention.

A second embodiment of the invention will now be described with reference to Figure 28 to 40. Referring to Figure 28, a second embodiment of canopy structure 502 in accordance with the invention is shown mounted over a stand 504. As in the canopy structure 502 comprises a plurality of elongate inflatable beams 506 joined together by a plurality of inflatable in fill panels 508. , Each inflatable beam 506 is supported by a rear support 510, a forward support 512 and an intermediate support 514. Although Figure 28 shows a canopy structure 502 with just one infill panel 508, it will be appreciated that the structure can comprise more than one such panel 508, as exemplified in Figure 29. Further details of this support system will be described below.

As in the earlier embodiment, each inflatable beam 506 is elongate, having curved forward and rearward ends 516, 518. Also, as in the earlier embodiment, each inflatable tube 506 tapers slightly in diameter from its forward end 516 to its rearward end 518.

As in the earlier embodiment, the inflatable beam 506 may be formed from any suitable, sufficiently strong air tight fabric which will allow the beam to resist environmental factors such as rain, sunlight and impact damage .

As shown in Figure 29, the centre lines 520 of the respective inflatable beams 506 are parallel. The spaces between the beams 506 is filled by the infill panels 508 which are generally rectangular in shape but having flared ends 522,524. Again the infill panels 508 are made from any suitable airtight weather resistant material or fabric such as type 3 PVC coated polyester.

As in the earlier embodiment, the infill panels 508 are formed with a series of ribs 526 extending transversely on each panel 508. As can be seen from the cross-sectional view in Figure 31, the panel is formed from an outer fabric skin 528 having a series of webs 530 extending between the upper and lower surfaces 532, 534 of the fabric skin 528. As in the earlier embodiment, each web 530 may be provided with a number of holes, so as to allow air to pass through the infill panel. In addition to the above, a series of vertical ties may be provided between adjacent webs 530 extending in. a longitudinal direction of the panel 508. Again these are connected to the upper and lower surfaces 532, .534 of the panel. This form of construction allows the panel to maintain its shape and to distribute forces within the structure in use. Different from the earlier embodiment, however, the upper and lower surfaces 532,534 of the panel 508 are generally parallel as seen best in Figure 30; This is somewhat easier to construct than the tapering panel construction of the first embodiment. . < Further discussion of this construction will occur later.

Returning to the beam structure 506, Figures 32 to 34 show details of the rear beam support 510.

The rear support 510 is again designed to be the primary structural support for the beam 506 which means that the forward support 512 need not be as substantial. As in the earlier embodiment, the rear support 510 comprises a rectangular truss structure 540 supported on a pin joint (not shown) at its lower end on a foundation of the stand structure 504.

Unlike the earlier embodiment, however, the upper end of the column 540 is not cranked. The column 540 may also be stabilised by bracing frames (not shown) as n the earlier embodiment.

¹ Mounted atop the column 540 is a rear support ring 542.^' The ring 542 is mounted to the column 540 through an intermediate frame 544 having mounting flanges

546,548. The upper mounting flange 546 is bolted to a corresponding flange 550 on the ring, and the lower flange 548 bolted to a flange 552 atop the column 540. These bolted connections resist shear forces applied to the beam 506 in use.

In addition to the bolted connection between the ring 542 and the column 540, a pair of tie cables or rods 553 extend between the lower ring segment 542D and the lower part of the frame 544.. This assists in transferring loads from the beam 506 into the column 540.

The rear support ring 542 is formed in four arcuate, tubular segments 542A, 542B, 542C, 542D. The segments are spliced together by bolts 554 which pass through openings in C-shaped clamp plates 556 and in the ends of the segments, as shown in the exploded detail in Figure 33. ^{' ■}

The ring 542 is attached to the beam 506 by lacing 558, as shown in Figure 34. The ring 542 has eyelets 560 provided on its outer circumference to receive^' the lacing 558. Flaps 562 of fabric are attached, e.g. welded and stitched to the beam 506 around its circumference. The flaps 562 are arranged to project sequentially on alternating sides of the ring 542. The attachment of the ring 542 to the beam 506 through the lacing provides good load transfer from the beam 506 into the ring 542.

As in the earlier embodiment air is supplied to the beam 506 through one or more pipes. These pass through airtight couplings 110 in the beam. Turning now to Figures 35, 35a and 35b, the construction of the forward support 512 will be described in more detail .

The front support 512 comprises a column or post 570 which is joined to the beam 506 at its upper end 572 and is mounted to the foundation construction of the stand 504 at its lower end 574. As in the earlier embodiment the column 570 may be circular in cross section and have similar dimensions to the column of the earlier embodiment.

The upper end 572 of the post 570 is attached to a front ring 576 through a clevis or pin joint 578 (Figure 34A) .

The front ring 576 may have a similar construction to the rear ring 542, also preferably being made from a number of spliced segments 576A, 576B, 576C, 576D. The front ring 576 is also preferably attached to the beam 506 in the same manner as the rear ring 542, i.e. by lacing. The pin joint 578 will permit some relative movement between the column 570 and the ring 576, thereby preventing bending of the ring 576 under horizontal loading. The pin joint 578 will also allow the column 570 to pivot relative to the ring 576 which may be advantageous in the erection of the structure.

Tie cables 580 extend between the ring 576 and lower intermediate mounting lugs 582 on the column 570. The cables 580 resist torsion in the system.

The mounting lugs 582 are provided generally at the level at which the column 570 extends through the stand structure 504. To prevent buckling of the slender column 570, a locating member such as a plate 584 is provided on the column for lateral engagement with locating surfaces provided on the stand 504. In an elongate structure such as that shown in Figure 29, central beams 506 need not be restrained against horizontal loading. However, at the ends of the structure, some such support needs to be provided. To this end, a cable 588 may extend from the upper end 572 of the column 570 to a ground anchor 590. Such cables 588 are also shown in Figure 28. As in the earlier embodiment, the rear and front supports 510, 512 will both counteract generally vertically acting forces i.e. gravity and upward and downward wind loading, and a further structure 514 is provided between intermediate the rear and forward supports 510, 512 specifically to deal with upwardly acting forces. The further structure 514 is shown in further detail in Figure 36.

The intermediate support 514 comprises a ring 600 which is attached to a column 602 by cables 604. The column 602 only extends up to the level of the stand 504 so that it will not obstruct spectators' vision.

The ring 600 is constructed and attached to the beam 506 in a similar manner as the rear and front rings 542, 576, and need not, therefore be described in further detail.

The above described arrangement of rear, front and intermediate rings 542, 576, 600 provides a simpler, more effective and more aesthetic support for the beam 506 than the support arrangement of the first embodiment .

As in the earlier embodiment, the beam 506 is supported with respect to both downwardly acting gravitational loads and also to upwardly and downwardly acting wind forces. Moreover, axial forces acting on the beam 506 are absorbed by the rear support 510. The means of joining the beams 506 and infill panels 508 is somewhat simpler in this embodiment than in the earlier embodiment, and is illustrated in Figures 37 and 38. In this embodiment, the connection is effected by upper and lower pairs of flaps 602, 604, 606, 608. A first upper flap 602 and first lower flap 604 are joined, e.g. welded and stitched, to a lateral region of the beam 506. A second upper flap 606 and a second lower flap 608 are jointed, e.g. welded and stitched, to an opposed lateral region of the panel 508. The upper flaps 602, 606 are laced together by lacing 610 and the lower flaps 604, 608 are laced together by lacing 612.

As can be seen in Figure 37, respective joined flap pairs are provided at each compartment of the panel 508. The above arrangement considerably facilitates assembly of the canopy structure.

Figure 38 also illustrates a gutter 612 provided between the beam 506 and panel 508 to allow for drainage of water from the beam 506 and panel 508.

The gutter 612 is formed by a length of waterproof fabric 614 which is attached, e.g. welded, at one side to the beam 506 and at the other side to the panel 508. The attachment to the beam 506 may be covered by a cover strip 616.

Water is channelled into the gutter 612 from the panel 508 by drainage channels 618 formed between the ribs 526 of the panel 508.

Unlike the earlier embodiment where the panel 508 slopes from its middle towards its edges, in this embodiment the upper and lower surfaces 532, 534 of the panel 508 are generally parallel. As such, water could merely accumulate in the troughs 620 formed between the ribs 526 and not be channelled towards the gutter 612. To avoid this, drainage sheets or panels 622 are provided in the troughs 620. The drainage panels 622 are attached, e.g. welded, to adjacent ribs 526 of the panel 508 along joins 624. The drainage panels 622 taper in width from the middle of the panel 508, as seen best in Figure 29, since they attach to the ribs 526 at a relatively high point towards the middle of the panel 508, and at a lower point towards the edge of the panel 508. This allows water draining off the ribs 526 to flow easily along the drainage panels 622 into the gutter 612.

The canopy structure 502 of the second embodiment may be erected in a similar manner to the first embodiment. The rings 542, 576, 600 may be mounted around the beams 506 prior to their lifting into position. The front column 570 may also be attached to the front ring 576 before lifting, the pin joint 578 allowing the column 570 to swing from the beam 506. The inflation pressures of the beams 506 and panels 508 may be similar to those of the earlier embodiment.

Claims

1. An inflatable canopy structure comprising first and second inflatable beams, and an inflatable panel secured between, and supported by, said beams.

2. An inflatable canopy as claimed in claim 1 comprising a plurality of beams and a plurality of panels arranged in an alternating fashion, the panels being supported by adjacent beams.

3. An inflatable canopy as claimed in claim 1 or 2 wherein the beams are elongate in shape, and of a tubular, circular cross section construction.

4. An inflatable canopy as claimed in claim 3 wherein the beams taper, preferably from front to rear.

5. An inflatable canopy as claimed in any preceding claim wherein the infill panel is generally planar .

6. An inflatable canopy as claimed in claim 5 wherein the infill panel has converging edges .

7. An inflatable canopy as claimed in claim 5 or 6 wherein the infill panel has a width to thickness ratio of between 4 and 8.

8. An inflatable canopy as claimed in any preceding claim wherein the panels are inflated to a higher pressure than the beams .

9. An inflatable canopy as claimed in any preceding claim further comprising respective supports arranged at spaced apart locations along the length of the beam.

10. An inflatable canopy as claimed in claim 9 comprising a first structural support provided at the rear of the beam and a second structural support provided at a location towards the front of the beam.

11. An inflatable canopy as claimed in claim 10 wherein the first structural support is constructed so as to resist both vertical and horizontal loads.

12. An inflatable canopy as claimed in claim 1-1 wherein the second support is constructed to support only vertical loads .

13. An inflatable canopy as claimed in any of claims 10 to 12 wherein the first support is formed as a frame structure

14. An inflatable canopy as claimed in claim 13 wherein the second support is formed as a relatively slender column.

15. An inflatable canopy structure comprising a first support arranged at the rear of the canopy structure and a second support arranged towards the front of the structure, said second support being relatively slender compared to said first support.

16. An inflatable canopy as claimed in any of claims 10 to 15 wherein the first support structure comprises a connector which engages over the rear end of the inflatable beam.

17. An inflatable canopy as claimed in claim 16 wherein the connector comprises a plurality of fingers which engage over the rear end of the beam and are suitably attached thereto.

18. A support for a- tubular inflatable beam, said support comprising a connector for engaging an end of the beam, said connector comprising a plurality of circumferentially spaced fingers engaging around the end of the beam.

19. An inflatable canopy as claimed in any of claims 10 to 16 wherein the first support comprises a ring which circumscribes a rear section of the beam.

20. A structure comprising an inflatable tubular beam and a support ring circumscribing and supporting a rear section of the beam. i

21. An inflatable canopy or structure as claimed in claim 19 or 20 wherein the ring is supported atop a support column positioned under the- beam and preferably vertically aligned with the support column.

22. An inflatable canopy or structure as claimed in claim 19, 20 or 21 wherein the ring is attached to the beam by means of lacing the ring to flaps provided on the beam structure, said flaps preferably having eyelets or other openings for receiving a rope or the like and said ring preferably having locating eyes through which the rope may pass provided at spaced apart intervals around its circumference.

23. An inflatable canopy or structure as claimed in claim 22 wherein successive flaps are provided on opposite sides of the ring.

24. An inflatable canopy or structure as claimed in any of claims 19 to 23 wherein the ring is made in more than one arcuate segment, with connections between the segments .

25. An inflatable canopy or structure as claimed in any of- claims 9 to 24 wherein lighting means is mounted to the rear of the beam

26. An inflatable canopy or structure as claimed in any of claims 9 to 25 wherein the first support is attached directly to the ground or to a seating stand.

27. An inflatable canopy or structure as claimed in any of claims 9 to 26 wherein the first support is stabilised by props.

28. An inflatable canopy or structure as claimed in claim 27 wherein the props extend both generally parallel to and laterally with respect to the axis of the inflatable beam.

29. An inflatable .canopy or structure as claimed in any of claims 9 to 28 wherein the beam is provided with reinforcement in the region of the attachment of the, forward support to the beam.

30. An inflatable canopy or structure as claimed in claim 29 wherein the beam comprises one or more reinforcing tubes aligned with the support and inflated to a higher .pressure than the remainder of the beam.

31. An inflatable canopy or structure as claimed in claim 29 or 30 wherein the second support structure is connected to the reinforcement via a cradle which ' engages the beam around the reinforcement .

32. An inflatable canopy or structure as claimed in any of claims 9 to 29 wherein the second support is attached to the beam by a ring externally circumscribing a front portion of the beam.

33. An inflatable tubular structure comprising a support ring externally circumscribing a front portion of the tubular structure.

34. An inflatable canopy or structure as claimed in claim 32 or 33 wherein the front support ring is mounted atop a or said support column.

35. An inflatable canopy or structure as claimed in claim 34 wherein the front support ring is attached to the column by a clevis type connection.

36. An inflatable canopy or structure as claimed in claim 34 or 35 further comprising one or more tension cables extending between the front ring and support column.

37. An inflatable canopy or structure as claimed in any of claims 34 to 36, further comprising a lateral support at an intermediate position along the length of the column .

38. An inflatable canopy or structure as claimed in claim 37 wherein said lateral support comprises one or more lateral support surfaces on a stand structure through which the front support column passes.

39. An inflatable canopy or structure as claimed in any of claims 32 to 38 wherein the front ring or the upper part of the front support column is braced e.g. by bracing cables .

40. An inflatable canopy or structure as claimed in any of claims 32 to 39 wherein the front ring is attached to the beam by means of lacing the ring to flaps provided on the beam structure, said flaps preferably having eyelets or other openings for receiving a rope or the like and said ring preferably having locating eyes through which the rope may pass provided at spaced apart intervals around its • circumference.

41. An inflatable canopy or structure as claimed in any of claims 32 to 40 wherein the front ring is made in more than one arcuate segment, with connections between the segments .

42. An inflatable canopy as claimed in any of claims 10 to 17, 19, 21 to 32 or 34 to 41 wherein a further structure for resisting uplift forces is , arranged between the rear and forward supports.

43. An inflatable canopy structure comprising forward and rear supports for counteracting forces acting on or due to the canopy and a further support intermediate the forward and rearward supports for counteracting uplift forces acting on the structure.

44. An inflatable canopy or structure as claimed in claim 42 or 43 wherein the intermediate structure comprises a tension member.

45. An inflatable canopy or structure as claimed in claim 44 wherein^' said tension member is a flexible tie down member, for example a tie-down cable or a tie- down strap.

46. An inflatable canopy or structure as claimed in claim 45 comprising a saddle formed around the beam and the tie-down member attached to the respective ends of the saddle.

47. An inflatable canopy or structure as claimed in any of claims 43 to 45 wherein the intermediate support comprises a ring circumscribing the beam.

48. An inflatable canopy structure comprising an inflatable tubular support beam, said support beam being supported by rings circumscribing the beam at a rear location, a front location and a location intermediate said front and rear locations .

49. An inflatable canopy as claimed in any preceding claim comprising a first connection for transmitting shear between the panel and the beam and a second connection for resisting rotation of the panel relative to the beam.

50. An inflatable canopy as claimed in any preceding claim comprising upper and lower, laced connections between the beam and panel .

51. An inflatable canopy as claimed in claim 50 wherein each connection comprises respective upper and lower pairs of flaps attached to the beam and the panel respectively, laced together.

52. An inflatable canopy as claimed in claim 51 wherein the flaps provided on the panel are formed from the same piece of material .

53. An inflatable canopy as claimed in any preceding claim wherein the panel comprises a plurality of transversely extending sections or compartments and a connection is provided at each panel section or compartment .

54. An inflatable canopy as claimed in any- preceding claim wherein the panel comprises a plurality of transversely extending sections or compartments .

55. An inflatable canopy as claimed in any preceding claim wherein the upper surface of the panel is transversely ribbed.

56. An inflatable canopy as claimed in claim 55 wherein the central section of the panel is deeper than its transverse edges, such that the troughs are formed which incline towards the transverse edges of the panel .

57. An inflatable canopy as claimed in claim 55 wherein the panel < is of substantially constant depth.

58. An inflatable canopy as claimed in claim 57 and further comprising a drainage sheet attached across a trough between adjacent ribs in such a manner that the drainage sheet slopes downwardly towards the edge of the panel .

59. A structure having a plurality of transversely extending ribs separated by respective troughs, and a drainage surface formed across a said trough between adjacent ribs, said drainage surface extending between a relatively high point on adjacent ribs to a relatively low point on adjacent ribs, thereby creating an inclined drainage surface.

60. A structure as claimed in claim 59 wherein the ribs are formed in an inflatable structure with generally parallel upper and lower surfaces.

' 61. A structure as claimed in claim 59 or 60 wherein the drainage surface is formed by panels or sheets which are attached the ribs of the structure.

62. A structure as claimed in any of claims. 59 to 61 wherein the drainage surface is formed from an shaped sheet of fabric.

63. A method of installing an inflatable canopy unit comprising first and second beams with a panel arranged between the two beams, comprising joining the beams and panels together prior to installation.

64. A method as claimed in claim 63 wherein the beams and panel are inflated prior to installation.

65. A method as claimed in claim 63 or 64 comprising assembling and inflating two or more said units, installing said units with a spacing between each unit and filling said spacing with a further panel.

66. An inflatable canopy unit comprising first and second inflatable beams, and an inflatable panel secured between, and supported by, said beams.

67. An inflatable canopy structure comprising an inflatable tubular support beam, said support beam being supported by rings circumscribing the beam at a rear location and a front location.

68. A connection between an inflatable support beam and an inflatable panel, comprising a first connection for transmitting shear between the panel and the beam and a second connection for resisting rotation of the panel relative to the beam.