WO2007060485A1

WO2007060485A1 - Inflatable structures and support stands therefor

Info

Publication number: WO2007060485A1
Application number: PCT/GB2006/050412
Authority: WO
Inventors: Christopher Charles Brindle
Original assignee: Christopher Charles Brindle
Priority date: 2005-11-28
Filing date: 2006-11-24
Publication date: 2007-05-31
Also published as: GB0524174D0; GB2425135A; GB2425135B

Abstract

The present invention provides an inflatable structure support stand (20, 5) comprising an upright member (22, 23, 24), a base (21) connected to the upright member to support it on a surface, and retaining means (26) connected to the upright member. The retaining means (26, 43) are adapted to receive parts of the inflatable structure when deflated and to restrain them when inflated. The support stand permits the inflatable structure to adopt an arched profile, and (10) the retaining means include a retaining member (26) that at least partially encircles the part of the inflatable structure located therein. The invention also provides a collapsible enclosure to be supported over an item to be covered such as a pool. The enclosure comprises a frame composed of inflatable support tubes (60, 66); at least two rigid support stands (20) adapted to receive (15) and retain the ends of the support tubes; and a cover (70) that locates over and is supported by the frame.

Description

Inflatable Structures and Support Stands Therefor

The present invention relates to an inflatable structure support stand and in a second aspect to a collapsible enclosure to be supported on a surface over an item to be covered. The second aspect of the present invention is further particularly directed to a collapsible enclosure constructed using a support stand of the first aspect.

Outdoor spas and outdoor swimming pools are becoming increasingly popular, but they tend not to be used when the weather conditions are inclement. To extend the times during which these recreation facilities are used it can be desirable to construct an enclosure over them. This has the effect of sheltering the user, improving the retention of heat within the spa or pool, and keeping debris such as leaves, dirt, insects and the like out of the water. An enclosure over a spa or pool may also act as a safety measure, for example preventing children coming too close when unsupervised.

Arguably the ideal enclosure would be robust, but of a temporary nature, and being easily erected and disassembled could be removed when true open air swimming is possible. Previously known enclosures suitable for this task vary, each offering differing degrees of flexibility of use and permanence. Some are constructed from steel and clear plastic with sections which slide or open in different ways. These are however expensive to make, difficult to assemble and take apart and bulky to store and transport. As such they tend to be used on a permanent rather than temporary basis, if used at all. Another type of enclosure consists of a plastic bubble which is kept inflated above the pool by a fan which is permanently running. With this type, if the fan is switched off then the bubble will collapse. These require constant power to keep them inflated and the enclosure must remain sufficiently sealed to prevent its collapse.

Another known temporary enclosure, which is however not used with pools or spas, comprises a structure formed from interconnected inflatable plastic tubes which are designed to be air-tight. Once inflated, the structure will stay inflated until the valve or valves on the tubes are opened. The overall shape of the structure is determined by the inter-connection of the tubes. Such a structure has tubes forming uprights that are inter-connected to form the roof of the structure. The lower ends of the uprights must be joined, so the structure further includes a ring of inflatable tubes that might typically form the base and are inflatable with the rest of the structure. A common use of this type of structure might be a mobile decontamination unit.

Not many commercial enclosures are suitable for covering above-ground pools. Some pool owners may attempt to use a variety of structures. Temporary garden "pavilion" structures do not have ideal dimensions and using narrow diameter steel tubes are unlikely to prove strong enough in use. Metalwork which attaches to the walls of above-ground pools may compromise the integrity of the pool. Agricultural "poly-tunnel" type construction requires considerable space and by its nature is a permanent structure once erected.

All of the prior types of enclosure have significant drawbacks, both for use in any situation but particularly for use over a pool, and the present invention aims to provide improvements in the construction of temporary enclosures. It further aims to provide an improved temporary enclosure that is ideal for outdoor pools and spas, as well as for other items/areas that need temporary cover. The present invention still further aims to provide an enclosure that may be configured and subsequently re-configure by a user to meet changing requirements. The present invention yet further aims to provide a support stand for use in supporting an inflatable structure. According to the present invention there is provided an inflatable structure support stand, comprising an upright member, a base connected to the upright member to support the upright member on a surface, and retaining means connected to the upright member and adapted to receive a part of the inflatable structure when deflated, and to restrain the inflatable structure when it is inflated, wherein the support stand permits the inflatable structure to adopt an arched profile, and wherein the retaining means includes a retaining member that at least partially encircles the part of the inflatable structure located therein.

In this way the inflatable structure may be located therein by a generally lengthwise motion, but prevented from lateral movement. One retaining member may be enough, but preferably two or more retaining members are provided on the upright member, and the inflatable structure will locate in and be held by all of them. Use of at least two retaining members spaced along the upright member minimises twisting of the inflatable structure relative to the upright member. When the inflatable structure located within the retaining means is inflated, it will expand. This expansion causes the surface of the inflatable structure within the retaining means to come into contact with the inner face thereof, and as expansion continues the inflatable structure is securely grasped by the retaining means. This restricts the removal of the inflatable means from the support stand when inflated so holding it into the stand, which either due to the weight thereof or anchoring of the stand to the surface, holds down the inflatable structure.

The first aspect of the present invention is preferably intended to support and anchor an inflatable structure having several elongate inflatable legs. The legs would be located in and retained by the retaining members, and it is advantageous that for such elongate legs the retaining members are aligned along the upright member such that part of the inflatable structure may be sequentially located in all retaining members.

The inflatable structure support stand of the present invention may be in a fixed configuration, and suitable for one or several types of specific inflatable enclosure. However, to provide enhanced flexibility in constructing enclosures of different design or to accommodate variation in the environment in which the enclosure is to be erected, it is desirable that the support stand may be adjustable by a user. Desirably, the angle of the upright member with respect to the base may be altered, because this permits variation in the angle of that part of the inflatable structure located therein.

The variable angular position of the upright with respect to the base may be achieved in a number of ways. For example the upright member may be pivotally connected to the base, with a locking member that holds the upright member at the desired angle with respect to the base. The locking member could for example be a locking nut on the pivot or an adjustable tie bar extending between the base and the upright member. Angular adjustment of the upright member might not be of the whole of the upright, it might only comprise adjustment of the upper part thereof. Therefore, the adjustment might occur by the same of other suitable means at a point above the connection between the base and upright member.

A further desirable amendment could be to the overall length of the upright member, and hence the height of the upper end. Further, the vertical position of the retention means or constituents thereof may be altered with respect to the base. This could be as a result of the overall length adjustment of the upright member, or could be achieved without that being changing.

The upright member may comprise two or more telescopically, or otherwise relatively sliding sections. The upright member may include an upper section, a middle section and a lower section, that are telescopically slidable with respect to each other. The retention means may be provided on the middle section and be adjustable with respect to the base and lower section. Suitable, locking means to fix the sliding sections at the desired positions may also be provided.

An upper part of the upright member may be curved to be complimentary with the desired profile of the inflatable structure located therein. This can be used to impart a curve or other shape to the inflatable structure as it emerges from the top of the stand, which aids the creation of an overall desired shape of enclosure. The profiled part of the upright member may be the upper section thereof, and may be vertically adjustable with respect to the base and/or the retention means - for example by telescopically sliding a lower part of the upper section with respect to the middle or lower section.

The inflatable structures located in support stands according to the present invention are preferably the elongate inflatable legs of an inflatable structure with several such legs. A support stand may be used at the end of each leg and the legs may be located generally around the area to be enclosed. It may be desirable to provide lateral parts on the structure which would extend between the legs, preferably at approximately 90° thereto. Therefore the upright member may be further provided with one or more secondary retaining member, adapted to receive and hold such a lateral part therein. This lateral part is preferably also inflatable, so the secondary retaining member may be adapted to hold such a member therein when inflated. The, or each, secondary retaining member may comprise a ring that at least partially encircles the lateral part.

The support stand may be constructed from any suitable material, but is preferably constructed substantially wholly from metal. The base is usually flat bottomed and is adapted to stand on a suitable surface. The base may be formed from a flat plate and may be provided with anchoring means to allow it to be held stably on the surface or fix thereto. The anchoring means could include apertures through which screws or bolts could pass, as well as weights to be placed on the base to hold it down. The support stand discussed above may be used in the construction of a great range of inflatable structures, for a variety of purposes. The present invention also provides a complete collapsible enclosure using a similar stand.

According to a second aspect of the present invention there is also provided a collapsible enclosure to be supported on a surface over an item to be covered; which collapsible enclosure comprises a frame composed of inflatable support tubes; at least two rigid support stands that locate on a surface and are adapted to receive the ends of the support tubes and, when those tubes are inflated, to retain them therein; and a cover that locates over and is supported by the frame. The various aspects of the present invention have been and will be discussed predominantly in respect of the use in creating an enclosure to cover a pool or spa. This is one of the primary uses intended for the present invention, but is not the only potential application. Therefore it will be appreciated that the present invention whilst preferably adapted for therefor is not limited to use in respect of pools and spas.

The frame may have several legs which each comprise an elongate support tube, and the free end of each elongate support tube may be located in a rigid support stand. Each leg is thereby located and held in the correct orientation. The support stands are preferably the same as discussed above with regard to the first aspect of the present invention and the potential modifications and preferred features discussed there are applicable here to use as part of the enclosure. In a similar way to that mentioned above the inflation of the tubes within the support stands cause expansion of the tubes until they are tightly gripped by retention means provided on each upright member. Any suitable configuration of frame is possible, and this can be constructed from any number of discrete inflatable elements connected to support stands. It may be desirable that at least some of the support tubes intersect or are joined, and are inflated simultaneously. In simple versions of enclosure there could be two long inflatable support tubes that intersect at right angles at approximately their midpoints. The four free ends are each located in a support stand and the intersection of the two tubes becomes the apex of the frame when inflated. A similar intersecting configuration with greater or fewer legs is possible as is any combination of inflatable tubes. The inflatable parts of the enclosure may have valves such that once inflated the valve may be closed to ensure they remain inflated. This avoids the need for constant input of air. They are also suitably airtight so they may be inflated to a high pressure to ensure sufficient rigidity in the frame. The cover may be formed from a flexible sheet material, and it may form an integral part of the frame. For example, it may be a continuous sheet bonded to the outside of the frame, or may have multiple discrete panels that extend between adjacent inflatable tubes. Alternatively the cover may be separate from the frame and simply be supported thereon. Such a separate cover could be placed over or removed from the frame as required.

As is mentioned above in respect of the first aspect of the present invention, the frame may further include one or more horizontal or lateral support member, preferably in the form of an inflatable ring that passes around the enclosure and is connected to the support tubes or the support stands. The frame may be held down by the grasping of the inflated tubes by the retaining means. However, further means to hold down parts of the enclosure, in particular a separate cover may be provided. One advantageous way of achieving this is to provide ballast means to anchor the lower edge of the cover adjacent the surface on which the enclosure sits. The ballast means may comprise weights placed on the cover, but preferably one or more collapsible water filled tube is provided. When empty this may be easily stored, but when needed may be filled with water. The cover may be held between the ballast and the surface, and the edge of the cover may be pulled to tension the cover.

The enclosure may be used to cover something to which access is not readily required. However, in the use for which the present invention was first developed as well as many others, easy access to the inside of the enclosure is required. To this end a door may be provided in the cover. Preferably the door is provided in a frame that is self supporting on the surface. More preferably the cover is provided with means to connect to the cover, so that it extends up to and around the frame.

The enclosure of the present invention is particularly suited to location over and around an in-ground swimming-pool, an above-ground swimming pool or a spa. In such contexts, it may be advantageous that when deflated the enclosure becomes a cover for the pool or spa. Such a cover may for example be for the purposes of safety, protection or insulation.

The tubes and the lateral elements of the frame may be formed from plastics material film, such as polyurethane film. This has good elastic properties and allows the frame to take the desired shape or curve. The cover may be formed from any suitable material including polyethylene, polyvinylchloride or polyurethane sheeting.

The upper end of the support stands are shaped to impart a curvature to the tubes retained therein. This allows the upper region of the erected frame to be given a shape other than that which might naturally be adopted by the inflated tubes.

The enclosure of the present invention is collapsible. It may be erected or dissembled as required. For example it may provide a temporary cover/enclosure for a pool, which may be removed in the warm months and erected to allow continued use when cold. It may also be deflated to temporarily minimise its visual impact or to cover the pool. In a simplistic embodiment, assembly would involve placing the required number of support stands around a pool (or other structure), configuring them to the desired height/angle and then sliding the deflated legs of a frame into the retention means. A cover could then be placed there over, the frame inflated, and the inflatable cells sealed. The cover could then be accurately positioned and fixed down with ballast. If required a door can be connected to an opening in the cover. Temporary deflation would simply involve releasing sufficient air from the inflatable cells of the frame until the frame and cover rested on the surface of the pool. Full disassembly for transport or storage would require the reverse of the inflation procedure.

The enclosures provided by the present invention are much more adaptable to different circumstances, such as sites on various levels, or where there is limited space around the outside of a pool. A variety of different tubes can be used to obtain a structure with the required floor-plan, and individual configuration of the support stands allows for variation in the surface etc. A particularly useful type of tube configuration is a cross, where two tubes cross at a cruciform central section.

By using the present invention it is possible to create an enclosure that adapts well to the seasons. When summer comes the cover and tubes may be easily removed and stored away in a small space, whilst the stands if desired may be left in situ or also stored. This is in contrast to the majority of swimming pool enclosures which are big, bulky and rigid and cannot be easily removed and stored. When autumn comes the tubes and cover can be replaced, keeping the pool clear of leaves and dirt and sheltering the swimmers. In countries where this is appropriate the cover may be at least partially formed from a mesh or otherwise vented to add shade or protection from insects whilst allowing ventilation.

For heated pools, the inexpensive enclosure adds greatly to energy efficiency by creating a large insulating air space between the pool and its cover (if it has a separate one) and the atmosphere. By directing the air intake of a heat pump to draw from this air space, heat escaping from the pool can be effectively recycled.

When used with above-ground pools the supporting stands of the enclosure are in close proximity to the pool walls, as is the cover. This makes possible two energy saving features. Firstly the space between the pool wall and the cover may be filled with insulation material. This may be accomplished by wrapping insulation round the pool walls and/or filling the space between the pool support legs with panels of insulation material. Secondly a pool cover can be used whose dimensions greatly exceed those of the pool's surface area. This cover in use is tucked down in the space between pool wall and support stands, and is placed in this position by a bather before leaving the pool. The cover is provided with floats to ensure it does not make too much contact with the water in the pool. This creates a large air space between water and cover which greatly improves insulating efficiency. On entering the pool, a bather pushes the cover so that it is contained largely in the space between pool wall and cover. These innovations taken together greatly improve the effectiveness of simple pool heaters, such that it becomes possible to heat a pool and continue swimming outside in the winter for moderate cost.

A further advantage of an enclosure constructed according to the present invention is that it is not rigid, but has the flexibility to move slightly in high winds, thus absorbing the wind's energy.

As mentioned above the frame can be covered in a single sheet of polyethylene, for example of the type used in agricultural steel-framed "poly- tunnels". An advantage of this is that the surface tension between the cover and the frame helps to hold the cover onto the inflatable tubes. The cover can also be restrained and tensioned by ballast means in the form of elongated water-filled tubes placed around the perimeter of the enclosure. A cover of this type is easily fitted and renewed at fairly low cost, without need of replacing the more expensive frame or stands. An alternative cover can be made out of a transparent, elastic polymer, e.g. polyurethane and fitted to the exact shape of the enclosure and staked to the ground.

In order that it may be better understood, but by way of example only, various embodiments of the present invention will now be described in more details with reference to the accompanying drawings in which: Figure 1 is a perspective view of a first embodiment of support stand according to the present invention;

Figure 2 is a similar perspective view with the upright member extended;

Figure 3 is a perspective view of a second embodiment of support stand;

Figure 4 is a perspective view of an ancillary stand for use in enclosures such as those shown in Figures 14 and 15;

Figure 5 is an expanded detail of part of an upright member showing a possible telescopic intersection locking mechanism;

Figure 6 is the base plate of a very simple fourth embodiment of support stand; Figure 7 is a similar view, but of the first embodiment of support stand, as shown in Figures 1 and 2 (it is also the same as the lower part of the ancillary stand shown in Figure 4);

Figure 8 is a perspective view of two support stands of the first embodiment supporting the ends of an inflatable arch; Figure 9 is a similar view in which the arch is supported by support stands according to the second embodiment shown in Figure 3;

Figure 10 shows an inflatable enclosure, without a cover, located over an above ground pool;

Figure 11 shows a similar four-legged enclosure with a different embodiment of stand over a spa;

Figure 12 shows a more complex enclosure over an above ground pool;

Figure 13 shows the same embodiment as Figure 12 but with the cover partially shown; Figure 14 is an embodiment of enclosure similar to that shown in Figure 11 but with two lateral support rings included;

Figure 15 is an embodiment similar to that shown in Figure 10 but with two lateral support rings shown and a dotted representation of a cover located thereover;

Figure 16 shows the embodiment of Figure 10 with the frame deflated and lying on top of the pool;

Figure 17 shows the same view as Figure 16 but includes a dotted representation of a cover; Figure 18 shows an enclosure (without cover) when deflated; and

Figure 19 shows an alternative embodiment of enclosure comprising two 4- legged frames similar to that shown in Figure 11 linked by a ridge member.

A first embodiment of support stand according to the present invention is shown in Figures 1 and 2 and is generally indicated 20. This support stand comprises a base 21 pivotally attached to which is a lower section 22. A middle section 23 is connected to the lower section 22 and in turn an upper section 24 locates on the middle section 23. The lower, middle and upper sections together define the upright member. Three rings 26 are connected to the middle section 23, and these provide the retention means for the inflatable member. An adjustable tie- bar 28 is pivotally fixed to the base 21 by linkage 29. The other end of the tie-bar

28 is connected to the lower section 22. As is best seen in Figure 7 an elongate aperture 30 is formed in the tie bar, and a threaded projection on the side of the lower section 22 is engaged therein. The angle of the upright member may be adjusted by loosening the threaded nut 31 on the treaded projection and pivoting the upright member via the pivot 32 connecting it to the base plate 20. When the desired angular position is reached the threaded nut 31 may be re-tightened to hold the upright in place.

Figure 6 shows a more simplistic fixed arrangement wherein the base plate 20 and lower section 22 are not adapted for relative angling. The linkage 29 may be connected to the base plate 20 at alternative points

34 and 35, dependent on the angle desired. Bores 36 are provided at the corners of the base plate through which screws or bolts may be passed in order that the base plate may be fixed down as desired. The lower, middle and upper sections 22, 23 and 24 are telescopically slidable with respect to each other. The middle section slidably locates within the lower section 22 and may be fixed at a desired point using the first coupling mechanism 38. The upper section 24 telescopically locates within the middle section 23 and may be locked at a desired extension using the second coupling mechanism 39.

Figure 5 shows an enlarged detail of the second coupling mechanism 39, but the first coupling mechanism 38 is equivalent. In Figure 5 the upper end of the middle section 23 is split and is provided with a split ring collar 40 with a tightening nut 41. The upper section 24 is telescopically slid to the desired position within the middle section 23, at which point the tightening nut is turned such that the split ring collar 40 clamps the upper part of the middle section 23 around the upper section 24 to hold it in place.

The rings 26 are adapted to receive the end of an elongate inflatable member as is shown further in the later drawings. The end is slid first through the uppermost ring and then the next lower ring until it has passed through all of them. It may be positioned such that it extends all the way down to the base, or the end of the inflatable member may be located somewhere in between that point and the lowermost of the rings 26. At the upper end of the upper section 24, there is provided a loop 43. As can be seen in later illustrations this loop is for the location of an inflatable lateral structural element forming part of the frame of the inflatable structure.

The upper section 24 is curved inwardly and is adapted to bear upon the outer surface of an inflatable member located therein. This curvature can be used to impart a matching shape to the part of the inflatable member to achieve a desired end result.

Figure 3 shows a second embodiment of support stand generally indicated 50 which in most respects is equivalent to the first embodiment 20 and like parts have been given like reference numerals. The difference between this second embodiment and the first is that the mechanism for adjusting the angle of the upright member relative to the base simply comprises a pivoting connector 51 which is provided with a locking mechanism (not shown) on the pivot. This obviates the need for a tie-bar. A second difference is in the shape of the loop 52. An ancillary stand generally indicated 55 is shown in Figure 4. This ancillary stand has a base 21 and lower section 32 equivalent to that shown in the first embodiment of support stand. No middle section is provided but instead a straight upper section 56 slideably locates within the lower section 22. A single hoop 57 located at the top of the straight upper section 56. The ancillary stand is intended to support a part of an inflatable structure extending horizontally between adjacent vertical parts of an inflatable structure. In particular, as is shown later in Figures 14 and 15, a lateral member 80 could be used and this ancillary stand could support a part thereof between adjacent support stands. Figures 8 and 9 show a simple arch arrangement constructed using an elongate inflatable tube 60, the ends of which have been located into the retaining rings 26 of the first and second embodiments of support stand. Figure 8 shows support stands 20 of the first embodiment connected to each end of the elongate inflatable tube 60. Each end of the inflatable tube 60 extends down to the base 21 and is held in place by the grasping effect of the rings 26 on the inflated tube 60. Figure 9 shows a similar view but the second embodiment of support stand 50 is utilised. In Figure 9 the elongate inflatable tube has not been inflated to its maximum extent and is not expanded to snugly fit within the retaining rings 26. Provision of retaining rings appropriately sized to engage the inflatable structure when at its desired inflation is not essential but is however advantageous as it will hold the inflatable structure down and prevent vertical lift from sliding of the ends of the inflatable tube from within the retaining means. It will also prevent wobble of the frame with respect to the stands.

Figure 10 shows four of the second embodiment of support stands 50 arranged round an above ground pool 65. A four-legged inflatable frame 67 is supported by the stands 50 with each of the four legs locating into the retaining means of one of the stands. No cover is shown in this drawing for convenience, but it would be draped over the outside of the frame.

Figure 11 shows a similar view of a four-legged frame supported by four support stands. The support stands in this drawing are of the first embodiment 20 and the enclosure it is arranged over a spa 68.

The present invention can provide almost limitless combinations of frames, with the legs of the frames being supported in support stands and covers being placed thereover. Figure 12 shows an alternative arrangement over an above ground pool 65 in which a four-legged frame 67, supported by four stands 20, is arranged next to a simple arch as shown in Figure 8. The apexes of each are connected by a ridge piece 69 which is also inflatable.

As shown in Figure 13, a cover in the form of a flexible plastics material sheet 70 is located over the frame and pool, which is the same as shown in Figure 12. For convenience only part of the cover 70 is shown but it would extend all over the frame and down to the floor. In Figure 13 a door 71 is shown and the cover would extend up to the edge of this door such that a person might gain access to the interior of the closing simply by opening and shutting the door without otherwise disturbing the cover or the enclosure. In this embodiment the cover is not connected to the frame but simply rests thereon. The lower edges of the cover are fixed down using one or more elongate water-filled tube 73 which restrains it by holding onto the ground. Once placed over the frame, the cover may be passed under the water-filled tubes (or the tubes may be placed on the cover and then filled with water). The free edge 74 of the cover 70 is then pulled upwards and inwards (in the direction of arrow A) thus tensioning the cover over the entire structure. The free edge may then be connected to the edge of the pool 65 by clips 75 such as those mentioned in the co-pending patent application GB0515274. The advantages of this are that it improves the insulation around the pool, and water condensing on the inside of the cover will run down into the gulley formed adjacent the water-filled tube 73 thus increasing the ballasting effect in holding the cover down.

Figures 14 and 15 show simple four-legged embodiments of enclosure including upper and lower ring like lateral member 80. These lateral members are also inflatable tubes which pass round the structure and locate within the loops 43 or 52 of the stands. The lower of the two lateral members 80 does not pass through a specific loop, although one could be provided, instead it is held in place by the compression between the inflated frame and the rigid middle section of the support stand. Shown by way of dotted lines in Figure 15 is a representation of a cover supported over the structure. Figure 16 shows the four-legged frame 67 as shown in Figures 10 or 11 in a deflated state resting upon the surface of the pool 65. As can be seen in Figure 17 (which includes a dotted representation of the cover) the cover would also sag as the frame deflates until such time as it rests upon the surface of the pool. As shown in Figures 16 and 17, to ensure the appropriate degree of sag the upper sections 24, which are optional, have been omitted from the supports 20. Upon re-inflation the upper sections may be reinserted as required.

Figure 18 shows the embodiment of enclosure shown in Figure 10 fully deflated but not around a pool. The upper sections 24 remain in place, and would prevent a cover from lying flush with the surface of the pool.

Figure 19 shows a further alternative embodiment of enclosure with the cover omitted for clarity. In this embodiment, generally indicated 90, two four-legged frames 67 each supported by four support stands 20 are arranged next to each other and their apexes are interconnected by an inflatable ridge piece 91. This allows the enclosure to be located over a longer in-ground pool 92. When a cover is placed over the arrangement as shown in Figure 19 a suitably elongate enclosure is formed into which a door could be provided, for example at one of the ends.

Claims

I . An inflatable structure support stand, comprising an upright member, a base connected to the upright member to support the upright member on a surface, and retaining means connected to the upright member and adapted to receive a part of the inflatable structure when deflated and to restrain the inflatable structure when it is inflated, wherein the support stand permits the inflatable structure to adopt an arched profile, and wherein the retaining means include a retaining member that at least partially encircles the part of the inflatable structure located therein. 2. An inflatable structure support as claimed in claim 1 , wherein the retaining member wholly encircles the part of the inflatable structure located therein.

3. An inflatable structure support stand as claimed in claim 1 or claim 2, wherein two or more retaining members are provided on the upright member.

4. An inflatable structure support stand as claimed in claim 3, wherein the retaining members are aligned along the upright member such that an elongate part of an inflatable structure may be located in all retaining members.

5. An inflatable structure support stand as claimed in any of the preceding claims wherein the angle of the upright member with respect to the base may be altered. 6. An inflatable structure support stand as claimed in claim 5, wherein the upright member is pivotally connected to the base, and a locking member holds the upright member at the desired angle with respect to the base.

7. An inflatable structure support stand as claimed in any of the preceding claims, wherein the length of the upright member is adjustable. 8. An inflatable structure support stand as claimed in any of the preceding claims, wherein the vertical position of the retaining means with respect to the base may be altered.

9. An inflatable structure support stand as claimed in any of the preceding claims, wherein the upright member comprises telescopically sliding sections. 10. An inflatable structure support stand as claimed in claim 9, wherein the upright member includes an upper section, a middle section and a lower section, that are telescopically slidable with respect to each other.

I I . An inflatable structure support stand as claimed in 10, wherein the retaining means are provided on the middle section.

12. An inflatable structure support stand as claimed in any of the preceding claims, wherein an upper part of the upright member is curved to impart a desired profile of the inflatable structure located therein.

13. An inflatable structure support stand as claimed in any of the preceding claims wherein there is further provided on the upright member one or more secondary retaining means, adapted to retain a second inflatable structure located therein.

14. An inflatable structure support stand as claimed in 13, wherein the or each secondary retaining means is positioned such that the second inflatable structure is retained at approximately 90° to the inflatable structure within the retention means.

15. An inflatable structure support stand as claimed in any of the preceding claims which is constructed substantially from metal.

16. An inflatable structure support stand as claimed in any of the preceding claims wherein the base is provided with anchoring means to hold it stably on the surface.

17. A collapsible enclosure adapted to be supported on a surface over an item to be covered, which collapsible enclosure comprises: a frame composed of inflatable support tubes; at least two rigid support stands as claimed in claim 1 that locate on a surface and are adapted to receive and retain the ends of the support tubes; and a cover that locates over and is supported by the frame.

18. A collapsible enclosure as claimed in claim 17, wherein the support stands are adapted to restrict the removal of the support tubes when those tubes are inflated.

19. A collapsible enclosure as claimed in claim 17 or claim 18, wherein the support tubes are elongate and the ends of the elongate support tubes are each located in a rigid support stand.

20. A collapsible enclosure as claimed in any of claims 17 to 19, wherein at least some of the support tubes intersect, and are inflated simultaneously.

21. A collapsible enclosure as claimed in any of claims 17 to 20, wherein the inflatable parts of the enclosure have valves such that once inflated the valve may be closed to ensure the inflatable part remains inflated.

22. A collapsible enclosure as claimed in any of claims 17 to 21 , wherein the cover is joined to the frame.

23. A collapsible enclosure as claimed in any of claims 17 to 21 , wherein the cover is not permanently connected to the frame, but is supported thereon.

24. A collapsible enclosure as claimed in any of claims 17 to 23, wherein the frame further includes one or more horizontal support in the form of an inflatable horizontal ring that passes around the enclosure and is connected to the support tubes or the support stands.

25. A collapsible enclosure as claimed in any of claims 17 to 24, wherein ballast means are provided to anchor the lower edge of the cover adjacent the surface.

26. A collapsible enclosure as claimed in any of claims 25, wherein the ballast means comprise a water filed tube.

27. A collapsible enclosure as claimed in any of claims 17 to 26, wherein a door is provided in the cover.

28. A collapsible enclosure as claimed in 27, wherein the door, is provided in a frame that is supported on the surface, the frame being provided with means for interconnection with the cover.

29. A collapsible enclosure as claimed in any of claims 17 to 28, which is adapted for location over an in-ground swimming-pool, an above-ground swimming pool or a spa.

30. A collapsible enclosure as claimed in claim 29, wherein when the inflatable tubes of the frame are deflated the enclosure becomes a cover for the pool or spa.

31. A collapsible enclosure as claimed in any of claims 17 to 30, wherein the tubes are formed from plastics material film, such as polyurethane film.

32. A collapsible enclosure as claimed in any of claims 17 to 31 , wherein the cover is formed from polyethylene or polyurethane sheeting. 33. A collapsible enclosure as claimed in any of claims 17 to 32, wherein the upper end of one or more of the support stands imparts a curvature to that part of associated inflatable above the retention means.

34. A collapsible enclosure as claimed in any of claims 17 to 32, wherein the support stand may be adjusted to alter one or more of: the overall height of the stand above the surface, the angle relative to the surface at which the ends of the support tubes are held, and the degree of curvature imparted to the tubes.