Swimming pool construction

A pool shell including a wall, a floor and a region of curvature running along a bottom of the wall and connecting the wall to the floor. A fastener-receiving formation, on an exterior of the region of curvature is for rigidly connecting the bottom to a support. Also discussed is a swimming pool including a pool shell, having a wall and two or more upright supports. The wall has a top, a bottom, a first elongate stiffening portion and an exterior. The upright supports are spaced along the exterior. The first elongate stiffening portion runs along the wall and is positioned more than 250 mm from each of the top and the bottom. Each of the upright supports are rigidly connected to the first elongate stiffening portion and at least one of the top and the bottom, and predominantly formed of elongate rigid members.

PRIORITIES AND CROSS REFERENCES

This Application claims priority from International Application No. PCT/AU2019/050857 filed on 16 Aug. 2019, Australian Application No. 2018903010 filed on 16 Aug. 2018, and Australian Application No. 2019203161 filed on 6 May 2019 the teachings of each of which are incorporated by reference herein in their entirety.

FIELD OF THE INVENTION

The invention relates to swimming pools.

BACKGROUND TO THE INVENTION

A swimming pool is a vessel for holding a volume of water sufficient for swimming.

Some swimming pools are formed of concrete applied in liquid form (with suitable reinforcement, etc.) and allowed to set in situ. Various surface finishes such as tiles are applied to provide the pool with an attractive interior.

Another mode of construction entails a freely pliable impermeable liner supported by a steel frame. This mode of construction is relatively inexpensive although the end result is less attractive. The pliable liner billows out between the frame members and generally appears to be flimsy.

Another approach entails the installation of a pool shell. A pool shell is a semi-rigid liner that when properly installed can be just as attractive as a concrete pool.

Pool shells are typically formed of fiber-reinforced polymer known as fiberglass, often in the vicinity of 5.5 mm thick. The initial applicant's pool shells are often in the range of 6 mm to 10 mm thick. In the context of a pool shell, 10 mm thick fiberglass is relatively flexible. As such pool shells must be carefully installed to produce a pool that is attractive and robust.

Pool shells are frequently installed ‘in ground’. This entails manipulating bulk material by digging a hole that is larger than the shell, placing the shell and then carefully backfilling thereabouts. As such, the earth and/or any groundwater supports the pool shell against the hydrostatic pressure of the water within the pool.

Some pool shells can also be installed ‘above ground’ (or partly above ground as in the context of installation in a hillside).

To suit such above ground installations, pool shells have been created with large vertical tubular ribs formed about their exterior. To install the pool shell, the site is first leveled and a trench encircling the site is excavated. The shell is then placed and leveled prior to concrete being supplied to each of the vertical ribs whereby the trench and ribs are filled with a single continuous body of concrete so that when the concrete sets an integral solid body of concrete defines a ring footing and a respective concrete finger within each of the vertical ribs.

Pool shells are typically formed by applying layers of material to a male mold. Typically the first layer is a gel coating that has an attractive appearance when the shell is pulled from the mould. Forming the tubular ribs to suit above ground installation is time consuming and expensive. Typically a shell akin to a typical ‘in ground shell’ must be produced and then cardboard rib-defining forms individually cut and placed about the exterior of the shell before the shell is returned for an additional series of fibreglassing operations to form the fiberglass about the exterior of the cardboard forms.

With the foregoing in mind, the present invention aims to provide improvements in and for swimming pools or at least to provide alternatives for those concerned with swimming pools.

It is not admitted that any of the information in this patent specification is common general knowledge, or that the person skilled in the art could be reasonably expected to ascertain or understand it, regard it as relevant or combine it in any way before the priority date.

SUMMARY

One aspect of the invention provides a swimming pool including

a pool shell having a wall;

two or more upright supports spaced along an exterior of the wall; and

mechanical fasteners fastening the upright supports to the shell;

the wall having a top, a bottom and a first elongate stiffening portion;

the first elongate stiffening portion running along the wall and being positioned more than 250 mm from each of the top and the bottom; and

the uprights supports being rigidly connected to the first elongate stiffening portion and at least one of the top and the bottom.

Preferably each of the upright supports is rigidly connected to the top and the bottom.

The pool shell may include

a floor;

a region of curvature running along a bottom of the wall and connecting the wall to the floor; and

a fastener-receiving formation, on an exterior of the region of curvature, for rigidly connecting the bottom to a support.

Another aspect of the invention provides a shell including

a wall;

a floor;

a region of curvature running along a bottom of the wall and connecting the wall to the floor; and

a fastener-receiving formation, on an exterior of the region of curvature, for rigidly connecting the bottom to a support.

The shell may be nestable. Preferably the fastener-receiving formation is not lower than an exterior of the floor.

Another aspect of the invention provides a swimming pool including

the shell; and

two or more upright supports;

the wall having

a top,an exterior, anda first elongate stiffening portion running along the wall and positioned more than 250 mm from each of the top and the bottom;
the upright supports being spaced along the exterior;
each of the upright supports being rigidly connected to the bottom and at least one ofthe top, andthe first elongate stiffening portion.

Optionally each of the upright supports is predominantly formed of elongate rigid members.

Another aspect of the invention provides a swimming pool including

a pool shell having a wall; and

two or more upright supports;

the wall having a top, a bottom, a first elongate stiffening portion and an exterior;

the upright supports being spaced along the exterior;

the first elongate stiffening portion running along the wall and being positioned more than 250 mm from each of the top and the bottom;

each of the upright supports being

rigidly connected to the first elongate stiffening portion and at least one of the top and the bottom, andpredominantly formed of elongate rigid members.

Preferably mechanical fasteners fasten the upright supports to the shell.

The pool shell may be a molded pool shell. The pool shell may be a fibre-reinforced polymer pool shell.

The supports may be metallic. Alternatively they may be plastic.

Preferably each of the one or more supports at least mostly consists of elongate portions of substantially constant cross-section. Most preferably the supports are arranged to engage the first elongate stiffening portion at three or more locations spaced along the first elongate stiffening portion.

Another aspect of the invention provides a method, of preparing a site for a swimming pool, including

manipulating bulk material to produce a surface; and

placing panels on the surface.

The manipulating bulk material to produce a surface may be levelling bulk material to produce a level surface.

Optionally the panels each have

a top and

a bottom compliant relative to the top.

Each of the panels may include plywood.

Each of the panels may include polystyrene.

Preferably the panels cover at least most of a margin encircling a contact patch of the swimming pool. The panels may define an opening substantially encircling the contact patch. The method may include supplying free-draining material to fill the opening level to a top surface of the panels.

Another aspect of the invention provides a method of installing a swimming pool including placing a pool shell on a site.

The method may include rigidly connecting supports to an exterior of the pool shell.

Another aspect of the invention provides a method of installing a swimming pool;

an in situ pool shell being substantially at a final position of the shell and having a wall;

the wall having a top, a bottom, a first elongate stiffening portion and an exterior;

the an elongate stiffening portion running along the wall and being positioned more than 250 mm from each of the top and the bottom;

the method including

spacing upright supports along the exterior of the in situ pool shell;fastening upright supports to a wall of the in situ pool shell such that upright supports are rigidly connected to the elongate stiffening portion and at least one of the top and the bottom.

The fastening preferably includes applying mechanical fasteners.

Another aspect of the invention provides a set, of panels, for paving a site for a swimming pool;

at least one of the panels defining a void for routing at least one line for the swimming pool.

Preferably the panels each have a top and a bottom compliant relative to the top. The panels include plywood and/or polystyrene. Most preferably, the panels are configured to define an opening substantially encircling a contact patch of the swimming pool.

Another aspect of the invention provides a set, for a swimming pool installation, including a swimming pool and the set of panels.

Another aspect of the invention provides a swimming pool including

a pool shell; and

one or more supports;

the pool shell having a first wall and a second wall;

the first wall having a top, a bottom and a first elongate stiffening portion;

the first elongate stiffening portion running along the first wall and being positioned more than 250 mm, e.g. more than 500 mm, from each of the top and the bottom of the first wall;

the second wall opposing the first wall;

each of the one or more supports

being rigidrunning under the pool shell at least from the first wall to the second wall andengaging the first elongate stiffening portion
to resist outward deformation of the first wall.

Pool shells may have trim, such as tiled finishes, within 250 mm of the top which may to some extent stiffen the walls. This aspect of the invention incorporates an elongate stiffening portion below this region to stiffen the wall.

The first elongate stiffening portion may comprise a ledge within the pool shell. The swimming pool may include a capping portion running along an exterior of the pool shell and capping an internal corner under the ledge to, together with the ledge, define a tubular portion running along the first wall.

Preferably each of the one or more supports engages the coping of the first wall. Most preferably each of the one or more supports extends upwardly behind the second wall. Optionally each of the one or more supports engages a coping of the second wall.

The second wall may have a top, a bottom a second elongate stiffening portion. The second elongate stiffening portion preferably runs along the second wall and is positioned more than 250 mm from each of the top and the bottom of the second wall. The supports may engage the second elongate stiffening portion to resist outward deformation of the second wall.

The swimming pool may be a transportable unit.

Another aspect of the invention provides a method, of manufacturing a swimming pool, including

applying bracing to align a first wall of a pool shell; and

engaging a rigid member with the first wall; and then

rigidly connecting the rigid member to at least one other rigid member to define a support for extending under the pool shell to resist outward deformation of the first wall; and then

removing the bracing.

The rigidly connecting may include welding.

The applying bracing to align may be applying bracing to hold straight.

DETAILED DESCRIPTION

FIG. 1illustrates a swimming pool1. The pool includes a shell3, a set of supports5and a base tray7. The shell3and supports5sit within the tray7. The tray7has upright walls to improve the structures' aesthetics and provides a base by which the structure1is conveniently transportable as a transportable unit. Other variants of the presently disclosed technology may be structures which are not conveniently transportable as transportable units.

The shell3is an upwardly open vessel having coping9running about its perimeter. The coping9defines the top of the pool shell. As the word ‘top’ and similar wording is used herein, the top of a pool shell is the lowest point at which water might overflow the pool shell when the pool shell is in use, aside from minor features such as weirs to which spas might be attached. As ‘bottom’ and similar wording is used herein, the bottom of the pool shell is the highest point upon which a bather might stand aside from minor features such as beaches, ledges, steps and seats.

The shell3has a first wall11and a second wall13opposing the first wall11. At one end of the shell the walls11,13are mutually connected by a wall15. At the other end of the shell the walls are connected by a wall17and stepped perimeter portion19. A ledge21runs along the walls11,15,13and is in three parts. Ledge portion21aruns along the wall11from the wall15to a beach area17aat the other end of the pool. Ledge portions21b,21crun along the walls15,13respectively. The ledge21is at a constant height in the vicinity of 650 mm from the top of the pool. Steps23are associated with the end of the wall13distal the wall15.

The ledge portions21a,21bare ‘step-ledges’ about 75 mm wide. The ledge portion21cis a shelf in the vicinity of 450 mm wide. The step ledges21a,21bprovide a convenient standing point for children at the side of the pool whereas the ledge21cprovides a comfortable seating area.

In addition to providing convenient features within the pool, the ledge21stiffens the pool walls. The ledge21ais an elongate portion running along the wall11to stiffen that wall against outward deformation under the influence of hydrostatic pressure. Likewise, the ledge portions21b,21cstiffen the walls15,13. The stiffener is preferably 500 mm to 700 mm from the top of the wall.

FIG. 7shows the ledge21ain further detail. In this particular example the internal corner25under the ledge21ais capped by a capping piece27to define a tubular portion running along the wall11. The ledge21aand capping portion27thereby form part of a tubular stiffening portion. A stiffening portion is a portion that is stiffer than the bulk of the wall material. In this example the tubular portion is hollow. In other examples it might be filled by a suitable filling material e.g. the capping material27might be laid over a length of wood fitted within the corner25.

The ledge portion21clikewise stiffens the wall13and (as illustrated inFIGS. 3 and 4) is associated with a capping piece defining a tubular stiffening portion.

Whilst the ledge21a, or more preferably the combination of ledge21aand the capping piece27, is a desirable form of stiffening formation, other stiffening formations are possible. By way of example, a suitable length of steel rectangular hollow section could be mounted to run along the exterior of the wall11.

FIG. 6illustrates the coping9in further detail. Advantageously the coping9is tubular. Most preferably it encapsulates material9a, e.g. wood, into which screws can be engaged to fasten the top caps29.

Advantageously the shell3can be constructed from a fiberglassing operation akin to the molding of a conventional ‘in ground’ shell followed by secondary operations to install the material9and capping piece27, etc. These secondary operations are inexpensive relative to the previously described steps necessary to form the tubular concrete-receiving ribs.

The inventors have found that an above ground shell can be adequately supported by bracing the exterior of the shell with a suitable arrangement of supports e.g. with one or more weldments of steel e.g. steel RHS. Surprisingly good results can be achieved when the rigid supports are engaged with the elongate stiffening formation21a,27spaced from the top and bottom of the wall. The engagement could be simple abutment although mutual fixation is preferred.

The inventors have also found that forming the rigid supports so as to wrap around under the pool is another important step towards cost-efficiently producing an aesthetically pleasing pool. As shown inFIG. 3, the rigid element5includes an upright member5arunning from the coping9down to a horizontal member5d. Member5bdefines a diagonal brace mutually connecting the members5a,5d. Oblique member5cconnects the stiffening formation21a,27to the members5a,5bof the element5. The horizontal member5druns under the pool shell from the wall11to the corner13aof the wall13. This extension distributes the load applied to the element5via the capping piece27. Indeed in this example the horizontal member5dextends beyond the corner13ato an arrangement of members5a′,5b′,5c′ akin to the members5a,5b,5c. In this way, both walls11,13are supported and tied together as a rigid unitary structure.

Once the shell3has been completed, frames A to E can be laid out as suggested inFIG. 8. In this example, each of the frames A to E is a respective weldment of 40×4 mm Square Hollow Section (SHS) having a galvanized finish. Top caps29are then added to the uprights of the frames. The top caps29are dimensioned to slide over the ends of the uprights. Each cap29has a pair of horizontal flanges, each of which has a screw hole.

Sheets of suitably compliant material are then laid between the horizontals of the frames to underlie the shell3. In this example the material is 50 mm thick polystyrene. The compliant material conforms to any imperfections (e.g. stones) on the surface onto which the structure3,5is eventually placed and thereby avoids stress concentrations being applied to the shell3. Preferably the sheet material is thicker than the horizontal portions of the frame are high and suitable covers of compliant material (e.g. 10 mm thick polystyrene strips) are adhered to the top of the horizontal members (FIG. 11) to separate the shell3from the horizontal members.

Glue is applied to compliant panels and the shell3is then lowered into the arrangement of frames (FIG. 12) and onto the glue. Support panels (e.g. plywood sheets) are then inserted to separate from the frames and support, the beach17aand the stairs23(FIGS. 13 and 14).

A frame E underlying the beach area17ais then lifted into engagement with the beach area and its support panel (FIGS. 5 and 15).

The shell can then be braced to ensure proper alignment e.g. to hold the main walls11,13straight. As schematically illustrated inFIG. 16, this may entail inserting a timber spacer TS into the pool shell3with suitable measures such as carpet strips CS to protect the gel coat.

With the shell in place, the caps29are then lifted (whilst remaining in sliding engagement with their respective uprights) and screwed into the coping9. The caps29are then welded to their respective uprights to form uprights of the rigid supports (such as the upright5aof the element5). Feet31akin to the top caps29are likewise welded to the lower ends of the two uprights of the frame E (FIG. 15).

The supports5ccan then be placed. In this example each support5cincludes a length of 40×4 mm SHS supporting a length of angle iron at its pool engaging end. The angle iron is oriented to sit flat against the capping piece27and has a pair of screw holes via which the support5cis screwed into that capping piece whilst the support5cis properly oriented to be welded to the members5a,5bto form a single unitary rigid element5.

The bracing TS, CS can then be removed to form a transportable structure3,5that can be craned into the tray7.

The pool1is well adapted for efficient manufacture in an industrial context and then efficient transport to the pool site. On the other hand, the present inventors have recognised that there is demand for the do-it-yourself (DIY) market, that is, for pools that can be supplied in kit form and assembled on site with minimal technical skill and without specialised equipment. Furthermore, the present inventors have recognised that the need for a crane to place the pool shell into the arrangement of frames (as inFIG. 12) is not desirable, particularly in a DIY context, and that pools that are easier to install also opens the way for retailers and others in the industry without the specialised skills of specialist pool installers to expand their businesses by competing with the pool installers.

FIGS. 18 to 21illustrate aspects of an alternate swimming pool, and components therefor, better suited to the DIY market. The pool37has a pair of long opposed walls39braced by upright supports41spaced therealong. Preferred variants of the support41are attached to the step ledge43and to one or both of the top45and bottom47of the wall39. The support41provides a reinforcing connection between relatively strong portions of the pool and thereby assists to maintain an aesthetically pleasing alignment of the wall39. Preferably no portion of the support41runs under the floor49of the pool shell51. Advantageously the support41is attached to the shell via mechanical fasteners, e.g. screws, bolts or rivets, etc. This enables the connections to be made by the home handyman with the shell in its final position, without a fibreglassing operation, although more preferably the pool37(including its supports41, etc.) takes the form of a transportable unit that can be transported by road and lifted (e.g. craned) into place.

When the pool37is supplied in kit form, the elongate members55,57,76may be supplied as separate members (potentially as part of a common pack). Leaving the assembly of the support41to occur on site can reduce transport and assembly costs.

The support41is mechanically fastened, or more specifically screwed in this example, to each of the step ledge43, top45and bottom47. The step ledge43and top45are akin to the step ledge21aand coping9of the pool1.

The bottom47incorporates an additional fastener-receiving formation53. The bottom of the wall47includes a radius connecting the wall39to the floor49. The fastener-receiving formation is a formation additional to the typical wall thickness of the shell. In this example it takes the form of a perforated steel plate bent to an angle substantially corresponding to the angle between the floor and the lower portions of the wall39. The plate is fibreglassed in place in the factory. In this example, the supports are spaced about 800 mm to 900 mm centres along the wall39and short fastener-receiving formations53have a complementary spacing along the corner47although in other variants the formation53may run the full length of the corner47.

The formation53is to receive fasteners by which a foot55of the support51is mechanically fastened to the shell51and thereby rigidly connected to the bottom47.

The formation53advantageously defines a distance into which fasteners can penetrate without projecting into the interior of the shell51.

The formation53sits no lower than the bottom of the floor49and only millimetres outward of an exterior of the wall39which does not materially reduce the ability of the shells51to be stacked for interstate transport. Advantageously the shells are manufactured in one location, stacked for efficient transport over long distances and then removed from the stack and transported individually to the final site.

This example of the support41includes a pair of horizontal feet55formed of glass-reinforced polymer in the form of pultruded 100 mm×100 mm (or more preferably 76.2×76.2×6.4 mm) square hollow section. Other plastics and modes of construction, and indeed other rigid materials more generally, are possible. For example, the supports41may be formed of galvanized steel as in the supports5and vice versa.

The pair of horizontal legs55bracket a single upright57. In this example the upright57takes the form of a single member of the same material as the legs55. A pair of bolts59skewer and mutually fasten the three members. The inner ends of the legs55carry an adjustable mounting plate61by which the legs55are made length adjustable. The plate61includes a simple plate portion from which a pair of square sockets63project to receive the ends of the legs55. Bolts65mutually connect the plate61,63to the legs55.

Preferably the plate61is attached to the fitting53before the bolt holes are drilled and the bolts65are placed to provide a degree of adjustability that takes up production variation, site variations and flexure of the components, etc. Other modes of length adjustment are possible. Preferably the shell51is aligned prior to the length of the adjustable length being set. This aligning operation may entail bracing akin to the process described in respect of the pool1.

An inclined support67includes a pair of members akin to the members55and an adjustable plate akin to the plate61and connects step ledge43to the upright member57. A top of the upright57is fitted with an adjustable plate69by which the member57is fastened to the top45.

Advantageously, relative to the support arrangement ofFIGS. 1 to 4, the supports41can be placed as required independently of any support called for on the other side of the pool. As such, the supports can be strategically located to make more efficient use of the available materials. By way of example, with reference to a pool akin to the pool1ofFIG. 1, supports41might be spaced at 650 mm centres along the long run of wall11between wall15and beach17a, whereas the portion of the wall13supported by the ledge21cmay be adequately supported by supports41and 900 mm centres. As such, the placement of the supports41may be more closely correlated with the inherent flexibility of the shell per se.

Preferably the pool is installed atop a concrete foundation, e.g. atop a slab or ring beam. Preferably the concrete is minimum 25 Mpa concrete.

FIGS. 20 and 21illustrate the swimming pool37and an alternative mode of site preparation.

As a first step bulk material (e.g. earth and road base) are manipulated to form a level pad71. Preferably this entails digging out a small quantity of earth, applying a layer of road base and then compacting the material. In other applications, it may be necessary to build up material.

A set of panels72are then laid down on site. Advantageously the panels are dimensioned for convenient handling, e.g. are in the vicinity of 8′×4′, and have a complaint base and a more rigid top. In this example, the base of each panel is formed of 50 mm thick extruded polystyrene (XPS) and is topped by a layer marine ply bonded to the polystyrene.

The compliant underside reduces deformations and associated stresses caused by imperfections in the surface71whilst the more rigid top provides support for the supports41and a convenient clean and dry mounting place for pool equipment75such as pumps filters and heaters.

Advantageously holes may be cut into the plywood and/or channels cut into the polystyrene to route lines such as electrical lines for powering underwater lights and various plumbing, e.g. plumbing for floor cleaning jets, to and from the interior of the pool.

The hydrostatic loadings on a pool shell vary dramatically depending on how it is installed. In true above ground installations wherein no portion of the shell is below the free surface of the ground, the panels73may define a substantially continuous deck underlying substantially all of the shell.

More often, the pool will be installed at least partly in ground and thereby potentially exposed to ground water pressure. To suit such installations preferably the panels73define an opening77corresponding to a footprint of the shell51. Advantageously the panels73are supplied to site pre-cut for connection in a defined pattern (e.g. a defined pattern specified by markings on the panels and/or by supplied instructions) to define the opening77.

Preferably free draining material for filing the opening77is supplied. Preferably at least the bulk of the free draining material is piled at a centre of the site prior to the boards being placed around it and then leveled off (and excess material removed and/or additional material added) to level off the free draining material in line with a top surface of the boards73. The free draining material may be coarse sand but is preferably minus 7 mm gravel without fines.

Preferred variants of the pool are equipped with one or more hydrostatic relief valves arranged to receive water via the free draining medium to relieve hydrostatic pressure on the pool.

The pair of 100 mm wide members making up the foot55provide bearing area for transmitting force downwardly. In some cases, this area may be sufficient for the foot55to sit directly on bulk material, e.g. compacted road base. In other circumstances, the panels may be necessary or desirable to spread the load.

FIG. 22shows an example of a small pool shell suited to DIY installation in small backyards and courtyards etc. The shell300is in the vicinity of 6 m long by 2 m wide. It comprises a beach301and a deep end303mutually connected by steps305. A step ledge307runs along each long side of the deep end303and together with one of the steps305and a similar step at the other end of the deep end303defines a single upward rectangular face surrounding the deep end303. Step309is positioned to enable a bather to step into the pool and then onto the beach301.

Whilst various examples are described, the invention is not limited to these examples. Rather the invention is defined by the claims.