WO2008034235A1

WO2008034235A1 - Covered pool structure

Info

Publication number: WO2008034235A1
Application number: PCT/CA2007/001663
Authority: WO
Inventors: Stéphane St-Hilaire; Sylvain Gendron
Original assignee: St-Hilaire Stephane; Sylvain Gendron
Priority date: 2006-09-18
Filing date: 2007-09-18
Publication date: 2008-03-27
Also published as: EP2064400A1; GB0618296D0; CN101360875A

Abstract

A covered pool structure (10) for containing a liquid (12). The liquid (12) defines a liquid top surface (13). The covered pool structure (10) includes a membrane (14) for containing the liquid (12), the membrane (14) defining a bottom wall (16) and a peripheral wall (18) extending therefrom. The peripheral wall (18) defines a top edge (20). A rim (22) extends from the peripheral wall (18) substantially adjacent the top edge (20). The rim (22) has a substantially toroidal configuration. An attachment flange (24) extends from the peripheral wall (18) substantially adjacent the rim (22). The attachment flange (24) is located peripherally relatively to the peripheral wall (18). A covering structure (26) defines a substantially flexible covering section (28) positionable so as to extend across the liquid top surface (13) and an attachment section (30) extending substantially peripherally and outwardly from the covering section (28). An attachment flange-to-attachment section releasable attachment (32) extends between the attachment flange (24) and the attachment section (30) for releasably attaching the attachment flange (24) and the attachment section (30) to each other. The attachment flange (24) and the attachment section (30) are both substantially resiliently deformable and have substantially similar elasticity moduli.

Description

TITLE OF THE INVENTION

COVERED POOL STRUCTURE

FIELD OF THE INVENTION

[0001] The present invention relates to the general field of pools and is more particularly concerned with a covered pool structure.

BACKGROUND OF THE INVENTION

[0002] Covering structures for swimming pools are well known in the art. In addition to improving the safety of the pool by preventing accidental falls thereinto, covering structures made out of a membrane also preserve water quality by reducing chlorine evaporation and reducing water contamination from external contaminants, such as bird droppings, that may fall into an uncovered pool.

[0003] Most covering structures for swimming pools are conceived for rigid swimming pools. However, non-rigid swimming pools, either of the self-supporting type or of a type in which a membrane is supported by a light structure made out of posts, have increasingly become popular in recent years. Because of their flexibility, such swimming pools are typically not usable with commonly used covering structures. Indeed, it is relatively difficult to attach such covering structures to a relatively flexible structure. Notably, attaching a covering structure to a flexible structure may lead to the creation of shear stresses in the attachment used to attach the covering structure. For example, in the case in which the attachment is of the zip-type, such shear forces may lead to damages to the attachment.

[0004] Another problem encountered in existing covering structures resides in that relatively waterproof covering structures may accumulate water, such as rain water, on their top surface. In relatively rigid swimming pools, this typically does not cause great problems, as the quantity of water that may be accumulated is relatively small due to the tension applied to the covering structure when it is attached to the rigid structure of the swimming pool. However, in a flexible swimming pool, there exists a risk that a relatively large quantity of water may accumulate on top of the covering structure as the swimming pool may deform in response to the accumulation of water and, therefore, allow a relatively deep puddle to form.

[0005] In turn, these puddles lead to an increased risks that small children or babies could drown in the puddle as the weight of a child falling onto the covering structure would add to the deformation of the covering structure, thereby increasing the depth of the pool thereby formed.

[0006] Another problem encountered in such flexible swimming pools, and more typically in self-supporting swimming pools, is caused by the fact that by their relatively small size and inexpensive nature, such swimming pools, when they include a pump and a filter for filtering the water contained therein, only include a single underwater inlet for drawing the water to filter out of the swimming pool. There have been many accidents in which hairs of a child have been drawn into the inlet by the pump and in which the child has been unable to remove the hairs from the inlet, which resulted in drowning of the child.

[0007] Accordingly, there exists a need for an improved covered pool structure. It is a general object of the present invention to provide such a covered pool structure. SUMMARY OF THE INVENTION

[0008] In a broad aspect, the invention provides a covered pool structure for containing a liquid. The liquid defines a liquid top surface. The covered pool structure includes a membrane for containing the liquid, the membrane defining a bottom wall and a peripheral wall extending therefrom. The peripheral wall defines a top edge. A rim extends from the peripheral wall substantially adjacent the top edge. The rim has a substantially toroidal configuration. An attachment flange extends from the peripheral wall substantially adjacent the rim. The attachment flange is located peripherally relatively to the peripheral wall. A covering structure defines a substantially flexible covering section positionable so as to extend across the liquid top surface and an attachment section extending substantially peripherally and outwardly from the covering section. An attachment flange-to-attachment section releasable attachment extends between the attachment flange and the attachment section for releasably attaching the attachment flange and the attachment section to each other. The attachment flange and the attachment section are both substantially resiliently deformable and have substantially similar elasticity moduli.

[0009] For the purpose of the present description, the terminology covered pool structure refers to any covered pool, such as, for example, covered swimming pools, covered spas and any other suitable covered structure that may contain a liquid. For example, the covered pool structure is either of the self-supporting type, or of the type supported by a relatively light structure including a rigid rim, posts supporting the rim, and reinforcing members extending between the posts, but which does not include rigid walls.

[0010] Having the attachment flange and the attachment section with substantially similar elasticity moduli causes the attachment flange and the attachment section to deform substantially similarly when external forces are exerted onto the covered pool structure. This reduces shear stresses in the attachment flange-to-attachment section releasable attachment, which in turn increases the reliability and durability of many types of usable attachment flange-to-attachment section releasable attachments, such as attachments of the zip-type.

[0011] For example, the external forces exerted onto the attachment flange may be forces due to the hydrostatic pressure of the liquid contained within the membrane, forces exerted by an intended user when attaching to and detaching from the covering structure the remaining portion of the covered pool structure, or forces exerted when the intended user of the covered pool structure enters or leaves the liquid.

[0012] In some embodiments of the invention, the covered pool structure includes a drain positioned so as to be able to remove water accumulating onto the covering section. This drain reduces the risk of a small child drowning in puddles of water accumulating on top of the covering section. Such drains also reduce the risk that the covering structure, or the membrane, becomes damaged due to forces exerted thereonto by such accumulated water.

[0013] The proposed covered pool structure is relatively easily manufacturable at relatively low costs using currently known materials and techniques. Furthermore, the proposed covering structure is relatively easily attachable to and detachable from the membrane using a relatively small number of quick and ergonomic steps.

[0014] In some embodiments of the invention, the covered pool structure includes a pump in fluid communication with two inlets formed into the membrane, for example into the peripheral wall. In these embodiments, if an object or a part of a body of an intended user of the covered pool structure becomes stuck into one of the pump inlets, the pump may continue circulating the liquid by drawing the liquid through the other pump inlet, which reduces the suction force exerted by the pump onto the object or part of the body of the intended user and facilitates removal of the object or part of the body of the intended user from the blocked pump inlet.

[0015] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non- restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] An embodiment of the present invention will now be disclosed, by way of example, in reference to the following drawings, in which:

[0017] Figure 1 , in a perspective view, illustrates a covered pool structure in accordance with an embodiment of the present invention;

[0018] Figure 2, in a side cross-sectional view with portions removed taken along the line M-Il shown in Fig. 1 , illustrates a portion of the covered pool structure shown in Fig. 1 ;

[0019] Figure 3, in a perspective view, illustrates a covered pool structure in accordance with an alternative embodiment of the present invention;

[0020] Figure 4, in a side cross-sectional view with portions removed taken along the line IV-IV of Fig. 3, illustrates the covered pool structure shown in Fig. 3;

[0021] Figure 5, in a perspective view, illustrates a covered pool structure in accordance with yet another embodiment of the present invention; and

[0022] Figure 6, in a side cross-sectional view with portions removed, illustrates a covered pool structure in accordance with yet another embodiment of the present invention.

DETAILED DESCRIPTION

[0023] Figures 1 and 2 illustrate a covered pool structure 10 in accordance with an embodiment of the present invention. Referring more specifically to Fig. 1, the covered pool structure 10 is provided for containing a liquid 12. The liquid 12 defines a liquid top surface 13.

[0024] The covered pool structure 10 includes a membrane 14 for containing the liquid 12. The membrane 14 defines a bottom wall 16 and a peripheral wall 18 extending therefrom. The peripheral wall 18 defines a top edge 20, better seen in Fig. 2.

[0025] Still referring to Fig. 2, a rim 22 extends from the peripheral wall 18 substantially adjacent the top edge 20. Typically, the rim 22 has a substantially toroidal configuration with a substantially circular cross-sectional configuration, or with any other suitable cross-sectional configuration. The rim 22 shown in Fig. 2 is an inflatable rim 22 part of a self-supporting swimming pool. However, in alternative embodiments of the invention, the rim 22 is any suitable rim 22.

[0026] An attachment flange 24 extends from the peripheral wall 18 substantially adjacent the rim 22. The attachment flange 24 is located peripherally relatively to the peripheral wall 18.

[0027] As seen in Fig. 1 , a covering structure 26 is also provided.

The covering structure 26 defines a substantially flexible covering section 28 positionable so as to extend across the liquid top surface 13. The covering structure 26 also defines an attachment section 30 extending substantially peripherally and outwardly from the covering section 28.

[0028] In some embodiments of the invention as shown, for example, in Fig. 1 , the covering section 28 has a substantially disc-shaped configuration and the attachment section 30 forms a substantially annular structure extending peripherally relatively to the covering section 28 and has a substantially arcuate cross-sectional configuration in a plane perpendicular to the covering section 30, as illustrated in Fig. 2. However, in alternative embodiments of the invention, the covering structure 26 has any other suitable shape.

[0029] An attachment flange-to-attachment section releasable attachment 32 extends between the attachment flange 24 and the attachment section 30. The attachment flange-to-attachment section releasable attachment 32 is provided for attaching the attachment flange 24 and the attachment section 30 to each other.

[0030] The attachment flange 24 and the attachment section 30 are both substantially resiliently deformable and have substantially similar elasticity moduli. Therefore, the attachment flange 24 and the attachment section 30 will deform substantially similarly when external forces are exerted onto the covered pool structure 10. In turn, this reduces shear stresses in the attachment flange-to-attachment section releasable attachment 32. Many typically used releasable attachments are sensitive to such shear stresses, which may damage these releasable attachments. Because of the relatively large labour involved in replacing such releasable attachments, it advantageous that the attachment flange-to-attachment section releasable attachment 32 used in the proposed covered pool structure 10 does not easily become damaged during normal use.

[0031] Deformation of the covered pool structure 10 may occur for many reasons. For example, when the covered pool structure 10 is first filled with the liquid 12, the hydrostatic pressure exerted by the liquid 12 onto the covered pool structure 10 tends to extend radially the covered pool structure 10. Since the attachment flange 24 and the attachment section 30 have substantially similar elasticity moduli, these two elements extend substantially similarly under the action of the hydrostatic pressure of the liquid 12, which reduces the possibility that large shear stresses are induced into the attachment flange-to-attachment section releasable attachment 32.

[0032] Furthermore, since the covered pool structure shown in Figs.

1 and 2 is of the self-supporting type, the intended user of the covered pool structure may relatively easily deform the covered pool structure 10 either during maintenance, during normal use of the covered pool structure 10, or when attaching to or detaching from the attachment flange 24 the covering structure 26. All these operations may create forces that may eventually damage the attachment flange-to-attachment section releasable attachment 32. Indeed, if the attachment flange 24 and the attachment section 30 deform differently under the action of external forces, the attachment flange 24 and the attachment section 30 will create shear forces into the attachment flange-to- attachment section releasable attachment 32, which may result in permanent damages to the attachment flange-to-attachment section releasable attachment 32.

[0033] Referring to Fig. 2, in some embodiments of the invention, the rim 22 defines a rim apex 34, a rim nadir 36 and a rim midplane 38 extending substantially mid-way between the rim apex 34 and the rim nadir 36. For example, the rim midplane 38 is located between the attachment flange-to- attachment section releasable attachment 32 and the rim apex 34. Because of the substantially toroidal configuration of the rim 22, in these embodiments, the attachment section 30 is, at least partially, wrapped around the rim 22. This positioning of the releasable attachment 32 further helps in maintaining the structural integrity of the covered pool structure 10. For example, in this configuration, any forces exerted onto the covering section 28 towards the liquid 12 tends to be, at least partially, transmitted to the rim 22 instead of being transmitted directly to the releasable attachment 32. Also, this configuration ensures that the attachment flange-to-attachment section releasable attachment 32 operates mainly in tension when such external forces are exerted onto the covered pool structure 10.

[0034] In a more specific example of implementation, the attachment flange-to-attachment section releasable attachment 32 is located between the rim nadir 36 and the rim midplane 38. This configuration ensures that the attachment flange 24 and the attachment section 30 together wrap around the rim 22, which enhances the above-mentioned advantages.

[0035] Typical values for an attachment-to-midplane distance 40 between the attachment flange-to-attachment section releasable attachment 32 and the rim midplane 38 are from about 50% to about 95% of an attachment- to-nadir distance 42 between the rim nadir 36 and the rim midplane 38. Indeed, these values have been found to lead to covering structures 26 that are relatively well secured to the attachment flange 24, while remaining relatively easily attached to and removed from the remainder of the covered pool structure 10. However, other relationships between the relative values of the attachment-to-midplane distance 40 and attachment-to-nadir distance 42 are within the scope of the present invention.

[0036] The rim 22 includes a rim body 44 having a substantially toroidal configuration and a rim flange 46 extending substantially radially outwardly from the rim body 44. For example, the rim flange 46 is attached to the peripheral wall 18 substantially adjacent the top edge 20 through a sonic weld. In some embodiments of the invention the rim 22 is formed by folding over itself a membrane and attaching end sections of this membrane to each other to form the rim body 44 and the rim flange 46.

[0037] The attachment flange 24 and the attachment section 30 are typically made out of the same material. Typically, the properties of this material should namely be water proof, high tear strength, high tensile strength, high stretching resistant, resistant to deterioration when exposed to elements such as chlorine, iodine and UV. For example material such as the make 'Denier 210' sold by Datong Inc. It has been found that this material is particularly well suited to the present application as it allows for the creation of relatively small deformations into both the attachment flange 24 and the attachment section 30 under external loads exerted onto the covered pool structure 10 during normal use. However, it is within the scope of the invention to include any other suitable materials in the attachment flange 24 and the attachment section 30.

[0038] Referring to Fig. 2, in some embodiments of the invention, the attachment flange 24 extends integrally from the membrane 14. For example, the attachment flange 24 is a prolongation of the membrane 14 and extends generally upwardly from the top edge 20. In other embodiments of the invention, as seen, for example, in Fig. 3 for an alternative embodiment of the present invention, the attachment flange 24' is attached to the membrane 14 through a sonic weld.

[0039] A type of attachment flange-to-attachment section releasable attachment 32 particularly well suited to the present invention is a zip-type fastener. For example, the zip-type fastener includes two zip bands 48 and 50 stitched respectively to the attachment flange 24 and the attachment section 30 and a slider 51 extending between the two zip bands 48 and 50 for selectively attaching to each other and detaching from each other the two zip bands 48 and 50 upon being slid relatively thereto. Such zip-type fasteners are well- known in the art to be relatively resistant to tension in a direction lateral to their longitudinal axis. Therefore, such a zip-type fastener is well-suited to the proposed covered pool structure as forces exerted vertically onto the covering structure 26 are relatively unlikely to lead to lead to permanent damages of the zip-type fastener.

[0040] Since in some embodiments of the invention the covering structure 26 is intended to protect children from drowning into the liquid 12, the relatively large resistance of the zip-type fastener to forces exerted onto the covering structure 26 ensures that even if a small child climbs onto the covering structure 26, it is relatively unlikely that the attachment flange-to-attachment section releasable attachment 32 will fail and lead to the child falling into the liquid 12. This unlikeliness of failure is enhanced by the equality of the elasticity moduli of the attachment flange 24 and of the attachment section 30, as shear stresses that could be induced into the zip-type fastener upon deformation of the covered pool structure 10 will then be relatively small, which will contribute to the ruggedness of the proposed covered pool structure 10.

[0041] Referring to Figs. 3 and 4, there is shown a covered pool structure 10' in accordance with another embodiment of the present invention. The covered pool structure 10' is substantially similar in many aspects to the previously described covered pool structure 10 and reference numerals used in describing the covered pool structure 10 will also be used when similar structures are present in the covered pool structure 10'.

[0042] A difference between the covered pool structure 10' and the covered pool structure 10 resides in that the covered pool structure 10' is not of the self-supporting type. Instead, a substantially rigid rim 22' of the covered pool structure 10' is supported in a spaced apart relationship relatively to a ground surface unto which the covered pool structure 10' is disposed by posts 52. The posts 52 are typically circumferentially spaced apart from each other and provide a surface against which a membrane 14' of the covered pool structure 10' abuts against. To prevent the posts 52 from being pushed radially outwardly by the hydrostatic pressure created by the liquid 12 (not shown in Figs. 3 and 4), reinforcing members 54 extend substantially circumferentially around the covered pool structure 10 and link the posts 52 to each other.

[0043] As seen in Fig. 4, in this embodiment of the invention, the membrane 14' is suspended from the rim 22', for example by looping the membrane 14' around the rim 22' and attaching the membrane 14' to itself so as to enclose the rim 22'. Also, the attachment flange 24' extends from the peripheral wall 18' and is sonically welded thereto.

[0044] Fig. 5 illustrates another covered pool structure 10". The covered pool structure 10" is substantially similar to the covered pool structure 10, except that it includes a filtration system 56 for circulating the liquid 12 present in the covered pool structure 10" through a conventional filter (not shown in the drawings) and reintroducing the filtered liquid 12 into the covered pool structure 10".

[0045] More specifically, in this embodiment of the invention, the membrane 14 defines as least two pump inlets 58. The at least two pump inlets 58 extend through the membrane 14. Also, a pump outlet 60 extends through the membrane 14. The covered pool structure 10 includes a pump 62 in fluid communication with each of the at least two pump inlets 58 and with the pump outlet 60 for circulating the liquid 12 by drawing the liquid 12 through the at least two pump inlets 58 and pushing the liquid through the pump outlet 60. For example, two pump inlets 58 are substantially adjacent to each other and connected to the pump 62 through a substantially Y-shaped tube 61. For example, the two pump inlets are spaced apart from each other by a secured distance of about 1.5 meter.

[0046] The presence of at least two pump inlets 58 in the covered pool structure 10" reduces the vacuum force exerted by the pump 62 onto objects that may become engaged into one of the pump inlets 58 and blocks partially or totally this pump inlet 58. This feature increases the safety of the covered pool structure 10", as it ensures that if a small child has body parts such as their hair engaged into the pump inlet 58, the other pump inlet 58 will allow water to be drawn by the pump 62 without creating a relatively large vacuum force, which will allow the child to remove himself from the pump inlet 58, thereby preventing drowning of the child.

[0047] Fig. 6 illustrates a covered pool structure 10'" in accordance with yet another embodiment of the present invention. The covered pool structure 10'" is substantially similar to the covered pool structure 10, except that it includes an alternative covering structure 26'. Also, the covered pool structure 10'" includes a drain 64.

[0048] The drain 64 extends from the covering section 28' of the covering structure 26'. The drain 64 defines a drain inlet 68 located substantially adjacent to the covering section 28, a drain outlet 70 located peripherally relatively to the peripheral wall 18 when the covering section 28' extends across the liquid top surface 13 and a drain passageway 72 extending therebetween.

[0049] The covering structure 28' defines a draining aperture 74 leading to the drain inlet 68. Typically, the drain 64 is substantially funnel- shaped substantially adjacent to the covering section 28' and tapers to a section of substantially constant diameter extending towards the drain outlet 70. The drain 64 allows water accumulating on the top of the covering structure 26' to be evacuated therefrom. Therefore, when rain falls onto the covered pool structure 10, or when water becomes present on the covering structure 26' for any other reason, the water may drain from the covering structure 26' through the drain 64, which reduces forces exerted onto the covering structure 26' and onto the attachment flange-to-attachment section releasable attachment 32, and helps in preventing small children from drowning in a puddle of water that could have accumulated on top of the covering structure 26'.

[0050] Typically, the drain 64 extends through the peripheral wall 18 and the drain outlet 70 is located closer to the bottom wall 16 than the drain inlet 68. This allows water to flow under the action of gravity through the drain 64 and, therefore, facilitates evacuation of the water from the top of the covered pool structure 10.

[0051] To help in maintaining this relationship between the drain 64 and the remaining portions of the covered pool structure 10'", in some embodiments of the invention, the drain 64 is made out of a drain material, the drain material being substantially buoyant in the liquid 12. For example, the drain material is substantially buoyant in water. However, in alternative embodiments of the invention, the drain 64 is made out of any other suitable material.

[0052] Although the present invention has been described hereinabove by way of preferred embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A covered pool structure for containing a liquid, said liquid defining a liquid top surface, said covered pool structure comprising:

- a membrane for containing said liquid, said membrane defining a bottom wall and a peripheral wall extending therefrom, said peripheral wall defining a top edge;

- a rim extending from said peripheral wall substantially adjacent said top edge, said rim having a substantially toroidal configuration; - an attachment flange extending from said peripheral wall substantially adjacent said rim, said attachment flange being located peripherally relatively to said peripheral wall;

- a covering structure, said covering structure defining a substantially flexible covering section positionable so as to extend across said liquid top surface and an attachment section extending substantially peripherally and outwardly from said covering section;

- an attachment flange-to-attachment section releasable attachment extending between said attachment flange and said attachment section for releasibly attaching said attachment flange and said attachment section to each other;

- wherein said attachment flange and said attachment segment are both substantially resiliently deformable and have substantially similar elasticity moduli.

2. A covered pool structure as defined in claim 1, wherein said rim defines a rim apex, a rim nadir and a rim midplane extending substantially midway between said rim apex and said rim nadir, said rim midplane being located between said attachment flange-to-attachment section releasable attachment and said rim apex.

3. A covered pool structure as defined in claim 2, wherein said attachment flange-to-attachment section releasable attachment is located between said rim nadir and said rim midplane.

4. A covered pool structure as defined in claim 3, wherein an attachment- to-midplane distance between said attachment flange-to-attachment section releasable attachment and said rim midplane is from about 50% to about 90% of an attachment-to-nadir distance between said rim nadir and said rim midplane.

5. A covered pool structure as defined in claim 1, wherein said attachment flange is made out of a flange material, said attachment section being also made out of said flange material.

6. A covered pool structure as defined in claim 5, wherein said flange material is selected from the group having a set of properties namely water proof, high tear strength, high tensile strength, high stretching resistant, resistant to deterioration when exposed to elements such as chlorine, iodine and UV.

7. A covered pool structure as defined in claim 1, wherein said attachment flange extends integrally from said membrane.

8. A covered pool structure as defined in claim 1, wherein said attachment flange is attached to said membrane through a sonic weld.

9. A covered pool structure as defined in claim 1, wherein said rim is an inflatable rim.

10. A covered pool structure as defined in claim 1, wherein said covered pool structure is supported by a supporting surface and said rim is substantially rigid, said covered pool structure further including posts extending substantially downwardly from said rim for supporting said rim in a substantially spaced apart relationship relatively to said supporting surface.

11. A covered pool structure as defined in claim 1, wherein said attachment flange-to-attachment section releasable attachment includes a zip-type fastener.

12. A covered pool structure as defined in claim 11, wherein said zip-type fastener includes a first zip band and a second zip band, said first and second zip bands being attached respectively to said attachment flange and to said attachment section, said zip-type fastener further including a slider operatively coupled to said first and second zip bands for selectively attaching to each other and detaching from each other said first and second zip bands upon being slid relatively thereto.

13. A covered pool structure as defined in claim 12, wherein said first and second zip bands are stitched respectively to said attachment flange and to said attachment section.

14. A covered pool structure as defined in claim 1 , further comprising a drain extending from said covering section, said drain defining a drain inlet located substantially adjacent said covering section, a drain outlet located peripherally relatively to said membrane when said covering section extends across said liquid top surface and a drain passageway extending between said drain inlet and said drain outlet, said covering structure defining a draining aperture leading to said drain inlet.

15. A covered pool structure as defined in claim 14, wherein said drain extends through said membrane.

16. A covered pool structure as defined in claim 15, wherein said drain outlet is located closer to said bottom wall than said drain inlet.

17. A covered pool structure as defined in claim 16, wherein said drain is made out of a drain material, said drain material being substantially buoyant in water.

18. A covered pool structure as defined in claim 1 , wherein said membrane defines at least two pump inlets extending therethrough and a pump outlet extending therethrough, said covered pool structure further comprising a pump in fluid communication with each of said at least two pump inlets and with said pump outlet for circulating said liquid by drawing said liquid through said at least two pump inlets and pushing said liquid through said pump outlet.