This invention relates to liquid containment and, in particular, to a system for creating a barrier for liquid, using individual liquid barrier units.

In recent years, localised flooding has occurred more frequently than predicted, and in locations not previously considered to be at risk from flooding. Flash flooding can cause significant damage to property, including buildings and vehicles, and can cause injury or even death to humans and animals.

Despite the risk of being affected by flooding, the majority of households and businesses do not own flood defence equipment. Even in areas that are at particularly high risk from flooding, flood defence equipment is generally not readily available when the need to use it arises suddenly, without warning.

A well known device for protecting property against flooding is a sand bag. A sand bag is a sealed bag, made from a woven sack-like material, which is filled with sand. Sand bags are typically laid on the ground in front of the building or object that they are intended to protect. The sand bags are piled up to form a wall, which restricts the flow of water caused by a flood. A disadvantage of sand bags is that, since they are filled with sand, the sand bags are heavy and difficult to transport. Furthermore, since the sand bags are sealed, it is not possible to easily empty the bags so that they can be stored, and subsequently fill the bags with sand when required. A further disadvantage is that sand bags are typically only used in flood defences. When their use as a flood defence is not required, sand bags typically lay unused, and can inconveniently cause an obstruction.

Another type of existing flood defence is a solid, wall-type defence. This type of flood defence is typically formed from a series of individual units, which are connected together to form a wall-like structure which acts as a defence against flooding. Such flood defence systems are expensive and constructed from solid material, making them difficult to store and transport. Furthermore, solid flood defences are inflexible and, therefore, it is often not possible to locate the defence in the most appropriate location.

An aim of the invention is to provide a flood defence, or liquid barrier system, which is inexpensive, convenient for storage purposes, and suitable for use wherever it is desirable to prevent, or at least restrict, flooding. It is also an aim of the invention to overcome, or at least mitigate, some of the problems of the prior art.

In a first aspect of the invention, a liquid barrier unit comprises a hollow, elongate, deformable structure, provided with an inlet valve for the ingress of ballast, the liquid barrier unit being such that, when ballasted, the passage of liquid from one side of the liquid barrier unit to the other side is restricted.

The liquid barrier unit may comprise means for detachably connecting the unit to one or more other liquid barrier units. The liquid barrier unit can be used alone, or in combination with one or more other liquid barrier units.

The deformable material used to make the liquid barrier unit allows it, when empty, to be folded or rolled up for convenient storage. When required for use, the liquid barrier unit can be filled with air, water, sand, or any other desired ballast. When filled with the air, or the preferred ballast, the liquid barrier unit forms a barrier structure capable of preventing or restricting movement past it.

Preferably, the liquid barrier unit further comprises means for detachably connecting a liner thereto. Attachment of a liner to the liquid barrier unit can create a larger liquid barrier volume. Connection of a plurality of liquid barrier units to a liner can create a swimming pool-like structure, capable of containing water within a perimeter of the structure. Advantageously, the means for connection are hook-and-loop connectors, zip connectors, popper connectors or strap and buckle connectors. Hook-and-loop connectors provide a non-permanent connection between two surfaces. Surfaces connected by hook-and-loop connectors would remain connected until the surfaces are eased apart, at a time when it is desirable to separate the surfaces. Zip connectors, popper connectors or strap and buckle connectors would create a secure but detachable connection between two surfaces. Preferably, the inlet valve is a one-way air inlet valve, which allows air to be inputted into the unit, but not out of the unit.

Preferably, the liquid barrier unit further comprises a second inlet valve. The liquid barrier unit can be filled with air, water, sand, or some other ballast to weigh it down. A unit having two inlets could be filled, with air via the first inlet, and/or water, sand or some other ballast via the second inlet.

Advantageously, the liquid barrier unit further comprises an outlet. When it is desirable to deflate the unit, or to empty the unit of its ballast, the outlet can be opened, to effect deflation or fast ballast removal. The inlet valves and/or the outlet may conveniently be provided with caps, lids, or some other form of cover.

Preferably, the unit is substantially semi-annular in shape. It may have a circular cross-section, a rectangular cross-section, or a cross-section of some other shape. The unit may conveniently have a flat bottom to make the unit more sturdy on the ground.

Advantageously, the unit is capable of being used as a flood defence.

Preferably, the unit comprises a housing for receiving a solid ballast and a fluid therein. Ideally, the fluid is water and/or air. An advantage of the unit being capable of receiving both ballast and air is that only a small amount of ballast is required to weigh the unit down, so that it is not easily movable. The shape of the unit is maintained by the input of air, which inflates the unit to the shape desired during use. The unit is suitable for use in locations where a large supply of ballast or water is not readily available.

In a second aspect of the invention, a liquid barrier system comprises a plurality of liquid barrier units, the units being detachably connectable to one another, wherein, in use, the liquid barrier system is capable of restricting the passage of liquid from one side of one or more of the barrier units to the other.

An advantage of using a plurality of liquid barrier units in a system is that the system can be used to contain, amongst other things, water in a particular location. Rather than simply restricting the flow of water such as that caused by a flood, the liquid barrier system is capable of containing non-flowing water for the purpose, for example, of using the system as a swimming or paddling pool. Preferably, the liquid barrier system further comprises a liner detachably connectable to the liquid barrier units. The liner, which is preferably waterproof, can be used as an additional water barrier surface forming, for example, the base of a swimming or paddling pool, the edges of which are defined by the liquid barrier units. The liner is detachably connectable to the units such that it can be removed when not in use, and folded or rolled up for convenient storage.

Advantageously, the liquid barrier system is capable of containing liquid within a perimeter formed by the liquid barrier units, such that a user is able to swim in the liquid.

Preferably, the liquid barrier system further comprises at least one connecting unit, the or each connecting unit being detachably connectable to two liquid barrier units.

The invention will now be described in greater detail, by way of non-limiting example, with reference to the drawings, in which:

Figure 1 is a perspective view of the top of a liquid barrier unit constructed according to a first embodiment of the invention;

Figure 2 is a perspective view of the bottom of the liquid barrier unit of Figure 1 ;

Figure 3 is a perspective view of the liquid barrier unit of Figure 1 in a deflated state; Figure 4 is a plan view of a liquid barrier system formed of two of the liquid barrier units of Figure 1 ;

Figure 5 is a perspective view of a swimming pool formed from two liquid barrier units of the type shown in Figures 1 and 2;

Figure 6 is a perspective view of one component of the swimming pool of Figure 4;

Figure 7 is a perspective view of a liquid barrier unit constructed according to a second embodiment of the invention;

Figure 8 is a perspective view of an alternative component of the liquid barrier unit constructed according to the second embodiment of the invention; Figure 9 is a perspective view of a liquid barrier unit constructed according to a third embodiment of the invention;

Figure 10 is a perspective view of an alternative component of the liquid barrier unit constructed according to the third embodiment of the invention; and

Figure 1 1 is a perspective view of a liquid barrier unit constructed according to a fourth embodiment of the invention.

Referring to the drawings, Figure 1 shows a liquid barrier unit constructed in accordance with a first embodiment of the invention, generally denoted 10. The liquid barrier unit 10 comprises a housing 1 1 , which is a generally semi-annular hollow construction, having a first end face 12 and a second end face 14, and a connecting part 16, having a substantially circular cross section. The liquid barrier unit 10 is formed from a flexible plastics material, for example polyvinylchloride (PVC), but a person skilled in the art would understand that it could be formed of any suitable deformable material. The material from which the unit 10 is formed is, ideally, a single layer waterproof material. Each end face 12, 14 of the unit 10 includes a non-permanent connector 16, 18. In this embodiment, the non-permanent connector 16, 18 is a hook-and-loop type connector, such as Velcro (RTM). The connector 16 attached to the first end face 12 is complementary to the connector 18 attached to the second end face 14. For example, if the hook-and-loop type connector is used, then the connector 16 would be the hook-type surface, and the connector 18 would be the loop-type surface. Alternative connectors may be used, for example zip connectors, popper connectors or strap-and-buckle connectors. A non-permanent connector strip 20 is provided around or near, or at least partially around or near, the inner circumference of the unit 10. Non-permanent connectors 22 and 24 are provided substantially on the top surface of the unit. In this embodiment, only two connectors 22, 24 are shown on the top surface of the unit. However, additional connectors may be provided around the unit, at regular intervals. The connectors 20, 22, 24 are, in this embodiment, formed from one type of hook-and- loop material, such that they are arranged to formed a non-permanent connection to a complementary piece of hook-and-loop material.

A first inlet 26 and a second inlet 28 are provided on the top surface of the unit 10. The first and second inlets 26, 28 are shown at one end of the unit 10, near the end face 14. However, the inlets 26, 28 could be positioned at any point around the top surface of the unit 10. The first inlet 26 is an air inlet valve. The air inlet valve 26 allows the input of air into the unit 10 by any standard means, for example by blowing into the inlet, or pumping air in via a pump, or via an air compressor (not shown). The air inlet valve 26 is arranged to prevent air from escaping from the unit 10. This may be achieved by a one-way air valve, or by an airtight cap or lid, or both.

The second inlet 28 is larger than the first inlet 26, and is arranged to allow the input of water, sand, gravel, or some other ballast, into the unit 10. Both inlets 26, 28 are of the known type, and can be provided with caps or lids (not shown) to prevent undesired passage of air or ballast in or out of the inlets. Alternatively, the first and second inlet valves 26, 28 may be combined into a single inlet valve (not shown). Such a valve is arranged to allow the input of water, sand, gravel, or some other ballast, and air. The single inlet valve allows the input of air into the unit 10, and is arranged to prevent air from escaping. This may be achieved by a one-way air valve, or by an airtight cap or lid, or both.

A handle 64, 66 is provided on each end of the unit 10 to facilitate movement of the unit when ballasted. Although it will generally be undesirable to move the unit 10 when in use, it may be necessary to move a unit containing ballast in order to re- position it, or to move it to a convenient position for emptying out the ballast. The handles 64, 66 are formed from the same material from which the unit 10 is formed, or can be formed from some other material, for example plastics material. The handles 64, 66 are connected to the unit 10 by any known means, for example adhesive. Although two handles 64, 66 are shown in the Figures, a person skilled in the art will appreciate that any number of handles can be included on the unit 10, depending on specific requirements.

In Figure 2, the underside of the liquid barrier unit 10 is shown. An outlet 29 is provided at one end of the unit 10. The outlet 29 is a standard outlet, having an aperture through which water, air or other ballast can pass, and a lid or cap 29A, connectable to the outlet 29 by known connection means, such as complementary screw threads. By removing the cap 29A from the outlet 29, one is able to remove any ballast from inside the unit 10, or to release air from within the unit. The outlet 29 may be positioned at any location on the unit 10, but ideally is positioned at or near the bottom of the unit to facilitate easy removal of air, water or ballast from within the unit.

The liquid barrier unit 10 is capable of being used alone, or as part of a modular system, comprising a plurality of units 10, for a variety of purposes.

A person skilled in the art will appreciate that the unit 10 can be made in any size, and that units of different sizes are useful for different situations. The size of the unit 10 will be such that, in use, an area having a diameter of between approximately 50cm and 10m will be protected. Preferably, the unit 10, in use, will be large enough to protect an area having a diameter of between approximately lm and 4m and, more preferably, an area having a diameter of between approximately 2m and 3m. The height of the unit 10, in use, is between approximately 20cm and 2m, preferably between approximately 30cm and 80cm. Ideally, the height of the unit 10, in use, is approximately 50cm.

Use as a Flood Defence Figure 3 shows a liquid barrier unit 10 in a deflated state, as it would be before use. In use, a user would position the deflated liquid barrier unit 10 in a desired location, for example, so as to form an arc around a doorway of a building. The cap or lid covering the second inlet 28 is removed, and ballast is poured through the second inlet 28 into the unit 10. In use against heavy flooding, ballast such as sand or gravel is desirable. In gentle flooding, it may be sufficient to pour water into the unit 10 to act as ballast. Once a sufficient amount of ballast has been poured into the unit 10 via the second input 28, the lid or cover of the input 28 can be attached. The lid or cover of the inlet 26 is then removed, and air is inserted into the unit 10 by any known means, for example by blowing air in through the mouth, by pumping air in via a pump, or by pumping air in via an electric air compressor. Input of air causes the unit 10 to inflate, and to form the semi-annular shape shown in Figure 1. Once inflated to a sufficient size, the lid of inlet 26 is replaced. The ballast inside the unit 10 exerts a downward force on the base of the unit, thus forming a seal between the base of the unit and the ground, or whichever surface the unit is placed on. Water is thus prevented from passing into the area denoted A from the area denoted B.

In the embodiment which includes a single inlet valve, a desired amount of water or ballast is poured through the single inlet valve. Air is then inserted into the unit 10 through the same single inlet valve, by any known means, for example by blowing air in through the mouth, by pumping air in via a pump, or by pumping air in via an electric air compressor. The pressure of the air in the unit 10 is sufficient for the unit to maintain its inflated structure during use. The end faces 12, 14 of the unit 10 can be positioned such that they abut a surface, such as a wall of a building, that the unit is intended to protect. Connection means (not shown) may be provided on the surface to which the connectors 16, 18 can be connected. Such connections would help to secure the unit 10 in a desired position, and would restrict the passage of water between the surface and the unit 10.

When the flood defence is no longer required, the cover of outlet 29 is removed, allowing air and water or ballast to exit the unit 10. Once all the water or ballast has been removed from the unit 10, the lid of outlet 29 is replaced, and the deflated unit 10 can be folded or rolled for convenient storage.

Use as an Enclosure

The liquid barrier 10 can be used in conjunction with one or more other liquid barrier units, to form a liquid barrier system, as exemplified in Figures 4 and 5. In Figure 4, two liquid barrier units 10A, 10B are positioned such that the end face 12A of the first unit 10A is detachably connected to the end face 14B of the second unit 10B. Similarly, the end face 12B of the second unit 10B is detachably connected to the end face 14A of the first unit 10A. The two units 10A, 10B form a substantially annular shape when connected together.

The system, generally denoted 30, is positioned in a desired location, while in its deflated state. The first and second units 10A, 10B are then filled with air and/or ballast, in a manner similar to that described above. Once inflated, the system 30 is substantially annular shaped, and creates a substantially circular enclosure, enclosing the area marked C. The enclosure is suitable for use in enclosing children, pets, toys, balls, or any other objects to be contained within an area. The system can also be used to surround an area or object, for example a pond, within the area C in order to prevent children or animals from accessing it.

Use as a Swimming or Paddling Pool The liquid barrier system 30, when constructed in the manner described above, is capable of being used as a temporary swimming pool or paddling pool, as exemplified in Figure 5. To use the system 30 as a swimming pool or a paddling pool, the two liquid barrier units 10A, 10B are positioned in a suitable location, and detachably connected together in the manner described above. The units 10A, 10B are inflated with air so that they form a substantially annular shape. A liner 32 is detachably connected to the unit 10A, 10B to form the base and the walls of the pool.

Figure 6 shows the liner 32 in more detail. The liner 32 is substantially circular in shape, and has a diameter slightly larger than the diameter of the outer perimeter of the annulus formed by the units 10A and 10B. A substantially circular connector 34 is formed on the underside of the liner 32. The connector 34 is formed from hook-and- loop type material and, in particular, is formed from a hook-and-loop type material which is complementary to the connector strip 20 formed on the inner perimeter of each of the units 10A, 10B (see Figure 4). The connector 34 is arranged to engage, and form a detachable connection with, the connector strip 20 when the liner 32 is positioned within the annular system 30. The position of the connector 34 on the liner 32 is such that, when the liner is connected to the annular system 30, the central region 36 of the liner is in contact with the ground, or whichever surface the system is placed on. Axial connectors 38 are positioned at regular intervals around the liner 32, extending from the perimeter of the liner to the connector 34. The axial connectors 38 are arranged to engage and form a detachable connection with the connectors 22, 24 on the top surface of each unit 10A, 10B. A person skilled in the art will appreciate that the number of axial connectors 38 on the liner 32 will ideally correspond to the number of connectors 22, 24 on each of the units 10A, 10B. Of course, a more secure bond between the liner 32 and the annular system 30 will be achieved if more connectors 22, 24 are provided.

Referring again to Figure 5, a swimming pool or a paddling pool results from the connection of the liner 32 to the annular system 30. Water (not shown) is poured into the central region 36 of the pool, and is prevented from flowing outside the area 36 by the units 10A, 10B. When it is desirable to release the water from within the pool, the units 10A, 10B can be deflated in the manner described above. Releasing the air from the units 10A, 10B will cause the units to deflate, and allow the water contained therewithin to flow away. The liner 32 can then be detached from the units 10A, 10B, and the liner and units can be folded or rolled for convenient storage. In the embodiment described above, the liquid barrier units 10A, 10B, when inflated, are generally semi-annular in shape. A person skilled in the art would understand that units of alternative shapes can be formed, and used to create alternatively shaped flood defences and/or pools. Figure 7 shows a liquid barrier unit 40 constructed in accordance with a second embodiment of the invention. The unit 40 is substantially cylindrical in shape, having a substantially circular cross-section. Non-permanent connectors (not shown, but similar to the connectors 16, 18 of the embodiment of Figures 1 and 2) are formed on end faces 42 and 44 of the unit.

Figure 8 shows a liquid barrier unit 46, formed in an alternative shape to that of the unit 40 of Figure 7. The unit 46 has a substantially circular cross-section, and has non-permanent connectors (not shown, but similar to the connectors 16, 18 of the embodiment of Figures 1 and 2) formed on end faces 48, 50 of the unit. The unit 46 forms a substantially 90 degree corner unit which can be connected to one or more of the units 40 shown in Figure 7.

Figure 9 shows a liquid barrier unit 52 constructed in accordance with a third embodiment of the invention. The unit 52 has a substantially square or rectangular cross section, with a non-permanent connector (not shown, but similar to the connectors 16, 18 of the embodiment of Figures 1 and 2) formed on one of its end faces 54. A second connector 56 is formed on one side of the unit 52, at the end opposite to the end face 54. The positions of the connectors allows a plurality of units 52 to be connected to form a substantially square enclosure. Alternatively, connectors can be placed on each end face of the unit 52, and a corner unit 58, shown in Figure 10, can be used to connect two units together. Figure 1 1 shows a liquid barrier unit 60 constructed in accordance with a fourth embodiment of the invention. The unit 60 is substantially the same as the unit 40 shown in Figure 7, but is formed with a flat bottom surface 62, enabling the unit to be more stably positioned on the ground.

A person skilled in the art will appreciate that any of the units shown in Figures 7 to 1 1 will include some or all of the features of the first embodiment of the invention, and are arranged to be used in substantially the same way. A skilled person will also appreciate that various modifications to the invention can be made without departing from the scope of the claims.