GB2457374A

GB2457374A - Flood defence for a building opening

Info

Publication number: GB2457374A
Application number: GB0902335A
Authority: GB
Inventors: John Mcnee
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-02-12
Filing date: 2009-02-12
Publication date: 2009-08-19
Also published as: GB0802544D0; GB0902335D0

Abstract

A flood defender (10) having a housing, which is mountable to a building (12) to protect an opening such as an air vent, the housing having first (16) and second (18) housing bodies together defining a passageway for the passage of air through the housing and a valve (20, 70), in the form of a buoyant float or a flap, disposed in the second housing body (18) having a first operative position in which air is permitted to flow through the passageway and a second operative position in which water is restricted from flowing through the passageway beyond the valve (20. 70), movement between the first and second positions being caused by ingress of water into the second housing body (18). The second housing body (18) being detachable from the first housing body (16) to assist in cleaning and/or the removal of debris, the second housing body (18) may also contain guide means to correctly position the valve element when subjected to rising water levels.

Description

Flood Defender This invention relates to a flood defender and, more specifically but not exclusively, to a flood defender for covering building vents.

Vents, such as air bricks, which may be installed in buildings to facilitate air circulation represent potential entry points for water and other fluids in the event of flooding in the building locality. If water enters a building via these vents, it can result in significant damage to the building interior and contents therein. This is a growing concern in the UK and abroad where flooding is becoming a more common occurrence.

Several arrangements have been proposed to automatically prevent the ingress of water into building interiors via these vents. GB2397592 (Taylor) and GB2418932 (Wainwright) disclose arrangements which may be installed in a building wall and :. used to replace the building vents that act as potential entry points for flood waters.

::*s: 15 When flood conditions arise, the proposed arrangements employ the use of valves *...

i:': which move automatically from an open configuration, whereby air can circulate through the building wall, to a closed configuration in which the ingress of water is restricted. These devices are often difficult to install retrospectively into building *S **.* * * *. walls and involve overly complicated sealing arrangements.

A different approach to preventing water from entering building interiors via vents has been disclosed in GB24 10973 (Tovey) and GB2382374 (Douglas). Both documents describe a cover for building vents which may be installed retrospectively by mounting them to the building wall. GB24 10973 in particular discloses an arrangement which uses floats to automatically seal the ventilation pathway in times of flood and thereby restrict the ingress of flood water into the building interior via the vent in the building wall.

However, a problem with this proposed system is that, once mounted to the building wall, it is difficult to clean and maintain.

The present invention seeks to provide an improved building vent cover that closes automatically in times of flood and is more simple and convenient to maintain.

According to the present invention, there is provided a flood defender comprising a housing, which is mountable to a building, having first and second housing bodies together defining a passageway for the passage of air through the housing and a valve disposed substantially in the interior of the second housing body having a first operative position in which air is permitted to flow through the passageway and a second operative position in which water is restricted from flowing through the passageway beyond the valve, movement between the first and second positions being caused by ingress of water into the second housing body, the second * ***, 15 housing body being detachable from the first housing body. S...

Advantageously, both the second housing body and the valve can be removed *:. from the first housing body enabling them to be simply cleaned and maintained. Thus any debris that accumulates in the second housing body can be removed so that the S. S 555 * . valve can operate correctly.

The housing may comprise any rigid, water impermeable material as will be apparent to the man skilled in the art. Suitable materials include, but are not limited to various plastics, especially reinforced ABS.

In a preferred embodiment, there is provided a plurality of passageways defined by the first and second housing bodies. Preferably, one or more valves is arranged to restrict the ingress of water through each passageway.

Preferably, water can enter and exit the second housing body via apertures in the second housing body when the water level rises or lowers.

Preferably, the housing is mounted to the building relative to a building vent such that the passageway is at least partly in register with the building vent. More preferably the passageway of the housing is completely in register with the building vent.

In a preferred embodiment, there is provided a first seal means arranged in use to restrict the ingress of water through the passageway from around the second housing body. Preferably there is provided a second seal means arranged in use to improve the ability of the valve to restrict the ingress of water through the passageway from the interior of the second housing body. Preferably, the valve comprises the **...* 15 second seal means and a valve element which is seated against the second seal means S...

when subjected to flood water. Preferably, the second seal means is dimensioned to be closable by the valve element. More preferably the second seal means conforms to the shape of the valve element. *...

Preferably, each seal means are made from any suitably resilient, water impermeable material apparent to the man skilled in the art, such as rubber. More preferably, the seal means are removable. More preferably, the first seal means and the second seal means are part of the same structure.

In a preferred embodiment, the first housing body has an inlet aperture and an outlet aperture with a passageway defmed therebeiween. Preferably, the inlet aperture and outlet aperture are defined in different parts of the first housing body. Preferably, the inlet aperture is defined in the part of the first housing body beyond which no water is intended to pass. More preferably, the inlet and outlet apertures are defined at opposite sides of the first housing body.

In a preferred embodiment, the second housing body is arranged relative to the inlet aperture of the first housing body such that the ability of the first seal means to restrict the ingress of water is improved by the upward force of the valve element acting on the seal when subjected to flood waters. Preferably, the second housing body is mounted on the external side of the inlet aperture of the first housing body.

More preferably, the second housing body is mounted beneath the inlet aperture of the first housing body. Thus, the valve element forces the first seal means upwardly against the first housing body thereby improving the first seal means' ability to restrict the ingress of water through the passageway.

Preferably the second housing body is mounted externally to the first housing s*..* 15 body. Thus the second housing body and valve are easily accessible.

In a preferred embodiment, the valve element is less dense than water.

Preferably, the valve element is a float. More preferably, the density of the float is such that it is seated against the second seal means before water contacts the seal.

** *.*s * * Preferably, the float is made from any suitably dense material apparent to the man skilled in the art, such as plastic. More preferably, the float is hollow.

The float may take any shape suitable for closing a corresponding aperture, such as a sphere, triangular prism or cuboid.

In a preferred embodiment, the second housing body comprises guide means operative to guide the float accurately into the second seal means. Preferably the guide means comprises a pair of grooves on opposing sides of the second housing body. More preferably, the float comprises protrusions that work in combination with the guide means to retain the float in a single plane.

In an alternative embodiment, the valve element may comprise a flap.

Preferably, the flap is pivoted at one end about a point on the interior of the second housing body and is operative to move from an open configuration to a closed configuration when water enters the second housing body to restrict the ingress of water through the passageway. Preferably the flap blocks the passageway when subjected to flood waters. More preferably the flap is seated against the second seal means.

In a preferred embodiment, the flood defender comprises a locking mechanism for manually retaining the float against the second seal means.

In order that the invention can be more clearly understood embodiments : thereof are now described, by way of example, with reference to the accompanying S...

drawings of which: * S. * S S S.. I Fig. I shows a section side view of a first embodiment of the assembled flood defender, in accordance with the present invention, in the open configuration; * *

I

III

Figs 2 (a) to (d) show a side view, an underside view, a front perspective view and a back perspective view respectively of the mounting support of the apparatus shown in Fig.l; Figs 3 (a) to (d) show a front perspective view, a side view, a plan view and an underside view respectively of the cassette of the apparatus shown in Fig. I; Fig.3 (e) shows a side view of a first embodiment of the flood defender, in accordance with the present invention, when in a separated configuration; Figs 4 (a) and (b) show a perspective view and an end view respectively of the seal shown in Fig.!; Fig.5 shows an enlarged view of the interface between the cassette, seal and mounting support of the flood defender shown in Fig. 1; Figs 6 (a) to (c) show a front view, a perspective view and an end view of the float shown in Fig.1; Fig.7 shows a side view of the assembled flood defender shown in Fig. 1 when in the closed configuration and subjected to flood conditions; Fig.8 shows a section side view of a second embodiment of the flood defender having : two separate sealing means; S... * . * S..

Figs 9 (a) and (b) show a plan view and an underside view of an alternative embodiment of the cassette; 15 Fig.9 (c) shows a section side view of a third embodiment of the assembled flood *..

defender which comprises the cassette of Figs 9 (a) and (b); Fig. 10 shows a section side view of a fourth embodiment of the assembled flood defender; Fig. 11 shows an enlarged side view of the cassette shown in Fig. 10; Fig. 12 shows a perspective view of the cassette shown in Fig. 11; Fig. 13 shows a plan view of the cassette shown in Fig. 11; Fig. 14 shows an underside view of the cassette shown in Fig. 11; Fig. 15 shows a section front view of the cassette shown in Fig. 11; Fig. 16 shows an enlarged section side view of the cassette shown in Fig. 11; Fig. 17 shows a side view of the float shown in Fig. 10; Fig. 18 shows a perspective view of the float shown in Fig. 17; Fig. 19 shows an enlarged view of the interface between cassette, mounting support and float of the flood defender shown in Fig. 10 when the float is subjected to flood waters; and * S.. * * *

Fig. 20 shows a perspective view of the mounting support of the apparatus shown in *5. S * * Fig. 10; * S 5 * I I..

* Referring to Fig. 1, a flood defender comprising a housing 10 is mounted to a building wall 12 around the external face of an airbrick inlet 14. The housing comprises a first housing body 16 which acts as a mounting support and a second housing body 18 which serves as a removable cassette. Disposed within the cassette 18 isafloat20.

Referring to Figs 2 (a) to (d), the mounting support 16 has an inner side 22 and an outer side 24. Extending from the outer side 24 of the mounting support 16 is a nose 26, the lower side 28 of which is inclined such that the front edge 30 is higher than the back edge 32. Defined in the lower side 28 is an inlet aperture 34 which permits air to enter and exit the mounting support interior. The inner side 22 of the mounting support 16 adjacent the building wall 12 has an outlet aperture 36 defined therein. The inlet and outlet apertures are in fluid communication with a passageway defined therebetween to permit the passage of air through the mounting support 16.

Referring to Figs 2 (c) and (d), a single, continuous flange 38 extends outwardly at right angles from each of the sidewalls of the mounting support 16.

Located around the flange 38 at suitably spaced intervals are mounting holes 40 for receiving mounting screws. Located on the underside 42 of the flange 38 is an impermeable sealant (not shown), an adequate quantity of which is applied to the flange 38 to ensure that, when mounted to the building wall 12, water is restricted from passing between the flange 38 and the wall 12.

Referring to Figs 3 (a) to (e), the cassette 18 has six sides, a hollow interior *S.. * **

and is sized and shaped such that it fits into the lower region beneath the nose 26 of

S

: the mounting support 16. Two tabs 44 with screw holes 46 extend substantially S.. S vertically up from the front edge of the top side 66 of the cassette 18. Referring again to Fig.2 (c), two corresponding recesses 48 with screw holes are located on the front *SS...

side of the nose 26 of the mounting support 16. The recesses 48 and tabs 44 are positioned on their respective bodies so that, when the cassette 18 is mounted to the mounting support 16, the tabs 44 sit within the recesses 48. Mounting means 52 are positioned on the bottom edge 54 of the front side of the lower region of the mounting support 16. The mounting means 52 are provided to support the bottom edge 56 of the inner side 57 of the cassette 18.

Refemng once more to Figs 3 (a) to (e), the bottom side 58 of the cassette 18 has defined therein an open aperture 60 which is sized and shaped to allow the float to be inserted into the interior of the cassette. The externally facing side 62 of the cassette 18 has further apertures 64 defined therein which correspond to those apertures found on traditional airbricks. The top side 66 of the cassette 18 is inclined at the same angle as the lower side 28 of the nose 26 of the mounting support 16 so that, when the cassette 18 is mounted to the mounting support 16, the two sides fit neatly together. The inclination of the two respective sides improves the ease with which the two bodies fit together and ensures that when a seal is located between the two bodies it is not displaced out of position during installation. The top side 66 of the cassette 18 has defined therein an open aperture 68 which is intended to be placed adjacent the inlet aperture of the mounting support. The top side aperture 68 is rectangular in shape which corresponds to that of the horizontal cross section of the float 20 and its dimensions are chosen such that it may be closed by the float 20. The cassette apertures 60, 64, 68 are all in fluid communication with one another to permit the passage of air through the cassette 18. A small lip 100 extends around the inner **.* edge of the top side aperture 68 of the cassette 18. The lip 100 is located on the S..

: interior facing side of the aperture 68 and is provided to support an optional seal S.. * * insert. I..

S

Referring to Figs 4 (a) and (b), the seal insert 70 is made from rubber and ** S**S comprises an upper portion 72 which is substantially cuboidal in shape and a lower portion 74 which extends downwardly from the under side of the upper portion. The upper portion 72 serves as a first seal means between the cassette 18 and the mounting support 16 and the lower portion 74 serves as a second seal means between the cassette 18 and the float 20. The upper portion 72 is inclined at an angle equivalent to that of the top side 66 of the cassette 18 and the lower side 28 of the nose 26 of the mounting support 16. The lower portion 74 is defined by two curved arms 76 the ends of which are linked together by a concave portion 78. The shape of the concave portion 78 is such that it conforms to the outer shape of the float 20 so that, when water levels are sufficiently high, the float 20 is securely seated against the seal 70.

The central core of the seal insert is removed to define an aperture or passageway 79 from the underside of the seal through to the upper side. The upper face of the upper portion 72 of the seal 70 has located around its outer edge a raised lip 80 which is dimensioned to surround the aperture 34 of the lower side 28 of the nose 26.

Referring to Fig.5, the dimensions of the upper rectangular portion 72 of the seal 70 are chosen so that it may fit within the top side aperture 68 of the cassette 18.

The dimensions of the lower portion 74 of the seal are chosen so that it may pass through the aperture 68 into the interior of the cassette 18. When inserted into the cassette 18 through the aperture 68, the upper portion 72 abuts the seal supporting lip and the lower portion 74 extends into the cassette interior. The sidewalls 82 of the S...

upper portion 72 of the seal 70 are such that, when seated in the top side aperture 68, * the raised lip 80 extends above the top side 66 of the cassette 18.

:.:. The arms 76 of the seal 70 serve to provide a large surface area relative to *. *

standard seals used in the art against which the float 20 may be seated. In addition, the *SS*.S arms 76 are chosen to have a degree of flexibility to permit them to move in response S..

to external water pressure. When subjected to flood waters, the arms 76 of the seal 70, which extend around the float 20, are surrounded by the water contained in the cassette interior. As the water level rises, the water pressure in the cassette increases, which results in the compression of the arms 76 around the float 20. This compression results in a clamping effect and serves to strengthen the bond between the float 20 and the seal 70 under flood conditions. To ensure a strong clamping effect it is desirable to have a float and seal that fit well together so that water cannot enter the region between the float 20 and the seal 70. In addition, it is desirable to have a float 20 whose buoyancy is such that it becomes seated in the seal 70 before water can enter the region between the float 20 and the seal 70.

Referring now to Figs 6 (a) to (c), the float 20 is cylindrical in shape and is made from plastic. Two small protrusions 82 are positioned at the centre of each end of the cylindrical float 20 and extend outwardly from the float along its longitudinal axis. The protrusions fit within a pair of grooves (not shown) which each run substantially vertically up the interior sidewalls of the cassette 18. The grooves are positioned beneath the top side aperture 68 of the cassette 18 and are provided to retain the float 20 in a substantially horizontal orientation whilst allowing it to move freely along a substantially vertical plane within the cassette 18. The substantially vertical plane along which the float 20 can travel bisects the opposing ends of the I...

lower portion 74 of the seal insert 70 to ensure the float 20 is securely and accurately *...

* seated against the underside of the seal 70 in flood conditions.

Referring back to Fig.2 (c), two lugs 84 extend perpendicularly out from the ***

S

front face of the lower region of the mounting support 16 and are dimensioned to fit S. within the cassette interior. The lugs 84 are positioned such that they lie beneath the S..

S

inlet aperture 34 of the mounting support 16 and are shaped on their upper surface to approximately conform to the outer shape of the float 20. Referring to Fig.3 (a), two vertical slots 86 that correspond to the outer facing dimensions of the lugs 84 are -12 -defined in the back face of the cassette 18. The two vertical slots 86 are provided to allow the lugs 84 to enter the interior of the cassette 18 and act as a seating support for the float 20 when in the open configuration. In addition, the lugs 84 ensure that, when the cassette 18 is mounted to the mounting support 16, the float 20 cannot fall out of the open aperture 60 through which it was originally inserted.

Before mounting the cassette 18 to the mounting support 16, the float 20 and seal 70 are inserted into the cassette 18 via the lower side aperture 60 and the top side aperture 68 respectively. The cassette 18 and float 20 combination is mounted to the mounting support 16 by first resting the bottom edge 56 of the back face of the cassette 18 on the mounting means 52. The cassette 18 is pivoted about the horizontal axis of the bottom edge 56 of the back face toward the front face of the lower region of the mounting support 16 until the tabs 44 of the cassette 18 sit within the corresponding recesses 48 of the mounting support 16. During rotation of the cassette 18, the two lugs 84 are allowed to enter the cassette interior via the vertical slots 86.

Throughout this mounting process, the float 20 is kept toward the upper region of the cassette interior to ensure that, when the cassette 18 is filly mounted to the mounting support 16, the lugs 84 are positioned between the float 20 and the lower aperture 60. * S..

* Referring to Fig.!, when mounted to the building wall 12 around the airbrick inlet 14 and in the absence of flood waters, the float 20 is seated on the lugs 84 of the S..

S

mounting support 16 and is clear of the seal insert 70 of the cassette 18. In this open S. S..S S * configuration, air is free to circulate through the passageway of the housing defined S..

S

through the mounting support 16, seal 70 and cassette 18 and into the building interior through the airbrick. Air is equally allowed to circulate out from the building interior through the airbrick and the passageway of the housing.

-13 -Referring to Fig.7, when flooding of the building locality occurs, water is permitted to enter the cassette 18 via the apertures 60, 64 which are immediately exposed to the external environment. Since the buoyancy of the float 20 is greater than its weight, there is a net upward force exerted by the water on the float 20. The float 20 naturally rises with the water level until it becomes seated against the second seal means 74. The buoyancy of the float 20 is chosen such that it becomes seated against the second seal means 74 before water can come into contact with the seal means. Since fluid can only enter the mounting support 16 of the housing from the interior of the cassette 18 via the passageway 79 of the seal 70, the float 20, which blocks the passageway 79, restricts the ingress of water through the passageway from the cassette interior.

Since the seal 70 and cassette 18 combination is located beneath the inlet aperture 34 of the mounting support 16, when flooding occurs, the net upward force of the float 20 is exerted on the seal 70. This in turn forces the seal 70 against the lower face 28 of the nose 26 of the mounting support 16. The raised lip 80 of the seal 70, which lies adjacent to the lower face 28 of the mounting support 16 and encircles e..

the inlet aperture 34, is pressed against the lower face 28 of the mounting support 16 * and restricts the ingress of water through the passageway of the housing from around the cassette 18. *** *

When flood waters recede, water is allowed to exit the cassette 18 via the ***.** apertures 60, 64 through which the water entered. The float 20 lowers with the water ***

S

level and moves down from the seal 70 and back to the lugs 84. In this open configuration, air is again permitted to ventilate through the airbrick via the passageway of the housing.

The assembled flood defender may also include a locking mechanism (not shown) which serves to optionally hold the float 20 in the closed configuration even / in the absence of flood waters. An example of an appropriate locking mechanism comprises two hollow plugs which can be inserted into the cassette interior through appropriately sized apertures. The two apertures are defined in opposite sidewalls of the cassette respectively and are positioned so that they lie along the central longitudinal axis of the float 20 when seated against the second seal means 74. The hollow plugs have recesses that are dimensioned to receive the two protrusions at either end of the float and have abutments at their opposite ends which are larger than their respective apertures to prevent them from being fully inserted into the cassette 18. To manually activate the closed configuration, the float 20 is seated against the seal means 74 and the plugs are inserted into the cassette and around the two protrusions 82 of the float 20. The sidewalls of the cassette 18 support the plugs which in turn support the float 20, thus, preventing the float 20 from moving out of its seated position. To unlock the float 20 and manually return it to the open configuration, the two plugs are removed from their respective apertures which allows :::. ** the float 20 to return under gravity to its seating means 84. S...

Should the cassette 18, seal 70 or float 20 become damaged in use or should they require cleaning to ensure proper operation of the flood defender, the cassette 18

S

can be removed simply from the mounting support 16 by reversing the process by S. SSS which it was initially installed. The cassette 18, seal 70 and float 20 components can thus be easily and conveniently cleaned or replaced.

It is envisaged that separate seal means may be provided between the mounting support 16 and the cassette 18. Referring to Fig.8, in an alternative -15 -arrangement, there is provided a first seal means 90 located on the upper face of the cassette 18 which surrounds the inlet aperture 34 of the mounting support. The first seal means 90 is recessed within a groove which is dimensioned to surround the apertures 34, 68 of both the cassette 18 and the mounting support 16. There is also provided a second seal means 92 that extends into the cassette interior from the sides of the top side aperture 68. This seal means 92 conforms to the shape of the float 20 and its dimensions are chosen so as to be closable by the float 20. When the float 20 is forced up against the second seal means 92 by flood waters, the float 20 forces the entire cassette 18 up against the lower face 28 of the nose 26. This in turn forces the first seal means 90 against the lower face 28 of the nose 26 and improves its ability to prevent the ingress of water through the passageway of the housing from around the cassette 18.

Referring to Figs 9 (a) to (c), in an alternative embodiment, the cassette 18 is constructed such that the top side aperture 68 is sized and shaped to allow the float 20 to be inserted into the cassette interior and the lower side aperture 60 is sized and shaped to be lower in cross section than the float 20. In this embodiment, the aperture :: : 60 of the bottom side is too small to let the float 20 pass through but large enough to allow flood water to enter and exit the cassette interior. Since the seal 70, which is * subsequently mounted to the top side 66 of the cassette, provides an abutment for the S..

float 20, the float is prevented from exiting the cassette 18 through the upper aperture S...

68. This arrangement removes the requirement for the supporting Jugs 84 of the S..

S

mounting support 16 and the corresponding vertical slots 86 in the cassette wall.

Referring to Fig. 10, in an alternative embodiment, the mounting support 200 takes the same general form as that described hereinbefore but does not comprise a pair of supporting lugs. Instead, a substantially horizontal platform 204 extends a distance out from the lower edge 206 of the mounting support 200. A cassette 210 is releasably mounted to the mounting support 200. The cassette 210, shown in more detail in Figs 11 to 16, also takes the same general form as that hereinbefore described and comprises an open bottom 212 through which the float can be inserted into the cassette interior. Three lugs 214 extend down from the bottom edge 216 of the inner side 218 of the cassette 210 and six substantially circular outlet apertures 220 are formed in the top side 222 of the cassette 210. The cassette 210 is divided into two substantially equal compartments by a central wall 230 so that three apertures 220 are associated with one compartment 232 and three apertures 220 are associated with the other compartment 234.

Mounting apertures 224 are formed in the platform 204 at the same corresponding points as the lugs 214 of the cassette 210. When mounting the cassette 210 to the mounting support 200, the lugs 214 can be inserted into these apertures 224 so that, when the cassette 210 is secured to the mounting support 200 using screws via the tabs 226 of the cassette 210 and recesses on the mounting support 200, the bottom S...

edge 216 is held securely in place. *...

* The outlet apertures 220 are formed in the top side 222 of the cassette 210 such that the diameter of each aperture 220 at the interior facing side is greater than the diameter of each aperture 220 at the outer facing side. Each aperture 220 is S. ***S tapered between the outer facing side and the interior facing side so that a sphere of S..

appropriate dimensions can be securely seated in each aperture 220 from within the cassette 210. The top side 222 of the cassette 210 has a shallow recess 235 for receiving a continuous seal 238 which extends around the six apertures 220. Thus, when mounted to the mounting support 200, the seal 238 restricts the ingress of water through the inlet aperture of the mounting support 200 from around the cassette 210.

Referring to Figs 17 and 18, the float 240, which is made from plastics material, is generally cuboidal in shape. The float 240 may be hollow and may have the bottom side removed. The float 240 is dimensioned to fit within a compartment 232, 234 of the cassette 210. Extending out from the top of the float 240 are three substantially hemispherical shapes 242. The hemispheres 242 are formed at the same intervals as the apertures 220 so that, when a float 240 is seated within a compartment 232, 234, the centre of a hemisphere 242 is aligned with the centre of a corresponding aperture 220. The diameter of each hemisphere is chosen so that each hemisphere 242 may be securely seated against the tapered edge of a respective aperture 220. The height of the float 240 is chosen to leave a gap between the top of the float 240 and the inner side of each aperture 220 so that air can pass througli the passageway defined by the mounting support 200 and the cassette 210 in the absence of flood water. When the cassette 210, having a float 240 disposed within its interior, is mounted to the mounting support 200, the float 240 is supported by the platform 204 which prevents the float 240 from exiting the cassette 210 via the open bottom 212.

Guide means 241 extend out from the interior side walls of the cassette 210 to ensure * ** * . * the float 240 is maintained in an approximately horizontal plane and to ensure that the * float moves from the open position to the closed position along an approximately S. .*SS vertical plane. *SS

A shallow recess 250 is formed on a substantially horizontal plane around the top of each hemisphere 242. The shallow recess 250 permits a seal 252 in the form of an 0-ring to be mounted to each hemisphere 242. Each recess 250 is positioned on the hemisphere 242 so that it is aligned with the tapered edge of a corresponding aperture 220. Thus, when the float 240 is subjected to rising flood water so that the hemispheres 242 are seated within the corresponding apertures 220, the seal 252 on each hemisphere 242 engages the tapered edge of each aperture 220 and helps restrict the ingress of water into the passageway via the cassette interior. The engagement of the float 240 with the apertures 220 in turn forces the cassette 210 against the underside of the mounting body 200. Since a seal 238 is positioned between the top side of the cassette 210 and the mounting support 200, an effective seal against the ingress of water into the passageway from around the cassette 210 is also achieved. In use, a float 240 is disposed within each compartment 232, 234 of the cassette 210.

It is of course to be understood that the invention is not to be restricted to the details of the above embodiments which have been described by way of example only. * *.* * * . ** * I... * S 555. * S. * S S

S

S S..

S 5555

S

S S..

Claims

CLAIMSI. A flood defender comprising a housing, which is mountable to a building, having first and second housing bodies together defining a passageway for the passage of air through the housing and a valve substantially disposed in the second housing body having a first operative position in which air is permitted to flow through the passageway and a second operative position in which water is restricted from flowing through the passageway beyond the valve, movement between the first and second positions being caused by ingress of water into the second housing body, the second housing body being detachable from the first housing body.
2. A flood defender as claimed in claim 1, comprising a plurality of passageways defined by the first and second housing bodies.
3. A flood defender as claimed in claim 2, wherein one or more valves is arranged to restrict the ingress of water through each passageway.

.. :
4. A flood defender as claimed in any preceding claim, wherein water can enter * I S...and exit the second housing body via apertures in the second housing body. d
5. A flood defender as claimed in any preceding claim which is mountable to a building via the first housing body. S *
6. A flood defender as claimed in any preceding claim, wherein there is provided a first seal means positioned between the first housing body and second housing body and arranged in use to restrict the ingress of water into the first housing body. -20 -
7. A flood defender as claimed in any preceding claim, further comprising a valve element disposed within the second housing body.
8. A flood defender as claimed in any preceding claim, wherein there is provided a second seal means disposed in the passageway which, together with the valve element, forms the valve.
9. A flood defender as claimed in claim 8, wherein the valve element is arranged to be seated against the second seal means when subjected to rising water levels.
10. A flood defender as claimed in claim 9, wherein the second seal means defines an aperture and is shaped and configured in such a way that the aperture is closable by the valve element.
11. A flood defender as claimed in claim 10, wherein the second seal means conforms to the shape of the valve element.
12. A flood defender as claimed in any of claims 8 to 11 wherein the first seal means and the second seal means are part of the same structure. * **
13. A flood defender as claimed in claim 6 or any of claims 7 to 12 when * * f.* dependent directly or indirectly upon claim 6, wherein the first seal means is ** * * removable from the housing of the flood defender.

*
14. A flood defender as claimed in claim 8 or any of claims 9 to 13 when S a... S *dependent directly or indirectly upon claim 8, wherein the second seal means is removable from the housing of the flood defender.
15. A flood defender as claimed in any of claims 7 to 14, wherein a seal means is provided on the valve element.
16. A flood defender as claimed in any preceding claim, wherein the first housing body has an inlet aperture and an outlet aperture with a passageway defined therebetween.
17. A flood defender as claimed in claim 16, wherein the inlet aperture and the outlet aperture are defined in different parts of the first housing body.
18. A flood defender as claimed in claim 17, wherein the inlet aperture is defined in the part of the first housing body beyond which no water is intended to pass.
19. A flood defender as claimed in any of claims 16 to 18, wherein the inlet aperture and the outlet aperture are defined in opposite sides of the first housing body.
20. A flood defender as claimed in any of claims 16 to 19 when dependent directly or indirectly upon claim 6, wherein the second housing body is arranged relative to the inlet aperture of the first housing body such that the ability of the first seal means to restrict the ingress of water is improved by the force of the valve element acting on the first seal means, directly or indirectly, when * *.S : the valve is subjected to rising water levels. **** * S S
21. A flood defender as claimed in claim 20, wherein the inlet aperture is defined ) ** in a substantially horizontal face of the first housing body, the second housing 55* body is mounted on the external side of the inlet aperture of the first housing *S)**S * 20 body and the first seal means is positioned between the first housing body and *S.the second housing body such that it is seated against the substantially horizontal face of the first housing body and surrounds the inlet aperture.

-
22 - 22. A flood defender as claimed in any preceding claim, wherein the second housing body comprises an inlet aperture and an outlet aperture.
23. A flood defender as claimed in claim 22 when dependent directly or indirectly upon claim 16, wherein the second housing body is mounted to the first housing body and arranged such that the outlet aperture of the second housing body is substantially in register with the inlet aperture of the first housing body.
24. A flood defender as claimed in any preceding claim, wherein the second housing body is mounted externally to the first housing body.
25. A flood defender as claimed in any preceding claim when dependent directly or indirectly upon claim 8, wherein the second housing body further comprises guide means operative to guide the valve element when subjected to rising water levels so that it is accurately seated against the second seal means.
26. A flood defender as claimed in claim 7 or any of claims 8 to 25 when dependent directly or indirectly upon claim 7, wherein the flood defender has **S.* : a valve locking mechanism for manually retaining the valve element in the S... * * S...second operative position. * .. * S S *5S **
27. A flood defender as claimed in claim 7 or any of claims 8 to 26 when S..Sdependent directly or indirectly upon claim 7, wherein the valve element is *S.... * S* 20 less dense than water. S..

S
28. A flood defender as claimed in claim 27, wherein the valve element is a float.
29. A flood defender as claimed in claim 28, wherein the float is substantially hollow.

-23 -
30. A flood defender as claimed in claim 7 or any of claims 8 to 27 when dependent directly or indirectly upon claim 7, wherein the valve element is a flap pivotally mounted at one end to the second housing body.
31. A building having a building vent and having mounted thereto a flood defender as claimed in any preceding claim.
32. A flood defender substantially as hereinbefore described with reference to the corresponding drawings. * S SS 55*5 * S *.S. * 5S * S S 5* SS 5.S*S....S S * S..S