Abstract:
An odor removal apparatus for a toilet wherein the apparatus and toilet has a bowl, an outlet from the bowl and a barrier between the bowl and the outlet which substantially prevents odors from the outlet passing to the bowl. A gas extraction apparatus is in communication with an area in the vicinity of the bowl and the outlet whereby operation of the gas extraction apparatus substantially removes odors from the vicinity of the bowl and transfers them to the outlet. The gas extraction apparatus comprises a fan operable to induce a flow of gases and entrained odors for removal of the odors from the vicinity of a toilet. The fan is immersed in the water in the cistern of the toilet.

Description:
FIELD OF THE INVENTION 
   This invention relates to odour removal apparatus and methods. In particular, the invention relates to odour removal apparatus and methods for removing gases which include undesirable odours from the vicinity of a toilet or lavatory bowl. However, the invention is not limited to this application. 
   BACKGROUND OF THE INVENTION 
   Most known methods of odour removal for toilets use a fan or the like which is mounted on an exterior wall of the room in which the toilet is located. Such extraction fans are often operated when a user enters the room in which the toilet is located and turns on a light for example. A disadvantage of this known system is that odours must leave the toilet bowl and enter the room before they can be removed from the room. Thus the system really only prevents odours escaping from the room in which the toilet is located rather than removing odours before they enter the room. 
   The fan constrictions used in these known systems are also cumbersome, making them awkward and expensive to install. Furthermore, they do not have any control system that allows characteristics of the fan to be altered to improve efficiency, performance or to provide a user with a greater range of operating conditions. For example, the known systems are prone to be noisy which can be bothersome to many users and there is no provision for altering fan operating parameters, such as speed, to reduce the noise. Known fans are often left running for long periods of time, which is inefficient and reduces the life of the fan. 
   Wall and ceiling fan systems typically have limited back pressure capabilities limiting the distance over which the air can be expelled. They thus typically require at least 100 mm ducting. This is very inconvenient to install. 
   OBJECT OF THE INVENTION 
   It is an object of the present invention to provide odour removal apparatus and/or methods which will at least go some way toward overcoming the foregoing disadvantages or other disadvantages of known constructions, or which will at least provide the public with a useful choice. 
   SUMMARY OF THE INVENTION 
   Accordingly, in one aspect, the invention is an odour removal apparatus for a toilet, the toilet having
         a bowl   an outlet from the bowl   a barrier between the bowl and the outlet which substantially prevents odours from the outlet passing to the bowl, and   a gases extraction means in communication with an area in the vicinity of the bowl and the outlet whereby operation of the gases extraction means substantially removes odours from the vicinity of the bowl and transfers them to the outlet.       

   Preferably the gases extraction means comprises a fan means operable to induce a flow of gases and entrained odours for removal of the odours from the vicinity of a toilet. 
   Preferably a flow control means is provided to substantially prevent odours flowing from the outlet to the bowl through the gases extraction means. 
   Preferably the flow control means is a one way valve. 
   In a further aspect the invention consists in a toilet or lavatory having
         a bowl   an outlet from the bowl   the bowl and outlet configured in use to be adapted to provide a substantially odour impermeable barrier,   a gases delivery passageway provided in or adjacent to the bowl, and a gases receiving passageway provided in communication with the outlet.       

   Preferably a gases extraction means is in communication with an area in the vicinity of the bowl and the outlet whereby operation of the gases extraction means substantially removes odours from the vicinity of the bowl and transfers them to the outlet. 
   Preferably the gases extraction means comprises a fan means operable to induce a flow of gases and entrained odours for removal of the odours from the vicinity of a toilet. 
   Preferably the barrier comprises a water trap. 
   Preferably a flow control means is provided to substantially prevent odours flowing from the outlet to the bowl through the gases extraction means. 
   Preferably the flow control means is a one way valve. 
   Preferably the apparatus includes control means for controlling the operation of the fan means. 
   Preferably the control means includes flow rate selection means to allow a user to vary the rate of gases flow induced by the fan means. 
   Preferably the fan means includes
         a housing,   a motor within the housing,   an impeller provided within the housing and coupled to the motor so that operation of the motor imparts rotational energy to the impeller,   an inlet provided in the housing adapted for attachment to a gas inlet conduit,   an outlet provided in the housing adapted for attachment to a gas outlet conduit.       

   Preferably the width of the housing being not substantially greater than the width of the inlet or width of the outlet. 
   Alternatively the fan means includes
         a housing,   a direct current motor within the housing,   an impeller provided within the housing and coupled to the motor so that operation of the motor imparts rotational energy to the impeller,   an inlet provided in the housing adapted for attachment to a gas inlet conduit, and   an outlet provided in the housing adapted for attachment to a gas outlet conduit.       

   In a further aspect the invention broadly consists in some odour removal apparatus for a toilet, the toilet having
         a bowl   an outlet from the bowl   a barrier between the bowl and the outlet which substantially prevents odours from the outlet passing to the bowl, and   a gas extraction means in communication with an overflow conduit in a cistern of the toilet and the gases extraction means being in communication with the outlet, whereby operation of the gases extraction means substantially removes odours from the bowl through the overflow conduit and transfers the gases to the outlet.       

   Preferably the gases extraction means comprises a fan means operable to induce a flow of gases and entrained odours for removal of the odours from the vicinity of a toilet. 
   Preferably a flow control means is provided to substantially prevent odours flowing from the outlet to the bowl through the gases extraction means. 
   Preferably the flow control means is a one way valve. 
   In yet a further aspect the invention consists in a toilet or lavatory having
         a bowl   an outlet from the bowl   the bowl and outlet configured in use to provide a substantially odour impermeable barrier   a gases passageway being provided between the bowl and a cistern of the toilet,   a gases extraction means in communication with the cistern and the outlet and a gases transfer region being provided within the cistern so as to provide communication between the passageway and the gases extraction means, and   operation of the gases extraction means substantially removing odours from the vicinity of the bowl and transferring them to the outlet.       

   Preferably the gases extraction means comprises a fan means operable to induce a flow of gases and entrained odours for removal of the odours from the vicinity of a toilet. 
   Preferably a flow control means is provided to substantially prevent odours flowing from the outlet to the bowl through the gases extraction means. 
   Preferably the flow control means is a one way valve. 
   Preferably the gases transfer region comprises a compartment within the cistern which compartment creates a seal between the passageway and the gases extraction means using the presence of water within the cistern. 
   Alternatively the gases transfer region comprises the air space above the water level in the cistern. 
   In a further aspect the invention consists in a toilet or lavatory having
         a bowl   an outlet from the bowl   a bowl and outlet configured in use to be adapted to provide a substantially odour impermeable barrier   a flushing inlet to in use receive water from a cistern, and   a gases delivery passageway provided in or adjacent to the bowl and located in a region or the bowl remote from the flushing inlet.       

   Preferably a gases extraction means is in communication with the cistern and the outlet and a gases transfer region being provided within the cistern so as to provide communication between the passageway and the gases extraction means, and operation of the gases extraction means substantially removing odours from the vicinity of the bowl and transferring them to the outlet. 
   Preferably the gases extraction means comprises a fan means operable to induce a flow of gases and entrained odours for removal of the odours from the vicinity of a toilet. 
   Preferably a flow control means is provided to substantially prevent odours flowing from the outlet to the bowl through the gases extraction means. 
   Preferably the flow control means is a one way valve. 
   Preferably the passageway includes a region of sufficient dimension to include a gases extraction means therein. 
   In yet a further aspect the invention consists in a toilet or lavatory having walls adapted to conceal a gases extraction fan means. 
   To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein purely illustrative and are not intended to be in any sense limiting. 
   The invention consists of the forgoing and also envisages constructions of which the following gives examples. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One preferred form of the present invention will now be described with reference to the accompanying drawings in which: 
     One preferred form of the invention and modifications thereof will now be described with reference to the accompanying drawings in which: 
       FIG. 1  is a diagrammatic side elevation in partial cross section of a toilet system including odour removal apparatus in accordance with the present invention; 
       FIG. 2  is a diagrammatic side elevation in partial cross section of a practical implementation of a toilet system in accordance with  FIG. 1 ; 
       FIG. 3  is an end elevation in cross section of the cistern of  FIG. 2 ; 
       FIG. 4  is an end elevation in cross section of an alternative cistern arrangement for the cistern of  FIG. 2 ; 
       FIG. 5  is an end elevation in cross section of a further alternative sister arrangement according to the invention; 
       FIG. 6  is a perspective view of a pan and cistern installation wherein the pan is designed to conceal a gases flow connection; 
       FIG. 7  is a plan view of a pan having an air inlet adjacent to the rim of the pan but at the front of the pan; 
       FIG. 8  is a plan view of a further arrangement of pan having an air inlet at the front of the pan; 
       FIG. 9  is a side elevation in cross section of the pan substantially as shown in  FIGS. 7  or  8  and including the gases extraction unit; 
       FIG. 10  is a further side elevation in cross section of the toilet pan showing another gases extraction arrangement according to the invention; 
       FIG. 11  is an end elevation (from the rear) of a toilet pan of  FIG. 10 , and 
       FIG. 12  shows an end elevation of toilet pan with another gas extraction arrangement and also including side walls on the pan as also diagrammatically illustrated in FIG.  6 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , a toilet or lavatory is shown generally referenced  1  having a bowl or pan construction  2  about the rim  3  of which a seat will usually be provided (not shown for clarity). The pan  2  is designed to have a water trap generally referenced  5  which provides a barrier between the central part  6  of the pan and an outlet  7  from the pan. In use, outlet  7  ends in a pan outlet  8  which will usually pass through the floor (S trap type toilet) or wall (as with P trap type toilet) of the building in which the installation is provided so as to interconnect with a sewerage system, or waste-water or septic tank for example. 
   As shown diagrammatically in  FIG. 2 , the present invention involves removal of undesirable odours in the vicinity of the bowl  6  by use of an extraction device  15  such as a fan, and delivery of the odours to the outlet  7 . Since outlet  7  is on the other side of the water trap (which acts as a gas transfer barrier), the odours are effectively removed from the environment surrounding the bowl  6 . To ensure that odours cannot escape from the outlet  7  through the extraction path, some form of non-return device  21  is provided in that path, for example being provided before or after the extractor  15 . 
   Although vents are often provided in gaseous communication with toilet outlets, such vents have the purpose of preventing the water in the water trap from siphoning away through the outlet. The vents are not used for odour extraction purposes. 
   Turning now to  FIG. 2 , a diagram of a possible practical implementation of the system is shown. The pan  2  is usually moulded from an appropriate material and the mould includes appropriate apertures  10 , which are in fluid communication with a cistern  4 . In this way liquid such as water which is in use provided in the cistern may be distributed through the apertures in order to flush the bowl  6  and ensure that water trap  5  maintains an appropriate level of liquid. 
   In the example illustrated in  FIG. 2 , the particular toilet installation has an internal overflow conduit  11  which is in fluid communication with the flushing apertures  10  of the bowl. The overflow conduit  11  has an inlet  12  which is usually above the high water level  13  of the liquid  14  in the cistern. However, should the liquid level  13  rise to an unexpectedly high level, the liquid will enter inlet  12  and drain into the pan  6  and therefore prevent a cistern overflow situation from occurring. The provision of the inlet  12  above the usual high water level  13  of the cistern means that inlet  12  is in gaseous communication with the bowl  6 . 
   In  FIG. 2 , the existing toilet installation as described above has been modified by the inclusion of extractor fan unit  15  which has an inlet  16  that is provided above the level of inlet  12 . The fan unit at  15  has an outlet  16   a  which passes through the base of the cistern at an aperture  17  and is connected by an appropriate tube or conduit for example  18  to the outlet  7  through an appropriate aperture or connection  19 . 
   Operation of the system as illustrated in  FIG. 2  is as follows. 
   Fan unit  15  includes any device which is capable of moving gases at an acceptable rate or vacuum. Usually, the device will include a motor such as a direct current electric motor which is capable of rotating at relatively high speeds and therefore moving a fan or other propelling device connected to the motor to create the needed vacuum at the inlet of the fan unit. This creates a negative air pressure in the vicinity of inlet  16  to the fan unit. Inlet  16  is provided within an optional housing  20  the lower edge of which is provided beneath the usual high water level  13  in the cistern. This creates a closed environment between inlet  16  to the fan and outlet  12  of the internal overflow conduit so that gases may be transferred between them. Accordingly, the vacuum created by the fan creates a negative air pressure in bowl  6  relative to the surrounding environment in the room in which the toilet is located. Therefore, a gases flow occurs from the bowl  6  through the housing  20  and into the fan unit  15 . From here, the gases flow continues through outlet  16   a  and through the gases flow tube  18  and into the outlet  7 . Since outlet  7  is provided on the side of the water trap which is opposite the bowl  6 , odours are effectively transferred from the bowl to the sewerage/septic tank side of the toilet installation. In order to ensure that gases from the outlet  7  do not return to the toilet bowl  6 , a non-return valve  21  is provided anywhere in the extraction flow path. In  FIG. 2 , a non-return device is shown provided after the outlet  16   a  of the fan unit, and as another alternative, before the inlet to the fan. Such a non-return device may be a known valve which is purchased from a plumbing outlet for example, or may be one which is especially designed for this installation. For example, the valve may include a diaphragm or valve member which is biased to a normally closed position by a spring or by gravity for example, but which may be opened by negative air pressure at the outlet of the fan unit  15  being created in the air pressure in the pan outlet  7 . The valve is lifted off the valve seal by the negative air pressure created by the fan. Therefore, when the fan  15  is not in use, the valve will return to its normally closed position to prevent any odours travelling from the outlet  7  to the pan  6 . 
   Referring now to  FIG. 4 , the cistern is shown in end elevation. Therefore, the fan  15  may be provided at one side of the cistern (being appropriately waterproofed or otherwise provided so that the liquid in the cistern does not interfere with the motor operation) and the outlet  16  of the fan may be directed to aperture  17  which is provided in alignment with the internal overflow pipe as a convenient location for the outlet  16   a  to exit the cistern. Furthermore, as illustrated in  FIG. 2 , the fan inlet  16  and overflow conduit  12  do not necessarily require housing  20  to be provided over the entrance. It will be sufficient for the cistern itself to provide an appropriate housing for transfer of gases between the overflow conduit and the fan provided the cistern is sufficiently air tight. 
   Also, it will be appreciated that an internal overflow pipe does not need to be used to implement the present invention. Therefore, the invention may make provision for the pan  2  to include in the moulding an appropriate cavity or cavities to include the fan and the appropriate apertures for connecting the fan between the bowl  6  and the bowl outlet  7 . Therefore a wide variety of arrangements is possible. For example, a specially formed aperture in the flushing assembly, or a separate new aperture provided adjacent to the bowl may be provided and the fan could be directly connected to this aperture and the fan outlet could be connected to an appropriate connector at inlet  19  provided in outlet  7  or at a point of entry to the sewerage or septic tank system which is external of the toilet assembly, if desired. 
   As another example, the end view of  FIG. 4  clearly shows the inlet  19  to bowl outlet  7  as being provided in the form of a spigot or the like and a hose or other conduit providing the connection  18  between the fan outlet and the pan outlet  7 . However, the connection at inlet  19  may be provided as a part of the pan moulding for example i.e. simply being a cavity provided in the appropriate place within the pan unit. Of course, a separate opening to the flushing apertures may be provided so that a conduit other than the internal overflow conduit may be provided within the cistern to connect directly to the fan inlet for example. However, the construction as described with reference to the figures in this example does provide an effective retro-fittable installation. 
   The fan unit which is used to create the air flow by making an area of relatively low pressure i.e. negative pressure with respect to ambient room pressure in the vicinity of the toilet bowl is preferably an axial flow fan which uses a DC electric motor, for example a 15 volt motor. Use of a DC motor and appropriate control mechanism such as pulse width with modulation for the power supply ensures that the motor can be speed controlled to reduce unwanted noise etc if required. Also, the motor can operate at very high rotational speeds (and thus provide an enhanced airflow) since it is not limited by supply frequency as is the case with most AC motors. Of course, since an area of relatively low pressure is provided between the fan unit and the inlet (which will usually be adjacent to the room of the toilet pan or bowl), an area of relatively high pressure i.e. pressure which is greater than or positive relevant to ambient room pressure will be created between the fan and the outlet (which in the present invention comprises the waste or sewerage outlet behind the toilet water trap). 
   Turning now to  FIG. 5 , a further arrangement in the cistern is shown which is similar to the arrangement illustrated in FIG.  2 . Like reference numerals indicate like features between the different drawings. Therefore, the outlet valve  11  is shown in greater detail, and in the preferred embodiment comprises a “geberit” outlet valve which has the internal overflow  12  as described in previous embodiments. The fan unit  15  is also shown and the non-return valve  21  is shown in greater detail adjacent to the inlet to the fan unit. Again, the vacuum lid  20  is illustrated. Additional features to those shown in  FIG. 2  include the inlet  30  which allows liquid to enter the cistern i.e. to refill the cistern and a flexible hose  32  from the inlet  30  which is directed to the base of the cistern in order to prevent liquid entering the cistern from flowing anywhere near the inlet to the fan unit  15 . 
   Turning now to  FIG. 6 , the cistern of  FIG. 5  for example may be located on a toilet bowl or pan that has extended rear side walls  34  which substantially conceal (at least from the side) a connector which may be used to provide a connection between the outlet of the fan  15  in the cistern and a waste outlet of the toilet bowl behind the water trap. Therefore, if the installation shown in  FIG. 6  is mounted in a room such that the rear wall of the cistern is adjacent to a wall, the wings  34  conceal the outlet conduit. 
   Turning now to  FIG. 7 , a plan view of a toilet bowl or pan is shown with the cistern removed. As described previously with reference to  FIG. 2 , the toilet bowl or pan typically has flushing apertures about the periphery of the bowl rim. The apertures  10  are generally illustrated in  FIG. 7 , but it will be seen that the bowl or pan has been moulded to provide an air inlet aperture  60  which is quite separate from flushing apertures  10 . Therefore, in use water in flushing apertures  10  is diverted away from the air inlet aperture  60 . Also, although air inlet aperture  60  is not specifically shown as having an inlet to the body or the pan, the inlet can be more clearly shown in the side elevation in cross section of FIG.  9 . The design is such that water being flushed through apertures  10  does not enter the air inlet aperture  60 , but that the air inlet aperture  60  is open to the pan so as to extract odours therefrom. 
   Turning now to  FIG. 8 , a plan view of a pan or system is again shown having an arrangement very similar to that of  FIG. 7 , but there is a slightly different design of air inlet in that the pan is contoured so that the air inlet aperture  60  is again separated from the flushing apertures  10 , but the air inlet has extended opening regions  62  to provide a greater area of the pan periphery through which air from the bowl can enter. Therefore, improved gases extraction is anticipated using this design. 
   Turning now to  FIG. 9 , an illustration of a pan in cross section which may be used in accordance with the air inlet illustrated in the plan views of  FIGS. 7 and 8  is shown. The air inlet aperture  60  includes a cavity  66  in the front wall or the pan which leads to a further enlarged concealed cavity  68  in the front of the pan unit. The fan unit  15  has an inlet which engages with cavity  66  and the fan unit itself is provided within cavity  68 . The outlet from the fan has a one way air valve  70  to prevent odours escaping from behind the water trap. Further conduit  72  is provided within the pan moulding to allow gases flow between the one way valve  70  and the waste outlet of the pan behind the water trap. 
   Turning now to  FIG. 10 , another toilet bowl or pan construction is shown in cross section having a moulded extraction cavity  80  from the rear of the pan which provides an inlet to which fan unit  15  is connected and concealed, and the waste outlet of the pan has a moulded aperture  82  to which the outlet of the fan unit  15  is connected to delivery the waste gases to the area behind the water trap. A one way air valve  70  should be situated somewhere between cavity  80  and aperture  82 . 
   Turning to  FIG. 11  a rear elevation of the construction illustrated in  FIG. 10  is shown. The one way air valve  70  is needed on either side of the fan to prevent reverse circulation. 
   In  FIG. 12 , a vertical orientation of the fan unit (as opposed to a horizontal orientation shown in  FIG. 11 ) is shown. This is similar to the construction illustrated in  FIG. 6  however rather than the fan unit  15  being provided within the cistern, the fan is provided axially within the air extraction conduit and is concealed between side walls  34 . 
   Therefore, from the foregoing, it will be seen that a very effective odour removal installation is achievable with this invention. In particular, the use of the water trap in the toilet as a barrier to prevent odours is highly desirable. Usually, fan installations and the like simply remove odours from the room in which the toilet installation is located and expel them to another location, such as out of the building or into a wall or ceiling cavity. The present invention provides a significant advantage that the sewerage system behind the toilet water trap, which contains foul odours in any case, is used as a disposal point for the odours in or surrounding the toilet bowl. The advantages are that; firstly odours immediately adjacent the bowl are removed before they enter the room in which the toilet is located; and secondly the odours are easily disposed of without the necessity of making further holes in the room in which the installation is located in order to deliver the odours to a location remote from the room. 
   Therefore, the invention provides for drawing air or gas and entrained odours from the toilet bowl/pan and discharging them to the outlet side of the toilet bowl/or pan water trap. The conveyance of the odours may be through the cistern via air ways, for example the internal overflow pipe, or through other passages such as waterways, or airways or any appropriate spaces that will bypass the cistern and/or the flush pipe and be delivered to the side of the toilet bowl pan which is on the sewerage side of the water trap. The delivery mechanism includes some form of gas extraction means such as a fan and may be implemented using hosing, tube or pipe or through appropriate spaces in the overall pan/cistern assembly. It will be seen that the extraction means may be a fan, or pulsing cistern, or pump, being mechanically operated or otherwise. The effect of making a negative air pressure within or adjacent to a toilet bowl means that the odours do not escape the toilet bowl into the room. We have found that the outlet from the fan or extraction means does not need to be connected immediately to the outlet of the bowl on the other side of the water trap, but can be connected to quite a remote area from the water trap, for example anywhere in the septic waste. In the preferred embodiment of the invention a non return valve is provided, but will be seen that other means of preventing reverse gases flowing may be employed. For example, an anti-siphon valve or similar may be used, or the fan may be operated continuously. 
   Finally it will be appreciated that various other alterations may be made to the foregoing without departing from the scope of this invention as set forth in the appended claims. 
   Throughout the description and claims of this specification the word “comprise” and variation of that word, such as “comprises” and “comprising”, are not intended to exclude other additives, components, integers or steps.