GB2327095A - Toilet odour removal apparatus - Google Patents

Abstract

Odour removal apparatus for a flush type toilet (1) includes an adaptor located over the internal overflow (25) of the toilet. The adaptor allows a substantially gas tight seal to be made between the internal overflow and a fan (15) so that gases and entrained odours may be removed from the toilet pan (6) upon activation of the fan (15). The internal overflow still functions to remove excess water from the cistern. The invention also provides a fan (15) that is sufficiently small to fit within a wall (3) cavity but has sufficient vacuum and flow rate characteristics for efficient operation. A controller is also provided to allow variable speed (47) fan operation, variable fan on time (48) in response to activation of an infrared detector (52), and night light (59) operation.

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 bowl. However, the invention is not limited to this application.

BACKGROUND ART 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.

Another disadvantage with these and similar systems is that they use altemating current (AC) motors to drive the fan impeller. The speed of AC motors is constrained by the frequency of the mains power supply. AC motors of a size suitable for use in toilet pan odour removal systems do not have adequate performance characteristics for effective odour removal in modem toilets.

The fan constructions 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 ineffident and reduces the life of the fan.

BRIEF DESCRIPTION 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.

Accordingly, in one aspect, the invention consists in odour removal apparatus for a flush type toilet having a cistern intemal overflow conduit, the apparatus comprising overflow adaptor means adapted for gaseous communication with a gases extraction means for inducing a flow of gases, the overflow adaptor means being in use located about an entry to the internal overflow conduit whereby a substantially gas tight seal is made between the internal overflow conduit and the overflow adaptor means when the cistern water level is at its normal full level so that gases and entrained odours may be extracted from the toilet pan through the internal overflow conduit by the gases extraction means; and when the cistern level reaches the entry to the internal overflow conduit, water from the cistern is free to flow through the internal overflow conduit to the pan.

In a further aspect the invention consists in a flush type toilet comprising, a cistern, an internal overflow conduit within the cistern, gases extraction means for inducing a flow of gases and entrained odours, overflow adaptor means in gaseous communication with a gases extraction means for inducing a flow of gases and the overflow adaptor means being located about an entry to the internal overflow conduit, whereby a substantially gas tight seal is made between the internal overflow conduit and the overflow adaptor means when the cistern water level is at its normal full level so that gases and entrained odours may be extracted from the toilet pan through the internal overflow conduit by the gases extraction means, and when the cistern level reaches the entry to the internal overflow conduit, water from the cistern is free to flow through the internal overflow conduit to the pan.

In a further aspect the invention consists in toilet odour removal apparatus comprising a fan means operable to induce a flow of gases and entrained odours for removal of the odours from the vicinity of a toilet control means for controlling the operation of the fan the control means including flow rate selection means to allow a user to vary the rate of gases flow induced by the fan means.

In a further aspect the invention consists in a toilet odour extraction fan comprising 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, and the width of the housing being not substantially greater than the width of the inlet or width of the outlet.

In a further aspect the invention consists in a toilet odour extraction fan comprising 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 consists in methods disclosed herein, 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 are pureiy illustrative and are not intended to be in any sense limiting.

The invention consists in the foregoing and also envisages constructions of which the following gives examples.

BRIEF DESCRIPTION OF THE DRAWINGS One preferred form of the invention and modifications thereof will now be described with reference to the accompanying drawings in which: figure 1 is a diagrammatic side elevation in partial cross section of a toilet system mounted in a building and including odour removal apparatus in accordance with the present invention; figure 2 is a plan view of the toilet pan of figure 1 with the seat removed; figure 3 is a front elevation in cross section through a part of a toilet pan; figure 4 is a diagrammatic side elevation in partial cross section of a toilet system mounted in a building and including odour removal apparatus in accordance with the present invention; figure 5 is a diagrammatic front elevation of the toilet system of figure 4, showing some altemative arrangements of the odour removal apparatus; figure 6 is a further diagrammatic front elevation of the toilet system of figure 4 showing a further alternative arrangement of the odour removal apparatus; figures 7 and 9 are diagrammatic side elevations of the toilet system of figure 4 with further altemative arrangements of the odour removal apparatus.

figures 8 and 10 are diagrammatic front elevations of figures 7 and 9 respectively; figures 11 and 12 are diagrammatic side elevations of a further toilet system have odour removal apparatus in accordance with the present invention; figure 13 is a diagrammatic side elevation in partial cross section of a toilet cistem mounted against a wall, showing odour removal apparatus in accordance with the present invention; figure 14 is a diagrammatic elevation in partial cross section of an altemative embodiment of odour removal apparatus.

figure 15 is a diagrammatic side elevation of a toilet system including odour removal apparatus in accordance with the present invention; figure 16 is a diagrammatic front elevation of the apparatus of figure 14; figure 17 is a diagrammatic side elevation of a toilet system including a seal for odour removal in accordance with the present invention; figure 18 is a diagrammatic plan view of the seal of figure 16; figure 19 is a front elevation of a face plate for control apparatus in accordance with the present invention; figure 20 is a front elevation of a mounting plate in accordance with the present invention; figure 21 is a side elevation in cross section of the face plate of figure 19, the mounting plate of figure 20 and a back plate; figure 21a is a plan view in cross section of the apparatus of figure 21; figure 22 is a rear elevation of the apparatus of figure 21 without the back plate; figure 23 is a side elevation of the apparatus of figure 21; figure 24 is a rear elevation of the apparatus of figure 21; figure 25 is a plan view of the apparatus of figure 21; figure 26 is a schematic diagram of control apparatus in accordance with the present invention; figure 27 is a front elevation of a fan assembly in accordance with the present invention; and figure 28 is a cross section in front elevation of the apparatus of figure 27.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Refening to figure 1, a toilet is shown generally referenced 1 being mounted upon a floor 2 adjacent to a wall 3 below a ceiling 4 above which a roof 5 is provided.

The toilet 1 comprises a toilet bowl or pan 6, a seat 7 and a cistem 8. The conventional flushing pipe which would normally be present between the cistem flushing outlet 9 and the flushing hom 10 of the pan has been removed and replaced by a 'T' joint 12. The connection point 13 of the 'T' joint opposite that connected to the flushing horn 10 is connected to a gas extraction conduit 14 which in tum is connected to a gas extraction means comprising a fan for example, such as axial fan 15 which has an outlet 16 for delivery of extracted gases to a location remote from the room in which the toilet is located.

It will be seen that the gas extraction conduit is provided within the wall 3. This is primarily for cosmetic purposes. The conduit 14 could be provided inside the room, or pass directly outside. A number of desired arrangements may be used as long as the result of transferring the extracted gases to a remote location is effected. It will also be seen that the fan 15, comprising a motor and fan impeller is provided within the wall 3. This is achieved by designing the fan components including the housing in such a way that the housing is not substantially larger than the air inlet and outlet of the housing.

In respect of flushing, the toilet system operates in the known way; water in the cistem is flushed through the joint and into the pan via flushing hom 10 so as to flush the toilet pan. The portion of the "r joint between connection point 13 and outlet 9 slopes downwardly from point 13 to the flushing hom 10, that is to say the lowest point of the connection point 13 is higher than the lowest point of the flushing hom 10. This ensures that flushing water does not remain in the 'T' joint where noise may be generated due to water movement as air is drawn past the water by the fan.

In use the fan 15 is in operation, at least when a person is using the toilet. A number of different devices may be used to activate the fan, as discussed below. The fan has the effect of creating a negative air pressure (relative to atmospheric pressure) in conduit 14 which creates a negative air pressure within the toilet pan 6 which removes or extracts gases from the pan. The gas passage is indicated by arrow 17. The extracted gases and entrained odours are expelled from the room in which the toilet is located to a location remote from the room. Thus the system has the effect of creating a negative pressure in the toilet pan or bowl to remove gases including odours in the pan through one or more flushing apertures of the pan, so that the odours are effectively removed before they enter the room.

The creation of a negative air pressure in the pan itself relative to atmospheric pressure ensures removal of odours. A relative pressure that is not negative has been found to be insufficient to allow effective operation of the invention.

Thus in use the fan 15 is preferably activated before and while a user is using the toilet so that gases that include undesirable odours are effectively removed from the toilet bowl before they enter the room, and therefore before they are detected by the user. Gases are not extracted while the toilet is being flushed, but this makes very little difference to the operation of the invention as odours are removed by the apparatus before flushing, and the source of odours is removed by flushing.

Referring to figure 2 the toilet pan 6 is shown in plan view with the seat removed.

There are three flushing holes 2o22 through which water may travel when entering the pan from the cistern. The central hole 21 directs water to the centre of the pan while the holes 20 and 22 direct water around the rims 23 at either side of the bowl. It can be seen that by connecting the extraction conduit 14 to the flushing hom the holes 2o22 are being used to extract the gases from the pan, and the design of the holes makes the extraction of gases and entrained odours from the entire pan very effective.

Figures 3a and 3b show a part of the pan in cross section so that the different forms of rim 23 can be seen more clearly. Figure 3a illustrates a standard "open" rim. Figure 3b illustrates a "box" rim which is substantially enclosed having a number of appropriate flushing apertures located around the rim in the base of the box section.

Tuming to figure 4, an altemative embodiment of the invention is shown on a toilet in which the cistem is immediately adjacent to the pan. Such a toilet is usually referred to as a "Close Coupled" toilet. The fan 15 in this arrangement is provided in the ceiling, but as mentioned above, the present invention allows the fan to be located in a number of other locations, such as the wall cavity as indicated by reference 15a which shows the fan in broken outline in the wall cavity as an alternative location. The location of the fan 15 in such varied locations is achievable by virtue of the design of the fan of the present invention which is provided in an enciosed housing of sufficient dimension to be provided in locations such as a wall cavity of a domestic dwelling.

Still referring to figure 4, nearly all close coupled toilets have an intemal overflow conduit 25 which has the effect of allowing excess water in the cistem to drain into an entry to the conduit 25 which delivers it to the pan via the flushing apertures in the pan. Because the overflow conduit 25 is connected to the pan flushing apertures, it can be used to extract gases from the pan to provide the desired result referred to in the description of the toilet odour extraction system of figure 1.

Figure 4 illustrates one altemative for use of the overflow conduit 25 to extract gases which is achieved by transferring the extracted gases through the air space 26 in the cistern above the water level 27. Thus the extraction conduit 14 enters the cistem and is open to the air space 26 within the cistem. The cistern is sealed in a substantially gas tight manner so that the negative air pressure generated by the fan is present in the pan. This can be achieved by sealing the cistern with a silicon compound or the like or by using a rubber or plastics grommet about the area of entry of the extraction conduit and the cistern lid.

Figure 5 shows two other arrangements by which the conduit 14 may enter the cistern to effect the method of odour removal described with reference to figure 4.

Another arrangement is shown in figure 6 in which the fan 15 is provided on an external wall of the building. Similarly, figures 7 and 9 show side elevations of further arrangements for external location of the fan, and figures 8 and 10 show the respective front elevations of these arrangements.

Figure 11 shows another form of toilet system in which the pan is dependant from a wall and the cistem is provided within the wall. Such systems are commonly referred to as "Wall Mounted" Again, the extraction conduit is shown in the cistem air space so that the air space is used for the extraction of gases as described above with reference to figures 4 to 10. Wall mounted toilets may also have automatic flushing systems. These systems are usually activated by an infrared or other form of proximity sensor. The automatic flushing mechanism is usually connected to the pan flushing hom by a flushing pipe in the form of an elbow. This allows the conduit 14 to be connected to the flushing pipe immediately above the elbow or immediately prior to the entry to the pan as shown in figure 1.

In figure 12 the wall mounted system is shown with the gas extraction conduit 14 connected to the flush pipe 30 between the cistem and the pan. This arrangement is similar to that described with reference to figure 1. A further addition is the provision of a weather proof hat 31 to the fan outlet.

A preferred embodiment of the present invention includes a gases extraction path that uses the cistem intemal overflow pipe without requiring the cistem to be airtight and does not require a direct connection to the overflow pipe so that the overflow pipe is not prevented from also providing an overflow path. Figure 13 illustrates use of a gas extraction conduit that has an end 35 which is adapted to fit over the entry to the internal overflow conduit. The adaptor 35 is provided sufficiently far over the overflow conduit 25 so as to be provided below the normal cistem water level 27 when the cistem is in its normal full state.

There is a gap 28 provided between the walls of the adaptor 35 and the walls of the overflow pipe 25. When the cistem water level is at the normal full level as shown in figure 15, the water present in the gap 28 creates a substantially airtight seal so that air present in the cistem is not removed by the action of the fan 15. Instead, gases and entrained odours are removed from the pan through by means of the overflow conduit which is in gaseous connection with the pan flushing apertures. When the toilet has recently been flushed, so that the cistem water level is below the normal full level 27, water will not be present in gap 28, so no seal will exist. Therefore, in this situation, the flow of gases from the pan will not be very great unless the cistem is substantially airtight. However it will be seen that the cistem does not need to be sealed because after flushing use of the toilet has ceased so there are no odours to remove. When the cistem fills again with water for the next flush, the seal will be re-established ready for odours to be extracted when the toilet is next used. if, for some reason, the water level regulation system in the cistem fails and the cistem water level rises unacceptably, the water will begin to flow down the overflow conduit 25 when it reaches the entrance of the overflow because it has access to the overflow entrance through gap 28.

Referring to figure 14, an embodiment of a stand alone adaptor member 35 is shown in location over an inlet to the intemal overflow conduit 25. The adaptor comprises an integral part of the gas extraction conduit 14. However, it may be provided as a separate component for attachment to the conduit 14 or for attachment directly to the fan, or it could be provided as an integral part of the fan housing. The adaptor has a shroud or mantle portion 38 which in figure 14 is expanded to ensure that a sufficient gap 28 is provided for overflow to occur. An outlet portion 42 is provided for attachment to the gas extraction conduit 14 or for direct connection to the fan inlet.

The arrangements described in figures 13 and 14 which use altemative adaptor methods provide the significant advantage that the cistem does not need to be air tight, as the water provides a seal between the two conduits. It will also be seen that this arrangement still allows the overflow conduit to function should the cistem water level get too high.

Refening to the embodiment illustrated in figures 15 and 16, the toilet seat 7 is provided with appropriate air extraction apertures (not shown) which are in direct gaseous connection with the conduit 14. Extracting gases through the apertures in the toilet seat provides a similar effect to removal through the flushing apertures in the embodiments referred to above.

Refening to figures 17 and 18 an embodiment is shown in which the seal 40 between the cistem and the pan of a close coupled toilet is provided with an aperture 32 which is open to the gases extraction conduit 14. The seal including conduit 14 is shown in more detail in figure 19. The conduit 14 is inclined relative to horizontal so that there is a slight downward slope toward the seal 40. In this way any water that enters the conduit 14 will drain into the pan. This prevents noise problems in use as mentioned in relation to the embodiment of figure 1 above.

As can be seen from the preceding figures, dependent on the set up required, the extraction conduit 14 can enter the cistem from any number of convenient locations, for example from the cistern base, back or sides. The cistem may be provided with the appropriate knockouts or holes to effect these constructions.

Another form of toilet system which is not illustrated is that which is usually referred to as the "One Piece" toilet in which the pan and the cistem are integrally moulded together as a single unitary item. It will be seen that as long as this form of toilet system, or any other toilet system, has a flushing aperture or overflow pipe which can be accessed to extract gases therethrough, then the present invention is applicable.

The fan 15 is preferably activated selectively, so that operation is efficient. Thus, although the fan may be operated in response to activation of a light switch as with other extraction systems, this method is not preferred as the fan may be left on for unnecessarily long periods of time. A preferred method of operation is to have a proximity sensor which senses close proximity to, or use of, the toilet and activates the fan. Such a sensor may comprise an infra-red sensor for example as discussed further below, or a motion sensor, or a pressure transducer located on the toilet It will be seen that many other forms of sensor may also be used.

Refening to figure 19 a face plate 50 for a detector such as a passive infrared (PIR) detector is shown. The face plate covers a mounting plate 53 (refer figures 20-22) on which control apparatus comprising electric and electronic circuitry 49 (refer figures 21 and 22) is mounted for operation of the fan including the power supply for the fan motor The construction provides considerable advantages for ease (and therefore reduction in cost) of installation. The circuit operation is described further below.

The mounting plate 53 (refer figure 21) has a detachable lens cover 54 behind which the PIR sensor 52 is located. The apparatus is shown in side elevation in figures 21 and 21a in which it can also be seen that a sensor lens 57 is provided, being located in the lens cover 54. The lens cover 54 is detachable to allow a light bulb 59 which is used as a night light to be easily installed and replaced. The apparatus can be mounted on a wall within the vicinity of the toilet so as to detect the presence of persons in the general vicinity of the toilet. In figure 21 the mounting plate 53 can be seen as can the back plate 55 which covers the electric and electronic components at the rear of the mounting plate. The back plate 55 ensures that the circuit board 49 on which the electrical and electronic circuit components are mounted is adequately secured and protected against air movement, damage and significant temperature changes that will affect the PIR sensor.

The apparatus is shown in rear elevation and in plan view from below in figures 24 and 25. Mounting holes 56 that comply with international standards are provided in the mounting plate 53 for mounting the apparatus on a wall. Referring to figure 24, openings 58+ and 58- allow connection of the fan motor power supply lines to a DC power supply provided on the circuit board mounted on the mounting plate 53. Openings 60 and 61 allow connection to a mains power supply. In figure 25 further openings shown in back plate 55 for screw terminals 58+, 58 and 60 and 61 are provided for accessing the screws of the terminals for wiring installation purposes.

Referring to figure 26 a schematic circuit diagram is shown. The mains supply is provided at terminals 60 and 61. Selection apparatus is provided at block 70 for selecting the voltage level of the mains altemating current input voltage, for example 220-240 volts or 110-115 volts AC. The DC power supply may be derived in a number of different ways, and preferably comprises an off iine switch mode power supply 74. The supply may have a number of DC output voltage levels for motor speed control. Alternatively, and preferably, a fan speed controller switch 47 is provided which uses Pulse Width Modulation (PWM) to control the speed of the fan in incremental stages, for example ten incremental stages. The selectable DC output levels allow a selection of DC voltages ranging from 6 to 17 volts in ten incremental stages to be supplied to the fan motor, depending on the required fan performance. A run timer 48 is provided, having an adjustable run time period, for example 1 minute to 16 minutes in ten incremental stages, that can be selected by a manual selector as illustrated by selector 48 in figure 20.

The power supply 74 also provides a DC supply to the PIR detector 52 (which is provided behind lens 57 in figure 19). Activation of the PIR detector 52 activates timer 48 which activates the motor switch 90 and the night light controller 95 which in tum activates night light 59 and begins timing the selected time period. The night light 59 is activated to provide light for a user of the toilet. A daylight detector 93 (refer figure 20) detects the level of ambient light in the vicinity of the toilet to ensure that the night light does not function when there is sufficient light, for example during daylight periods, which also reduces electricity consumption during day time use. The light 59 is preferably a dimmed light.

Activation of the motor switch 90 supplies the power supply to the DC motor connection terminals 58+ and 58- so that the motor 92 receives the DC supply at the voltage level selected or specified PWM selected by selector 47 and is operational so that the impeller is rotated. Once the timer 48 times out, the night light 59 is deactivated and the motor switch 90 is deactivated, tuming the motor off.

The use of a DC motor provides considerabie advantages. Firstly, the speed of operation of the motor may be much higher than that of the AC motors used in prior art fans, the speed of which is constrained by the mains supply frequency. The speed of operation of the Direct Current motor of the present invention allows the invention to be used effectively on modem toilet apparatus.

The use of a DC motor allows greater speed and torque to be achieved for a given motor size than prior art embodiments. Therefore, the present invention allows a greater vacuum to be achieved than the prior art embodiments and thus a much higher gas flow rate or gas movement capacity than the fans of the prior art systems. A high flow rate is necessary for effective gas extraction and thus effective odour removal on modem toilet apparatus.

The use of a DC supply also minimises the risk of electric shock to a user and minimises the risk of fire should the motor develop a fault. The ability to select the rotational speed of the DC motor (and thus the flow rate of the fan) allows some fine tuning of the apparatus during or after installation. For example, if the apparatus is not very effective at removing odours at an initial voltage level or fan rotational speed such as that corresponding to 6 volts (possibly due to pipe size restrictions for example), the level can be adjusted to a higher level up to that corresponding to 12 volts (or greater if required) in ten incremental stages to increase fan speed until effective operation is achieved. Similarly, if the apparatus is operating at a level where gas removal is very effective, but for example which engage with the end of the motor adjacent to the output shaft 118 to hold the motor relative to the housing. The fan impeller 120 is attached to the output shaft 118 by gluing for example, or by a frictional engagement or a spring loaded circlip for example.

Parts 106 and 108 of the housing comprise the housing end caps which are engaged with central part 102. End cap 106 has an inlet 121 and end cap 108 has an outlet 122. The inlet and outlet receive gases conduit 14.

Extracted gases are in use drawn into the fan housing through inlet 121, so the direction of gases flow is as illustrated by arrow 124 (figure 27), they pass through the blades 126 of the rotating impeller and thereafter through gaps provided in the mounting bracket 110 which includes radial webs 111 that act as stator vanes to linearise the gas flow and to provide minimal impedance to the gas flow. The gases exit the assembly through outlet 122.

It will be seen that the fan assembly design provides a number of advantages. The first is the width (i.e. the diameter) of the housing is in the range of only approximately 60mm to 80 mm, and is preferably 75mm which is not substantially greater than that of the fan inlet 121 or outlet 122 which correspond to the width of conduit 14 which is preferably approximately 40mm to 60mm. This allows the assembly to be located in wall cavities of residential dwellings so that the apparatus can be installed easily which reduces cost. Also, the resultant installation is easily hidden, whether it is mounted inside a wall cavity or on an extemal surface of a wall. Due to the size and design of the fan 15, the installation is aesthetically pleasing. The construction is also clearly robust. The fan is a self contained unit which can be placed at a number of points in the system flow path.

In installations in which the extracted gases are removed via the intemal overflow conduit, the fan 15 should be provided at a level which is above the overflow level of the cistem so as to minimise the risk of the fan buming out in the event of a flood. The low voltage DC power supply limits the risk of fire or electrocution.

Furthermore, it will be seen that the fan 15 may be provided at a number of other locations in the system dependent on the accessibility or concealment requirements of a user. For example, the fan could be provided in or above the cistern, or in the wall immediately behind the cistem, or above the roof 5 if required. Also, a single fan, or source of negative air pressure can be used to extract gases from a plurality of toilet systems. For example, a ventilation shaft comprising part of the air conditioning system of a building may be used in place of the fan 15 for providing the source of negative air pressure required to extract the gases.

The present invention provides significant advantages over prior art systems as it can be easily installed in various types of toilet, in particular Close Coupled types. The system can be easily installed using plastics PVC conduits, for example constructed from PVC which can be glued for ease of connection and sealing. Without the use of a DC fan motor, which enables sufficient vacuum and flow rates to be achieved for the size of motor, the system does not work satisfactorily in modem toilet installations given their restrictive piping configurations. This is especially significant because modem toilets are mostly of the close coupled type and are often located in rooms in the middle of houses (i.e. rooms that are not immediately adjacent to an extemal wall) so that hidden installation of an effective system providing sufficient vacuum and flow rates cannot be achieved without the present invention.

Claims (16)

WHAT I CLAIM IS:

1. Odour removal apparatus for a flush type toilet having a cistern internal overflow conduit, the apparatus comprising overflow adaptor means adapted for gaseous communication with a gases extraction means for inducing a flow of gases, the overflow adaptor means being in use located about an entry to the internal overflow conduit whereby a substantially gas tight seal is made between the internal overflow conduit and the overflow adaptor means when the cistern water level is at its normal full level so that gases and entrained odours may be extracted from the toilet pan through the internal overflow conduit by the gases extraction means; and when the cistern level reaches the entry to the internal overflow conduit, water from the cistern is free to flow through the internal overflow conduit to the pan.

2. Odour removal apparatus as claimed in claim 1 wherein the overflow adaptor means comprises a body having a circumferential wall adapted to be located about the entry to the internal overflow conduit and spaced away from the entry, and an outlet for gases to flow to the gases extraction means.

3. A flush type toilet comprising, a cistern, an internal overflow conduit within the cistern, gases extraction means for inducing a flow of gases and entrained odours, overflow adaptor means in gaseous communication with a gases extraction means for inducing a flow of gases and the overflow adaptor means being located about an entry to the internal overflow conduit, whereby a substantially gas tight seal is made between the internal overflow conduit and the overflow adaptor means when the cistern water level is at its normal full level so that gases and entrained odours may be extracted from the toilet pan through the internal overflow conduit by the gases extraction means, and when the cistern level reaches the entry to the internal overflow conduit, water from the cistern is free to flow through the internal overflow conduit to the pan.

4. Toilet odour removal apparatus comprising a fan means operable to induce a flow of gases and entrained odours for removal of the odours from the vicinity of a toilet control means for controlling the operation of the fan the control means including flow rate selection means to allow a user to vary the rate of gases flow induced by the fan means.

5. Apparatus as claimed in claim 4 wherein the control means includes sensing means operable to activate the fan means upon sensing usage or probable usage of the toilet.

6. Apparatus as claimed in claim 4 or claim 5 wherein the control means includes timing means for providing a predetermined time period after activation of the fan means, the fan means being deactivated once the predetermined time period elapses.

7. Apparatus as claimed in claim 6 including timer control means whereby the duration of the predetermined time period is selectable by a user.

8. Apparatus as claimed in any one of the preceding claims wherein the fan means include an electric motor and the flow rate control means comprise motor speed adjustment means to vary the rotational speed of the motor.

9. Apparatus as claimed in any one of the preceding claims including a light and wherein the control means include light activation means for activating the light.

10. Apparatus as claimed in claim 9 wherein the control means include ambient light sensing means to sense the level of ambient light in the vicinity of the toilet and activate the light if the ambient light level is below a predetermined minimum level.

11. A toilet odour extraction fan comprising 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, and the width of the housing being not substantially greater than the width of the inlet or width of the outlet.

12. A toilet odour extraction fan as claimed in claim 11 wherein the width of the housing is substantially between 60mm and 80mm.

13. A toilet odour extraction fan comprising 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.

14. A fan as claimed in claim 13 wherein the operating rotational speed of the motor is substantially between 4000 revolutions per minute and 17000 revolutions per minute.

15. Any novel feature or combination of features disclosed herein.

16. Any novel method disclosed herein.