GB2319268A

GB2319268A - Ventilation and flushing unit for a toilet

Info

Publication number: GB2319268A
Application number: GB9623244A
Authority: GB
Inventors: Michael Graham Nichola Hawkins
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-11-07
Filing date: 1996-11-07
Publication date: 1998-05-20
Anticipated expiration: 2016-11-07
Also published as: GB2319268B; GB9623244D0

Abstract

A toilet ventilation and flushing unit has a ventilation airway 14, a flushing device 12, a two way air valve 22 and a air suction device 4 which can be located in the water cistern 6, adjacent to it, or remotely. The air suction device is connected to the flushing and ventilation unit by means of piping 17, and utilises the water passageway 5 and 11 of the toilet 13 to draw air, odours and aromas from bowl 1 into the ventilation airway 14, when the water level 27 is above the housing of the two way air valve 22. During operation of the toilet, water 2 is released into the passageway 5 and 11 which temporarily obstructs the ventilation airway 14. When this occurs, the water level 27 simultaneously falls and permits air to be drawn from the water cistern atmosphere 8 into the air valve the inlet 24 and relieves the stall condition created in the air suction device. After the bowl has been rinsed and the water cistern has been emptied, air will be drawn from both inlets 24 and 14 until the water level reaches the air valve housing and forms a seal which shuts off inlet 24.

Description

VENTILATION AND FLUSHING UNIT FOR A TOILET This invention relates to the general field of toilets and particularly to devices which both flush and ventilate toilet bowls.

The removal of odours from toilets can be achieved by chemical deodorisers through air-borne or water-borne means. Their effect generally has a limited duration, does not treat all odours, and otherwise does not adequately solve the problem of toilet odors. In addition, substances are introduced into the environment which, in confined spaces, can cause adverse reactions in people who have a high allergic sensitivity to some chemical products used for deodorisation.

Previous disclosures have adapted or modified toilets in order to draw odours from the toilet by introducing additional ducting into the toilet bowl, lid or seat. However, at least two inventions WO 88/06662 and WO 95/30802 describe devices which draw odours through the water passages present in conventional toilets having a water cistern (tank) and bowl.

In invention WO 8g106662, a control valve is interposed in the flush pipe between the toilet bowl and water cistern. Air is drawn from the toilet bowl through the flush pipe and vented to the exterior without passing through the cistern. This system has the disadvantages that it cannot be used with close coupled toilets, it requires an additional outlet, and is visible.

In invention WO 95/30802, the air from the toilet bowl is drawn through the flush pipe and water overflow into the cistern and then evacuated from the cistern by an external vacuum motor mounted remotely. The disadvantages of this invention are that a strong vacuum is necessary for it to work properly and it requires good sealing throughout the air pathway to facilitate vacuum suction. Among the consequences of these requirements are that seals should be added to the cistern lid and any other spaces to achieve optimum performance, and several valves are necessary to permit adequate release of water from the cistern due to the negative pressure built up during the ventilating action. Further, it does not offer the immediate facility to recirculate deodorised, sanitised or conditioned air removed from the toilet bowl.

Both these and other disclosures have incorporated the toilet ventilation system as a additional and separate facility from the flushing system. It is an object of the present invention to provide a combination of flushing and ventilation facilities for a toilet in one unit, in which the ventilation system induces an air flow through the water passage of a conventional toilet bowl, and directs contaminated air out of the toilet to piping adjacent to the toilet, or alternatively, to the surrounding atmosphere after conditioning. In this way, odours and aromas are also be removed from the vicinity of the toilet bowl. Another object is to operate the ventilation system with a weak vacuum which facilitates the additional objects of quieter operation, lower power consumption, less noise and lower cost. Still another object is to be able to operate the ventilation system with the air suction equipment located inside, adjacent or remotely from the cistern. Further objectives are to be able to construct the ventilation and flushing unit with flushing systems which include siphon, cascade and water valve types and, in the event of a failure of the ventilation equipment, to ensure that the flushing operation of the toilet is not impaired. These and other objects, advantages and features of this invention are advantageously accomplished in a unique toilet flushing and ventilation unit.

The ventilation and flushing unit is used with a conventional toilet having a water cistern directly connected or connected by a connecting duct to a toilet bowl. In conventional toilets, a water passageway or connecting duct is available to allow water to pass from the outlet of the cistern to the bowl. This invention utilises this waterway as an air passageway to remove contaminated air from the bowl when used in conjunction with an air drawing or inducing means. The air induction means draws air through the passageway and piping to create a vacuum suction which causes air to flow out of the toilet bowl, and may be operated continuously or activated only while the toilet is in use. A two way air valve may be incorporated which directs air to be drawn from the toilet bowl or from within the cistern depending on the water level in the cistern. When the toilet is flushed, the fall in water level in the cistern causes the air valve to draw air from the cistern instead of drawing air from the toilet bowl. The temporary stall condition in the air flow caused by the interruption by water entering the toilet passageways during flushing is relieved as soon as this re-direction is completed. When the cistern has refilled, the air valve reverts to drawing air from the toilet bowl.

According to the present invention there is provided a ventilation and flushing unit for a conventional toilet to remove odours from said toilet and to release water into the toilet bowl, said toilet having a water cistern, a connecting duct, and a bowl with a conduit in the rim with apertures to enable the passage of water from the water cistern in order to rinse the bowl, comprising: a) means, mounted in said water cistern and adapted to provide an airway to permit the flow of air from the connecting duct; and b) means, mounted with said airway and adapted to release water from the water cistern into the connecting duct and the bowl, whereby the water in the cistern is substantially emptied into the bowl once a discharge cycle has been initiated, and after discharge, to prepare automatically to receive another charge of water without further intervention.

The first embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows a cross section of the general arrangement of the toilet Figure 2 shows the entry to the ventilation airway positioned below the water outlet valve Figure 21 shows the general arrangement with the ventilation system connected to a sewer outlet Referring to the drawing, it will be appreciated that this invention is utilised with a conventional toilet assembly 13 which includes a bowl 1, water cistern 6 as illustrated in Fig 1. In the bowl 1 there is a water passageway 5 which leads into a conduit 11. In the cistern 6 there is a ventilation and flushing unit 3 with a water outlet valve 12 and ventilation airway 14, and a water overflow 16 as shown in Fig 2. Outside the water cistern 6, there is piping 17 which connects to an air suction device 4 mounted on an adjacent wall 10 and a control panel 18.

The air suction device 4 generates negative pressure and air flow by means which can include a motorised fan or vacuum pump, and evacuated air is discharged into an area remote from the toilet. Air discharged from the system can be treated in ways which include direct dispersal into the atmosphere, conditioning for return into the local area and discharge into the sewer outlet via a non-return valve 31 as shown in Fig 21. The control panel 18 provides a means for activating or de-activating the air suction device 4 and offers the facility for manual or automatic control. In the automatic mode, activating or de-activating the air suction device 4 is in accordance with the presence of a user in the vicinity of the toilet 13. The presence of a user may be detected by means which include infra-red and ultrasonic sensors that detect body heat and movement. Once the user has left the vicinity of the toilet, a timer may keep the ventilation system operating for a pre-selected period. The water overflow 16 is un-pressurised and provides for protection against the water inlet valve (not shown) failing in the open position.

In the operation of the toilet 13, water 2 in the cistern is released by the water outlet valve 12 and flows into the water passageway 5 and through the conduit 11 to rinse the toilet bowl 1. When the toilet is not being operated, this invention uses the water passageway 5 and conduit 11 to induce an air flow opposite to the direction of the water flow, to draw contaminated air from the toilet bowl 1 into the ventilation airway 14 and then to the suction device 4 as illustrated by the arrows in Fig 1. When in use, the aperture in the toilet seat 7 is largely obscured by the user, and forms a partially closed chamber with the toilet bowl 1 so that air will be drawn primarily through the gaps 9 between the toilet bowl 1 and the toilet seat.

The ventilation airway 14 is adapted so that it reduces the impedance to the airflow from the toilet bowl 1 via the water passageway 5 and consequentially, it reduces the pressure drop in the system. This allows ventilation of the toilet bowl to be achieved with a weaker vacuum or less negative pressure, than would be possible if any constrictions were present in this airway.

During operation of the toilet, the action of the water release causes the cessation of air flow to the suction device 4 for about ten seconds by water obstructing the ventilation airway 14. In this period, the uptake of water into the ventilation airway will correspond to the negative pressure available from the air suction device 4 in its stalled or no air flow condition. Once the water has been flilly released from the cistern 6, it ceases to obstruct the ventilation airway, but there is insufficient surface tension to maintain the column of water so that it collapses allowing normal ventilation of the bowl to resume. This phenomenon does however limit the maximum negative pressure that the system can sustain before water is sucked into the air suction device.

The second embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 3 shows the air suction device mounted adjacent to the cistern Referring to the drawing, it will be appreciated that this embodiment is in accordance with the first embodiment having the same components, features, characteristics and relationships with the exception that the air suction device 4 is mounted adjacent to the cistern 6.

The third embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 4 shows the air suction device mounted in the cistern Referring to the drawing, it will be appreciated that this embodiment is in accordance with the first embodiment having the same components, features, characteristics and relationships with the exception that the air suction device 4 is mounted in the cistern 6.

The fourth embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 5 shows the air suction device mounted in the cistern with air recirculation Referring to the drawing, it will be appreciated that this embodiment is in accordance with the first embodiment having the same components, features, characteristics and relationships with the exceptions that the air suction device 4 is mounted in the cistern 6 and the exhaust air is directed into an air purifier 20 for recirculation. The cistern lid 15 is loose fitting in conventional toilets and permits the outflow of air expelled from the air purifier as indicated by the arrows in Fig 5.

The fifth embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 6 shows entry to the ventilation airway positioned at the base of the outlet of a siphon water release device Referring to the drawing, it will be appreciated that this embodiment is generally in accordance with the first embodiment having the same components, features, characteristics and relationships with the exceptions that the ventilation airway 14 is utilised with a siphon water release device 19, and the external water overflow 16 is omitted.

The cistern water overflow protection, which is necessary when the water inlet valve (not shown) fails in the open position, is achieved when the water level in the siphon inlet exceeds the level of the apex of the arch of the siphon 21. The height of this apex also limits the amount of negative pressure which can be applied to this system, since there is a rise in the level of the water in the inlet of the siphon commensurate with the amount of air suction generated. The air suction device 4 can be mounted as illustrated in Fig 6 or in various positions including those described in embodiments 2, 3 and 4, together with any components, features, characteristics or relationships described therewith.

The sixth embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 7 shows the ventilation airway positioned in the outlet of the siphon water release device Referring to the drawing, it will be appreciated that this embodiment is in accordance with the fifth embodiment having the same components, features, characteristics and relationships with the exception that the ventilation airway 14 is incorporated into the outlet of the siphon water release device 19.

The seventh embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 8 shows the inlet to the ventilation airway positioned centrally in the water outlet valve Referring to the drawing, it will be appreciated that this embodiment is generally in accordance with the first embodiment having the same components, features, characteristics and relationships with the exception that the ventilation airway 14 is positioned centrally in the water outlet valve 12. The air suction device 4 can be mounted as illustrated in Fig 8 or in various positions including those described in embodiments 2,3 and 4, together with any components, features, characteristics or relationships described therewith.

The eighth embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 9 shows the general arrangement of the toilet with the two way air valve drawing air from the bowl Figure 10 shows the general arrangement of the toilet with the two way air valve drawing air from the cistern Figure 11 shows the two way air valve with air being drawn from the bowl inlet Figure 12 shows the two way air valve with air being drawn from the cistern inlet Figure 13 shows the two way air valve in an overflow condition Referring to the drawing, it will be appreciated that this embodiment is in accordance with the first embodiment having the same components, features, characteristics and relationships with the exceptions that the two way air valve 22 has been added and that the water overflow 16 has been removed.

In this embodiment, the air suction device 4 can be mounted as illustrated in Fig 9 and Fig 10 or in various positions including those described in embodiments 2, 3 and 4, together with any components, features, characteristics or relationships described therewith. The embodiment of the air valve into the ventilation and flushing unit generally enables a reduction of stall time and prevention of prolonged stall conditions, provides a water overflow facility, increases the permissible air flow rates, and restricts water uptake into the air suction device during stall conditions.

In the air valve 22, air is drawn through the outlet 26 from the bowl inlet 25 or from the cistern inlet 24 or both, as shown in Fig 11 and Fig 12 depending on the water level 27.

The cistern water level 27 forms a seal between the cistern inlet and the outlet which is opened when the water level falls below the valve housing as illustrated in Fig 12. Air may then be drawn through the cistern inlet 24 as well as through the bowl inlet 25. The expansion chamber 23 is provided in case the inlet 25 becomes blocked. In these circumstances, the combined action of water overflowing into the ventilation airway 14 and being drawn up into the expansion chamber will normally lower the water level 27 in the cistern, and allow air to be drawn into the air valve via the cistern inlet 24. As soon as air is admitted the column of water cannot be sustained, although some oscillation may occur in this condition. It is important that the valve housing should not extend too deeply into the water because it will lengthen the time to clear stalled conditions, which occur when there is no airflow to the air suction device, and will increase the amount of water that can be drawn into the air valve.

If the water level rises above bowl air inlet 25, it will overflow and be drained away as shown in Fig 13. Fig 9 illustrates that when the ventilation and flushing unit is incorporated into a toilet 13, the ventilation airway 14 performs the dual function of an airway and a water overflow passage which leads from the cistern 6 through water passageway 5 into the bowl 1 as shown in Fig 9. When the water level 27 in the air valve 22 is above the valve housing as illustrated in Fig 9, a steady flow of air will be drawn from the ambient atmosphere into the toilet bowl 1, through the water passageway 5, through the ventilation airway 14, through the air valve expansion chamber 23, to the air suction device 4. When the toilet is flushed, water is released into the water passageway S which causes the ventilation airway 14 to be obstructed and the air flow to the air suction device 4 is interrupted. During this air flow interruption, there can be a momentary rise in the water level within the air valve in proportion to the negative pressure which can be achieved by the air suction device in a stalled condition. As soon as the water level in the cistern falls below the air valve housing as a result of the water release, the inlet 24 opens and relieves the stalled condition as shown in Fig 10.

The cistern air 8 continues to be drawn from the cistern via the air valve inlet 24 which in turn draws air from the surrounding atmosphere through a loose fitting lid 15.

Conventional toilets allow air into the cistern to permit equalisation of pressure with the surrounding atmosphere and facilitate correct release of water during operation of the toilet.

Once the water has been fully released from the cistern, the conventional cycle of refilling the cistern with water is initiated and the water passageway 5 is cleared. During this stage, air is drawn mainly through the cistern inlet 24 but some air will also be drawn from the bowl inlet 25. The ratio will depend on the relative air impedances of the two paths. This continues until the water level 27 again reaches the valve housing and forms a seal between the cistern atmosphere 8 and the ventilation airway 14. At this point, ventilation of the toilet bowl 1 is fully resumed.

The ninth embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 14 shows the two way air valve with the entry to ventilation airway positioned centrally in the water outlet valve Referring to the drawing, it will be appreciated that this embodiment is generally in accordance with the eighth embodiment having the same components, features, characteristics and relationships. In this embodiment, the air suction device 4 can be mounted as illustrated in Fig 14 or in various positions including those described in embodiments 2, 3 and 4, together with any components, features, characteristics or relationships described therewith.

The tenth embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 15 shows the two way air valve with the entry to the ventilation airway positioned below the water outlet valve Referring to the drawing, it will be appreciated that this embodiment is generally in accordance with the eighth embodiment having the same components, features, characteristics and relationships. In this embodiment, the air suction device 4 can be mounted as iilustrated in Fig 15 or in various positions including those described in embodiments 2, 3 and 4, together with any components, features, characteristics or relationships described therewith.

The eleventh embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 16 shows the two way air valve with entry to the ventilation airway positioned at the base of the siphon water release device Referring to the drawing, it will be appreciated that this embodiment is generally in accordance with the eighth embodiment having the same components, features, characteristics and relationships. In this embodiment, the air suction device 4 can be mounted as illustrated in Fig 16 or in various positions including those described in embodiments 2, 3 and 4, together with any components, features, characteristics or relationships described therewith.

The twelfth embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 17 shows the two way air valve with the external overflow mounted in the side of the cistern Referring to the drawing, it will be appreciated that this embodiment is generally in accordance with the eighth embodiment having similar components, features, characteristics and relationships. In this embodiment, the air suction device 4 is mounted outside the cistern and is adapted to be able to provide a weak vacuum and to drain overflow water.

The thirteenth embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 18 shows the two way air valve with the external overflow mounted in the bottom of the cistern Referring to the drawing, it will be appreciated that this embodiment is generally in accordance with the eighth embodiment having similar components, features, characteristics and relationships. In this embodiment, the air suction device 4 is mounted outside the cistern and is adapted to be able to provide a weak vacuum and to drain overflow water.

The fourteenth embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 19 shows the float operated air valve in the closed position Figure 20 shows the float operated air valve in the open position Referring to the drawing, it will be appreciated that this embodiment is generally in accordance with the eighth embodiment having similar components, features, characteristics and relationships with the exception that a floated operated air valve 30 is specified. In this embodiment, the air suction device 4 can be mounted as illustrated in Fig 19 and Fig 20 or in various positions including those described in embodiments 2,3 and 4, together with any components, features, characteristics or relationships described therewith, and the ventilation airway can be positioned centrally in the water outlet valve.

The air valve 30 is held in the closed position by the upward pressure exerted by the water on the float 28 via the linkage 29 on the valve. In this position, a stronger vacuum can be established in the ventilation airway 14 than the water actuated air valve 22. When the toilet is operated, the water level 27 falls and water enters the water passageway as illustrated in Fig 20. The fall in the water level causes the valve 30 to open and allows air to be drawn from inside the cistern as indicated by the arrows in Fig 20. This air flow will be maintained until the water level rises sufficiently to close the valve and resume ventilation of the toilet bowl.

While the invention has been shown in several forms, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit thereof.

Claims

CLMMS

A ventilation and flushing unit for a conventional toilet to remove odours from said toilet and to release water into the toilet bowl, said toilet having a water cistern, a connecting duct, and a bowl with a conduit in the rim with apertures to enable the passage of water from the water cistern in order to rinse the bowl, comprising: a) means, mounted in said water cistern and adapted to provide an airway to permit the free flow of air from the connecting duct; and b) means, mounted with said airway and adapted to release water from the water cistern into the connecting duct and the bowl, whereby the water in the cistern is substantially emptied into the bowl once a discharge cycle has been initiated, and after discharge, to prepare automatically to receive another charge of water without further intervention.
2 A ventilation and flushing unit as claimed in claim 1 further including means to regulate the flow of air from the connecting duct and cistern atmosphere comprising: a) a valve, in communication with the airway, wherein the raising or lowering of the water level, with the water itself being the means of sealing of the air flow, closes or opens respectively the air inlet from the cistern atmosphere, providing an air source alternative to the toilet bowl when the water released into said connecting duct terminates communication between the toilet bowl and the airway; and b) an expansion chamber in said valve to accommodate water uptake occasioned when there is increased air suction pressure due to the cessation of air flow through the airway, and to prevent continuous cessation of this air flow; and c) a water overflow in said valve offering containment of water in the cistern up to the normal operating level, and adapted to allow water to overflow into the airway when this is exceeded.
3 A ventilation and flushing unit as claimed in claim 1 further including means to regulate the flow of air from the connecting duct and cistern atmosphere comprising: a) a valve, in communication with the airway which is connected to a floatable device in the water such that the valve is actuated concomitantly with the lowering and raising of the water in the cistern, opening or closing respectively the air inlet from the cistern atmosphere and providing an air source alternative to the toilet bowl when the water, released into said connecting duct, terminates communication between the toilet bowl and the air inducement means; and b) an expansion chamber in said valve to accommodate water uptake occasioned when there is increased air suction pressure due to the cessation of air flow through the airway, and to prevent continuous cessation of this air flow.
4 A ventilation and flushing unit as claimed in claims 1, 2 and 3 further including means, mounted to or connected to and in communication with said airway means, for inducing air flow through the airway, the connecting duct and the conduit in the rim of the bowl, to draw odours from the bowl and away from the water cistern and to transfer them to remote areas, including through walls and sewer outlets, or alternatively, to the local surrounding atmosphere after conditioning.
5 A ventilation and flushing unit as claimed in claims 1, 2, 3 and 4 further including a means for automatically activating and de-activating the air inducement means in accordance with the presence or not respectively of a person in the vicinity of the toilet.
6 A ventilation and flushing unit as claimed in claims 1, 2, 3 and 4 further including a means for water release having a water outlet valve and an airway in communication with said connecting duct wherein the water valve is adapted to permit air to be drawn through the centre of the water valve.
7 A ventilation and flushing unit as claimed in claims 1, 2, 3 and 4 further including a means for water release having a water outlet valve and an airway in communication with said connecting duct wherein the airway is adapted to draw out air before reaching the water valve.
8 A ventilation and flushing unit as claimed in claims 1, 2, 3 and 4 further including a means for water release having a siphon or cascade and an airway in communication with said connecting duct wherein air is drawn out at the base of the outlet chamber of the siphon or cascade.
9 A ventilation and flushing unit as claimed in claims 1, 2, 3 and 4 further including a means for deodorising air evacuated from the bowl.
10 A ventilation and flushing unit as claimed in claims 1, 2, 3 and 4 further including a means for sanitising air evacuated from the bowl.
11 A ventilation and flushing unit as claimed in claims 1, 2, 3 and 4 wherein said air inducement means is mounted in the cistern and provides for evacuated air to be dispersed to a remote area or recirculated and conditioned to be dispersed in a local area.
12 A ventilation and flushing unit as claimed in claims 1, 2, 3 and 4 wherein said air inducement means is mounted adjacent to the cistern and provides for evacuated air to be dispersed to a remote area or recirculated and conditioned to be dispersed in a local area.
13 A ventilation and flushing unit as claimed in claims 1, 2, 3 and 4 wherein said air inducement means is mounted remotely from the cistern.
14 A ventilation and flushing unit substantially as described herein with reference to Figures 1-16 of the accompanying drawing.

14 A ventilation and flushing unit as claimed in claims 11, 12, and 13 wherein said evacuated air from the air inducement means is released into the sewer outlet together with means to prevent odours from being introduced from the sewer.

15 A ventilation and flushing unit as claimed in claims 1,2, 3 and 4 further including means for the air inducement means adapted for the concurrent use for the evacuation of air and for water overflow.

16 A ventilation and flushing unit substantially as described herein with reference to Figures 1-21 of the accompanying drawing.

Amendments to the claims have been tiled as follows A ventilation and flushing unit for a conventional toilet to remove odours from said toilet and to release water into the toilet bowl, said toilet having a water cistern, a connecting duct, a bowl with a conduit in the rim with apertures to enable the passage of water from the water cistern in order to rinse the bowl, means mounted in said water cistern and adapted to provide an airway to permit the free flow of air from the connecting duct, means mounted to or connected to and in communication with said airway means, for inducing air flow through the airway, the connecting duct and the conduit in the rim of the bowl, to draw odours from the bowl and away from the water cistern and to transfer them to remote areas, including through walls and sewer outlets, or alternatively, to the local surrounding atmosphere after conditioning, comprising: a) a valve, in communication with the airway, wherein the raising or lowering of the cistern water level, with the water itself being the means of sealing of the air flow, closes or opens respectively the air inlet from the cistern atmosphere, providing an air source alternative to the toilet bowl when the water released into said connecting duct terminates communication between the toilet bowl and the airway; and b) an expansion chamber in said valve to accommodate water uptake occasioned when there is increased air suction pressure due to the cessation of air flow through the airway, and to prevent continuous cessation of this air flow; and c) a water overflow in said valve offering containment of water in the cistern up to the normal operating level, and adapted to allow water to overflow into the airway when this is exceeded.

2 A ventilation and flushing unit as claimed in claim 1 further including a water overflow, comprising: a valve, in communication with the airway which is connected to a floatable device in the water such that the valve is actuated concomitantly with the lowering and raising of the water in the cistern, opening or closing respectively the air inlet from the cistern atmosphere and providing an air source alternative to the toilet bowl, when the water released into said connecting duct terminates communication between the toilet bowl and the air inducement means.

3 A ventilation and flushing unit as claimed in claims 1 and 2 further including a means for automatically activating and de-activating the air inducement means in accordance with the presence or not respectively of a person in the vicinity of the toilet.

4 A ventilation and flushing unit as claimed in claims 1 and 2 further including a means for water release having a water outlet valve and an airway in communication with said connecting duct wherein the water valve is adapted to permit air to be drawn through the centre of the water valve.

5 A ventilation and flushing unit as claimed in claims 1 and 2 further including a means for water release having a water outlet valve and an airway in communication with said connecting duct wherein the airway is adapted to draw out air before reaching the water valve.

6 A ventilation and flushing unit as claimed in claims 1 and 2 further including a means for water release having a siphon or cascade and an airway in communication with said connecting duct wherein air is drawn out at the base of the outlet chamber of the siphon or cascade.

7 A ventilation and flushing unit as claimed in claims 1 and 2 further including a means for deodorising air evacuated from the bowl.

8 A ventilation and flushing unit as claimed in claims 1 and 2 further including a means for sanitising air evacuated from the bowl.

9 A ventilation and flushing unit as claimed in claims 1 and 2 wherein said air inducement means is mounted in the cistern and provides for evacuated air to be dispersed to a remote area or recirculated and conditioned to be dispersed in a local area.

10 A ventilation and flushing unit as claimed in claims 1 and 2 wherein said air inducement means is mounted adjacent to the cistern and provides for evacuated air to be dispersed to a remote area or recirculated and conditioned to be dispersed in a local area.

11 A ventilation and flushing unit as claimed in claims 1 and 2 wherein said air inducement means is mounted remotely from the cistern.

12 A ventilation and flushing unit as claimed in claims 9, 10, and 11 wherein said evacuated air from the air inducement means is released into the sewer outlet together with means to prevent odours from being introduced from the sewer.

13 A ventilation and flushing unit as claimed in claims 1 and 2 further including means for the air inducement means adapted for the concurrent use for the evacuation of air and for water overflow.