GB2292395A

GB2292395A - Ventilating a water closet

Info

Publication number: GB2292395A
Application number: GB9515894A
Authority: GB
Inventors: Robert James Thompson
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-08-19
Filing date: 1995-08-03
Publication date: 1996-02-21
Also published as: GB9416822D0; GB9515894D0

Abstract

A water closet, or toilet, having a sanitary bowl with an involute rim is ventilated by means of an air extraction fan connected to the sanitary bowl. In operation, the extraction fan is actuated when the toilet is used and removes foul air directly from the sanitary bowl and thereby creates an air curtain which isolates the sanitary bowl from the surrounding atmosphere. In the case of a water closet foul air is extracted from the sanitary bowl the flush pipe. <IMAGE>

Description

TOILET The present invention relates to a toilet and, in particular, a toilet incorporating means for extracting foul air.

Toilets for the disposal of human excrement can take a variety of forms. The most common form of toilet in use today is the water closet, in which human excrement is disposed of into a bowl, the sanitary bowl, linked to a waste disposal pipe by a water trap, usually referred to as the "U" bend. Excrement, deposited in the sanitary bowl is removed by supplying a sudden flow of water, a flush, from a water tank linked to a mains water supply by a water level actuated valve. The water tank and its associated valves are referred to as the cistern. Numerous variations on the basic design of water closet are known, but for the purposes of the present invention the key features of a water closet are the provision of a sanitary bowl, having an involute rim, sealed at its lower end by a U bend, and means for supplying a water flush.As will be explained later the use of the present invention is not limited to water closets, although the extensive use of water closets in modern plumbing'means that the principle application of the invention will be to water closets.

A common problem encountered with any toilet is the unpleasant odour that may occur in the vicinity of the toilet during and after use. Solutions commonly used in an attempt to overcome this problem include the addition of bleaches, or other chemicals, to the water in the U bend, deodorising tablets and enhanced ventilation in the room containing the toilet. None of the common solutions to the problem of toilet odour are entirely effective.

The present invention overcomes the problem of toilet odour by extracting the foul air responsible for the odour at source, i.e. from the sanitary bowl itself.

In effect an air curtain is created which seals the toilet bowl from the space surrounding it.

According to a first aspect of the present invention, there is provided a toilet, including a sanitary bowl, having an involute rim, a waste disposal pipe, connected to the sanitary bowl at the base thereof and seal means between said sanitary bowl and said waste disposal pipe arranged, when actuated, to permit passage of waste from said sanitary bowl to the waste disposal pipe and, at other times, to seal said waste disposal pipe from the said sanitary bowl, characterised in that extraction means are provided for the extraction of air directly from said sanitary bowl.

According to a second aspect of the present invention, there is provided a water closet, including a sanitary bowl having an involute rim, a waste disposal pipe, connected to the sanitary bowl at the base thereof by a U bend, and a water cistern, connected to the sanitary bowl by a flush pipe, characterised in that extraction means are provided for the extraction of air directly from said sanitary bowl.

Preferably the extraction means inhibits the escape of foul air from the sanitary bowl into the surrounding atmosphere by creating an air curtain between the sanitary bowl and the surrounding atmosphere.

Preferably the extraction means extracts air from the sanitary bowl via the flush pipe.

The extraction means may be connected to the flush pipe by a tee joint and air pipe.

Said air pipe may include a filter means for preventing the passage of water dropets.

Said filter means may comprise a gauze diaphragm.

Alternatively the extraction means may be connected to the flush pipe via the cistern.

In a preferred form of the invention the extraction means extracts air from the sanitary bowl via the involute rim thereof.

Preferably the extraction means is an electrically powered extraction fan.

The extraction fan may be actuated by a pressure sensor disposed in a toilet seat located on the rim of the sanitary bowl.

Preferably the extraction fan is connected to a timer switch arranged to switch off the extractor fan a predetermined time after the extractor fan was switched on.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 illustrates, in section, a water closet, together with associated plumbing and electrical connections, according to a first embodiment of the present invention.

Figure 2 illustrates a toilet bowl according to the present invention and shows the pattern of air movement into the toilet bowl.

Figure 3 illustrates, in projection, the water closet of Figure 1.

Figure 4 illustrates, in section, a water closet, together with associated plumbing and electrical connections according to a second embodiment of the present invention.

Figure 5 illustrates, in projection, the water closet of Figure 4.

Figure 6 illustrates the operation of the cistern used in the embodiment of the invention shown in Figures 1 to 3.

Figure 7 illustrates the operation of the cistern used in the embodiment of the invention shown in Figures 4 and 5.

Referring to Figures 1 to 3 of the drawings, there is shown one embodiment of a water closet according to the present invention. The water closet comprises a sanitary bowl, 1, which is connected to a waste disposal pipe, 3, via a U bend, 2, a water cistern, 7, connected to the sanitary bowl, 1, at 10, via a flush pipe, 6 and 8, and an electrical air extraction fan, 12, connected via an air pipe, 11, and tee joint, 9, to the flush pipe, 6 and 8. The sanitary bowl, 1, has an involute rim 4, i.e. an inwardly and downwardly turned rim that defines either an open, or closed, passage used to direct water from the cistern, during flushing, over the surface of the sanitary bowl. A water droplet filter, 19, is provided in air pipe, 11, to prevent water droplets generated during flushing of the toilet being sucked into the air ventilation duct 18.The filter comprises a simple gauze diaphragm stretched across the air passage contained within the filter. It has been found that the material used for ladies stockings, stretched across a pipe coupling serves quite adequately as a water droplet filter. Alternatively, a valve, capable of isolating the lower part of air pipe 11, from the upper part of the air pipe, during flushing may be used. Such a valve may be operated by a mechanical linkage connected to the cistern flushing mechanism.

There are many designs for sanitary bowls, in one of the most common forms, the involute rim of the sanitary bowl forms an open inverted channel through which the flush is directed. In an alternative design of sanitary bowl, the involute rim takes the form of a closed channel in which holes are formed at intervals, through which the flush is directed into the sanitary bowl. The term "involute rim" is intended to include all arrangements of sanitary bowl in which a closed, or open channel, is disposed on, or in proximity to, the upper perimeter of the sanitary bowl.

When actuated, the extraction fan 12, sucks foul air from the sanitary bowl, 1, via the involute rim, 4, and the lower portion, 6, of the flush pipe and air extraction pipe, 11. Foul air is vented into the external atmosphere at 13. When the extraction fan, 12, is operating, the air pressure in the sanitary bowl, 1, is slightly less than that of the surrounding atmosphere, so that escape of foul air, from the sanitary bowl, into the surrounding atmosphere is prevented by an air curtain.

The air flow is believed to be as illustrated in Figure 2, by flow lines 5.

The extraction fan is connected to the mains electric supply by wiring, 16, cord actuated switch, 14, fuse, 17, and on/off switch, 15. The extraction fan may typically be of the type used in showers, such as the Manrose Shower Fan SF1 or SF2. These fans have a maximum airflow of 23 litres per second and use approximately 20 watts of electric power.

The flush pipe typically may have a bore of 32mm and is connected via tee joint, 9, and pipe, 11, to 10cm ducting, 18, which is, in turn, connected to the extraction fan. The use of narrow pipe work will, of course, reduce the air flow produced by the extractor fan, but provided the length of pipe is not excessive, and wider ducting is employed at not too great a distance from the sanitary bowl, sufficient air flow can be maintained to enable the air extraction system to operate effectively. The detailed design and construction of suitable pipe work is a matter which can be undertaken relatively easily by those skilled in the art.

As illustrated, the extraction fan is actuated by a cord switch, 14, however it will be readily apparent to those skilled in the art, that a pressure sensor attached to a toilet seat, not shown, or an infra red proximity switch, disposed in the vicinity of the sanitary bowl, could be used to actuate the extractor fan. It is even possible to incorporate a pressure switch, or micro-switch, in a toilet seat cover as a means of operating the extraction fan. The electrical circuitry used in conjunction with the extraction fan may incorporate a timer switch to automatically switch the extractor fan off after a predetermined period of time, say 15 minutes. Many variations in the electric actuation and control of the extractor fan are possible and such variations will be readily apparent to those skilled in the art.

In a second embodiment of the invention, illustrated in Figures 4 and 5 of the accompanying drawings, the extractor fan is linked to the sanitary bowl via pipe 11, sealed cistern 7, and flush pipe 8.

In all other respects the embodiment illustrated in Figures 4 and 5 is similar to that illustrated in Figures 1, 2 and 3, and like elements have been denoted by the same reference numerals. The difference between the operation of the two embodiments of the invention is best understood from a consideration of the operation of the cisterns used in each of the embodiments, both of which are well known designs.

Referring first to Figure 6, there is shown a design of cistern in common use in the United Kingdom.

The cistern, 7, is fed with water from the mains water supply via a water level actuated valve, (not shown).

The flush pipe, 8, emerges from the base of the cistern.

The flush pipe, 8, is linked to a pipe, 28, in the shape of an inverted "U", which is in turn connected to cylinder, 29, in which a piston 20 is located. In operation, the piston, 20, is raised by means of piston rod 24, lever, 22, and handle, 23, forcing water into pipe, 28, and establishing a syphon which facilitates the discharge of water in the cistern into the flush pipe, thereby creating the flush. In this type of cistern a separate overflow pipe, (not shown), must be provided. It should be noted that there is no direct passage from the space in the cistern above the water level, 25, to the flush pipe, 8, when the cistern is filled with water.

In the cistern shown in Figure 7, commonly used in New Zealand, the mode of operation is similar to that shown in Figure 6. However, flush pipe, 8, is linked to a double walled tube, 27, the inner portion of which extends above the normal water level, 25, in the cistern. The inner tube acts as an overflow pipe. The water flow initiated by the flushing action of the cistern passes through the annular space defined by the inner and outer walls of tube, 27. In this design of cistern a passage exists between the space above the normal water level in the cistern, 25, and the flush pipe, 8.

Thus in the case of the cistern described with reference to Figure 6, the air extraction path is conveniently linked into the flush pipe by a tee joint external to the cistern. In the case of the cistern described with reference Figure 7, the air extraction path can conveniently be routed through the cistern itself. This permits a more compact and convenient design for the associated pipe work.

As described above, both embodiments of the invention have been described with reference to a water closet. However, the invention is applicable to any toilet, provided that the sanitary bowl has an involute rim and is connected to the waste disposal pipe by a seal, so that the extraction fan does not suck foul air from the waste disposal pipe. In a water closet, the seal is provided by a water trap contained in the U bend, in other toilet systems the seal may be in the form of a flap valve.

Claims

1. A toilet, including a sanitary bowl having an involute rim, a waste disposal pipe, connected to the sanitary bowl at the base thereof and seal means between said sanitary bowl and said waste disposal pipe arranged, when actuated, to permit passage of waste from said sanitary bowl to the waste disposal pipe and, at other times, to seal said waste disposal pipe from the said sanitary bowl, characterised in that extraction means are provided for the extraction of air directly from said sanitary bowl.

2. A water closet, including a sanitary bowl having an involute rim, a waste disposal pipe, connected to the sanitary bowl at the base thereof by a U bend, and a water cistern, connected to the sanitary bowl by a flush pipe, characterised in that extraction means are provided for the extraction of air directly from said sanitary bowl.

3. A water closet, as claimed in claim 2, characterised in that the extraction means extracts air from the sanitary bowl via the flush pipe.

4. A water closet, as claimed in claim 3, characterised in that the extraction means is connected to the flush pipe by a tee joint and air pipe.

5. A water closet, as claimed in claim 3, characterised in that the extraction means is connected to the flush pipe via the cistern.

6. A water closet as claimed in either claim 4, or 5, characterised in that said air pipe includes a filter means for preventing the passage of water dropets.

7. A water closet as claimed in claim 6, characterised in that said filter means comprises a gauze diaphragm.

8. A water closet, or toilet, as claimed in any preceding claim, characterised in that the extraction means inhibits the escape of foul air from the sanitary bowl into the surrounding atmosphere by creating an air curtain between the sanitary bowl and the surrounding atmosphere.

9. A water closet, or toilet, as claimed in any preceding claim, characterised in that the extraction means extracts air from the sanitary bowl via the involute rim thereof.

10. A water closet, or toilet, as claimed in any preceding claim, characterised in that the extraction means is an electrically powered extraction fan.

11. A water closet, or toilet, as claimed in claim 10, characterised in that the extraction fan is actuated by a cord switch.

12. A water closet, or toilet, as claimed in claim 10, characterised in that the extraction fan is actuated by a pressure sensor disposed in a toilet seat located on the rim of the sanitary bowl.

13. A water closet, or toilet, as claimed in claim 10, characterised in that the extraction fan is actuated by an infra red proximity sensor disposed in the vicinity of the sanitary bowl.

14. A water closet, or toilet, as claimed in any of claims 10 to 13, characterised in that the extraction fan is connected to a timer switch arranged to switch off the extractor fan a predetermined time after the extractor fan was switched on.

15. A water closet, or toilet, as claimed in any of claims 10 to 13, characterised in that the extraction fan is arranged to discharge foul air via a pipe connected to a soil pipe.

16. A water closet, or toilet, as claimed in any of claims 10 to 13, characterised in that the extraction fan is arranged to vent foul air outside a building in which the toilet, or water closet, is located.

17. A water closet substantially as hereinbefore described with reference to Figures 4, 5 and 7 of the accompanying drawings.

17. A water closet substantially as hereinbefore described with reference to Figures 1 to 3 and Figure 6 of the accompanying drawings.