A VALVE ARRANGEMENT AND AN ODOUR EXTRACTION DEVICE

Field of the Invention

The present invention relates to a valve arrangement for a suction means and an odour extraction device for a toilet pan.

The invention has been primarily developed for use in toilets in fixed homes and will be described hereinafter with reference to this application. However, the invention is not limited to this particular use and is also applicable for use with toilets in other environments such as: marine vessels; mobile homes; campervans; recreational vehicles; caravans; portable buildings and portable toilets.

The valve arrangement aspect of the invention also finds application in respiratory devices.

Background of the Invention

The Applicant's international PCT patent application No. PCT/AU2007/000003 (WO 2007/079524) discloses embodiments of an odour extraction device for gravity flushing and syphonic flushing toilet pans. The disclosed odour extraction devices include a one way valve to prevent unpleasant odours from flowing from the sewer back to the toilet pan. The disclosed odour extraction devices utilise a suction fan to draw gas from within the pan and expel it through a duct into the pan's flushing outlet pipe. The gas then flows through the pan's flushing outlet pipe into the sewer.

The valves used in devices of this type often include a relatively rigid rubber valve member which seals against a plastic valve seat. The valve members are often delivered with a protective silicone film thereon, .which improves the sealing of the rubber valve member against the plastic valve seat. A disadvantage of such valve members is the flow of gases past the valve members can dry out the silicone film and lead to a loss of sealing effectiveness between the valve member and the valve seat. Another disadvantage is the flow of gases can introduce dust and other contaminants to the valve member and/or valve seat, which again reduces sealing effectiveness. Yet another disadvantage is the silicone film can produce superior sealing results during initial testing (e.g. for regulatory compliance) which may not be achievable during longer term use.

Object of the Invention

It is the object of the present invention to substantially overcome or at least ameliorate one or more of the above disadvantages. Summary of the Invention

Accordingly, in a first aspect, the present invention provides a valve arrangement for a suction means, the valve arrangement including:

a valve inlet;

a valve outlet;

a one-way valve between the inlet and the outlet, the one way valve including a elastomeric valve member and a valve seat, the valve member being baised towards a closed position substantially blocking gas communication between the inlet and the outlet by sealing engagement of the valve member with the valve seat, the valve member adapted for disengagement from the valve seat to allow gas to flow between the inlet and the outlet responsive to a predetermined minimum pressure diffential being generated across the valve member by energising of the suction means; and

a water source adapted to supply water to the valve member and/or the valve seat.

The valve arrangement is preferably for a toilet odour extraction device.

In a second aspect, the present invention provides an odour extraction device for a toilet pan, the odour extraction device including:

a gas inlet adapted for gas communication with an interior of the toilet pan above a water level in the pan;

a gas outlet in gas communication with the inlet and adapted for gas

communication with a sewer pipe;

a valve inlet in gas communication with the gas inlet;

a valve outlet in gas communication with the gas outlet;

a suction means adapted to, upon energisation, propel gas from the gas inlet to the gas outlet;

i

a one-way valve between the valve inlet and the valve outlet, the one way including an elastomeric valve member and a valve seat, the valve member being biased towards a closed position substantially, blocking gas communication between the valve inlet and the valve outlet by sealing engagement of the valve member with the valve seat, the pressure differential generated across the valve member by the energised suction means disengaging the valve member from the valve seat to allow the gas to flow therethrough; and

a water source adapted to supply water to the valve member and/or the valve seat. The valve seat is preferably within a water trough in fluid communication with the water source. The water trough is preferably fed water by one or more water channels in fluid communication with the water source. The water trough is preferably within a valve body.

5 The valve arrangement or odour extraction device preferably includes a manifold in fluid communication with the water source. The manifold preferably includes one or more nozzles adapted to supply water to the valve member. The one or more nozzles are preferably adapted to supply water to the side of the valve member that is adjacent to the valve seat. The manifold is preferably connected to a valve body.

io The valve body is preferably connected to a housing for the suction means. The

. water channels are preferably fed water by one or more ducts in fluid communication with the water source.

The water source is preferably in fluid communication with a cistern flushing water inlet valve, most preferably via a pipe,

i s In one form, the valve member is biased towards the closed position by gravity.

In another form, the valve member is biased towards the closed position by a spring or a magnet. In these forms, the valve member is preferably relatively rigid.

In yet another form, the valve member is biased towards the closed position by its inherent resilience. In this form, the valve member is preferably relatively flexible. ₂ o In a yet further form, the valve member is biased towards the closed position by a combination of gravity and by its inherent resilience. In this form, the valve member preferably includes a relatively rigid inner part and a relatively flexible outer part.

Brief Description of the Drawings

Preferred embodiments of the present invention will now be described, by way 25 of examples only, with reference to the accompanying drawings wherein:

Fig. 1 is a schematic cross sectional side view of an odour extraction device within a toilet cistern that includes a first embodiment of a valve arrangement for a suction means;

Fig. 2 is an exploded perspective view of the suction means and valve

30 arrangement shown in Fig. 1 ;

Fig. 3 is a cross sectional side view of the valve arrangement shown in Fig. 2;

Fig. 4 is a top view of the valve body shown in Fig. 3;

Fig. 5 is a top perspective view of the valve body shown in Fig. 4;

Fig. 6 is a cross sectional side view of the suction means and valve arrangement 35 as shown in the earlier figures, with the valve member in the closed position; Fig. 7 is a cross sectional side view of the suction means and valve arrangement shown in Fig. 6, with the valve member in the open position;

Fig. 8 is a cross sectional side view of a second embodiment of a valve arrangement;

Fig. 9 is a cross sectional side view of a third embodiment of a valve

arrangement, with the valve member in the closed position;

Fig. 10 is a cross sectional side view of the valve arrangement shown in Fig. 9, with the valve member in the open position;

Fig. 11 is an exploded perspective view of an odour extraction device that includes a fourth embodiment of a valve arrangement for a suction means.

Detailed Description of the Preferred Embodiments

Fig. 1 shows a cistern 20 comprising a hollow cistern body 20a, filled with flushing water W, and a cistern lid 20b. A flushing water inlet valve 22 is mounted within the cistern body 20a, the operation of which is triggered by a float 24. A flushing mechanism 26 is also mounted within the cistern body 20a which includes an overflow pipe 28 and flush actuation button 30. The construction and operation of these components is well known to persons skilled in the art.

An odour extraction device, indicated generally by the reference numeral 32, is also mounted within the cistern body 20a. The odour extraction device 32 includes a first embodiment of a valve arrangement, in the form of a one way valve 34, a suction means, in the form of a gas extractor fan 36, and a gas outlet pipe 38. As is also understood by persons skilled in the art, the gas extractor fan 36 draws gaseous odours from the toilet pan through the one way valve 34 and propels it to the sewer through the gas outlet pipe 38.

Fig. 1 also shows that the flushing water inlet.valve 22 includes an auxiliary outlet 38 which is connected to the one way valve 34 by a pipe 40, the function of which shall be described in more detail below.

Fig. 2 shows the one way valve 34 and the gas extractor fan 36 in more detail. More particularly, the one way valve 34 includes a valve member 42 in the form of a relatively rigid rubber valve disc and a plastic, generally cylindrical, open ended valve body 44. The valve body 44 includes three valve inlets in the form of segmented openings 44a. The gas extractor fan includes a plastic upper fan housing 46, a plastic impeller 48, and a plastic lower fan housing 50 with an inlet 52 and an outlet 54. The inlet 52 is in the form of three segmented openings 52a. The fan housing inlet 52 (i.e. the openings 52a) also functions as an outlet for the one way valve 34. The lower fan housing outlet 54 is connected to the gas outlet 38. The impeller 48 is driven by an electric motor, not shown.

As best seen in Fig. 3, the valve body 44 includes a central boss 56 which is supported by three radially extending arms 58. The valve member 42 includes a blind cylindrical recess 42a which locates over the boss 56 and allows the valve to move along the boss 56 in the directions indicated by double headed arrow 60. The valve body 44 also includes an annular water trough 62 of approximately the same diameter of the outermost peripheral edge of the valve member 42. The trough 62 acts as a valve seat for the valve member 42. The valve body 44 also includes ducts 64, through each of the arms 58, which are in fluid communication with the pipe 40. Each of the arms 58 also include an outwardly downwardly sloping channel 66 leading into the valve seat/trough 62.

Fig. 3 shows the valve member 42 is lifted to an open position in response to a pressure differential being created across the valve member 42 by the energising of the impeller 48. When the impeller 48 is not energised, there is no pressure differential created and gravity lowers the valve member 42 to a position against the valve seat/trough 60, thereby closing the valve inlet and preventing unpleasant odours from flowing from the sewer back to the toilet pan.

The operation of the odour extraction device 32 shall now be described. At the end of the flushing cycle of the cistern 20, the water inlet valve 22 is activated to open by the float 24 and refill the interior of the cistern body 20a with flushing water W. During this filling process, a small percentage of the mains pressure water being supplied to the cistern 20 passes through the auxiliary outlet 38 and into the pipe 40. This water is then forced through the ducts 64 and sprayed, at S, onto the underside of the valve member 42. This wetting of the valve member 42 maintains the sealing effectiveness between the valve member 42 and the valve seat/trough 62. The water also cleans the valve member 42 and washes away dust and other contaminants, which could also affect sealing effectiveness. Some of the water that passes through the ducts 64 also travels through the three channels 66 and pools in the valve seat/trough 62 as an annular body of water 70. This water maintains a wet surface between the valve seat/trough 62 and the valve member 42 in order to maintain sealing effectiveness. The water 70 also has a cleansing effect on the valve seat/trough 62 which again prevents a reduction of sealing

effectiveness.

Fig. 6 shows the valve member 42 in the closed position in the absence of any suction in the impeller 48. As previously mentioned, in this position, the peripheral edge of the valve member 42 sits within the water 70 contained in the valve seat/trough 62. Fig. 7 shows the valve member 42 drawn to an open position due to the suction generated by the energised impellor 48. The flow of gases through the valve 34 and the fan 36 is shown by arrows 72.

Fig. 8 shows a similar valve body 44 to that shown in the earlier Figs., but with a second embodiment of flexible rubber valve member 42'. The flexible valve member 42' is shown flexed to an open position in response to the pressure differential created by energising of the impeller 48. In the absence of the pressure differential created by the impeller 48, the inherent resilience of the material of the flexible valve member 42' returns it to a position closing the valve inlet 44a with the peripheral edge of the valve member 42' sealing against the valve seat/trough 62.

Figs. 9 and 10 show similar valve body 44 to that shown in the earlier Figs., but with a third embodiment of valve member 42". The valve member 42 has a relatively rigid inner part which functions in a similar manner to that shown in Figs. 1 to 7 and a relatively flexible outer part which functions in a similar manner to that shown in Fig. 8.

Fig. 9 shows the valve member 42" in the closed position in the absence of a sufficient pressure differential and Fig. 10 shows the valve member 42" in the open position due to the influence of a sufficient pressure differential.

Fig. 10 shows a second embodiment of a valve arrangement, in the form of a one way valve 34', and the gas extractor fan 36. The gas extractor fan 36 is the same as that described with references to Figs. 1 to 7 and like references numerals are indicated with like features.

The one way valve 34' is similar to that described with references to Figs. 1 to 7 and like references numerals are indicated with like features. However, the one way valve 34' does not include a water trough but instead a water manifold 80 that has six water misting nozzles 82. During each cistern filling cycle, water is supplied to the pipe 40 which is in turn supplied to the manifold 80. The water supplied to the manifold 80 is then sprayed or misted onto the underside of the valve member 42 via the six water misting nozzles 82. This wetting of the valve member 42 maintains the sealing effectiveness between the valve member 42 and the valve seat 62. The water also cleans the valve member 42 and washes away dust and other contaminants, which could also affect sealing effectiveness.

Although the invention has been described with reference to preferred embodiments, it will be appreciated by persons skilled in the art that the invention may be embodied in many other forms.