AU4740399A - Device for controlling a WC flush - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT r 0

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Name of Applicants: Actual Inventors: Address for Service: Invention Title: John van HALDEREN Detlev RAHL John van HALDEREN Detlev RAHL CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, QId. 4000, Australia.

DEVICE FOR CONTROLLING A WC

FLUSH

The following statement is a full description of this invention, including the best method of performing it known to us: Device for controlling a WC flush Technical field The invention relates to a device for controlling a WC flush in accordance with the preamble of claim i.

In respect of the reduction of drinking water consumption, devices have proved to be very advantageous which make it possible to meter the amount of flush water for a WC in dependence on the contents to be flushed out of the toilet bowl.

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Prior art The amount of flush water of traditional WC flushing systems is designed for the least favourable case of flushing away faecal matter in waste pipes with a very slight slope. In the majority of cases, admittedly only the disposal of urine, connected with brief cleaning of the toilet bowl, is required. In this .case, an amount of 30 to 50% of the amount of flush water required for a full flush is sufficient, such that in a full flush large amounts of valuable drinking water are wasted unnecessarily.

In the past, WC flushing systems have therefore been developed which render possible manual halting of the flush, such that the WC-user can himself decide the amount of flush water required. However, too frequent and unjustified use of this flush-halting function can lead to blockages in the sewerage system, since faecal matter cannot discharge completely from the waste pipes if the amount of flush water is insufficient.

From DE 196 38 831 Al is known a system for extracting odours from toilet bowls which, by means of a fan, sucks air from the toilet bowl via the flush water supply pipe and the overflow pipe into the cistern.

The air is conveyed via the region of the cistern not filled with water, into a pipeline which opens out into the discharge pipe of the WC. A valve ensures that the extracted air cannot penetrate into the fresh water supply line.

Attempts have been made to solve this problem in that optical sensor devices recognise the contents of the toilet bowl and then control the release of a full or partial flush. Such a device is known from DE 33 39 go•• 896 Al. Optical sensor devices of this kind, however, because of their construction, can only distinguish between liquid or solid contents of the toilet bowl; clear differentiation as to whether e.g. faeces or toilet paper are to be found in the toilet bowl is not possible. This embodiment requires, in addition to the fitting of the optical sensor unit on the toilet bowl, the attachment of a reflector on or in the base of the toilet bowl.

Presentation of the invention The technical problem underlying the invention is to make available a device, which, with low outlay, can quickly and precisely identify the contents of a toilet bowl and correspondingly supplies to the toilet bowl the necessary amount for flushing.

This problem is solved through a device with the features in the characterising part of claim 1.

Underlying the invention is the recognition that an analysis of the gases to be found in the toilet bowl quickly and easily renders possible clear identification of the type of contents of the toilet bowl. With the gas sensor according to the invention, the gases typical of human faeces can be recognised.

For this purpose a gas sensor can be used which is sensitive to methane gas, which is typically present in human faeces, and simultaneously insensitive to the ammonia gas typical of urine. Gas sensors of this type are commercially available. The signals from the gas I sensor are passed to the control unit which then meters the amount of flush water via the valve which can be arranged in the flush water supply pipe. This valve is preferably a magnetic valve which can be triggered electronically.

The flush can be initiated either automatically or by hand. Regulated via a control unit, an adequate amount of water for flushing is supplied corresponding to the recognised contents of the toilet bowl. In this way it is ensured that, firstly, a sufficiently large amount of water is made available for flushing so that the contents of the toilet bowl are flushed out of- the bowl and can be transported through the sewerage system without forming blockages, and, secondly, unnecessarily high water consumption is avoided.

Further preferred developments of the invention are characterised by the subordinate claims.

With the further preferred development of the invention according to claim 2, both the fan unit can be controlled according to requirement and a flush can be automatically initiated. The flush is preferably triggered after a defined time delay in order to avoid annoyance for the user from splashed water.

According to claims 3 and 4, an extraction pipe is provided on or in the flush water supply pipe and is preferably equipped with a fan unit and the gas sensor.

Through the use of the extraction pipe, the gas sensor can be arranged externally of the flush water supply pipe, by which means the gas sensor is protected from the flush water and at the same time does not prevent the flow of flush water. The use of the fan unit guarantees quick and purposeful conveying of the gases ~from the toilet bowl to the gas sensok.

eo e According to a further embodiment of the present invention, the flush water supply pipe is used to extract the gases located in the toilet bowl, and the fan unit, the gas sensor and the control unit are "accommodated in the cistern. In accommodating, according to the invention, the components of the control system for the WC flush in the cistern, it is not necessary to undertake any modifications to the flush water supply pipe. The components for controlling the WC flush are thus also removed from the user's field of vision, where they can possibly be felt to be obtrusive when attached to the flush water supply pipe. When the components for controlling the WC flush are disposed in the cistern, the gases extracted from the toilet bowl are not released into the surrounding space where they can lead to increased odour annoyance, but are released to the cistern.

In the cistern, the gases from the toilet bowl are sucked up by the overflow pipe which is connected to the fresh water supply pipe and serves, in the case of unwanted continuous water supply in the cistern, to divert the excess water into a discharge pipe, in order to prevent damage from water. An overflow pipe of this kind is present as standard in all conventional cisterns.

According to the invention, a moulding is provided which can be pushed into or onto the overflow pipe.

The moulding has substantially the shape of a T-piece, one of the branches opening out in an angle below the water level of the filled cistern, whilst the other end of the moulding projects into the space above the water level. In this way it is possible to prevent water, o. verflowing into the overflow pipe, from causing a short circuit in the electrical components of the *control system for the WC flush. What is guaranteed at the same time is that, in the case of faulty continuous supply of fresh water into the cistern, the excess water is able to flow away reliably through the overflow pipe. Since the outflow of the branch serving the outflow of the water extends below the surface of the water in the filled cistern, what is avoided is e that air is sucked up by mistake by the fan unit from the cistern and is led to the gas sensor, which would make it impossible to identify the contents of the toilet bowl.

Preferably, the moulding is so designed that the gas sensor and the fan unit may be easily fastened to the moulding. The control unit can alternatively also be attached to the moulding, or be fastened inside the cistern.

According to a further embodiment of the present invention, the end of the moulding, to which the gas sensor and the fan unit may be attached, can be connected with an outgoing air pipe, via which complete 6 odour extraction of the gases from the toilet bowl can come about through the overflow pipe. The outgoing air pipe, which is directly connected to the overflow pipe via the moulding, leads the extracted gases out of the space in which the WC is located. In this way the device for controlling the WC bowl according to requirements can be simultaneously combined with an odour extraction system, such that the moulding fulfils a double function.

The arrangement in the cistern of the components for controlling the toilet bowl, according to the invention, is particularly suitable for retrofitting S. traditional WC systems. For assembly, only the moulding has to be pushed onto the overflow pipe, and energy supply of the electrical components has to be ensured. Use of the invention is thus possible both with concealed cisterns and surface cisterns of every kind.

Brief description of the drawings e* The invention is described below purely by way of example, with the aid of the enclosed drawings. These show: Fig. 1 a schematic representation of the device for recognising the contents of a toilet bowl and for automatically metering the amount of flush water for a WC; Fig. 2 a schematic representation of a partially broken-open cistern with moulding according to the invention; and 7 Fig. 3 an enlarged view of the moulding shown in Fig. 2.

Description of embodiments of the invention A device according to the invention for recognising the contents of a toilet bowl 14 and for automatically metering the amount of flush water is represented schematically in Fig. 1. A fan unit 20, triggered via a control unit 24, conveys gases from the toilet bowl 14 to a gas sensor 22 via an extraction pipe 18. The extraction pipe 18 is here attached to the flush water :supply pipe 10 or can run partially through the flush .water supply pipe 10. The gas sensor 22 is so designed that it can identify gases typical of human faeces and can emit corresponding electronic signals. The data detected by the gas sensor 22 in respect of the contents of the toilet bowl 14 are then passed on to the control unit 24, which thereupon passes the optimal amount of flush water for the flushing process from the cistern 12 via valve 16 in the flush water supply pipe 10 into the toilet bowl 14.

An additional sensor 26, which is attached in or behind the wall, can supply the control unit 24 with data about whether the toilet bowl 14 is in use and at what point in time the WC is released again by the user.

This renders possible, firstly, the requirement-related use of the fan unit 20; secondly, a flush appropriate for requirements can be automatically initiated by means of the data from the additional sensor 26, as soon as the user has stood up from the toilet.

By preference, the flush appropriate for requirements is only initiated by the control unit 24 with a defined delay, such that possible annoyance for the user from splashed water is avoided.

Moreover, in Fig. 1 is represented by reference numeral 28 a device for damping the water hammer when the valve 16 is closed abruptly.

All the components, represented in Fig. i, of the device for recognising the contents of a toilet bowl and for automatically metering the amount of flush water are characterised by the fact that they can be easily integrated into traditional WC systems and thus retrofitting of a WC with an intelligent flushing oo system is rendered possible.

In Fig. 2, which shows a further embodiment of the invention, a cistern 12 for a toilet bowl is represented schematically. A flush water supply pipe branches away from the cistern 12 and leads flush water into a toilet bowl 14 during flushing. A suction bell 32 is disposed in the cistern 12 and shuts off the flush water supply pipe 10 as long as no flush is initiated. Furthermore, there is provided in the cistern 12 an overflow pipe 34, via which water can be led through the flush water supply pipe 10-into the discharge pipe, if the water level exceeds a critical value as a result of a malfunction of the water supply.

Pushed onto the overflow pipe 34 is a moulding 36 which is shaped like a T. One end 42 of the moulding 36 is connected with the overflow pipe 34, a further end 38 is configured as an angle such that the end 38 below the water level 44 opens into the water located in the filled cistern. A further end 40 of the moulding 36 extends away from the water level 44 in the cistern 12 into the region of the cistern 12 filled with air.

9 In the enlarged view of Fig. 3 it can be seen that a fan unit 20 is pushed onto end 40 of the moulding 36.

Moreover, a gas sensor 22 is disposed in a side wall of the moulding 36. According to a further embodiment of the present invention, the fan unit 20 can be directly connected, at its end remote from the moulding 36, with an outgoing air pipe (not represented, which leads out of the cistern 12 and the space in which the WC is installed.

If, for example, the signal is emitted, via the sensor 26, that the WC is in use, the control unit 24 can set [.the fan unit 20 in motion. By this means, air is sucked out of the toilet bowl via the flush water .o supply pipe 10 and the overflow pipe 34 and led through the moulding 36. The gases sucked out of the toilet bowl are led past the odour sensor 22 which protrudes into the moulding 36. The data detected by the gas sensor 22 in respect of the contents of the toilet bowl are then passed on to the control unit which thereupon supplies to the toilet bowl an optimal amount of flush water for the flushing process from the cistern 12 via the flush water supply pipe As shown in Fig. 2, end 38 of the moulding 36 extends so far under the water level 44 of the filled cistern 12 that it is ensured that no surrounding air from the cistern can up sucked by the fan unit 20 via the aperture of end 38 of the moulding 36. At the same time, the moulding 36 is so designed that, if the water level 44 in the cistern 12 is too high, the water can flow over the end 38 to the end 42 opening into the overflow pipe 34. If the water level is too high by mistake, water damage as a result of the cistern overflowing can be avoided, whilst simultaneously the gas sensor 22 and the fan unit 20 are saved from coming into contact with the f lush water, which could lead to a short circuit.

Claims (11)

1. Device for controlling a WC flush, having a sensor device for recognising the type of contents of the toilet bowl and for automatically metering the necessary amount of flush water in dependence on the contents of the bowl, characterised in that, as the sensor device at least one gas sensor (22) is provided which recognises gases typical of faeces, and e.a control device (24) which processes the signals of oooo the gas sensor (22) and a valve (16) in such a way that an amount of flush water optimised according to the type of contents of the toilet bowl (14) is supplied to the toilet bowl (14)

2. Device according to claim 1, characterised in that an additional sensor (26) is present which establishes 0: whether the WC is in use and at what point in time the 0.00 a* WC is released by the user, and which passes corresponding signals on to the control unit (24)

3. Device according to one of claims i or 2, characterised in that that an extraction pipe (18) is disposed on and/or in a flush water supply pipe the at least one gas sensor (22) being disposed on or in the extraction pipe (18)

4. Device according to one of claims 1 to 3, characterised in that there is disposed on the extraction pipe (18) at least one fan unit (20) which sucks air out of the toilet bowl (14) via the extraction pipe (18) and/or the flush water supply pipe and supplies it to the gas sensor (22) Device according to one of the preceding claims, characterised in that the extraction pipe (18) is configured as a prefabricated pipe piece fitted with fan unit gas sensor control unit (24) and valve which pipe piece may be integrated into the flush water supply pipe (10) to retrofit commercially available WC systems.

6. Device according to one of claims 1 or 2, characterised in that the gases from the toilet bowel are supplied (22) via the flush water supply pipe and an overflow pipe (34) of a cistern (24) to the gas sensor (22) which is accommodated in the cistern (12) •gig o o DiDO

7. Device according to claim 6, characterised in that a moulding (36) is present which may be placed on the overflow pipe and to which the gas sensor (22) and the fan unit (20) for sucking in the gases are attached. o e•

8. Device according to one of claims 6 or 7, characterised in that there is provided on the moulding (36) a branch, the end (38) of which opens out below the water level (44) of the filled cistern (12) into the flush water.

9. Device according to one of claims 6 to 8, characterised in that the gas sensor (22) and the fan unit (20) are so arranged on the moulding (36) that, when the water level in the cistern (12) is too high, excess water can flow through the end (38) of the moulding (36) into the overflow pipe without coming into contact with the gas sensor (22) or the fan unit 13 Device according to one of claims 6 to 9, characterised in that the control unit is housed in the cistern (12).

11. Device according to one of claims 6 to characterised in that there is directly connected with the moulding (36) an outgoing air pipe which leads the gases extracted from the toilet bowl out of the area in which the WC is located.

12. Device according to one of the preceding claims, characterised in that the control unit (24) is so designed that the fan unit (20) may be controlled in dependence on the signals from the additional sensor and the valve (16) opens automatically after the release of the toilet seat

13. Device for controlling a WC flush substantially as *:'herein described with reference to the accompanying drawings. DATED this 6 th day of September 1999 John van HALDEREN Detlev RAHL By their Patent Attorneys CULLEN CO.