AU600164B2 - Electronic flushing system - Google Patents

Description

COMMONWEALTH OF AUSTRALI6 0 |4 FORM PATENTS ACT 1952 COMPLETE S P E C I F I CATION FOR OFFICE USE: Class Int.Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: This document coitalma tbe anuaiments made udM S*wtotn 4.

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Priority: SRelated Art: oo.9 [Name of Applicant: Address of Applicant: JAMES HARDIE BUILDING PRODUCTS PTY. LIMITED 12-16 Blaxland Road, Campbelltown, New South Wales 2560, Australia o a c Actual Inventor: Neil Ralph Musgrovo Address for Service: SHELSTON WATERS, 55 Clarence Street, Sydney SComplete Specification for the Invention entitled: 0 "ELECTRONIC FLUSHING SYSTEM" The following statement is a full description of this invention, including the best method of performing it known to us:- 1 Complete of PI 4190 dated 7th September, 1987 .rp,-l i jFRC P The present invention relates to a flushing system for urinals, toilet pans and the like and in particular to automated or "flush-on-demand" systems.

A variety of known flushing systems each with inherent problems and advantages are presently in use.

The most common flushing systems use a pull-chain or press-button operated cistern and these are satisfactory in private homes but have hygiene problems when used in "olo commercial or public facilities due to hand contact with ,ol0 the user. Manual flush valves wherein the water supply is connected directed to the urinal have a similar hygiene 0°0 problem and also need header tanks to provide the "air gap" required by health authorities to isolate the water supply from the urinal or the like.

In order to overcome the abovementioned hygiene °'Vx problems in communal and public toilet facilities a number o0°, 0 of different forms of "automatic" flushing systems have been devised. The most commonly used form provides a cistern which slowly fills and then flushes on a cyclic basis. The flush usually occurs every 5 to 6 minutes, whether the urinal is in use or not and thus results in a large wastage of water. The operation of such systems is also effected by flush pipe and spreader arrangements, and hence they are problematic ii, operation.

In an attempt to reduce this water wastage "flush on demand" systems have been devised which are essentially modifications of the "automatic" systems with their operation being controlled by triggering of a sensing 2 device. The sensing device is typically an electronic or pneumatic device connected to the compartment door so that automatic flushing only commences when the door is opened. Such systems suffer from the same problems as the normal automatic systems.

A further modification of such automatic systems places a high pressure solenoid valve on the supply side of the automatic cistern to control the flow of water thereto and thus the flushing cycle. This disrupts the normal flush cycle of the automatic cistern thereby increasing the likelihood of operational problems. The high pressure solenoid valves also have a ter.dency to become blocked by impurities in the supply water. High pressure solenoid valves have also been used to control direct flushing from the water supply but again suffer from the need for a separate header tank and problematic °operation of the solenoid valves.

The present invention seeks to overcoime or at least ameliorate the abovementioned problems and disadvantages 1, 20 of known flushing systems.

According to one aspect the invention provides apparatus for flushing urinals, toilet pans or the like including: o0o aa sensing means; a cistern having an outlet and an inlet for flushing water; a controllable valve on said outlet for controlling the release of flushing water from said cistern; said valve being responsive to said sensing means to 3- IA3- 0j open said outlet for a first predetermined period following which said valve is closed, and to open said outlet following a second predetermined time period, said valve remaining open for a third predetermined time period.

Preferably, said valve is controlled by an electric solenoid responsive to an electric signal provided by said sensing means. For preference, said sensing means will detect the presence of a person or persons in the vicinity of the urinal, toilet pan or the like and will open said valve in response to such a presence being detected.

A preferred embodiment of the invention will now be described, by of example only, with reference to the S accompanying drawings in which:- Figure 1 shows a schematic block circuit diagram of the apparatus according to the invention, and o Figure 2 shows a sectional front elevation view of the S flushing cistern according to the invention.

Referring to Figure i, the basic components of the control system for the flushing apparatus are shown. The sensor device 5 in this embodiment comprises a passive infrared sensor though any suitable form of sensing device may be used. The sensor is preferably mounted in the ceiling directly in front of the urinal and the beam width selected to reduce the chance of 4, passers-by triggering the sensor. Varying beam widths may be used to suit different length urinal installations.

The control unit 6 receives signals from the sensor unit and in response to those signals provides power to the cistern solenoid 7 to cause opening of the cistern flushing valve 4 for a pre6etermined period of time.

4 The unit is preferably mounted in a totally sealed housing which may be surface mounted in either an exposed or concealed position. The unit is for preference, powered from the 240V mains supply and is provided with power lead adapted to fit a general purpose power outlet.

The control signals to and from the unit are preferably low voltage D.C. to provide electrical safety. A plug-in D.C. back-up unit 9 may also be fitted to the control unit if required.

o a <o 10 The operation and construction of the flushing 3 "cistern 10 is detailed in Figure 2. The cistern comprises a tank 11 with a bottom opening outlet 12. The main water 0Q QQ supply is connected to the tank from an inlet pipe 13 on one side of the tank and controlled by valve 8 operated by Sa ball float 14. Flushing of the cistern by release of 0'J water in the tank through outlet 12 is controlled by an overflow tube 15 having a radially extending circumferential flange 16 at its base which is fixed so as to effectively close outlet 12 when resting on the 4 20 periphery 17 thereof. This arrangement is conventional apart from the outlet valve not being provided with the normal float so that in this case the valve will close immediately any lifting force is removed from the tube The flushing valve 4 is opened by a lifting lever 18 coupled at one end by a linkage 19 to a lifting collar slidably engaging said tube 15 and adapted to lift said tube by bearing against an enlarged portion 21 thereof at its upper end. The lever 18 is fulcrumed at the wall 22 5 of the cistern tank and connected at its other end to a low voltage D.C. solenoid 7.

The minimum air gap required by health regulations is maintained in the conventional manner, that is, by setting the central overflov tube 15 height lower than the inlet valve discharge port 13.

The D.C. solenoid 7 is preferably mounted to the outside of the tank to isolate the electrical circuitry as much as possible from any moisture which may cause operational problems. Although shown mounted on the side of the cistern in this embodiment it may be located in any suitable position.

In operation the passive infrared sensor 5 will detect the presence of a user within its beam width and will send a signal to the control unit 6. A predetermined time, in this example 5 minutes, after the user has entered the beam, the control unit will activate the solenoid 7 raising the valve 4 and opening outlet 12. The valve will be held open for a different predetermined 0 period and then allowed to close by deactivating the solenoid 7. The urinal will preferably continue to be flushed at 5 minute intervals so long as users are present. If the sensor is not triggered for a 5 minute o period the flushing sequence will cease. The actual flushing time, the second predetermined period, is variable and may be selected to give the correct flush volume required by the type of urinal fixture and to comply with authority requirements.

6 The system may also be provided with several additional features. A cleansing flush may be given by the system at a longer predetermined period, for example every 4 hours, when the urinal is not in use, that is at night and weekends. It is also desirable that the D.C.

current to the solenoid be reversed in polarity at the end of each flush cycle to negate the effects of residental magnetism in the solenoid core and thus prevents the solenoid eventually becoming a permanent magnet.

It will be appreciated by those skilled in the art that the valve system according to the invention may be used with conventional cisterns and is ideally suited to retro-fitting to presently installed systems. Further, although the embodiments relate to urinals it will be appreciated that the invention is applicable to any form of flushing installation. It is also apparent that any form of submersible electrically operated valve may be used and that the particular valve arrangement used in the "620 embodiment is merely an example.

The system according the invention provides many Sadvantages over tie prior art, these include reduction of water usage to a minimum, positive flush action, accurate control of flush volume, it is not actuated by passer'sby and is not effected by the flush pipe configuration.

-7 ~hLiU It will be further appreciated by those skilled in the art that other embodiments of the invention are possible without departing from the spirit or scope of the invention described.

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Claims (7)

1. 3. Apparatus according to claims 1 or 2 wherein said sensing means detects the presence of a person or persons in the vicinity of the urinal, toilet pan or the like and will open said valve in response to such a presence being detected. J 4. Apparatus according to claims i, 2 or 3 wherein said o sensing means is a passive infrared sensor. Apparatus according to anyone of the preceding claims i wherein said valve is opened and closed at regular intervals 4 t in response to said sensing means, said opening and closing continuing for a fourth predetermined time period.
2. 6. Apparatus according to any one of the preceding claims including means for operating said valve at a fifth predetermined time interval. 9
3. 7. Apparatus according to any one of the preceding claims including means for selectively varying said predetermined time periods.
4. 8. Apparatus according to any one of claims 2 to 7 wherein said solenoid is operable by a D.C. current to open said valve and including means for reversing the polarity of the D.C. current supplied to said solenoid following each operation thereof.
5. 9. Apparatus according to any one of the preceding claims wherein said valve comprises a tube having a radially extending circumferential flange at one end adapted to close said outlet when resting on the periphery thereof, said tube °oo o being raised from said outlet in response to said sensing means so as to open said valve.
6. 10. Apparatus according to claim 9 including a lifting lever coupled at one end by a linkage to a lifting collar slidably engaging said tube and adapted to lift said tube by bearing against an enlarged portion thereof at its other end.
7. 11. Apparatus for flushing urinals, toilet pans or the like substantially as hereinbefore described with reference to the accompanying drawings. DATED this 8th day of MAY, 1990 JAMES HARDIE BUILDING PRODUCTS PTY. LIMITED Attorney: PETER HEATHCOTE Fellow Institute of Patent Attorneys of Australia of SHELSTON WATERS 10 L_ i. i I