SYSTEM FOR CONTROLLING FLUSHING OF A CISTERN

Abstract

A control system for a cistern, the control system comprising a user activated sensor (13), a controller (14), a pump (15) and a pneumatic line (16) connected to the pump (15) and adapted to be connected to the drain valve (11) of a cistern (10), wherein the user activated sensor (13) and controller (14) are adapted to interpret a plurality of signals and operate the pump (15) in a pre-defined manner associated with a detected signal, thereby enabling a plurality of flushing actions to be effected using a single user activated sensor.

Claims

1. A control system for a cistern, the control system comprising a user activated sensor, a controller, a pump and a pneumatic line connected to the pump and adapted to be connected to the drain valve of a cistern, wherein the user activated sensor and controller are adapted to interpret a plurality of signals and operate the pump in a pre defined manner associated with a detected signal, thereby enabling a plurality of flushing actions to be effected using a single user activated sensor.

2. A control system as claimed in claim 1 wherein the user activated sensor is a motion detector.

3. A control system as claimed in claim 1 wherein the user activated sensor is a pressure or touch sensor.

4. A control system as claimed in claim 1 wherein the motion detector is an infra red proximity sensor.

5. A control system as claimed in claim 1, wherein the system further comprises a pressure release valve incorporated in a pneumatic line and which is configured to close when the pump is powered and to open when the pump is not powered.

6. A control system as claimed in claim 1, further including one or more sensors for monitoring the water volume in the water filled system which is to be flushed and wherein the controller is appropriately configured to determine and effect the most economical flush of the water filled system.

7. A control system as claimed in claim 6 wherein the controller is configured to override a received flush signal if the flush signal does not demand the most economical flush.

8. A control system as claimed in claim 1, wherein the controller is adapted to cause reverse as well as forward action of the pump in response to appropriate signals.

9. A control system as claimed in claim 1, which is powered by a low voltage DC supply.

10. A control system as claimed in claim 9 wherein the power supply is a 6V battery.

11. A control system as claimed in claim 9 wherein the power supply is a 4V battery.

12. A control system as claimed in claim 1, which includes a plurality of pumps each configured to cause a specific and pre defined flushing action and wherein the controller associates each pump with a different signal received by the user activated sensor and elects an appropriate pump to operate in reaction to a detected signal.

13. A control system as claimed in claim 1, wherein the controller is configured to compensate for any variation in the power supply by adjusting the duration of a pneumatic pulse to the pump, such that, irrespective of the power of the pulse, constancy of the volume of air and consequent volume of water in a flush are maintained.

14. A control system as claimed in claim 1, wherein the user activated sensor comprises an infra red transmitter/receiver and is embodied with the controller in a PCB which also houses one or more light emitting indicators, the controller being configured to activate the or each light emitting indicator in a pre defined manner to give an indication of the current status of the system.

15. A control system as claimed in claim 14 wherein the infra red transmitter/receiver and one or more light emitting indicators are enclosed behind a multi-layer lens, each layer of the lens comprising an emulsion selected to transmit a frequency of light which corresponds to a frequency emitted by one or more of the light emitting indicators and the infra red transmitter/receiver.

16. A control system as claimed in claim 14, including two light emitting indicators and the controller being configured to display a first of the indicators during a partial flush and the second during a whole flush.

17. A control system as claimed in claim 16 wherein the light emitting indicators are blue and green LEDs.

18. A control system as claimed in claim 1, wherein the controller incorporates a timer which monitors a pre defined period since the last flush of the system generates a flush at the expiry of the pre defined period and resets after each flush of the system.

19. A lavatory cistern incorporating a control system as claimed in claim 1.

20. A lavatory cistern as claimed in claim 19 wherein the user activated sensor is associated with a mechanical pull chain or handle and wherein operation of the pull chain or handle is translated into a signal to which the user activated sensor is receptive.

Description

[0018] Some embodiments of the invention will now be further described with reference to the following figures in which:

[0019] FIG. 1 shows a first embodiment of a cistern embodying a control system in accordance with the present invention.

[0020] FIG. 2 shows second and third embodiments of a cistern embodying a control system in accordance with the present invention.

[0021] FIG. 3 illustrates schematically a printed circuit board PCB suitable for use as a controller and user activated sensor in a control system in accordance with the invention.

[0022] FIG. 1 shows a cistern composed of a reservoir of water 10 connected via conduit and a pneumatically actuated valve 11 to a toilet 12. The cistern is provided with an infrared proximity and motion sensor 13 which detects the presence of a user's waving hand (not shown) signifying a desire to flush the toilet. Upon receiving a corresponding signal from the sensor, control logic 14 supplied with a 6V battery power supply causes the pneumatically actuated valve to open, thereby causing the toilet to flush. As previously mentioned a 4V battery power supply has also been found to be effective.

[0023] Specifically, the control logic 14 outputs the power supply to a pump 15 which in turn pumps air in to flexible pneumatic lines 16 connected between the pump and the pneumatically actuated valve 11. The pneumatically actuated valve 11 is then caused to open when the static pressure in the pneumatic lines reaches a threshold. Depending on the duration of the increased pressure in the pneumatic line, partial or full flushes may be achieved.

[0024] Connected to the pneumatic lines 16 is a solenoid valve 17 which in an unpowered state allows release of pressure in the pneumatic lines. In a powered state, which occurs when the pump is powered, the solenoid valve is closed.

[0025] Also connected to the pneumatic lines 16 is a safety valve 18 which opens when the static pressure in the pneumatic lines exceeds a particular threshold (in excess of that necessary to cause the pneumatic actuator valve 11 to open).

[0026] The above embodiments use an infrared proximity and motion sensor but other modes of control are contemplated including the use of a timer and manual switching. In the present embodiment, the infrared sensor is responsive to a hand waving signal and a stationary hand signal. When a waving hand signal is detected, the controller prompts actuation of a pneumatic pulse of short duration causing a partial flush of the system. In response to a stationary hand signal, the controller prompts a pneumatic pulse of longer duration and a full flush of the system.

[0027] As previously discussed, the system may include other sensors and a suitable adaptation of the controller which enables the controller to intelligently determine whether the instructed flush is necessary or the most ecologically efficient flush given the current condition of the water in the lavatory system. The controller is thus enabled to override instructions for inappropriate flushes.

[0028] FIG. 2 shows an alternative embodiment of the invention. As can be seen from FIG. 2,

[0029] In common with FIG. 1, FIG. 2 show a cistern composed of a reservoir of water 10 connected via a conduit and a pneumatically actuated valve 211 to a toilet 212. The cistern is provided with a user activated sensor 213 which detects a user provided signal signifying a desire to flush the toilet in an elected manner (e.g. full flush or partial flush). The sensor may be a motion sensor, pressure or touch sensitive, light sensitive or sound sensitive. Upon receiving a corresponding signal from the sensor, the controller 214, powered by a battery supply with of 4 to 6V determines an appropriate flushing action and operates the appropriate one of pumps 215a and 215b, thereby causing the toilet to flush.

[0030] Specifically, the controller 214 outputs the power supply to one of the pumps 215a and 215b which in turn pumps an appropriate volume of air in to flexible pneumatic lines 216 connected between the pumps and the pneumatically actuated drain valve 211. The drain valve 211 is then caused to open when the static pressure in the pneumatic lines reaches a threshold. Duration of the increased pressure in the pneumatic line and consequent volume of air transferred differs for each pump allowing a partial or full flush as appropriate.

[0031] Connected to the pneumatic lines 216 and associated with each pump 215a, 215b is a solenoid valve 217 which in an unpowered state allows release of pressure in the pneumatic lines. In a powered state, which occurs when the associated pump is powered, the solenoid valve is closed.

[0032] The broken line illustrates an optional additional sensor and its communication with the controller. As previously discussed the optional sensor monitors water levels in the cistern and the controller may override a flushing instruction provided manually via the user activated sensor to ensure flushing is ecologically efficient.

[0033] As can be seen from the FIG. 3, a PCB includes a control chip 30 communicating with an infra red transmitter 31, infra red receiver 32, first coloured LED 33 and second coloured LED of different colour 34. The dotted line shows the position of a suitably configured lens 35 which allows transmission of infra red and lights of the frequencies emitted by the LEDs.

[0034] From reading the present disclosure, other modifications will be apparent to persons skilled in the art. Such modifications may involve other features which are already known in the design and use of pneumatic control systems and component parts thereof and which may be used instead of or in addition to features already described herein.