GB2165271A - Electrically controlled flushing system - Google Patents

Abstract

A flushing system for flushing waste water from a toilet bowl, urinal or other basin comprises a water supply (11) and a valve (12), the valve (12) being electrically operable to open for a set time under the control of a control means (13), to enable a predetermined quantity of water to pass from the supply (11) to an outlet (17) of the valve (12) to which the basin (14) to be flushed is connected. <IMAGE>

Description

SPECIFICATION Flushing system This invention relates to a flushing system of the kind for flushing waste water from a toilet bowl, urinal or other basin, herein referred to generically as "basin".

Such flushing systems usually comprise a valve which is opened to enable a predetermined quantity of water from a supply, such as a cistern or a mains water supply, to pass into the basin at a fixed rate when either manually actuated, or automatically actuated at time intervals, e.g. when a cistern has filled to a predetermined level, to flush the basin.

The problem with such systems which are not in, for example, domestic dwellings, which are manually actuated, is that they can be mis-used resulting in a considerable wastage of water due to too frequent and unnecessary flushing. In automatically actuated systems such as used in public conveniences, changes in water pressure can change the rate at which the cistern is filled throughout the day, and hence the intervals between flushing are not constant. This can again result in wastage of water where too frequent flushing occurs, or inadequately frequency flushing where the cistern is filled too slowly.

Accordingly, it is an object of the present invention to provide a new or improved flusing system which overcomes or reduces the abovementioned problem.

According to one aspect of the invention, we provide a flushing system for a basin comprising a water supply and a valve, the valve being electrically operable to open for a set time under the control of a control means, to enable a predetermined quantity of water to pass from the supply to an outlet of the valve to which the basin to be flushed is connected.

The use of an electrically operable valve enables the rate of flushing to be controlled so that too frequency manual flushing can be prevented, or accurately determined intervals between automatic flushings can be achieved.

In one arrangement, the control means may signal the valve to open to actuate a flush upon receiving a signal from a manual input, but the control means may only signal the valve to open when a selected time period has elapsed since the basin was last flushed.

For example, the control means may be arranged only to permit the basin to be flushed once in every twenty minutes or whatever time period is selected.

Alternatively or in addition, the control means may automatically signal the valve to open to actuate a flush when the control means senses a selected time interval has elapsed, since the basin was last flushed.

Preferably, the valve is solenoid operated and is normally closed when power is not present, for example by resilient means or gravity, so that the water cannot pass. Alternatively if desired, the valve may be retained open in the absence of power to the solenoid by resilient means or gravity, although the former arrangement is preferred.

The valve may comprise a diaphgram type valve, the pressure of water from the water supply normally retaining the diaphragm in a closed position until the solenoid receives said signal from the control means. If desired, means may be provided to overide the control means to facilitate cleaning of the basin for example, when more frequent flushing that that allowed by the control means may be required.

When the control means is manually operated to provide said signal to the valve, the manual input is preferably provided by a touch switch or switch actuated by interruption of a photo-electric beam, or other switch having no moving parts so that there is no temptation to mis-use the switch.

The control means may be microchip controlled, means being provided in the circuit such as capacitors to provide a time base to enable said control means to determine said selected time period or interval.

Alternatively, the circuit may be microprocessor controlled and may use other means to provide the time base, such as a quartz crystal.

The invention will now be described with the aid of the accompanying drawings, in which: Figure 1 is a diagrammatic representation of a flushing system in accordance with the invention; Figure 2 is a diagrammatic cross-section through one type of electrically operable valve which may be used with the flushing system of Fig. 1; Figure 3 is an example of a control means which may be used with the system of Fig. 1.

Referring first to Fig. 1, a flushing system 10 comprises a water supply which in this example comprises a cistern 11, an electrically operable valve 12 controlled by an electronic control means 13. Water passes from the cistern 11 when the valve 12 is opened, to a basin, which in this example comprises a toilet bowl 14. In another embodiment (not shown) in place of the cistern, the water supply may comprise a mains supply and in place of the toilet bowl 14, there may be a urinal, or any other basin it is desired to flush. Electrical power is supplied to the control means 13 and valve 12 by a lead L via a transformer TR if the control means 13 and the valve 12 requires a reduced voltage, or directly if the control means 13 and valve 12 operate at mains voltage.

The system is designed so that upon operation of the control means 13, as hereinafter described, the valve 12 opens for a set time to permit a predetermined quantity of water to pass from the cistern 11 into the bowl 14 at a predetermined rate, determined by the pipe size, pressure of water and resistance of the valve 12 and bowl 14 to water flow.

The bowl 14 is in front of a panel P whereas the cistern 11, valve 12, and control means 13 are behind and hidden by the panel P. A coaxial cable CA extends from the control means 13 to a control panel CP. In this example, the panel CP has a touch switch 50 to operate the control means 13 to actuate a flush, as hereinafter described. The control panel CP may include other operating switches, such as a light switch L and an alarm button A in suitable applications, for example if the system is installed in a prisoner's cell in a prison.

Referring now to Fig. 2, one suitable type of electrically operable valve 12 is shown which has a body 15 with an inlet 16 which, in use, is connected to the cistern 11, or other water supply, and an outlet 17 which is connected to the toilet bowl 14 or other basin to be flushed.

The valve 12 is a diaphragm type valve and has a resilient diaphragm 18 therein.

The diaphgragm has a central sealing part 19 and side parts 20, 21, the side parts 20, 21 being trapped between parts of the valve body 15 to provide a seal therebetween.

The side parts 20, 21 of the diaphragm 18 and the body 15 of the valve 12 define an annular chamber 22 which is connected to the inlet 16 so that water from the supply fills the chamber 22. It can be seen that the side 21 of the diaphragm 18 has a small opening 23 therethrough, so that a proportion of the water from the chamber 22 can pass from the chamber 22 to a further chamber 24 above the diaphragm 18.

It will be appreciated that the water in chamber 24 will exert a greater downward pressure on the diaphragm 18 than the upward pressure exerted by the water in annular chamber 22, as water in chamber 24 acts over a larger area. Accordingly, the diaphgragm 18 will be urged downwardly into contact with seats 26, 27 provided by the valve body 15, so that water cannot pass from the inlet 16 to the outlet 17.

However, there is a small passage 28 in the valve body which extends from chamber 24 to a still further chamber 30, but a valve member 31 in chamber 30 which is provided on the end of a solenoid plunger 33, closes the passage 28.

A further passage 34 in the valve body 15 opens from chamber 30 to the outlet 17, but this passage 34 is also closed by the valve member 31 in chamber 30 so that no water can flow from the chamber 24 through passage 28 into chamber 30, and then through passage 34 to the outlet 17.

The solenoid plunger 33 is normally biased into this closed position by a spring 35, although any other suitable resilient means could alternatively be provided, or in another arrangement gravity may be adequate to retain the member 31 in its downward position.

However, coils 36 of the valve 12 can be energised upon receipt of an electrical signal from the control means 13 of the system, which will move the plunger 33 and hence raise the valve member 31 against the force of the spring 35 when it is desired to open the valve, to achieve a flush.

In this event, water can flow from chamber 24 above the diaphragm 18 through passageway 28 into the chamber 30, and then into passageway 34 and hence to the outlet 17.

Thus, the pressure above the diaphragm 18 in chamber 24 will be equalised with the pressure below the diaphgram in outlet 17 which acts on the underside of the central sealing part 19 of the diaphgram.

Hence the pressure in annular chamber 22 lifts the diaphragm 18 from engagement with the seats 26 and 27 so that water can flow directly from the inlet 16 to the outlet 17.

The control means 13 may be arranged to operate as follows. When a touch switch, or other switch preferably having no movable parts, is actuated, the control means 13 may be arranged to pass an electrical signal to valve 12 unless the cistern has been flushed previously within a selected time period, for example twenty minutes.

If the touch or other switch is actuated within that time period, no signal is passed to the valve 12 which thus remains closed, This type of arrangement is particularly suited with the system shown in Fig. 1, although in an alternative arrangement, for example in flushing a urinal, the following arrangement may be adopted.

The electronic control means 13 may include a timer which automatically passes a signal to the valve 12 at selected time intervals, again for example, every twenty minutes, so that a flush automatically occurs once in each twenty minutes.

In both cases, if desired, an overriding means may be provided which is preferably not normally accessible to a user of the flushing system so that when more frequent flushing than that normally allowed by the control means 13 is required, can be achieved during cleaning of the basin to be flushed, for example.

One typical electronic control means for use with the system of Fig. 1 will now be described with reference to Fig. 3, although it will be appreciated that many alternative electronic control arrangements are possible.

The control means 13 shown is intended for manual operation upon a user touching the touch switch 50 which is connected via a capacitor C1 to a base terminal 51 of a first transistor T1. Thus, the base terminal 51 of the transistor T1 is biased sufficiently for cur rent to pass from the collector terminal 54 to the emitter terminal 55.

The collector terminal 54 is connected to the central core of the coaxial cable CA whilst outer sheath 57 of the cable CA is connected to the emitter terminal 55. In place of a touch switch 50 as described, if desired a push or pull switch could be used, or any other type of switch which permits completion of a circuit between the central core 56 and outer sheath 57 of the cable. Of course any other cable or lead having two conductors could alternatively be employed. A touch switch is however preferred as there are no moving parts to abuse.

The control means 13 includes five sections as follows: 1. A power supply section which includes resistor R1, diodes D1, regulator, and a pair of capacitors C2, C3 to smooth the power supply to the remainder of the circuit from power supply S, for example, provided from a transformer TR. The circuit is intended to operate on 24V d.c. although could be adapted to operate on other voltages if required.

2. An output section including a relay RE comprising a coil CO and switched contacts B1, B2, a further capacitor C4, and a pair of diodes D2, D3. One of the switched contacts B1 is connected via a line 57 and external wiring E to the solenoid coils 36 of the solenoid valve 12 described hereinbefore, or other valve.

3. A first timer section including resistor R2, variable resistor VR and capacitor C5.

4. A second timer section including resistors R3, and capacitor C6.

5. A feedback section including capacitor, transistor T2, resistors R4, R5.

The five circuit sections are all connected to a central circuit 58 conveniently provided as a microchip such as an integrated circuit or microprocessor.

The purpose of the output section of the circuit is to provide power to the solenoid coils 36, the capacitor C4 suppressing noise generated by contacts B1, B2, whilst the diode D2 suppresses back E.M.F. In the coils of the relay RE. Diode D3 prevents current passing back along the line 60 from the output section to the microchip 58.

Power is supplied to the line 60 to actuate the relay RE from the microchip 58 for a set time, determined by the value of capacitor C5 and the setting of the variable resistor VR in the first timer section. For example, power may be supplied for up to six seconds. Thus the solenoid 12 will be actuated for this time period so that a flush will continue for this time.

The second timer section of the control means 13 ensures that a signal will not be passed to the output section to actuate the solenoid 12 even when the switch 50 is actuated, if a predetermined time interval determined by the valve of resistor R3 and capacitor C6, has not elapsed since the circuit was last actuated. For example, the second timer section may not allow the bowl 14 to be flushed within four minutes of the last flush, or longer if required, for example up to twenty minutes.

The feedback section of the circuit inhibits timer 1 when the timer 2 is active.

As described above, many modifications to this circuit are possible. If desired, in place of the control means 13 shown in Fig. 3, a suitable control means may be used so that in place of a flush being achieved by operation of the touch switch 50, flushing occurs automatically, for example once every twenty minutes. In this event, the touch switch 50 and associated transistor T1 and capacitor C1 may be replaced by a further timer section.

In a prison for example, or other location where a plurality of flushing systems as hereinbefore described are installed, if desired each of the control means 13 of the systems may be interconnected via a master control.

The master control may have means to disable the control circuit 13 selectively so that, for example, each of the bowls may not be flushed at night or when otherwise required.

Further, the master control may cause each of the bowls 14 to be flushed one or more times during a iong time period, for example twenty four hours, should the respective touch switches 50 not have been activated to flush the bowls during that time.

As described, as all of the working parts of the system shown in Fig. 1, including the solenoid valve 12 of Fig. 2 and the control means 13 of Fig. 3, are behind panel P, a prisoner for example in a prison installation cannot interfere with the working of the flushing system. The provision of the second timer section in the control circuit considerably reduces the ability of a user to flush the bowl too frequently and thus risk flooding as well as wasting considerable quantities of water.

As described, a single cistern 11 is provided for each installation. If required a single cistern may be used to supply water to a plurality of flushing systems as hereinbefore described. In this event the cistern would need to be of large capacity, depending upon the number of systems to which the cistern 11 supplies water.

The features disclosed in the foregoing description, or the accompanying drawing, expressed in their specific form or in terms of a means for performing the disciosed function, or a method or process for attaining the disclosed result, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (12)

1. A flushing system for a basin comprising a water supply and a valve, the valve be ing electrically operable to open for a set time under the control of a control means, to enable a predetermined quantity of water to pass from the supply to an outlet of the valve to which the basin to be flushed is connected.

2. A system according to claim 1 wherein the control means signals the valve to open to actuate a flush upon receiving a signal from a manual input.

3. A system according to claim 2 wherein the manual input is provided by a switch having no moving parts.

4. A system according to claim 2 or claim 3 wherein the control means only signals the valve to open when a selected time period has elapsed since the basin was last flushed.

5. A system according to any one of claims 1 to 4 wherein the control means automatically signals the valve to open to actuate a flush when the control means senses a selected time interval has elapsed, since the basin was last flushed.

6. A system according to claim 4 or claim 5 wherein the control means is microchip controlled, means being provided in the circuit to provide a time base to enable said control means to determine said selected time period or interval.

7. A system according to any one of the preceding claims wherein the valve is solenoid operated.

8. A system according to claim 7 wherein the valve is normally closed when power is not present.

9. A system according to claim 7 or claim 8 wherein the valve comprises a diaphragm type valve, the pressure of water from the water supply normally retaining the diaphragm in a closed position until the solenoid receives said signal from the control means.

10. A system according to any one of claims 4 to 9 where appendant to claim 4 or claim 5 wherein means are provided to override the control means to facilitate cleaning of the basin.

11. A flushing system substantially as herein before described with reference to and as shown in the accompanying drawings.

12. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.