GB2197669A - Automatic flushing control unit - Google Patents

Abstract

A control unit suitable for regulating the automatic flushing of a urinal, includes an infra-red detector linked to a control valve via electrical control circuitry. The detector, circuitry and valve are contained in a housing which is installed adjacent the urinal so that the presence of a user of the urinal is detected by the infra-red detector which in turn causes the valve to be opened. Such a unit reduces the wastage of water caused by the urinal being flushed when it is not in use.

Description

AUTOMATIC FLUSHING CONTROL UNIT Field of the Invention This invention relates to a control unit for controlling the automatic flushing of a water cistern.

One form of automatic flushing system commonly used for the urinals provided in mew 5 toilets comprises a cistern which is filled slowly with water and then, when the water reaches a predetermined level, the water Is discharged into the urinal so as to flush it. Such a system provides for round-theclock flushing of the urinal, the normal time between flushes being about 20 minutes.

The disadvantage of such a system is that it is wasteful in that flushing is effected whether or not the toilets are in use and proposals have accordingly been made for limiting flushing to only various times when the toilets are actually being used.

One such arrangement is described in European patent specification number 56 309 in which a solenoid operated flush control valve is actuated by an electrical signal generated by an entrance detection means such as a switch triggered by opening of the lavatory door or by the use of a pressure pad at the entrance to the lavatory.

Such an arrangement reduces the overall water consumption but It does involve electrical installation work at a number of different locations thus complicating installation of the control arrangement and facilitating disruption of the system by vandals.

It is accordingly an object of the present invention to provide a control unit for the purposes outlined above the installation of which is simplified as compared to previous proposals.

Summary of the Invention According to the invention there is provided a control unit for controlling the automatic flushing of a water cistern, said unit comprising a housing for mounting adjacent a urinal, said housing containing: a) an electrically operable control valve for inclusion in the supply line of said cistern, b) an electrical control circuit for controlling operation of the control valve. and c) an infra-red sensor for sensing the presence of a user of the urinal and generating a signal to initiate operation of the control valve.

The electrical control circuit preferably includes first and second timers, the first timer being arranged to receive the signal generated by the infra-red sensor and then, after a predetermined time delay, to transmit a signal to the second timer which is arranged to effect operation of the control valve to move it into an open position and maintain it there for a time sufficient to allow flushing of the cistern.

In a typical installation, the time delay between receipt of a signal from the infra-red sensor by the first timer and transmission of a signal from the first timer to the second timer may be 20 minutes with the time for which the control valve is held open being adjustable within the range of from say 1 minute to 3 minutes.

An important advantage of the arrangement described above is that, not only is a significant saving in water consumption obtained but it is ensured that the urinal is flushed after each use thereof.

The electrically operable control valve is preferably a solenoidoperated valve which is mounted in the lower portion of the housing, the control valve being contained within a water supply line having aligned inlet and exit fittings, one on each side of the housing. In this way, not only is installation of the control unit faciIitated, but the overall appearance of the installed unit is improved.

The first timer may include a facility whereby, on operation of the control valve a signal from the second timer initiates operation of an extended delay, for example, either a 12 hour delay or a 24 hour delay, whereby on completion of the extended delay, a signal is then transmitted from the first timer to the second timer to effect operation of the control valve and hence flushing of the cistern.

This extended delay facility will ensure that, if the urinal is located in, for example, an office block to which access Is only obtained on weekdays, flushing of the urinal is effected during weekends and holiday periods.

In order to facilitate testing of the controlled unit, a test button facility is preferably provided whereby, on pressing of the button, a signal is transmitted directly to the second timer to operate the solenoid. The second timer may be linked to an electro-magnetic counter which operates to record the number of times that the solenoid is energised, this reading then giving an indication of the overall water consumption.

The housing is conveniently formed as a plastics moulding having mounting facilities facilitating installation thereof, the housing having a lid which is held in position by screwthreaded fasteners - some of which may include a locking facility thereby preventing access being obtained to the interior of the housing by unauthorised persons.

Brief Description of the Drawings Figure 1 of the drawing is a block circuit diagram of the control unit.

Figure 2 is a block circuit diagram of a modified version of the invention.

Description of the Preferred Embodiment The control unit comprises a moulded plastics housing in the form of a generally rectangular housing having a lid which is secured in position by four screw-threaded fasteners, one at each corner of the lid. Two of the fasteners incorporate locking devices so that only authorised users can gain access to the interior of the housing. The housing is intended to be mounted on the wall of a toilet adjacent a urinal and the lid of the housing carries an infra-red sensor which is positioned within the housing and is directed so as to sense the presence of a person using the urinal.

A water supply line incorporating a solenoid-operated valve is contained within the lower portion of the housing, the infra-red sensor being positioned in the upper part of the housing. The water supply line terminates in conventional fitments, located one at each side of the housing, the inlet and outlet unions being arranged in alignment so as to facilitate installation of the control unit in the water supply line leading to a water cistern for effecting flushing of the urinal.

Within the upper part of the housing there is a control circuit which includes a first timer T1 and a second timer T2. When the infra-red sensor IR senses the presence of a user of the urinal it transmits a signal to the first timer T1. The circuitry of the first timer T1 is that, after a preset time delay, in this case 20 minutes, the first timer T1 will then transmit a signal to the second timer T2. The second timer T2 is arranged to control the operation of the solenoid S of the water control valve to hold the solenoid in its energised condition for an adjustable period of say from 1 minute to 3 minutes, this period being sufficient to allow filling of the water cistern and flushing of the urinal.When the second timer T2 is actuated It causes the operation of an electro-magnetic counter C which is operated to record the number of times for which the solenoid is energised and thus an indication is obtained of the total water consumption of the system.

The circuitry of the first timer T1 is such that, after it has received its input signal from the infra-red sensor IR, it will go through its time delay period and transmit a signal to the second timer T2 regardless of the number of times that further signals are then generated by the infra-red sensor IR. There is thus a controlled delay period, during which no further cycle of operations is initiated, between a user.

of the urinal entering the vicinity of the urinal and the solenoid being energised to effect flushing of the water cistern.

This ensures that, not only will the urinal not be flushed more than once each 20 minutes but also that the urinal will be flushed after each use thereof.

The second timer T2 is arranged, each time that it energises the solenoid S, to transmit a signal to the first timer T1 on receipt of which the first timer T1 will initiate an extended delay period of either 12 hours or 24 hours. This extended delay period will continue to run, assuming that no further signal is generated by the infra-red sensor IR, to transmit a signal on completion of the extended period from the first timer T1 to the second timer T2 which then operates in the normal way to energise the solenoid S and operate the counter C.

The control circuit includes a facility whereby, on pressing a button B, a signal is transmitted directly to the second timer T2 to energise the solenoid S thereby to open the control valve, this button being used during installation for adjustment purposes and, subsequently, for test purposes.

The modified version shown in Figure 2 has a second button A which is used in conjunction with button B. Pressing button A after the button B has been pressed, and before the timer T2 completes its cycle of operation, causes the timer T2 to be re- set and to de-energise the solenoid S.

Button A can thus be used to close the control valve before the timer T2 completes its cycle. This facility enables the water cistern to be initially filled to the correct level when the system is first installed. The button A also enables an installation engineer to test the system without having to wait for the timer T2 to complete its cycle of operation.

The moulded plastics housing of the control unit may, instead of being generally rectangular in vertical cross-section, have a front face which slopes in a way which allows the infra-red detector to be inclined downwardly and mounted flush with the front face. this enables the infra-red detector to be more easily mounted in the casing.

The interior of the casing may be split into two separate com partments. One of these compartments contains the unit ' s elect rical control circuitry, whilst the other contains the water supply line. This arrangement minimises the risk of damage to the electrical components in the event of the water supply line leaking.

Claims (9)

1. A control unit for controlling the automatic flushing of a water cistern, said unit comprising a housing for mounting adjacent a urinal, said housing containing: a) an electrically operable control valve for inclusion in the supply line of said cistern, b) an electrical control circuit for controlling operation of the control valve, and c) an infra-red sensor for sensing the presence of a user of the urinal and generating a signal to initiate operation of the control valve.

2. A control unit according to Claim 1 in which the electrical control circuit includes first and second timers, the first timer being arranged to receive the signal generated by the infra-red sensor and then, after a predetermined time delay, to transmit a signal to the second timer which is arranged to effect operation of the control valve to move it into an open position and maintain it there for a time sufficient to allow flushing of the cistern.

3. A control unit according to either of the preceding claims, in which the electrically operable control valve is a solenoid-operated valve which is mounted in the lower portion of the housing, the control valve being contained within a water supply line having aligned inlet and exit fittings, one on each side of the housing.

4. A control unit according to Claim 2 or Claim 3, in which the first timer includes a facility whereby an operation of the control valve a signal from the second timer initiates operation of an extended delay, for example, either a 12 hour delay or a 24 hour delay, whereby on completion of the extended delay, a signal is then transmitted from the first timer to the second timer to effect operation of the control valve and hence flushing of the cistern.

5. A control unit according to any of Claims 2 to 4 in which a test button facility is provided whereby, on pressing of the button, a signal is transmitted directly to the second timer to operate the solenoid.

6. A control unit according to any of Claims 2 to 5 in which the second timer is linked to an electro-magnetic counter which operates to record the number of times that the solenoid is energised, this reading then giving an indication of the overall water consumption.

7. A control unit according to any of the preceding claims in which the housing is formed as a plastics moulding having mounting facilities facilitating installation thereof, the housing having a lid which is held in position by screwthreaded fasteners some of which include a locking facility thereby preventing access being obtained to the interior of the housing by unauthorised persons.

8. A control unit substantially as described herein with reference to Figure 1 of the drawings.

9. A control unit substantially as described herein with reference to Figure 2 of the drawings.