FLUSH CONTROL APPARATUS

Abstract: A flush control apparatus for urinals (10) including a remotely operable valve (20) connected between a header tank (16) water supply and one or more urinals (10), control circuitry (50) for operating the remotely controlled valve (20) in response to the output of the detection means (22) indicating the detection of use of the urinal (10), the control circuitry (50) including adjustable timing means for controlling the time of operation of the remotely operable valve (20) to allow a defined quantity of water to be flushed regardless of the head of water controlled by the remotely operable control valve (20).

Description: FLUSfr CONTROL APPARATUS The present invention relates to flush control app¬ aratus particularly for the controlled automatic flushing of urinals, water closets and the like. Hereinafter the term urinal will be used but it is to be understood that is includes water closets and the like. Automatic flush control apparatus for urinals is known. In a first known system the urinal is flushed once every few minutes with a fairly large amount of wat¬ er. Typical systems flush five gallons every twenty minutes. This type of system may also be equipped with timing apparatus to shut down the flushing action for a defined period, for example overnight, to save water. A disadvantage of this type of system is that it takes no account of usage. If the urinal is in heavy use then the period between flushes should be reduced so as to elimin¬ ate unwanted smell from the urinal. If the usage is low then the period between flushes may be too short. To overcome this disadvantage, numerous systems have been developed which monitor the number of persons enter- ing the lavatory and alter the time period between flush¬ es in accordance with the number of persons. Such a de¬ vice is described in United Kingdom Patent Application No.2,065,190 in which a photo-electric device is used to monitor the number of persons entering a lavatory and to open a valve allowing water to flow to a cistern for a predetermined period following each detection. A disad¬ vantage of such a system is that although under low usage conditions substantial water saving is achieved the urin¬ al is not flushed for a long period. This leads to a health risk. There is, therefore, seen to be a difficult balance to be made between the conservation of water and the necessity of maintaining adequate hygiene levels. An additional problem is that in known flush control apparatus a cistern is used and to reduce the amount of water which is flushed at any time the size of the cist¬ ern must be changed. The present invention seeks to obviate the above dis- advantages and provides a flush control apparatus which conserves water whilst at the same time providing an ade¬ quate safeguard against health risks. According to the present invention there is provided a flush control apparatus for urinals including a remote- ly operable valve connected between a header tank water supply and one or more urinals, control circuitry for operating the remotely controlled valve in response to the output of the detection means indicating the detec¬ tion of use of the urinal, the control circuitry includ- ing adjustable timing means for controlling the time of operation of the remotely operable valve to allow a de¬ fined quantity of water to be flushed regardless of the head of water controlled by the remotely operable control valve. According to the present invention there is also provided a flush control apparatus for urinals including detection means for detecting the presence of a user in the immediate vicinity of a urinal a controlled valve connected to the piping of a water supply to the urinal for control of the passage of water to the urinal to flush the urinal, first timing means for controlling the opening of the controlled valve for a preset time period and second timing means for timing the presence of the user to actuate the controlled valve for a second time period following the completion of use by the user. Embodiments of the present invention will now be des¬ cribed with reference to the accompanying drawings, in which:- Figure 1 shows diagrammatically in side elevation a typical urinal with flush control apparatus according to the present invention; Figure 2 shows the arrangement of Figure 1 in part¬ ial front elevation; Figure 3 shows in greater detail a first sensor fix- ing suitable for use with a urinal with a plumbers alley; Figure 4 shows in greater detail a second sensor fix¬ ing suitable for use with solid walls; Figure 5 shows in greater detail a fixing for a se¬ cond type of sensor; Fiure 6 shows in block diagrammatic form the control circuitry for the flush control apparatus according to the present invention; and Figure 7 shows the timing circuitry of Figure 6 in greater detail. With reference now to Figure 1, a typical urinal is shown with a bowl 10 and outlet 12 of any suitable known design. A mains water supply 14 supplies water to a header tank 16, the height of the water in the header tank 16 being controlled in known manner by a stop cock 18. shut-off valve 19 may be provided for maintenance purposes. The outlet of header tank 16 is connected via a sol¬ enoid operated valve 20 to a distribution outlet 22 on the bowl 10. A sensor 24 is mounted in the wall 26 to which the bowl 1.0 is attached. Conveniently, if a plumb¬ ers access alley 30 is provided the solenoid valve 20, header tank 16 and most of the pipework can be concealed behind the wall 26. With reference now to Figure 2, the sensor 24 is pre- ferably mounted in the wall 26 on one side of the down- pipe 21 from valve 20. In an alternative embodiment, shown by dotted outline, downpipe 21 may be T-jointed to feed other bowls 32, 34. The number of bowls fed by a solenoid 20 may be varied to suit the design of each in- dividual toilet system. The output of sensor 24 is connected to a controller 50, the circuitry of which is shown in greater detail in Figures 6 and 7. The output of controller 50 controls the opening time of valve 20. The number of solenoid 5 valves 20 controlled by each controller 50 may also be varied to suit the design of the toilet system and the desired operation, as will be explained hereinafter. In a first embodiment a source 52 of infrared micro¬ wave or like radiation is provided, the sensor 22 being 1° sensitive to such radiation. The radiation source is obscured by a person using the urinal and the sensor 22 is arranged to provide an output signal for the duration of the period that the user is directly in front of the urinal bowl 10. 15 in an alternative embodiment the sensor 22 is of the type sensitive to ambient light conditions. A user wi'll cast a shadow over the sensor which will, therefore, give an output during the time that the urinal is in use. Alternatively, if either of the above sensors is of 20 the type that gives a pulse output on change of a con¬ dition, then the time interval between pulses signifying the time of entry and leaving a position in front of the urinal bowl can be similarly measured. In any case, very short time intervals possibly caused by a person ?5 walking past rather than using the urinal can be arranged to be ignored by the control cicuitry. With reference now to figure 3, a first sensor unit 22 and its fixing are shown. The sensor compries an el¬ ectronic sensing device 60 with output leads 62 for conn- 0 ection to the control 50. In front of the operative end of sensor 60 is positioned a protective element compris¬ ing a disc 64 of armour plated glass or poly-xylene plas¬ tics material. The disc 64 buts up against, for ex¬ ample, the back of tiles 66 which form the decorative 35 front face of the wall 26. A hole 68, preferably of app- roximately one eighth of an inch (3 mm) diameter is drilled in a tile to allow radiation access to the sensor 60. The sensor 60 and disc 64 are embedded in the wall 26 with a high impact sealing compound 70. 5 The sensor 60 may, as described hereinbefore, be of the infra red or ambient light type. The small diameter hole 68 and armour plate or poly-xylene disc 64 embedded in the sealing compound make it virtually impossible for the detector 60 to be damaged. ° With reference now to Figure 4, a sensor fixing arr¬ angement for a solid wall 80 with no rear access is shown. A large diameter hole 82 is drilled in the wall, a sensor 84 is positioned in the hole and lead wires 84 are- fed via trunking 86 to the control 50 (Figure 1). 5 Again, the front of sensor 60 is protected by an armour plate glass or poly-xylene protective disc 64 which is then covered by the tiles 66. As in the arrangement of Figure 3, the space surrounding the sensor 60 is filled with a high impact sealing compound 70. Also, the hole 68 in the tile is preferably of approximately one eighth of an inch (3 mm) diameter and therefore the sensor is well protected from vandalism. With reference now to Figure 5, an alternative fixing to that shown in Figure 3 is shown. The sensor 90 is protected by a perforated metal disc 92, preferably stainless steel, and is held in a wall 94 by the high impact sealing compound 70. The wall tiles 96 may not be present and are not necessary since the metal disc 92 is inset from the front edge 96 of wall 94. The opening 98 in the wall for the sensor is preferably at least one inch (25 mm) in diameter. Each hole in disc 92 is pref¬ erably approximately one sixteenth of an inch (1.5 mm) in diameter and therefore again the sensor 90 will be well protected against vandalism. The output of sensor 90 on lead 100 is connected to control 50 (Figure 1). -6- With reference now to Figure 6, the electronic con¬ trol box 50 is shown in block diagrammatic detail. The lead 100 (or 84 or 62) to the sensor comprises three wires 102, 104, 106 respectively supplying from a connec- 5 tor block 108 earth and posotive voltage to the sensor and the switched output from the sensor which is connect¬ ed via a first relay 110 to a first timer 112. The output of the first timer 112 is connected to a second timer 114. Both timers are adjustable by respective var- 10 iable resistors 116, 118. The output of the second timer 114 is connected to control a relay 120 which when acti¬ vated supplies power to solenoid valve 20 via a second connector block 122. Operating power for the relays is provided by a transformer and rectifier circuit 124 sup- 15 plied by mains voltage on line 126 via connector block 122. A suitable fuse 128, preferably 2 amp is provided for circuit protection. With reference now to Figure 7, the operational por¬ tion of control unit 50 is shown in greater detail. The 20 reference numerals used are, where possible, the same as for Figure 6. The input from the sensor on line 106 is fed to relay 110 to actuate the relay on receipt of a signal signall¬ ing that a user is present in front of the urinal bowl. 25 A signal is given on line 130 to actuate timer 112. Ener¬ gisation of relay 110 also causes contacts 132 in trans¬ former circuit 124 to be changed over, thereby energising relay 120 for a period determined by timer 114 as set by variable resistor 118. The supply to solenoid 20 is 30 therefore provided for a brief period, say 2 seconds, as determined by timer 114. Following this initial flushing, timer 112 continues to time the period that the sensor remains actuated. This may be only a few seconds or it may be one or more 35 minutes, the latter period being usual if a large crowd of people are present thereby blocking out the infra red or ambient light from the sensor 24. When the sensor is uncovered and is thereby de-acti¬ vated, timer 112 is de-energised and an output is given to timer 114 after a preset time delay set by variable resistor 116. Timer 114 causes operation of the solen¬ oid valve 20 for its preset interval of 2 seconds. In an alternative embodiment, the output of timer 112 may be used to maintain timer 114 in an operative con- dition for a time proportional to the time registered by timer 112. Thus, if the sensor has been covered for a long time period, then a longer flush will be obtained. The system, therefore, operates to flush small quant¬ ities of water both before and after use of the urinal and may in an alternative embodiment flush a variable quantity of water dependent on the detected length of use. The sensor detects the presence of a person only when directly in front of and close to the urinal. For this reason, it is preferable for the sensor to be either of the infra red type with an infra red source 52 being pro¬ vided at a central position or else of the ambient light type relying on either natural light or artificial light for its operation. if the sensor 20 is obstructed by, for example, chew¬ ing gum, then the system will be controlled by timer 112 to flush for a defined time at set intervals, e.g. 20 minutes. In a preferred embodiment the components of Figure 7 are as follows:- 124 15v Transformer REG 1 Regulator REC 1 Rectifier 112 & 114 555 Timers Ri IK ohm Resistor R2 & R3 10K ohm Resistors 116 & 118 ' 4.7M ohm Potentiometers C2 2.2 mf Capacitor C3 1000 mf Capacitor C5 47 mf Capacitor C4 & C6 0.1 mf Capacitors C7 & C8 0.01 mf Capacitors D1,D2,D3 & D4 1N4148 Diodes Tl BFX 85 Transistor Cl 100 mf Capacitor 110 & 120 12v lOamp Relays 128 2amp Fuse The system therefore provides the facility to flush any desired amount of water to either one or more urinal bowls as shown in Figure 2. The system flushes both be¬ fore and after use and the second flush may be variable in time to allow for a prolonged use of the urinal. Since detection of ambient light only occurs when a user is directly in front of a urinal bowl the system does not operate when a person walks past the bowl but only when a user stands close to a bowl. By using a sensor with a relatively slow operating period e.g. 1 second any shadow passing across the sensor can be ignored. If only fast operating sensors are available the output of a sensor can be effectively slowed by using a resistor-capacitor timing circuit. Since timer 114 can be adjusted to operate over . very long time intervals the amount of water flushed can be adjusted regardless of the pressure. Thus for example in a hotel a single cistern can be used to supply the water to all urinals on all floors of the hotel. In setting up the time interval for example for the uppermost floor the time interval set by timer 114 can be made long because of the lack of pressure on the uppermost floor. For the ground floor however the pressure at the urinal will be great due to the height of the cistern above the urinal and therefore to deliver the same quantity of water the time set by variable resistor 118 for timer 114 can be set extremely short allowing the same quantity of water to be dispensed but in a shorter period of time. In a practical system the amount of water dispensed can be one tenth of a litre both before and after a single use. As explained hereinbefore if a prolonged use is detected then one tenth of a litre can be dispensed on initial detection and a multiple of one tenths of a litre can be dispensed when the sensor no longer detects the presence of a user. The advantage of a small flush before and after use is that the flusing action of the water prevents cryst- allisation of deposits on the urinal bowl thereby pre¬ venting infection. By control of the delay produced by timer 112 the number of flushes that timer 114 is allowed to make in any defined period may be limited. Thus for example if timer 112 produces a delay of 30 seconds and the minimum delivery allowed by timer 114 is 0.1175 litres (approximately one tenth of a litre) then a maxi¬ mum of 4.5 litres can only be delivered every 20 minutes. The system therefore may be adjusted to meet the requirements of any particular water authority in that by measuring the amount of water delivered at a urinal by operation of timer 114 and altering this to a specified amount using variable resistor 118 the minimum amount of water delivered each time can be controlled exactly. Since the system works from a large cistern which is al- ways a defined height above a urinal then the head of water will not vary and therefore the amount delivered, once set, will remain constant for each urinal no matter where it is in a building. Additionally by using ambient light sensors to de- tect only the presence of a person standing immediately in front of a urinal and having an individual solenoid valve for that urinal it is possible to flush only that particular urinal bowl and thereby flush an extremely small amount of water (e.g. one tenth of a litre) before and after use of the urinal. Thus although more expens¬ ive in initial installation costs the saving in water consumption over a long period of time can be consider¬ able. In addition since in many instances the waste wat¬ er is processed in a sewage plant and this is charged to the user on a pro-rata basis according to the water usage then the consumer saves in two ways. Thus an install¬ ation can rapidly pay for itself over a fairly short time period. The above description relates to the use of the app- aratus in flushing urinals but the apparatus can with modifications be used to flush water closets. The pre¬ ferred sensor in this application is an ambient light sensor which if positioned in the wall at the back of a water closet, in the same manner as shown in Figures 3, 4 or 5 for the urinal, will detect the presence of a person using the water closet. In a confined area where a light may be switched on to illuminate a particular cubicle such as in an invalid toilet the ambient sensor may be of the type using two sensing elements one positioned to receive light at a position remote from the water closet and one positioned as described. The outputs of the two sensors will, in the case where the toilet is not in use be approximately the same whether the light is on or off. When the toilet is in use it is assumed that the light will be on and therefore the sensor closest to the water closet will give a lower output reading which can be de¬ tected. The circuitry can, if desired be left as for the urinal, with a small initial amount of water being flush- e d and a larger amount being flushed at a predetermined time interval foLlowing the detection of the user leaving the water closet. The second, larger amount of water will not however in a preferred system be dependent on the amount of time that the water closet has been in use 5 but will be a defined amount of water say for example 2 gallons (8.6 litres) to give a complete flush. In this preferred system the timer 114 can be set to operate the relay 120 to operate the solenoid valve for a period de¬ termined by variable resistor 118. Thus as in the case 0 of the urinals once the system is installed the resistor 118 can be set such that regardless of the head of water above the water closet the correct amount of water can be delivered to flush the closet. The system can be modified to eliminate the first ■5 small amount off flushing water. Thus timer 112 will in this embodiment be used only to time the interval between the time of a person leaving the water closer, and the commencement of the flush for a period set by timer 114 as adjusted by variable resistor 113. Thus variable re- 0 sistor 116 may be eliminated thereby giving a standard delay period preset into timer 112 (by for example a fix¬ ed valve external resistor in place of variable resistor 116). If desired variable resistor 113 may be retained thus allowing a variable time delay between the detector 5 24 sensing the departure of a user and the flushing of the closet. This may be desired particularly for toilets used by persons in wheelchairs where it may be desirable to have a slightly longer delay interval say one minute rather than the normal interval of for example fifteen seconds so as to allow a disabled person sufficient time to get back into their wheelchair. For both flashing urinals and water closets there¬ fore the system is adjustable to give desired quantities of water. No cisterns are required, the system being capable of being operated from cold water header tank which may be the normal cold water tank for the building or may if the plumbing system requires be a header tank for a communal toilet system. If the header tank is re- positioned then it is only necessary to adjust the vari- able resistors 116, 118 to restore the correct amount of flushing water. To adjust the amount of water flushed it is similarly only necessary to adjust the variable resis¬ tors 116, 118. The system can be operated using a header tank or if the mains water supply is reliable and local regulations allow it the system can be run directly from the mains without any requirement for a header tank. In the event that the mains water pressure substantially decreases, say for example during the summer months then it is extremely easy to alter the variable resistors to compensate thereby maintaining the quantities of water flushed. Because the timer 114 has a capability of being set for a relatively long time the system can be used to flush a single urinal, requiring a relatively short flush, or if desired a set of urinals the supply pipework of which is common thereby requiring a long flush. The system therefore is capable of universal use with changes being able to be effected by simple alter¬ ation of variable resistors and installation of solenoid operated valves. This eliminates the need to change cistern sizes if and when changes in flushing quantities are required and makes the system substantially infinite¬ ly variable.

Claims: CL IMS 1. A flush control apparatus for urinals including a remotely operable valve connected between a header tank water supply and one or more urinals, control circuitry for operating the remotely controlled valve in response to the output of the detection means indicating the de¬ tection of use of the urinal, the control circuitry in¬ cluding adjustable timing means for controlling the time of operation of the remotely operable valve to allow a defined quantity of water to be flushed regardless of the 10 head of water controlled by the remotely operable control valve. 2. A. flush control apparatus for urinals including de¬ tection means for detecting the presence of a user in the immediate vicinity of a urinal, a controlled valve connected to the piping of a wat¬ er supply to the " urinal for control of the passage of water to the urinal to flush the urinal, first timing means for controlling the opening of the controlled valve for a preset time period and second 20 timing means for timing the presence of the user to actu¬ ate the controlled valve for a second time period follow¬ ing the completion of use by the user. 3. A flush control apparatus as claimed in Claim 1 or Claim 2 in which the detection means comprises a detector "- - mounted in close proximity to a urinal, the detector be¬ ing responsive to detect the presence of a user when in a position in front of the urinal. 4. A flush control apparatus as claimed in Claim 2 or Claim 3 in which the detection means is responsive to the 0 detection of a change in the level of infrared radiation from an infrared source situated within the room in which the urinal is positioned. 5. A flush control apparatus as claimed in Claim 1, 2 or 3 in which the detection means is responsive to the 5 detection of a change in ambient light conditions. 6. A flush control apparatus as claimed in any one of Claims 2 to 4 in which the first timing means is opera¬ tive to flush the urinal immediately on detection of a user and in which the second timing means is operative to flush the urinal for said second time period, said second time period commencing after a predetermined delay foll¬ owing detection of completion of use by a user. 7. A flush control apparatus as claimed in any on of Clain s 2 to 6 in which the second timing means is res¬ ponsive to the length of time that a user is detected to adjust the second timing period such that the second time period increases in a predetermined manner as the period of continuous detected use increases. 8. A flush control apparatus for urinals substantially as described witn reference to the accompanying " drawings.

Inventors: BIRD WILLIAM DEREK, BIRD, WILLIAM, DEREK
Applicants: ROBOTRONICS LIMITED
Application year: 1985
Main classification: E03D5
IPC codes: E03D5