GB2460034A

GB2460034A - Sensor controlled water outlets

Info

Publication number: GB2460034A
Application number: GB0808588A
Authority: GB
Inventors: Robin John Mccoye; Andrew Hunter
Original assignee: Pegler Ltd
Current assignee: Pegler Ltd
Priority date: 2008-05-12
Filing date: 2008-05-12
Publication date: 2009-11-18
Anticipated expiration: 2028-05-12
Also published as: GB2460034B; GB0808588D0

Abstract

A sensor controlled water outlet comprises a sensor 106 operable over a short range wherein the sensor 106 detects a presence within a first short distance 110 of the sensor 106 and a longer range detection mode wherein the sensor 106 detects a presence at a greater distance from the sensor 106 but within a second longer distance 120 of the sensor 106. The outlet further comprises a control unit 105 connected to the sensor 106; and one or more flow control valves 103 operable in response to the control unit 105 to enable or disable the flow of water through the outlet wherein if immediately subsequent to the flow of water being disabled a presence is detected within the shorter first distance of the sensor 106. The control unit 105 is operable to prevent the flow of water being enabled again until consecutive null results are obtained for presence detection within said first distance of the sensor 106 for the duration of a hold off period. The aim is to stop the sensor being fooled into allowing the water supply to run constantly by an object being left within the shorter sensor distance, the object may be left accidentally such as a paper towel or it may be deliberate vandalism such as chewing gum being placed on the sensor.

Description

Sensor Controlled Water Outlets The present invention relates to a sensor controlled water outlets such as taps aridlor showers.

In many public washrooms, the flow of water from taps andlor showers is controlled automatically by valves operable in response to suitable sensors. Typically such sensors are infra red sensors operable to determine the presence of an object *:: : (typically a person) within the sensing range of the sensor. When such a presence is detected, the flow of water is enabled and when no such presence is detected, the flow S...

of water is prevented.

S S..

* 10 In some systems, such as that disclosed in US5829072, a sensor having a shorter range mode and a longer range mode is provided. Before water flow is * initiated the sensor is in the shorter range mode and thus a presence must be detected close to the sensor to initiate flow. Subsequently, the sensor switches to longer range mode and to maintain flow a presence must be detected within the longer range.

Controlling activation by the detection of a presence helps to prevent accidental activation of the tap/shower and thus improves the efficiency of water use.

Unfortunately, both known one arid two range sensor controlled taps are liable to be fooled into operation by blocking the sensor with, for instance gum or dampened paper, as is not unknown in public environments. In the event that the sensor is blocked this can lead to continuous ongoing tap operation increasing water and power costs and also presenting a potential flooding danger.

It is therefore an object of the present invention to provide a sensor controlled water outlet that at least partially overcomes or alleviates the above problems.

According to a first aspect of the invention, there is provided a sensor controlled water outlet comprising: a sensor operable in a shorter range detection mode wherein the sensor is operable to detect a presence within a first shorter distance of the sensor and a longer range detection mode wherein the sensor is operable to detect a presence at greater than said first shorter distance from the sensor but within a second longer distance from the sensor; a control unit connected to said sensor; and S.. S * a.. one or more flow control valves operable in response to said control unit to enable or *, * 10 disable the flow of water through the outlet wherein if immediately subsequent to the * flow of water being disabled a presence is detected within the shorter first distance of the sensor, the control unit is operable to prevent the flow of water being enabled SI * : again until consecutive null results are obtained for presence detection within said first distance of the sensor for the duration of a hold off period.

Monitoring the detection of a presence during a hold off period subsequent to disabling the water flow can determine whether the sensor is likely to have been blocked. Accordingly, water flow from an outlet with a potentially blocked outlet can be prevented saving water and power resources and lowering the risk of flooding.

The hold off period may be any period in the range 1-10 seconds and may be say 5 seconds. In the event that a presence is detected during the hold off period, the hold off period is preferably restarted. The hold off period may be monitored by a hold off timer. The hold off timer may be a dedicated timer unit or may form part of the control unit. The hold off period may be preset or may be adjustable.

The water outlet may be a tap or a shower. The sensor may be provided upon a wall or other suitable surface in the vicinity of the outlet. Additionally or alternatively, the sensor may be mounted on a portion of the outlet.

The or each flow control valve may be opened to enable water flow and closed to disable water flow. The or each flow control valve may be a solenoid valve. * S * * * S...

The outlet may be provided with a plurality of different water supplies. For **S.

example, there may be separate hot water and cold water supplies. The different I..

* 10 water supplies may be combined by a mixer valve. In the case of hot and cold supplies, the mixer valve may be a thermostatic mixer valve. Where there are a * plurality of water supplies, a single flow control valve may be provided to control the mixed water supply after the mixing valve. Additionafly or alternatively, separate S..' dedicated flow control valves may be provided for each supply before the mixing valve.

The control unit may be a microprocessor or may incorporate a microprocessor. The control unit may be operable to switch the sensor between the longer range and shorter range detection modes. S 55

The sensor may be an infra red sensor. In particular the sensor may be an active infra red sensor. The shorter first distance may be say 50mm from said sensor.

The longer second distance may be say 3 00mm from said sensor. In particular cases the first shorter and second longer distances may be selected as are appropriate to a particular arrangement of the sensor and outlet.

Preferably, once the hold off period has expired without the detection of a presence within the first distance, the outlet switches to a standby mode wherein the flow is disabled and the sensor is operable in the shorter range detection mode. Upon detection of a presence within the first distance during standby mode preferably the * outlet switches to activated mode. In activated mode, the water flow may be enabled * S.... and the sensor may be switched to operate in the longer range detection mode. *.*. I...

*.* 10 Preferably, in activated mode, if consecutive null results are obtained for *:. presence detection in the range between said first distance and said second distance *: , from the sensor for the duration of a preset operation period, the control unit disables the water flow. The operation period may be any period in the range 1-60 seconds, more particularly in the range 5-15 seconds and may be say 10 seconds. In the event that a presence is detected during the operation period, the operation period is preferably restarted. The operation period may be monitored by an operation timer.

The operation timer may be a dedicated timer unit or may form part of the control unit. The operation period may be preset or may be adjustable. Monitoring in this manner enables the flow through the outlet to be disabled when no person is using it.

Additionally or alternatively, in activated mode, if the water has being flowing for a duration exceeding a guard period, the control unit disables the water flow. The guard period may be any period in the range 1-20 minutes and may be say 8 minutes.

The guard period is preferably restarted upon each occasion that the flow of water is enabled. The guard period may be monitored by a guard timer. The guard timer may be a dedicated timer unit or may form part of the control unit. The guard period may be preset or may be adjustable. Monitoring in this manner enables the outlet to be disabled automatically after a maximum flow period defined by the guard period.

According to a second aspect of the present invention there is provided a * method of operating a sensor controlled water outlet according to the first aspect of *** S ** * the present invention, the method comprising the steps of: disabling the flow of water; *. 10 switching the sensor to the shorter range detection mode; monitoring the output of the sensor for the detection of a presence in within said first shorter distance of the sensor : wherein if a presence is detected immediately, the enabling of the flow of water is S. * * .: prevented until consecutive null results are obtained for presence detection within said first distance of the sensor for the duration of a hold off period.

The method of the second aspect of the present invention may incorporate any or all features of the first aspect of the present invention as are required or desired.

In order that the invention is more clearly understood specified embodiments will now be described, by way of example only and with reference to the following drawings, in which: -Figure 1 is a schematic block diagram of a shower according to the present invention; Figure 2a is a flow diagram indicating the method of operation of the shower of figure 1; arid Figure 2b is continuation of the flow diagram of figure 2a.

Turning to figure 1, there is provided a schematic block diagram of a shower 100 according to the present invention. The shower 100 comprises a shower head 101; a shower head connection pipe 102; a valve 103 controlling the flow of water * : : : through pipe 102 and shower head 101; and a water supply pipe 104 connected to the *::::* mains andlor a hot water supply. The valve 103 is a solenoid valve and is operated to *: enable or halt the flow of water from water supply pipe 104 to shower head 101 in :. 10 response to signals received from a control unit 105 connected to a sensor 106.

Whilst a single exemplary valve 103 and water supply 104 are shown, it is possible for a single valve 103 to control water from two or more supplies 104. In such case, it may be convenient for the water supplies to pass through a mixer valve before reaching the flow control valve 103. Alternatively, in cases where a two or more water supplies are provided, a dedicated flow control valve 103 may be provided for each supply. In such a case, the flow control valves 103 may be operated together or independently as required or desired. Similarly to the previous case, a mixer valve may be provided for mixing the water from the two or more supplies before it exits the shower 100.

The sensor 106 is an infrared sensor operable to detect the presence of a user within its sensing range. The sensor 106 is typically an active infra red sensor operable to emit infrared radiation and deduce the presence of a user 150 by detecting radiation reflected therefrom. The sensor 106 is operable in two different modes: a shorter range mode; and a longer range mode. In the shorter range mode, the sensor 106 is operable to detect the presence of a user 150 within say 50mm of the sensor. In the longer range mode, the sensor 106 is operable to detect the presence of a user 150 at greater than say 50mm from the sensor 106 but at less than say 300mm from the sensor 106.

The method of operation of the shower 100 is illustrated by the flow diagram of figures 2a and 2b. The shower 100 starts in standby mode at step 201 wherein r 10 valve 103 is closed and sensor 106 is operating in shorter range mode. At step 202 a

S

5* . . . . * determination is made as to whether there is a presence within the shorter range. If :* there is no presence detected, the shower 100 reverts to step 201. Upon detection of a S. user 150 by the sensor 106 at step 202, the control unit 105 is operable to switch the sensor 106 to operate in the longer range mode at step 203 and also to enable water flow at step 204 by opening valve 103.

In addition to the above the control unit 105 is further operable to reset an internal guard timer at step 205 and to reset an operation timer at step 206. The guard timer enables the total time that the water flow has been enabled to be monitored. In the example shown, the guard timer counts down from a maximum guard period of 8 minutes to zero and is monitored at step 207. In the event that the count on the guard timer reaches zero the method advances to step 210.

If it is determined at step 207 that the count of the guard timer is greater than zero, the method proceeds to step 208 and the determination of whether a presence is detected 50-300mm from the sensor 106. If a presence is detected, the method reverts to step 206 and resets the operation timer. If no presence is detected, the count on the operation timer is checked at step 209.

If it is determined at step 209 that the count of the operation timer is greater than zero, the method reverts to step 207. In the event that the count on the operation *::: timer reaches zero the method advances to step 210. * S *5*e

In this manner, the operation timer enables the total time since the last S...

S :. s

* 10 detection of a user 150 in the range 50-300mm from the sensor 106 to be monitored. **S

S

In the example shown, the operation timer counts down from an operation period of 5-15 seconds to zero. In summary for as long as the shower 100 has not been in operation for longer than 8 minutes and a presence is detected in the range 50-300mm from the sensor 106 within a period of 5-15 seconds since the previous detection event, the flow of water from the shower 100 is maintained.

In conventional showers, once the guard timer has expired andlor there is no detection within the period of the operation timer, the method would revert to step 201 and enable the shorter detection range. If in such a case, the sensor was blocked by, gum, tissue paper or similar, the shower would then cycle through the various steps above until the sensor was unblocked. The present invention avoids such problems by following the method shown in figure 2b (in continuation of figure 2a).

After the sensor 106 has been switched to shorter range operation at 210, it is determined whether a presence is detected less than 50 mm from the sensor at step 212. If no presence is detected, the sensor can be considered not to be blocked and the shower may revert to step 201. If a presence is detected at 212, the sensor 106 can be considered to be blocked and normal operation of the shower 100 is suspended until such time as sensor blocked ioop 213-215 results in a determination that the sensor 106 is not blocked.

The initial step of the ioop is at step 213 to reset a hold off timer. If at step *::: : 214 a presence is detected within 50mm of the sensor, the sensor 106 is considered to *.S.

remain blocked and the method reverts to step 213 and resets the hold off timer. If no presence is detected, the count on the hold off timer is checked at step 215.

S

If it is determined at step 215 that the count of the guard timer is greater than * :* * zero, the sensor 106 is considered to remain blocked and the method reverts to step 214. If it is determined at step 215 that the count of the hold off timer reaches zero the sensor can be considered to be not blocked and thus normal operation can resume at step 201.

In this manner if a user 150 blocks the sensor 106, normal operation is suspended until the sensor blocked loop determines that the sensor 106 is not blocked.

This prevents the shower remaining in constant operation or constantly cycling through periods of operation whilst the sensor is blocked. As such operators of such a shower 100 can save water and power and lessen the risk of flooding.

-10 -In some embodiments, it may be possible for the control unit 105 to transmit an indication to an external monitoring means when the shower 100 enters the sensor blocked loop.

The sensor ranges and period durations listed above and in figure 2 may be varied, as required or as desired. In particular, the ranges may be varied in accordance with the relative positioning of the sensor 106 and the main outflow from the shower 100. This can ensure that a person standing under the main flow of the shower 100 is within the longer range but is not within the shorter range. The period *:: : durations might typically be varied in response to the type of outlet controlled. For * ,. 10 instance, a shower would typically require a considerably longer guard period than a tap associated with a washbasin. **** *.

Whilst the invention has been described above in relation to an embodiment ** ** : comprising a shower, it should be realised that the invention may be equally applied to a tap (single or mixer) or any other water outlet, if required or if desired.

It is of course to be understood that the invention is not to be restricted to the details of the above embodiments which are described by way of example only. * **

Claims

CLAIMS1. A sensor controlled water outlet comprising: a sensor operable in a shorter range detection mode wherein the sensor is operable to detect a presence within a first shorter distance of the sensor and a longer range detection mode wherein the sensor is operable to detect a presence at greater than said first shorter distance from the sensor but within a second longer distance from the sensor; a control unit connected to said sensor; and one or more flow control valves operable in response to said control unit to enable or disable the flow of water through the *:: : outlet wherein if immediately subsequent to the flow of water being disabled a *IS* * . .. 10 presence is detected within the shorter first distance of the sensor, the control unit is operable to prevent the flow of water being enabled again until **** * consecutive null results are obtained for presence detection within said first *:* distance of the sensor for the duration of a hold off period.
2. A sensor controlled water outlet as claimed in claim 1 wherein the hold off period is in the range 1-10 seconds.
3. A sensor controlled water outlet as claimed in claim 2 wherein the hold off period is 5 seconds.
4. A sensor controlled water outlet as claimed in any preceding claim wherein in the event that a presence is detected during the hold off period, the hold off period is restarted.
5. A sensor controlled water outlet as claimed in any preceding claim wherein the hold off period is monitored by a hold off timer. -12-
6. A sensor controlled water outlet as claimed in claim 5 wherein the hold off timer is a dedicated timer unit.
7. A sensor controlled water outlet as claimed in claim 5 wherein the hold off timer forms part of the control unit.
8. A sensor controlled water outlet as claimed in any one of claims I to 7 wherein the hold off period is preset.
9. A sensor controlled water outlet as claimed in any one of claims 1 to 7 wherein the hold off period is adjustable.
10. A sensor controlled water outlet as claimed in any preceding claim wherein the S... : 10 water outlet isatap. *5** * S S...
11. A sensor controlled water outlet as claimed in any one of claims 5 to 9 wherein **..the water outlet is a shower. *.

* :.
12. A sensor controlled water outlet as claimed in any preceding claim wherein the * : * * sensor is provided upon a wall or other suitable surface in the vicinity of the outlet.
13. A sensor controlled water outlet as claimed in any one of claims 5 to 11 wherein the sensor is mounted on a portion of the outlet.
14. A sensor controlled water outlet as claimed in any preceding claim wherein the or each flow control valve is opened to enable water flow and closed to disable water flow.
15. A sensor controlled water outlet as claimed in any preceding claim wherein the or each flow control valve is a solenoid valve.

-13 -
16. A sensor controlled water outlet as claimed in any preceding claim wherein the outlet is provided with a plurality of different water supplies.
17. A sensor controlled water outlet as claimed in claim 16 wherein the different water supplies are combined by a mixer valve.
18. A sensor controlled water outlet as claimed in claim 17 wherein the mixer valve is a thermostatic mixer valve.
19. A sensor controlled water outlet as claimed in claim 17 or claim 18 wherein a single flow control valve is provided to control the mixed water supply after the mixing valve. S...* : 10
20. A sensor controlled water outlet as claimed in claim 17 or claim 18 wherein S... * * S...separate dedicated flow control valves are provided for each supply before the S... *S..mixing valve.5...
21. A sensor controlled water outlet as claimed in any preceding claim wherein the * * control unit is a microprocessor or incorporates a microprocessor.
22. A sensor controlled water outlet as claimed in any preceding claim wherein the control unit is operable to switch the sensor between the longer range and shorter range detection modes.
23. A sensor controlled water outlet as claimed in any preceding claim wherein the sensor is an active infra red sensor.
24. A sensor controlled water outlet as claimed in any preceding claim wherein the shorter first distance is 50mm from said sensor.
25. A sensor controlled water outlet as claimed in any preceding claim wherein the longer second distance is 300mm from said sensor. -14-26. A sensor controlled water outlet as claimed in any preceding claim wherein once the hold off period has expired without the detection of a presence within the first distance, the outlet switches to a standby mode wherein the flow is disabled and the sensor is operable in the shorter range detection mode.27. A sensor controlled water outlet as claimed in claim 26 wherein upon detection of a presence within the first distance during standby mode the outlet switches to activated mode.28. A sensor controlled water outlet as claimed in claim 27 wherein in activated mode, the water flow is enabled and the sensor is switched to operate in the *S..: 10 longer range detection mode. *.. . * S *.S.29. A sensor controlled water outlet as claimed in claim 28 wherein in activated *** mode, if consecutive null results are obtained for presence detection in the range S..between said first distance and said second distance from the sensor for the ** S. * S S * duration of a preset operation period, the control unit disables the water flow.30. A sensor controlled water outlet as claimed in any preceding claim wherein the operation period is in the range 1-60 seconds.31. A sensor controlled water outlet as claimed in claim 30 wherein the operation period is in the range 5-15 seconds.32. A sensor controlled water outlet as claimed in claim 31 wherein the operation period is 10 seconds.33. A sensor controlled water outlet as claimed in any one of claims 29 to 32 wherein in the event that a presence is detected during the operation period, the operation period is restarted. -15-34. A sensor controlled water outlet as claimed in claim 33 wherein the operation period is monitored by an operation timer.35. A sensor controlled water outlet as claimed in claim 34 wherein the operation timer is a dedicated timer unit.36. A sensor controlled water outlet as claimed in claim 34 wherein the operation timer forms part of the control unit.37. A sensor controlled water outlet as claimed in any one of claims 29 to 36 wherein the operation period is preset.38. A sensor controlled water outlet as claimed in any one of claims 29 to 36 *...wherein the operation period is adjustable. *.. . * . S..39. A sensor controlled water outlet as claimed in any one of claims 29 to 38 *SS* wherein in activated mode, if the water has being flowing for a duration * exceeding a guard period, the control unit disables the water flow.40. A sensor controlled water outlet as claimed in claim 39 wherein the guard period is in the range 1-20 minutes.41. A sensor controlled water outlet as claimed in claim 40 wherein the guard period is 8 minutes.42. A sensor controlled water outlet as claimed in any one of claims 39 to 41 wherein the guard period is restarted upon each occasion that the flow of water is enabled.43. A sensor controlled water outlet as claimed in any one of claims 39 to 42 wherein the guard period is monitored by a guard timer.-16 - 44. A sensor controlled water outlet as claimed in claim 43 wherein the guard timer is a dedicated timer unit.45. A sensor controlled water outlet as claimed in claim 43 wherein the guard timer forms part of the control unit.46. A sensor controlled water outlet as claimed in any one of claims 39 to 45 wherein the guard period is preset.47. A sensor controlled water outlet as claimed in any one of claims 39 to 45 wherein the guard period is adjustable.48. A method of operating a sensor controlled water outlet according to the first S..aspect of the present invention, the method comprising the steps of: disabling S...the flow of water; switching the sensor to the shorter range detection mode; S...S... . . . . . * momtoring the output of the sensor for the detection of a presence in within saidS* first shorter distance of the sensor wherein if a presence is detected immediately, the enabling of the flow of water is prevented until consecutive null results are obtained for presence detection within said first distance of the sensor for the duration of a hold off period.49. A method as claimed in claim 48 wherein once the hold off period has expired without the detection of a presence within the first distance, the outlet switches to a standby mode wherein the flow is disabled and the sensor is operable in the shorter range detection mode.50. A method as claimed in claim 49 wherein upon detection of a presence within the first distance during standby mode the outlet switches to activated mode.-17 - 51. A method as claimed in claim 50 wherein in activated mode, the water flow is enabled and the sensor is switched to operate in the longer range detection mode.52. A method as claimed in claim 51 wherein in activated mode, if consecutive null results are obtained for presence detection in the range between said first distance and said second distance from the sensor for the duration of a preset operation period, the control unit disables the water flow.53. A method as claimed in claim 52 wherein in the event that a presence is detected during the operation period, the operation period is restarted. * * S S. S S...* * 10 *SS. *S*.S *SSS S.. *S *S * S * * . S. * * ..