GB2201699A

GB2201699A - Automatically flushing urinal

Info

Publication number: GB2201699A
Application number: GB08704164A
Authority: GB
Inventors: John Lloyd Parry Jones
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-02-23
Filing date: 1987-02-23
Publication date: 1988-09-07
Also published as: GB8704164D0

Abstract

Apparatus for automatically flushing a urinal comprises a sensor means for detecting a rise or fall in temperature of the urinal outlet relative to the ambient temperature, and valve means operatively connected to said sensor moans and adapted to permit or arrest, respectively, the influx of flushing water into said urinal.

Description

Automatically Flushing Urinal The present invention relates to an automatically flushing urinal. More particularly, it relates to a urinal whose operation is substantially unaffected by fluctuations in the temperature of the surroundings.

Urinals incorporating manually-controlled flushing mechanisms are widely used in many countries.

The maintenance of a hygienic environment in such systems is clearly dependent upon the co-operation of the user. Thus in those countries, such as the United Kingdom, where manual flushing systems are rare, the unfamiliarity of users with manual flushing suggests that widespread re-education of the male population might need to be undertaken before manual systems could supplant traditional non-manual systems.

In the most common non-manual systems, the bursts of flushing water are supplied at regularlyspaced intervals, irrespective of the number of users which the urinal has had in the intervening periods or the time of day. Thus, if no usage is made of the urinal in the interval between flushes, a wastage of water clearly results. Conversely, if heavy usage of the urinal occurs in the interval between flushes this may lead to, and promote, an unhygienic environment within the urinal itself.

Attempts have therefore been made in the past to provide a urinal flushing system whose operation is automatic and is directly correlated with the number of persons making use of the urinal.

In general, two main systems are in current usage.

Such systems either exploit the pressure pulses generated in the cold water supply by usage of handwash basins or W.C.'s in the same premises, o. detect by electrical means (e.g. by infra-red sensors) the presence of a person or persons, thereby triggering off a flushing device for a pre-determined time. However, as will be apparent, such devices are relatively costly. Moreover, in the former case there is no guarantee that users of the urinal will make any use of the handwash or W.C. facilities. Still further, devices of this nature necessarily flush all the stalls when a single handwash is performed. Thus one user may initiate the cleansing of, say, 20 stalls and 95% of the flushing water is thereby wasted.

I am aware that some 70 years ago a device was proposed for automatic flushing utilising the fact that the temperature of the liquid within the outlet pipe directly beneath the urinal bowl increases when the urinal is used. To my knowledge, this device was never manufactured, no doubt because of its erratic operation resulting from fluctuations in ambient temperature and seasonal temperature variations throughout the year.

According to the present invention there is provided apparatus for automatically flushing a urinal comprising sensor means for detecting a rise or fall in temperature of the urinal outlet relative to the ambient temperature, and valve means operatively connected to said sensor means and adapted to permit or arrest, respectively, the influx of flushing water into said urinal.

It will be appreciated that, in common with the prior art arrangements discussed above, the apparatus according to the invention is designed to exploit the ract cnat a temperature rise occurs within the urinal outlet upon usage of the urinal.

However, the sensor means is arranged to be responsive to a differential between the urinal outlet temperature and the ambient temperature, and not to the absolute value of the urinal -outlet temperature. A positive temperature differential of a determined value, e.g. 2-10 C, preferably about 50C, will cause the valve means to release flushing water, whilst the absence of such positive temperature differential will cause the valve means to close or to remain closed. The ambient temperature may be the air temperature or, more preferably, the temperature of the flushing water supply.

By "sensor means will be understood any means capable of detecting a temperature differential of the order under consideration. In a preferred embodiment of the invention, the sensor means comprises a reservoir of volatile fluid (such as, for example, refrigerant fluid) mounted on the urinal outlet.

Upon usage of the urinal the temperature within the outlet will increase, causing the volatile fluid to evaporate and thereby quickly expand.

Narrow-bore (e.g. capillary) tubing, which connects the reservoir to a pressure-sensitive valve or diaphragm, will relay thereto the increase in pressure resulting from evaporation and expansion of the volatile fluid, and thereby activate the valve or diaphragm to cause flushing water to be admitted into the urinal bowl. The passage of flushing water into the urinal outlet will effect a fall in temperature therein; this will cause the volatile fluid to recondense in -the reservoir, and the resultant pressure decrease will cause the valve or diaphragm to close and thereby arrest the influx of flushing water.In order to render the sensor means responsive to a differential between the urinal outlet temperature and the ambient temperature there is preferably provided a collapsible chamber (e.g. bellows), which contains a suitable fluid at a pressure greater than that of the supply of flushing water and is co-operatively mounted so as to act in conjunction with the valve means. Such an arrangement is described in greater detail hereinbelow.

In a further embodiment, the sensor means may comprise, for example, an electronic heat sensor capable of relaying a signal, via appropriate electrical connections, to a device such as, for example, a pre-programmed microprocessor, whose outputs will electronically control the operation of the valve means. In this context, compensation for the effects of external temperature fluctuations may advantageously be provided by a thermosensitive electronic device comprising, for example, two thermistors acting in conjunction with an operational amplifier and capable, in appropriate circumstances, of overriding the signal relayed to the valve means by the electronic heat sensor within the urinal outlet.Electronic variants of the apparatus according to the invention will, however, in general be less preferred than their thermo-mechanical counterparts owing to their greater expense and complexity, the need to have a power supply in situ and the acknowledged undesirability of bringing electrical circuits into close proximity with running water.

An embodiment of the invention will now be described by way of example and by reference to the accompanying drawings in which: Figure 1 is a diagrammatic representation of the apparatus as a whole; and Figure 2 is a more detailed representation of the apparatus in the region of the valve means.

When the urinal is used, warm urine passes from the urinal bowl 1 into the urinal outlet 2.

This causes the volatile fluid in the reservoir 3 to evaporate and thereby rapidly expand. The resultant increase in pressure is relayed via the capillary tube 4 to the pressure-sensitive bellows 5, which themselves undergo a corresponding expansion, forcing open the valve 6. Flushing water is thereby permitted to emerge from the supply pipe 7 and be admitted to the urinal bowl 1. The passage of flushing water into the bowl 1 results in a lowering of temperature in the urinal outlet 2, causing the volatile fluid to recondense in the reservoir 3. The resultant pressure drop in the reservoir 3 and capillary tube 4 causes the bellows 5 to contract, closing the valve 6 and thereby arresting the influx of flushing water.

Compensation for the effects of external temperature fluctuations is achieved by the bellows 8, which are filled with a suitable fluid at a pressure greater than the pressure of the water in the supply pipe 7. The two sets of bellows 5 and 8 are conjoined by a common shaft 9 extending therebetween. Thus, when the urinal is not in use the excess pressure in the bellows 8 will force the valve 6 closed; conversely, when the urinal is in use, the bellows 5 will exert the greater pressure and force the valve 6 open. In the absence of bellows 8 an increase in ambient temperature might in principle cause the valve 6 to be held open constantly as a result of the rise to the prevailing temperature of the liquid in thf- urinal outlet 2, which would maintain the volatile liquid of the reservoir 3 in the vapour phase and thus the bellows 5 in the expanded position.With the bellows 8 in position as shown in Fig. 2 an increase in ambient temperature would cause the pressure of the fluid within the bellows 8 to rise concomitantly with the rise in temperature of the flushing water in the supply pipe 7 and the liquid in the urinal outlet 2; this would accordingly cause the bellows 8 to exert a greater than normal pressure on the valve 6, thereby maintaining the valve 6 in the closed position. If the urinal were subsequently to be used, the temperature within the urinal outlet 2 would rise still further, the pressure of the volatile fluid (already in the vapour phase owing to the increased ambient temperature) in the reservoir 3 and capillary tube 4 would be increased correspondingly and the additional expansion of the bellows5 required to open the valve 6 would thereby be generated.

Initial calibration of the bellows 8 can be effected by means of the adjusting screw 10.

It will be appreciated that, once an initial calibration of the screw 10 has been made, no further adjustment should thereafter be necessary under normal operating conditions.

Claims

1. Apparatus for automatically flushing a urinal comprising sensor means for detecting a rise or fall in temperature of the urinal outlet relative to the ambient temperature, and valve means operatively connected to said sensor means and adapted to permit or arrest, respectively, the influx of flushing water into said urinal.

2. Apparatus according to claim 1, wherein the sensor means is capable of detecting a rise or fall in temperature in the range from 2 to 10 Centigrade degrees.

3. Apparatus according to claim 2, wherein the sensor means is capable of detecting a rise or fall in temperature of about 5 Centigrade degrees.

4. Apparatus according to any preceding claim, wherein the sensor means comprises a reservoir of a volatile fluid capable of evaporating and thereby rapidly expanding.

5. Apparatus according to claim 4, wherein narrow-bore tubing connects the reservoir to a pressure-sensitive valve or to a diaphragm or like means capable of activating the valve.

6. Apparatus according to claim 5, which includes a collapsible chamber containing a fluid at a pressure greater than that of the flushing water and cooperatively mounted so as to act in conjunction with the valve means.

7. Apparatus according to claim 1, 2 or 3, wherein the sensor means comprises an electronic heat sensor capable of providing a signal which can be transmitted, via appropriate electrical connections, to a device capable electronically of controlling the operation of the valve means.

8. Apparatus according to claim 7, wherein the device is a pre-programmed microprocessor.

9. Apparatus according to claim 7 or 8, which includes means for compensating for the effects of external temperature fluctuations.

10. Apparatus according to claim 9, wherein the compensation means comprises a thermosensitive electronic device.

11. An apparatus according to claim 10, wherein the thermosensitive electronic device comprises two thermistors acting in conjunction with an operational amplifier and capable, in appropriate circumstances, of overriding the signal relayed to the valve means by the electronic heat sensor.

12. A urinal, equipped with apparatus according to any preceding claim.

13. Apparatus according to claim 1, substantially as hereinbefore described with reference to, and as illustrated in, Figures 1 and 2 of the accompanying drawings.