PORTER-COOTE, Robert (14 Doyle Street, Jerrys Plains, NSW 2330, AU)
| CLAIMS 1. A control system to safeguard against water loss in a water supply system fed from a source of water via a pump to at least one occludable outlet, said water supply system having a water pressure sensitive electrical switch located downstream of said pump and upstream of said outlet(s), said electrical switch being connected in series with an electrical supply for said pump, turning said pump on in response to a drop in water pressure downstream of said switch and turning said pump off in response to water pressure downstream of said switch reaching a predetermined minimum pressure; said control system comprising a timer connected in parallel with said pump and energized via said water pressure sensitive electrical switch, and a normally closed safeguard switch connected in series with said pump and being rendered non-conductive by said timer being energized for a predetermined period, whereby said safeguard switch presents said pump operating continuously for more than said predetermined period. 2. The control system as claimed in claim 1 wherein said safeguard switch and said pump are connected in series to form a series connection which is connected in parallel with said timer, 3. The control switch as claimed in. claim 1 or 2 wherein a reset switch is connected in series with said timer. 4. The control system as claimed in any one of claims 1-3 wherein said timer is reset after being de-energized by operation of said water pressure sensitive electrical switch. 5. The control system as claimed in any one of claims 1 -4 wherein said pump is located relative to said source of water to prevent syphoning of said water from said source through said pump when said pump is not operating. 6. The control system as claimed in any one of claims 1 -4 wherein said pump is located relative to said source of water to permit syphoning of said water from said source through said pump when said pump is not operating, and a normally open valve is connected in series with said pump, said valve being closed by said timer when said safeguard switch is rendered non- conductive. 7. The control system is claimed in any one of claims I -6 wherein an alarm is associated with said timer and activated when said safeguard switch is rendered non-conductive. 8. A control system to safeguard against water loss in a water supply system fed from a pressurized source of water via an inlet pipe to at least one occludable outlet, said control system having a flow detector located in said inlet pipe upstream of said outlet(s), a normally open solenoid valve located in said inlet pipe downstream of said flow detector and upstream of said outlet(s), said flow detector having a normally open flow switch closable by flow of water in said inlet pipe and said solenoid valve having an operating coil energizable by • a timer connected to an electric supply via said flow switch, wherein said timer is energizable by flow in said inlet pipe via said flow switch and flow in said inlet for longer than a predetermined period set by said timer eneTgizes said solenoid valve via said timer to stop said flow. 9. The control system as claimed in claim 8 wherein a relay is energized by said timer and has a pair of normally open relay contacts connected in parallel with said flow switch to form a locking circuit to maintain said timer energized in the absence of flow which is blocked by said solenoid valve. 10. The control system as claimed in claim 9 including a reset button to deactivate said timer. 11. A method of safeguarding against excessive water loss in a water supply system fed from a source of water via a pump to at least one occludable outlet, said water supply system having a water pressure sensitive electrical switch located downstream of said pump and upstream of said outlet(s), said electrical switch being connected in series with an electrical supply for said pump, turning said pump on in response to a drop in water pressure downstream of said switch and turning said pump off in response to water pressure downstream of said switch reaching a predetermined rninimum pressure; said method comprising the step of limiting the time of continuous . operation of said pump to a predetermined maximum time, 12. The method as claimed in claim 11 comprising the step of connecting a timer in parallel with said pump, energizing said timer via a said electrical switch, connecting a normally closed safeguard switch in series with said purnp, and rendering said safeguard switch non-conductive after said timer has been energized for said predetermined time. 13. The method as claimed in claim 12 including the step of connecting said safeguard switch and said pump in series to form a series connection, and connecting said series connection in parallel with said timer. 14. The method as claimed in claim 12 or 13 including the step of connecting a reset switch in series with said timer, 15. The method as claimed in claim 14 including the step of resetting said reset switch only after a leak downstream of said water pressure sensitive electrical switch has been rectified. 16. The method as claimed in any one of claims 11-15 including the step of: connecting a normally open valve in series with said pump and closing said valve when said pump is turned off. 17. The method as claimed in any one of claims 11-16 including the step of: providing an alarm activated when said pump is turned off. 18. A method of safeguarding against excessive water loss in a water supply system fed from a pressurized source of water via an inlet pipe to at least one . occludable outlet, said system having a flow detector located in said inlet pipe upstream of said outlet(s), a normally open solenoid valve located in said inlet pipe downstream of said flow detector and upstream of said outlet(s) and a timer energizable by flow detected by said flow detector, said method comprising the step of limiting by operation of said solenoid valve the time of continuous flow through said inlet pipe to a predetermined maximum time determined by said timer. 19. The method as claimed in claim 18 including the further step of providing a locking circuit for said timer to maintain said timer energized and said solenoid valve operated in the absence of flow which is blocked by said solenoid valve. 20. The method as claimed in claim 17 including the further step of providing a reset button arranged to deactivate said timer. |
Field of the Invention
The present invention relates to a water supply system fed from a source of water. Typically such water supply systems are available at rural dwellings where no reticulated town water supply is available in which case the supply is via a pump to at least one outlet which is able to. be occluded, Alternatively the water supply system is a reticulated town water supply system.
Such rural water supply systems generally have source of harvested water such as a rain water tank, a dam, a stream, or similar. So, particularly in times of drought, it is of the utmost importance that the source of water not be depleted by water being inadvertently pumped from the tank. The cause of the inadvertent pumping may be an outlet such as a garden hose which has been left running in error, a pipe downstream of the pump which has developed, a leak, a stock trough the ball valve of which has been damaged by cattle or other stock, an act of vandalism in relation to the downstream equipment, and the like.
It is also important in reticulated town water supply systems to minimize inadvertent losses to prevent the imposition of various types of water restrictions upon town water users and/or large bills to water users.
Genesis of the Invention
The genesis of the present invention is a desire to provide a control system to safeguard against excessive water loss in the event of such a problem arising. Such a control system would substantially prevent the situation arising where a leak which developed during the night, when the occupants of the house were asleep or absent from the property, for example, resulted in the entire contents of the harvested- water being pumped out of the tank or reservoir and thereby going to waste. Such a situation requires the source of water to be replenished at considerable expense by means of a water carter, if available. Alternatively such losses in a town water supply system can eventually lead to the imposition of water restrictions and/or large invoices to the water user from the water supplier. Background Art
It has been proposed in US Patent No, 6,568,426 (to which WO99/63225 corresponds) to provide a manually operated timer switch, which is pressed each time the user of a caravan, for example, wishes to operate a tap. In this way irritating intermittent operation of the water pump is avoided, for example brought about by very low volume leaks. However, the abovementioned prior art arrangement suffers from the significant disadvantage that automatic equipment such as a washing machine or dishwasher cannot be allowed to operate automatically. Instead, manual intervention is required on each occasion where the washing machine or dishwasher requires a fresh load of water. Similarly self monitoring flow valve applications triggered by a demand foτ water, cannot function with this prior art arrangement. It is not known by the applicant whether this prior art arrangement has ever been used commercially.
Summary of the Invention
In accordance with a first aspect of the present invention there is disclosed a control system to safeguard against water loss in a water supply system fed from a source of water via a pump to at least one occludable outlet, said water supply system having a water pressure sensitive electrical switch located downstream of said pump and upstream of said outlet(s), said electrical switch being connected in series with an electrical supply for said pump, turning said pump on in response to a drop in water pressure downstream of said switch and turning said pump off in response to water pressure downstream of said switch reaching a predetermined minimum pressure; said control system comprising a timer connected in parallel with said pump and energized via said water pressure sensitive electrical switch, and a normally closed safeguard switch connected in series with said pump and being rendered non-conductive, by said timer being energized for a predetermined period, whereby said safeguard switch prevents said pump operating continuously for more than said predetermined period.
In accordance with a second aspect of the present invention there is disclosed a control system to safeguard against water lass in a water supply system fed from, a pressurized source of water via an inlet pipe to at least one occludable outlet, said control system having a flow detector located in said inlet pipe upstream of said outlet(s), a normally open solenoid valve located in said inlet pipe downstream of said flow detector and upstream of said outϊet(s), said flow detector having a normally open flow switch closable by flow of water in said inlet pipe and said solenoid valve S having an operating coil energizable by a timer connected to an electric supply via said flow switch, wherein said timer is energizable by flow in said inlet pipe via said flow switch and flow in said inlet for longer than a predetermined period set by said timer energizes said solenoid valve via said timer to stop said flow.
10 In accordance with a third aspect of the present invention there is disclosed a method of safeguarding against excessive water loss in a water supply system fed from a source of water via a pump to at least one occludable outlet, said water supply system having a water pressure sensitive electrical switch located downstream of said pump and upstream of said outlet(s), said electrical switch being connected in series with an
15 electrical supply for said pump, turning said pump on in response to a drop in water pressure downstream of said switch and turning said pump off in. response to water pressure downstream of said switch reaching a predetermined minimum pressure; said method comprising the step of limiting the time of continuous operation of said pump to a predetermined maximum time.
20
In accordance with a fourth aspect of the present invention there is disclosed a method of safeguarding against excessive water loss in a water supply system fed from a pressurized source of water via an inlet pipe to at least one occulable outlet, said system having a flow detector located in said inlet pipe upstream of said outlet(s), a
25 normally open solenoid valve located in said inlet pipe downstream of said flow detector and upstream of said outlet(s) and a timer energizable by flow detected by said flow detector, said method comprising the step of limiting by operation of said solenoid valve the time of continuous flow through said inlet pipe to a predetermined maximum time determined by said timer.
30 .
Brief Description of the Drawings
A preferred embodiment of the present invention will now be described with reference to the drawings in which: Fig, 1 is a schematic liquid flow and electrical circuit diagram of the arrangement of a first embodiment,,
Fig, 2 is a diagram similar to Fig. 1 but of a second embodiment, and Fig, 3 is a similar circuit diagram but of a third embodiment.
Detailed Description
As seen in Fig. 1 , three outlets 1 , 2 and 3 are each provided with a corresponding tap or cock C1-C3. Each of the outlets could represent a hand basin, a shower, a washing machine, a garden hose, stock trough, or like domestic, rural Ot commercial outlets. Upstream of the three cocks C1-C3 is normally a main cock C4 which enables the downstream piping to be isolated for the purposes of repairs, changing tap washers and the like. The main cock C4 is supplied by a pump 5 via a pressure sensitive switch Sl which is normally open when the pressure in the pipe between, the switch Sl and the main cock C4 exceeds a predetermined minimum pressure. This indicates that there is no open cock C1-C3 and thus no present demand for water. However, in the event that water is demanded at any of the outlets 1-3 then the pressure within the piping system drops and thus the switch Sl closes to complete an operating circuit for the pump 5 (which is preferably an AC pump and supplied by a mains supply having an active terminal A and a neutral terminal N). The pump 5 is supplied with water by means of a tank 6 which, as indicated by solid lines in Fig. 1, is preferably arranged to have a water level lower than the level of the pump 5. As indicated by broken lines in Fig. 1 , the tank 6 could be positioned above the pump 5.
Connected between the switch Sl and the pump 5 is a timer T- which is connected in series with a reset switch S3 which is normally closed. The timer T is connected to a relay having a relay coil R2 and a pair of normally closed contacts (constituting a safeguard switch S2) which are operated by means of the relay coil R2,
The operation of the circuit of Fig. 1 is as follows: On each occasion that the switch S I is activated, the pump 5 commences operation and the timer T is also energized thereby beginning to count a predetermined period which typically is in the range of 15-30 minutes. This time is selected to be just longer than the maximum titrie for which a shower may be taken, the dishwashing machine operated for a single part of its cycle, the washing machine operated for a single part of its cycle, and so on.
If the demand for water is caused by a flow F2 via cock C2, for example, then the 5 pump 5 operates to provide the requested water. Provided that the cook C2 is turned off within the predetermined time period, the timer is not activated and the pump 5 ceases pumping because there is no longer a demand for water and so the pressure rises to operate the switch Sl.
10 However, in the event that there is a leak LI-L3 (or similar water loss circumstance) at any of the positions of the pipework indicated, or a person forgets to turn off the cook C2 (for example, whilst watering the lawn or garden), then the timer T reaches its predetermined time. When this happens the relay coiL R2 is energized, thereby opening the normally closed switch S2 and stopping the pump 5, This prevents the
15 tank 6 being inadvertently emptied.
It soon becomes apparent to the household that there is no pressurised water supply and thus the reason for this is investigated. For example, it may be that the person
' who neglected to turn off the cock C2 remembers this failure and turns off the cock
20 C2. Alternatively, the leak (any one or more of L 1 -L3) which caused the problem can be identified by the resultant puddle of water (or area of moist soil, green grass, or similar) and rectified. Once the cause of the problem has been rectified, the reset switch S3 can be momentarily operated, thereby resetting the timer T and allowing it to be re-energized via the switch Sl.
• 25 . ■
An advantage of having the tank 6 lower than the pump 5 (as indicated in solid lines in Fig. 1) is that water cannot siphon through the pump 5 in the event of a leak. However, under these circumstances the pump 5 may not be self-priming. In the alternative, if the tank 6 is positioned above the pump 5 (as indicated by dashed lines.
30 in Fig. 1), then the pump 5 will be self-priming. However, in the event of an . overnight leak, for example, even though the pump 5 is disabled by the timer T, a small flow of water may still flow past the impeller of the pump 5 aαd thereby contribute to the leak. However, the total flow will be relatively small and thus the danger of the tank or other source of water being inadvertently emptied will be substantially avoided.
Turning now to Fig, 2, the arrangement of a second embodiment is illustrated. Those components which are the same as for Fig. 1 retain the same designation numbers. It will be seen that the relay R2 is- provided with two sets of contacts designated S2A and S2B respectively. Contacts S2A in Fig. 2 are normally closed and function as contacts S2 of Fig. 1. However, contacts S2B are normally open and are used to connect both a solenoid valve V and an alarm A to the active A and neutral N of the mains supply.
In the event of leak or like circumstance, after the timer T reaches its predetermined (and adjustable) maximum time, the relay R2 is energized. Thus normally closed contacts S2A open thereby halting the operation of the pump 5 as before. In addition, ' the normally open contacts S2B close, hereby energizing both the solenoid valve V and the alarm A. The alarm A can be a visible and/or audible alarm such as a flashing lamp or buzzer, bell, or the like,
The solenoid valve V is normally open but when energized (only when the pump 5 is stopped) closes to prevent any siphoning action through the pump 5, Although the solenoid valve V is illustrated as connected to the pump inlet, it could be connected to. the pump outlet instead. As before, pressing the reset switch S3 de-energizes the relay R2, returns contacts S2A and S2B to their normal condition, and resets the timer T.
Turning now to Fig. 3, a third embodiment of the present invention is illustrated which is applicable to reticulated town water supplies which have a mains supply pipe 100 and a branch supply pipe 110. The direction of water flow is as indicted by arrows F. A normally open main cock C4 as before enables the entire system to be closed off for maintenance. Interposed in the branch pipe 110 between the main cock C4 and the taps or cocks C1-C3 (which Eire as before) are a flow detector FD and a solenoid valve SV having a solenoid coil S. The flow detector FD is associated with a flow switch FS which is open when there is no flow and closed when flow is detected. Connected in parallel with the flow switch FS is a pair of normally open relay contacts CRI which are operable by a relay RL A normally closed reset switch S3 connects the flow switch FS and relay contacts CRl to an active line A of an AC mains electric supply (typically 240V 50Hz or 110V 60Hz).
A timer T as before has a normally open timer switch TS energized by a timer coil TC, An alarm AL is connected in parallel with the solenoid coils and relay Rl, this parallel connection being connected to the active A via the timer switch TS.
In operation, once flow is detected, the flow switch FS is closed thereby connecting the timer T to the active A and starting the count for a predetermined (and adjustable) time. If the flow slops during this period, as is expected for normal operation, the flow switch FS re-opens and the timer T is deactivated.
However, if the flow does not stop because of some fault or a cock, eg C2, being left open, then the timer T energizes the timer coil TC which closes the timer switch TS. As a consequence, the relay Rl is energized, thereby closing the relay contacts CRl which maintains the timer T energized and hence the timer switch TS is maintained closed.
In addition, the solenoid coil S is energized thereby closing the normally open solenoid valve SV and stopping the prolonged flow. Simultaneously the alarm AL (which «an have various forms including audible, visual, SMS message etc) is activated.
Once the problem is rectified, the reset switch S3 can be momentarily depressed, thereby deactivating the timer T, relay Rt and solenoid coil S, which returns the circuit to its initial state. The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the plumbing arts, can be made thereto ■ without departing from the scope of the present invention.
For example, the switch S2 in Fig, 1 (and switch S2A in Fig 2) can be located in any one of the three alternative positions illustrated by broken lines. In an alternating current system it is preferable to switch the active line rather than the neutral line. Similarly, the pump 5 can be powered by DC circuit rather than an AC circuit, if desired.
In the event of a bushfire, for example, where a sprinkler system may be intended to operate for longer than the predetermined period and exhaustion of the harvested water supply is to be preferred to loss of the dwelling through fire, the timer T can. be disabled, for example, by switching off its electrical supply.
Similarly a non-return valve can be located in the branch supply pipe 110 to prevent any possibility of contamination of the mains supply pipe 100.
Furthermore, a suitable timer T is that sold under the model number H3 JA by the OMRON company of China. Although an AC mains supply is illustrated, a DC supply is also able to be used.
The term "comprising" (and its grammatical variations) as used herein is used in the inclusive sense of "including" or "having" and not in the exclusive sense of "consisting only of .