WO1993006709A1

WO1993006709A1 - Pump control system

Info

Publication number: WO1993006709A1
Application number: PCT/AU1992/000533
Authority: WO
Inventors: Robert Sydney Crook; Verne Charles Condon
Original assignee: Verncon Pty. Limited
Priority date: 1991-10-04
Filing date: 1992-10-02
Publication date: 1993-04-15
Also published as: IL103334A0

Abstract

A pump control system comprises a fluid precipitation sensing means (10, 12, 14), a switching means (32, 34, 36, 42) adapted to switch off the pump in response to a signal from the sensing means (10, 12, 14) and a regulating means (48) provided for exhausting fluid from the sensing means (10, 12, 14). The switching means (32, 34, 36, 42) is adapted to switch on the pump after a predetermined quantity of fluid is exhausted from the sensing means (10, 12, 14).

Description

PUMP CONTROL SYSTEM

TECHNICAL FIELD

This invention lies in the broad field of the control of watering systems. More particularly, this invention relates to a pump control system capable of sensing precipitation and adjusting the watering system accordingly.

BACKGROUND ART

There are many applications in which watering apparatus is set to operate at particular timed intervals. This applies to broad acreage irrigation, to domestic garden watering and to local government watering of parks and playing fields, for example. If rain falls during the watering period, there is no means of halting the watering process, other than by manual intervention.

This is not always possible or desirable. Consequently, it is an object of this invention to provide means for sensing precipitation and automatically halting watering once a threshold has been reached.

In the case of sewage reticulation, when certain sewage fluids are reticulated as a means of recycling, problems are encountered if the reticulation continues during heavy rain. Consequently, it is another object of this invention to provide a system which is capable of halting reticulation in these conditions. In the field of hydroponics, which is a method of cultivating plants by growing them in gravel and the like, through which water containing dissolved inorganic nutrient salts is pumped, problems can be encountered because of precipitation.

The growing of plants hydroponically involves setting of plants in a system of tubs where the plants are fed by a nutrient chemical solution without soil being employed. The bulk of the solution, having a predetermined concentration balance, is held in a holding tank which is connected to the tubs. A pump is used to circulate the solution through the tubs and back to the holding tank.

Although this system is simple and reasonably efficient, it suffers serious disadvantages. Typically, the tubs are substantially open to allow access to rainfall, for example. Therefore, when it rains, the solution in the tubs becomes diluted. When the diluted solution is circulated back to the holding tank, the concentration balance of the whole of the solution becomes upset resulting in the hydroponic grower having to exhaust the solution. This can amount to significant economic losses.

To date, the common reaction to rainfall has been an attempt to cover the hydroponic tubs or manually turn the hydroponic pump off in order to prevent circulation of the solution back to the holding tank. However, these practices have not proved to be effective. Although the present invention will often be described herein in connection with hydroponic systems, it will be appreciated that, as previously described, the invention may find many different applications. In fact, the principle disclosed in connection with hydroponic systems can be adapted to any system in which it is desirable to stop fluid flow once rain or other precipitation is encountered.

In this specification, the term "precipitation" includes rain, both natural and artificial. Artificial rain is encountered, for example, in the case of broad acreage irrigation, when the area being irrigated by one boom accidentally overlaps with the area being watered by a second boom. In the interest of water conservation, it may be desirable to cut off the water in the overlapping area of one of the booms.

The term "fluid" includes not only water, but other fluids, as appropriate. However, it is contemplated that the most frequent application of the system of the present invention will be in circumstances where rain is the fluid encountered.

DISCLOSURE OF THE INVENTION

The present invention provides a pump control system comprising:

a fluid precipitation sensing means; a switching means adapted to switch off the pump in response to a signal from the sensing means? and

a regulating means provided for exhausting fluid from the sensing means,

wherein after a predetermined quantity of fluid is exhausted from the sensing means the switching means is adapted to switch on the pump.

Preferably, the fluid precipitation sensing means is located in or close to the area in which precipitation is to be sensed. The sensing means may include a funnel and a container connected thereto by way of a hose, pipe or the like. Conveniently, the funnel is substantially open to provide access to rainfall and positioned in such a way as to allow gravitation of rainfall via the hose into the container.

Typically, the container is positioned on a floor plate of a main frame in which the sensing means may be positioned and is rigidly attached thereto by any suitable means such as lugs or welding, for example. The container may be manufactured from a plastic material such as polyvinyl chloride (further referred to as PVC) or the like. However, any other material capable of maintaining its shape for an appreciable period of time under the conditions of use, as well as its structural integrity, may also be suitable. The container may further include an overflow aperture. In addition, stabilising means may be provided as explained in more detail in connection with the drawings, below.

The switching means may comprise a rod, having a float body at one end thereof and a switch module at the other end, wherein the rod protrudes through both a roof of the container and a restraining member. Conveniently, an upper bar of the main frame may serve as the restraining member. However, any other appropriate arrangement may also be suitable.

At least one stop member may be provided for mounting on the rod below the restraining member so as to limit movement of the rod beyond a predetermined distance in an upward direction. The distance at which the stop member is allowed to travel may be determined by the volume of water permitted to be present in the solution before the concentration balance thereof becomes affected.

In a preferred embodiment of the present invention two stop members are provided for mounting on the rod on each side of the restraining member so that the stop member which is mounted on the rod above the restraining member, when coming in contact with the restraining member, may ease the weight of the switching means applied to the switch module during the operation of the pump.

The switch module having a lip at one end thereof may be mounted on the rod by any suitable means. The lip may have a variety of cross-sectional shapes. In a preferred embodiment of the present invention, the lip is formed into an elongated "U" shape. The bridge of the "U", forming a hook when inverted, may be positioned over and attached (flexibly or rigidly, as may be required) to a push button located on an ON/OFF switch provided to be connected to an electrical circuit of the pump. The legs of the "U" need not be of the same length.

The switching means may further include a perforated cylinder adapted to receive the float body therein so as to facilitate substantially vertical positioning of the switching means within the container. Preferably, the cylinder is placed inside the container and may be integral with or rigidly attached to a floor thereof.

The main frame may be manufactured from a durable material such aluminium or the like. However, any other durable material such as stainless steel, for example, may also be suitable.

Preferably, the rod is manufactured from a material such as stainless steel or the like. However, any other material capable of resisting corrosion for an appreciable period of time may also be suitable.

For the sake of uniformity, the funnel, the float body and the perforated cylinder may be manufactured from the same material as the container, namely PVC, or from a different material as appropriate. Preferably, the regulating means is connected to the container in such a manner as to allow discharge of fluid therefrom to a predetermined level. The regulating means, in one embodiment, is a needle type relief valve.

Typically, the fluid level is predetermined by the level reached by approximately 1 litre of fluid which is manually poured into the container. The relief valve may then be positioned on the outside of the container at a height determined by said fluid level.

Preferably, both the sensing means and the regulating means are adjustable so that the amount of precipitation encountered before the switching means will stop the pump is variable, and the rate at which the fluid is exhausted is also variable.

In one embodiment, the system of the invention includes a timer, which, in response to a signal from the sensing means or regulating means, is capable of overriding any timer on the watering system apparatus. The purpose of this is to ensure that watering is still carried out in an adequate manner, despite the fact that the pump may have been switched off during rain.

The timer may operate via a battery provided for the purpose, or by some other suitable means, for example via a radio signal.

BRIEF DESCRIPTION OF THE DRAWING

By way of example only one preferred embodiment of the present invention will now be described with reference to the accompanying drawing which shows an elevational view of a pump control system of the present invention, absent a front wall to the container.

DETAILED DESCRIPTION OF THE DRAWING

In the drawing, there is depicted funnel 10 connected to container 12 via flexible hose 14. Funnel 10 is substantially open to provide access to rainfall and positioned above container 12 in such a way as to allow gravitation of rainfall via hose 14 into container 12. Funnel 10, container 12 and hose 14 are part of the fluid precipitation sensing means.

Container 12 is positioned on and rigidly attached to floor plate 16 of main frame 18 by way of lugs 20 and includes overflow aperture 22. Container 12 is manufactured from a plastic material, namely PVC.

Holding bolt 24 having nut 26 is provided to add to the stability of the structure. Tightening of nut 26 against upper bar 28 of main frame 18 allows head 23 of holding bolt 24 be pressed against roof 30 of container 12, supplementing the rigidity of the structure.

Rod 32, having float body 34 at one end thereof and switch module 36 at the other end, protrudes through both upper bar 28 and roof 30. Stop member 38a is mounted on rod 32 below upper bar 28 so as to limit the movement of rod 32 to a predetermined distance in an upward direction. The distance at which stop member 38a is allowed to travel is determined by the volume of water permitted to be present in the solution before the concentration balance thereof becomes affected and is approximately 25 mm in this embodiment.

Stop member 38b is mounted on rod 32 above upper bar 28 in such a manner that, when coming in contact with upper bar 28, stop member 38b relieves the weight of rod 32, stop member 38a and float body 34 applied to switch module 36 during the operation of the hydroponic pump.

Perforated cylinder 40 adapted to receive float body 34 therein is provided in order to ensure substantially vertical positioning of rod 32 within container 12.

Switch module 36 having lip 42 is mounted on rod 32 by way of threaded surfaces indicated at 37. Lip 42 is provided in a form of an elongated inverted "U" shape. The bridge 43 of the "U" engages and disengages push button 44 located on ON/OFF switch 46 connected to an electrical circuit for the pump (not shown).

Needle type relief valve 48 is connected to container 12 in such a manner as to allow discharge of water therefrom to a predetermined minimum water level at a predetermined rate. The minimum water level, indicated by dashed line 49, is determined by the level reached by approximately 1 litre of water which is manually poured into container 12. Relief valve 48 is then positioned on the outside of container 12 at a height determined by said water level 49.

It should be noted that the volume of water required to set the minimum water level is determined by and will differ in accordance with the size of container 12.

Main frame 18 is manufactured from a durable material such as aluminium, whereas rod 32 is manufactured from stainless steel.

For the sake of uniformity, funnel 10, float body 34 and perforated cylinder 40 are manufactured from the same material as container 12, namely PVC.

To operate the pump control system of the present invention, after the minimum water level 49 has been set, lip 42 of switch module 36 is positioned over push button 44 of ON/OFF switch 46 and then released. Push button 44 is maintained in the depressed position under the weight of rod 32, stop member 38a and float body 34. Depression of push button 44 will switch the hydroponic pump on, which will remain in its operational mode until pressure applied to push button 44 is withdrawn.

When it rains, water collected by funnel 10 gravitates via hose 14 into container 12. The water level in container 12 rises forcing float body 34 and rod 32 to travel in an upward direction, consequently withdrawing pressure from push button 44 by disengaging lip 42. This results in ON/OFF switch 46 turning the hydroponic pump off, which in turn prevents the circulation of the rain- diluted solution from the tubs back into the holding tank.

Rod 32 is prevented from further travel in the upward direσtion when stop member 38a contacts upper bar 28. This results in float body 34 becoming submerged and any excessive volume of water is exhausted from container 12 via overflow aperture 22.

When rain ceases to fall, water is exhausted from container 12 at a predetermined exhaust rate via relief valve 48. The water level in container 12 subsides, permitting float body 34 and rod 32 to travel in the downward direction, until pressure is again applied to push button 44 by engaging lip 42. This results in ON/OFF switch 46 turning the pump on so as allow the preserved hydroponic solution to be pumped from the holding tank into the tubs.

At the same time, the diluted solution in the tubs is exhausted to waste via gravity or pumped out to another area for recovery of the nutrients, if desired. The exhaust rate via relief valve 48 is adjusted in such a manner as to allow the water level in container 12 to return to its minimum level only after the diluted solution has been exhausted from the tubs.

INDUSTRIAL APPLICABILITY

It will be appreciated that some of the components of the preferred embodiment of the present invention are commercially available. For example, push button 44 may be part of BURGESS Single Pole 1 way Microswitch.

It will be also appreciated that the preferred embodiment of the present invention disclosed herein is given by way of example only and is not intended to be limiting on the scope of the present invention. As will be readily apparent to one skilled in the art, the example described can be readily adapted to the other applications disclosed here.

It will be further appreciated that changes obvious to those skilled in the art are not considered to be beyond the scope of the present invention.

Claims

1. A pump control system comprising:

a fluid precipitation sensing means;

a switching means adapted to switch off the pump in response to a signal from the sensing means; and

a regulating means provided for exhausting fluid from the sensing means,

2. The pump control system as claimed in claim 1, wherein the sensing means is located in or close to the area in which precipitation is to be sensed.

3. The pump control system as claimed in claim 1 or 2, wherein the sensing means includes a funnel positioned in such a way as to allow gravitation of fluid to a container connected thereto by way of a hose, pipe or the like.

4. The pump control system as claimed in claim 3, wherein the container has an overflow aperture.

5. The pump control system as claimed in any one of claims 1 to 4, wherein the switching means includes a rod, having a float body at one end thereof and a switch module at the other end, the float body being adapted to be received within the container.

6. The pump control system as claimed in claim 5, wherein a stop member is mounted on the rod so as to limit movement of the rod beyond a predetermined distance away from the container.

7. The pump control system as claimed in claim 6, wherein a second stop member is mounted on the rod to limit movement of the rod beyond a predetermined distance towards the container.

8. The pump control system as claimed in any one of claims 5 to 7, wherein a switch module, having a lip at one end thereof, is mounted on the rod and adapted to engage and disengage a push button located on an ON/OFF switch of an electrical circuit of the pump.

9. The pump control system as claimed in any one of claims 5 to 8, wherein a perforated cylinder is positioned within the container and adapted to receive the float body therein so as to facilitate substantially vertical positioning of the switching means within the container.

10. The pump control system as claimed in any one of claims 1 to 9, wherein the regulating means comprises a needle type relief valve connected to the container so as to allow discharge of fluid therefrom to a predetermined level at a predetermined rate, the valve being positioned at a selected height.

11. The pump control system as claimed in any one of claims 1 to 10, wherein the sensing means and the regulating means are adjustable to allow a variation in the amount of precipitation encountered before the switching means will stop the pump and the rate at which the fluid is exhausted.

12. The pump control system as claimed in any one of claims 1 to 18, which further includes a timer responsive to a signal from the sensing means or regulating means.

13. A pump control system as claimed in claim 1 substantially as herein described with reference to the drawing.