WO1998053668A1

WO1998053668A1 - Fluid store and dispenser

Info

Publication number: WO1998053668A1
Application number: PCT/NZ1998/000071
Authority: WO
Inventors: Elizabeth Patricia Witehira; Pita Witehira
Original assignee: Elizabeth Patricia Witehira; Pita Witehira
Priority date: 1997-05-30
Filing date: 1998-05-29
Publication date: 1998-12-03
Also published as: AU7942198A

Abstract

A fluid storage and dispensing system associated with a container suitable for potted plants is disclosed which may be used to provide water and nutrient solutions to plants within the container for extended periods. This system provides a fluid reservoir (5) in which the fluid is held against gravity by atmospheric pressure. Fluid for use by plants is drawn from the reservoir (5) against the atmospheric head by capillary forces in the potting medium and by osmetic forces from the potting medium into the root system. The fluid in the reservoir (5) enveloping the plant container (3) may be heated to provide a local tropical environment to enhance plant growth. The quantity of fluid in the reservoir (5) can be monitored with the aid of a suitable level indicator. No free fluid surfaces are exposed to the atmosphere.

Description

DESCRIPTION

FLUID STORE AND DISPENSER

TECHNICAL FIELD

This invention relates to a fluid storage and dispensing system. In particular, the present invention is in the form of a fluid storage and dispensing system for potted plants, although this should not be seen as limiting.

BACKGROUND ART

Potted plants are plants that are grown in a container which holds soil or a suitable growing medium and sufficient water to allow the plant to grow. It is found that almost all such plant containers need to have a hole in the bottom of the container to allow excess water to escape. The absence of a drain hole creates waterlogging and few plants will grow in such conditions.

In most cases potted plants are watered from the top. A few plants which can tolerate "wet feet" can be watered from the bottom by means of a tray in which the plant container is placed, and which is filled with water from time to time. However unless the tray has a very large water capacity, the loss of water by evaporation and by plant usage requires the tray to be refilled at frequent intervals.

It is also desirable to have a tray under the plant container for potted plants which are kept indoors to prevent water mess and damage when the plants are watered. However a more common problem is that the soil or growing medium in the pot cannot hold very much water. Usually its absorption capacity is only sufficient for a few days to meet the consumption of water by the plant and evaporative losses. Most of the water in the soil or growing medium is held by capillary action, and it is drawn into the plant through the root by osmosis. Therefore it is necessary to water potted plants at frequent intervals.

Watering at irregular intervals causes stress and poor growth or sometimes the plant dies. Over-watering causes leaching of nutrient from the growing medium and reduces the available nourishment for the plant.

A common consequence of leaving pot plants un-watered for an extended period of time such as when watering is forgotten or the owner goes on vacation is that the plants die.

One method of countering this problem is to have a water reservoir at the base of the plant. This system has a number of disadvantages. Firstly the reservoir usually has insufficient capacity to provide water to the plant for a long enough period of time to substantially reduce the frequency of watering needed. Secondly such reservoirs can be difficult to fill with water. Thirdly, it is difficult to provide a reservoir which can supply water to the plant as it is required and at the same time not over-water the plant to cause waterlogging or "wet feet" when the reservoir is full of water.

Attempts to overcome these problems with water reservoirs have resulted in the use of wicks to draw water from the reservoir into the plant growing medium. This method has not been very successful because the wick fails to accommodate to the changing needs of the plant as it grows or as the humidity or temperature changes.

Another method of providing a water reservoir for plants is the placement of a pot plant container with holes in the base into an outer container which does not have a hole in the base, analogous to a deep tray such as mentioned above. The disadvantages are limited water capacity, the tendency to produce waterlogging and difficulty of filling.

A further disadvantage with existing plant containers is that the water is exposed to atmospheric conditions which result in evaporation of the water before the plant has been able to absorb it. This results in the tray or reservoir situated below the plant being needed to be filled more frequently.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

The disclosure and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

DISCLOSURE OF INVENTION

According to one aspect of the present invention, there is provided a fluid store and dispenser including

a) a first container for holding the item to which fluid is to be applied, and b) a second container positioned and sealed [apart from c) and d)] with respect to the first container so there is an air-tight reservoir for fluid between an outer surface of the first container and an inner surface of the second container, and

c) a fluid entry system that allows the passage of fluid from the said reservoir between the container walls to the inside of the first container, and

d) a sealable hole, port or other method of access which allows the said fluid reservoir to be filled with fluid.

For ease of reference throughout this specification the fluid store and dispenser will now be referred to as a plant pot as this is the preferred form of the present invention. It should be appreciated however that the present invention could be used to apply fluid to items other than plants in plant pots and to items other than those in pot plant containers.

Likewise, the item to which the fluid is to be applied shall now be referred to as a plant.

The fluid may be any suitable fluid, however in most embodiments it is envisaged that the fluid will be water.

The fluid may however in some instances include fertilisers, plant nutrients and other substances which may assist in the growth of the plant. The terms 'water' and 'fluid' are used herein to include aqueous solutions of such plant nutrients and fertiliser.

In other instances the fluid may have chemicals or additives to alter the properties, growth or appearance of the plant. For example, preservatives, perfumes or colours may be added to the water so that the plant becomes preserved or different in smell or appearance or growth from what it otherwise might have been.

Providing an air-tight reservoir for fluid between the outer wall of the first container and the inner wall of the second container overcomes a number of the problems associated with the prior art.

Firstly, there is provided an additional storage capacity for fluid for the plant. This obviates the need to have sources with all of the aforementioned problems including lack of aesthetics, spillage and insufficient fluid available for extended periods.

Another advantage of the additional volume is that a far greater capacity and therefore prolonged life of plants between watering is possible in comparison with conventional saucers, trays and typical reservoirs that are positioned at the base of plant pots.

Yet another advantage of the present invention is that it is not necessary to fill a reservoir at the base of the plant pot which can lead to spillage and damage to the plants.

The present invention allows for a sealable port within the second container, preferably at or near the top of the plant pot which is readily accessible allowing for simple filling of the reservoir via the port. This port may also contain a feature which indicates to the consumers when the water reservoir between the walls of the first and second container is empty or near to empty.

In one embodiment of the present invention the port incorporates an air tight cap which can be opened to re-fill the reservoir between the two containers, once the indicator informs the consumer that the level of water is nearing empty. In a preferred embodiment of the present invention the inner and outer containers may be fixedly attached to each other, although it is envisaged that in other embodiments a looser arrangement may be possible.

It is envisaged that in preferred embodiments the containers are attached to each other and sealed at their respective top edges. Not only does this contribute to the aesthetics of the present invention, but this also provides an air-tight reservoir for the fluid. This ensures that the exposure of the water in the reservoir to external atmospheric conditions is minimised and therefore the water is not subject to evaporation (except through the soil) or available for growth of mould and breeding of insects such as mosquitoes. This has the advantage of preserving the fluid contained in the reservoir for the sole use by the plant, thus preventing more frequent fillings being necessary, which is the case when conventional plant reservoirs are exposed to evaporation.

In an alternative embodiment of the present invention the container can be sealed using a base on the bottom which forms the flat surface for the container to rest upon. This may form the lower section of the reservoir space. The air tight cap at the top of the container allows for the container to be filled with water and then sealed to maintain a partial vacuum above the water surface.

In a further alternative embodiment of the present invention, a method of manufacture of the reservoir may be to have an inner and an outer container, with the inner and outer containers being joined by means of matching screw threads near the top of these vessels. The tightening of the thread exerts pressure on a sealing washer or O-ring to make a gas tight seal such that a vacuum can be maintained in the upper part of the reservoir thus created. For refilling of the container, the thread is undone and aqueous fluid poured into the reservoir between the containers to a set level, such as may be marked on the outer container. The two containers are then re-united by screwing them together. Alternatively, a bayonet fitting or clip fitting, together with a sealing device, may be used to hold the inner and outer containers together and airtight at the join.

In preferred embodiments, the present invention adopts a feature of the conventional plant container, in that the inner container features one or more hole(s) at its base and/or sides which allows the growing medium and/or the plant's roots to draw water from the reservoir. The water transfer from the reservoir between the two containers into the growing medium and the plant's roots is achieved through hole(s) at the base and/or sides of the inner container. This forms part of the passage from the reservoir to the soil in the first container.

In an alternative embodiment of the invention, some or all of the base or lower part of the inner container may be porous to water, or have one or more hole(s) which are covered with a porous material to produce a porous interface between the growing medium and the reservoir in order to allow water to be drawn into the inner container by capillary action while preventing any soil or growing medium from falling through the hole(s) into the bottom of the water reservoir. The use of such a porous interface can also assist in controlling the usage of water by the growing medium and the plant.

The space between the two containers which forms the reservoir for the water to be stored in may be divided into two sections. The two sections may be sealed except for one or more hole(s) which allow water and air to pass between the two sections. In another embodiment of the present invention, the rate of water transfer into the growing medium for use by the plant may be controlled by a pressure valve or slow release system. The valve may be in the form of an air leak in the top of the reservoir or in the reservoir filling hole cap which allows sufficient air to leak in each day to allow the reservoir to supply an equal volume of water to the plant. Alternatively the valve may be placed in the passage between the reservoir and the growing medium and allow water to pass, but regulate the water flow to suit the requirements of the growing medium and the plant.

In a further embodiment, the admission of water to the growing medium and plant is controlled by an electronic system which determines the moisture content of a region of the growing medium and operates one or more valves allowing the passage of air or water to enable water to be transferred to the growing medium to maintain the correct moisture content. Such an electronic system may also incorporate an alarm or warning when the available water supply is exhausted or is not operating. This electronic control system may be used with one or more plant containers, and it may be used to control the filling of the reservoir from a second water supply or to supply the growing medium direct from an external water supply.

In a further embodiment of the present invention, the inner and outer containers may form only one component. These can be moulded leaving a cavity between the two for the storage of water.

The versatility of the invention can be further improved by incorporating attachments or cavities for plant frames, stakes or other supports within or as part of the mouldings of the container. Attachments can also be used to allow the invention to be used for hanging the container. These additions allow climbing or hanging plants and plants that need support to be grown in the container with the minimum of attention.

A further aspect of the present invention is that the outer container may feature a clear strip which could act as a water indicator. This feature would inform the consumer of when the reservoir of water was nearing empty and therefore needed refilling.

A further aspect of the present invention is that either or both of the walls of the inner and outer containers may be transparent thereby informing the consumer of the level of water in the reservoir.

Another aspect of the invention provides a water level measuring system that indicates to the operator when the water level in the reservoir is low and needs replenishing. For example this can be effected by the use of probes in the reservoir associated with an electronic circuit for sensing and warning of low water levels. Such a circuit may be self powered by using electrodes of different metals such as copper and zinc which form a potential difference when immersed in an aqueous electrolyte which can operate a meter or an electronic device. Alternatively a float within the reservoir containing magnetic material can roll or slide a corresponding magnetic material indicator on the outside of the container up and down as the water level varies to indicate the level.

In another embodiment of the present invention, the fluid level indicator consists of an array of one or more, rods or bars of transparent material of different lengths formed as part of a unit, arranged so that the array of bars or rods extends downwards into the fluid from a point at or near the top of the fluid reservoir. The lower end of each rod or bar is shaped in the form of a cone or prism such that internal reflection of light entering the bar from the top causes the upper end of the bar to appear to be illuminated. Such internal reflection occurs from the bottom end of each bar or rod when the prism or conical end is not immersed in an aqueous fluid. When it is immersed in aqueous fluid, internal reflection does not occur and so light is not reflected back up the rod or bar. The top end of the bar therefore appears to be dark when the shaped part of the lower end is immersed in fluid, and illuminated or ight' when this end is not immersed in fluid, ie. is above the fluid level. To make this construction useful, the upper ends of the bars or rods are united into a common transparent block which may be part of the sealing cap for the reservoir. Each area on the upper face of the transparent block corresponding to a rod or bar extending from the underside may have a figure or annotation on it which relates to the fluid level. By using an array of different lengths of bars, an indication of the liquid level can be obtained by noting the corresponding ight' annotations on the upper block.

An alternative fluid indicator is obtained by forming a transparent cap or cover which is applied at or near the top of the fluid reservoir. A shaft or wire may extend downwards from under this cap to contain and guide a lightweight float such as one made of plastic foam. Annotations are inscribed on the top of this float, or on a thin plate or label attached to said float so that an indication of the height of the float and thus the fluid level is visible through the transparent material on the cap or the cover. One form of this is to have the underside of the cap or cover frosted so that the annotations on the float are only visible when it is close to the cap. Another is to have the underside of the cap or cover angled so that refraction of the light passing through the cap or cover makes a different part of the annotations on the top of the float visible according to its level. Alternatively, the transparent cap may incorporate concentric lens forms or prism sections such that different parts of the top of the float are visible at different levels of the float. The annotations on the float that are visible in each case indicate the water level in the reservoir.

In yet another aspect of the present invention there may be included in the reservoir a method of display of information, messages or advertising through a transparent version of the outer container. This may be by means of a device which may float near the level of the water surface or may be fixed within the reservoir or on the outer wall of the first container or the inner wall of the second container. The said device may be made of any material and may portray pictorial or written information of any shape, nature or design. It may be symmetrical or asymmetrical and may float or be arranged to stay above, on or below the surface of the water.

A further aspect of the present invention is that there may be positioned in the water reservoir a heating element and temperature control circuits and/or regulators, or alternatively, a hot plate. This would allow the water contained in the water reservoir to be heated to a preset temperature and maintained at that temperature. Accordingly if the consumer wished to grow tropical plants or plants requiring warm temperatures, they would obtain the version of the present invention which features the heating ability and allow the plant's roots to be kept warm and/or to draw in warm water. This eliminates the need for a glass or hot house, and allows exotic and tropical plants and flowers to be grown year round in diverse climatic conditions external to the plant pot. A further aspect of the present invention is that there may be positioned in the reservoir, either by fixed means or not, a device to measure the level of the water or its temperature or to portray other information that may be relevant to the present invention.

An advantage of the present invention is that there is provided a method of eliminating the necessity for protective trays under plant containers, or for wick(s) between containers, whilst at the same time providing a self regulating watering system which is aesthetically pleasing and useful.

A preferred embodiment of the invention is a self regulating plant watering system which relies on the vacuum created by the sealing of the water reservoir between the inner and outer containers to stop the water flowing freely into the inner container through the hole or porous medium in or near its base. Provided contact is maintained between the water in the reservoir and the growing medium in the inner container via the hole(s) or porous material in the base of the inner container, capillary action draws water into the growing medium and keeps this wet to a level which depends on the capillary spaces in the growing medium. The water in the growing medium rises to a height where the capillary force is balanced by the vacuum force in the upper region of the reservoir. As water is removed from the growing medium by the plant roots and by evaporation through the soil, the capillary head is maintained by drawing more water from the reservoir. If the height of water in the reservoir changes by, for example, 300 mm, the vacuum pressure in the chamber will alter by less that 1/30 of an atmosphere, and so the capillary head height will remain relatively constant. This mechanism results in a self-watering plant system. The relative wetness conditions required for different plants can be controlled by using different growing media with different average pore dimensions which maintain a different capillary head, as indicated by Gauss' equation for capillary force. In addition, cyclic temperature changes can alter the pressure in the relative vacuum above the water in the reservoir and drive additional water into the growing medium.

This cycle is repeated over a period of time until the water within the cavity is used up. The plant remains healthy because it is not flooded continually or subjected to a wet/dry/wet cycle as with conventional systems.

Self watering plant containers based on these principles may require priming in order to ensure that there is a continuous body of water between the growing medium and the water reservoir. Priming is typically carried out by placing the growing medium in the container and planting the seeds or plants in the medium. Then the reservoir is filled with water or a suitable nutrient solution and the airtight sealing cap is left off long enough for the fluid to soak into the growing medium and form a continuous body of water between the reservoir and the medium. The reservoir may be further topped up at this time, and then it is sealed by closing the filling hole with the sealing cap.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 is a cross-sectional view of a plant pot in accordance with one embodiment of the present invention. Figure 2 is a cross-sectional view of a plant pot in accordance with a further embodiment of the invention.

Figure 3 is a cross-sectional view of a plant pot in accordance with a further embodiment of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

The plant container generally indicated by arrow 1 consists of an outer container 2 which can be transparent or decorative and may be made of any material such as plastic, ceramic, aluminium, glass or terracotta for example.

The inner container 3 can be made of any material either rigid or flexible but would have to be of a generally similar shape and somewhat smaller size than that of the outer container 2.

The two containers are attached together by an upper rim 4 which connects the two containers thereby holding the inner container 3 in a fixed position in relation to the outer container.

The space between the two containers forms a water reservoir 5.

The two containers are attached at the top with the upper rim 4 which forms an air tight seal between the two containers. It is either removable or contains a hole which can be sealed by the use of an air tight cap 6. This allows water to be poured into the reservoir 5 between the two containers.

The inner container 3 contains one or more hole(s) or porous sections 7. The plant situated in the inner section 8 of the inner container 3, by capillary action absorbs the water in the reservoir 5 through the hole(s) 7. The absorption speed is at least partly regulated by the speed of the plant absorbing the water.

The embodiment showing the heating element and temperature control circuits and/or regulators or alternatively the hot plate is shown in Figure 2. A heater element 9 is placed in the bottom of the reservoir 5 with its heating controlled by a thermostatic unit 10 to ensure that a suitable water temperature in the reservoir, and by thermal conduction in the plant growing medium, is maintained. Accordingly the water being absorbed by the plant's roots would be heated and maintained at a preset temperature.

The embodiment showing a method of display is shown at Figure 3. Accordingly the water temperature, advertising, messages or other information may be displayed by such a device 11 which may be incorporated into the construction of the container or fixed to the walls of the inner and/or outer container or alternatively another device 12 can be left free to float in the water and to display messages and indicate the water level in the reservoir. In this embodiment the outer container 2 consists of transparent material through which to view such displays.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.

Claims

1. A fluid store and dispensing unit which includes an integral fluid reservoir for providing water and nutrient to the plants in the container.

2. A fluid store and dispensing unit including a fluid reservoir wherein the plant can draw water or nutrient solution from said reservoir to sustain itself for prolonged periods.

3. A fluid store and dispensing unit including

a) a first container for holding the item to which fluid is to be applied, and

b) a second container positioned with respect to the first container to provide an air-tight reservoir for fluid between the first and second containers, and

c) a fluid entry system that allows the passage of fluid from said reservoir to the item to which fluid is to be applied, and

4. A fluid store and dispensing unit as claimed in claims 1 to 3 in which the fluid in the reservoir is supported against gravity by means of a partial vacuum above the fluid.

5. A fluid store and dispensing unit as claimed in claims 1 to 4 in which there is provision for a body of water to form a continuous connection between the reservoir and the growing medium surrounding the plant roots.

6. A fluid store and dispensing unit as claimed in claims 1 to 5 in which the two containers are attached together by an upper rim that is either removable or contains a hole which can be sealed by the use of an air tight cap, through which the reservoir may be filled with fluid.

7. A fluid store and dispensing unit as claimed in claims 1 to 5 in which the two containers are attached together by the flat base of the container which forms the lower section of the reservoir space.

8. A fluid store and dispensing unit as claimed in claims 1 to 5 in which the two containers are attached together and sealed by matching screw threads, bayonet fitting, clip fitting or other attachment means with a deformable sealing material to provide air-tightness.

9. A fluid store and dispensing unit as claimed in claims 1 and 8 which contains an air tight cap at the top of the container which allows for the reservoir to be filled with fluid and then re-sealed.

10. A fluid store and dispensing unit as claimed in claims 1 to 9 wherein there is porous material separating the growing medium containing the plant roots from the fluid reservoir.

11. A fluid store and dispensing unit as claimed in claims 1 to 10 in which fluid is drawn into the growing medium surrounding the plant roots from the fluid reservoir by means of capillary action.

12. A fluid store and dispensing unit as claimed in claims 1 to 11 wherein the fluid is released to the plant by a controlled leak of air into the partial vacuum supporting the head of fluid in the reservoir.

13. A fluid store and dispensing unit as claimed in claims 1 to 12 wherein a valve is used to regulate the amount of fluid supplied to the plant from the reservoir.

14. A fluid store and dispensing unit as claimed in claims 1 to 13 that is self watering in that it automatically draws fluid from a reservoir to maintain a suitable moisture content in the growing medium around the plant for an extended period of time until the reservoir is empty and continues to operate in this manner as long as the reservoir is periodically refilled.

15. A fluid store and dispensing unit as claimed in claims 1 to 14 in which the fluid level in the reservoir is indicated by the change in relative refractive index between transparent material immersed in aqueous fluid and the same transparent material immersed in air causing the absence or presence of total internal reflection in one or more rods or bars of different lengths extending downwards into the fluid reservoir, with said internal reflection illuminating markings on the upper surface of the transparent material connecting to or containing the transparent bars or rods.

16. A fluid store and dispensing unit as claimed in claims 1 to 14 in which the fluid level in the reservoir is indicated by a rollable or slidable magnetic object which is magnetically attracted to and held adjacent to a magnetic float within the reservoir that floats on the surface of the fluid in the reservoir.

17. A fluid store and dispensing unit as claimed in claims 1 to 14 in which the fluid level in the reservoir is indicated by the visibility of markings associated with a float which floats in the fluid within the reservoir and which is guided by an extension from the reservoir filling cap such that the level indicating markings associated with the float are visible through the filling cap when there is adequate fluid in the reservoir.

18. A fluid store and dispensing unit as claimed in claims 1 to 17 in which the reservoir contains nutrients, chemicals, perfumes, colours or other chemicals in order to alter the growth, appearance or properties of the plant within the container.

19. A fluid store and dispensing unit as claimed in claims 1 to 18 wherein there is provision for connection to an external water supply to refill the reservoir manually or automatically.

20. A fluid store and dispensing unit as claimed in claims 1 to 19 wherein fluid is provided to the plant in the container via one or more holes or porous apertures in the base and/or sides of the inner container.

21. A fluid store and dispensing unit as claimed in claims 1 to 20 in which visible or audible means are provided for indicating the water level in the reservoir and for showing when the water level in the reservoir has deceased to a point where refilling is desirable.

22. A fluid store and dispensing unit as claimed in claims 1 to 21 wherein the outer wall is transparent or has a transparent section.

23. A fluid store and dispensing unit as claimed in claim 22 wherein advertising, messages, information or writing is placed within the reservoir volume such that it is visible from outside of the plant container.

24. A fluid store and dispensing unit as claimed in claims 22 and 23 wherein the advertising, messages or information is placed on a floating device within the reservoir that changes position as the water level in the reservoir changes.

25. A fluid store and dispensing unit as claimed in claims 1 to 24 that includes a moisture sensor within the inner container containing the growing medium surrounding the plant roots which controls the amount of fluid supplied to the growing medium for the plant to grow in.

26. A fluid store and dispensing unit as claimed in claims 1 to 25 which is externally sealed such that fluid cannot leak from the plant growing medium to any object supporting or placed near or under the plant container.

27. A fluid store and dispensing unit as claimed in claims 1 to 26 wherein there is a heater and thermostatic control of the heater to keep the fluid in the reservoir and the plant growing medium at a higher than ambient temperature.

28. A fluid store and dispensing unit as claimed in claims 1 to 27 in which the reservoir is permanently or semi-permanently connected to a water supply wherein water is provided from the water supply to the plant in the container via one or more holes or porous apertures in the base of the inner container.

29. A fluid store and dispensing unit as claimed in claims 1 to 28 which includes apertures, orifices or attachment points for plant support structures and for hanging the container in order to allow plants which require such support or such an environment to be grown in the said container.

30. A fluid store and dispensing unit as claimed in claims 1 to 29 in which no free water or liquid is exposed to the surrounding air or atmosphere.

31. A fluid store and dispensing unit substantially as herein described with reference to and as illustrated by the accompanying examples and/or drawings.