Technical field

The invention relates to cultivation, particularly to automatic watering systems. It is also related to a self-actuated control valve, particularly the one that can be opened or closed itself under the effect of water flowing through it.

Description of the related arts

In addition to other factors such as nutrients (fertilizers) and care, plants need regular watering at a certain degree for their growing, i.e. for their roots to get sufficient moisture.

An ordinary watering method is to regularly feed water to maintain the moisture at roots. Nevertheless, over-watering can turn top soil either hardened or flooded and consequently, roots fail to expose to oxygen in a long time. In the other hand, high moisture is favorable for diseases, mosses and moulds to develop at roots and as a result, plants are stunted, Under-developed and all that lead to low yields.

In general, plants should be exposed to proper temperature, light and low humidity of the air. Besides the water consumed by plants in their growth, some of water evaporates from the soil /growing medium to the air and the soil moisture is therefore reduced. When the. weather is hot and dry, the high air temperature and low humidity speed up evaporation and the moisture of soil/growing medium is quickly reduced, and eventually, if water is not fed timely and sufficiently, plants are likely to be weakened or even dead after several days of dehydration. Therefore, it is always necessary to provide a proper system to maintain moisture of soil /growing medium.

With any system for sprinkling water over soil /growing medium, a large amount of water is wasted because some water falls in furrows, some evaporates shortly from the surface, and only a small part can reach the soil around roots and function to maintain moisture there. Drip or trickle watering is more advantageous as water is directly fed to the soil around roots. Nevertheless, drip watering systems require big investment as they need specialized pumps and watering pipes, which should have very small diameters for dripping and at the same time, an ability against moss in order to avoid choking, etc. Further, a drip watering system usually accompanies with high operational expenses as its pump should continuously work in order to maintain sufficient pressures to bring water through very small pipes, that means it continuously consumes energy, not to say it requires workers for regular monitoring and maintenance to avoid troubles that might discontinue watering and badly affect the growth of plants. Meanwhile, shifting from frequent or continuous regime to an on-and-off regime based on moisture of soil /growing medium necessitates complicated equipment and devices such as sensors, valves, control switches, etc., that means large investments and inappropriateness to current conditions of rural areas.

There are many solutions for automatic watering plants, for instance, use of a wick to carry water from a container to the soil /growing medium.

Another approach is using the wick properties of the soil/growing medium itself as disclosed in the Vietnamese patent application numbered 1-2003-01778 of the same author of this invention. Accordingly, a self-watering pot with a body having two layers to provide a water container therebetween, two communicating pipes connected to the bottom of the upper part of the body; the middle part of the body having an upper portion, a middle portion having through holes and a lower portion; a support plate stopping the lower end of the lower portion of the middle part of the body is distanced from the lower part of the body; and growing materials are packed inside the middle part of the body, thereby water can infiltrate from the water container to growing materials, that is automatic watering based on consumption.

A drawback of those solutions is that the water containing part has a small capacity and their scope of application is thereby limited, i.e. only to pot plants.

In order to decrease the feeding frequency of water to a container, it is possible to apply the principle of communicating vessels (containers containing a homogeneous fluid, when the liquid settles, it balances out to the same level in all of the containers) in order to extend the water containing part. It is also possible to apply the principle of communicating vessels for watering pot plants, for instance, self- watering flower pots, where water from the container is wicked (via a wick with one end in water and another end in soil) to soil. Still, solutions in this group are dependent upon the absorbability of wick, and therefore infeasible when pots or growing areas are far from water containers. It is apparent that a matter in those wick- using solutions that how to feed water to the wick in a frequent and stable manner. To date, there is no solution that focuses on this matter and therefore there is an unsatisfied demand for an automatic watering system, particularly the one with low investment and operation costs, the ones which are simple yet effective in reduction of water consumption, and more importantly, the ones that can apply to various kinds of plants such as industrial plants, fruit trees that grow in soil/growing medium.

The present invention provides an automatic watering system that meets the aforementioned demand. Disclosure of the invention

An object of the invention is to provide a simple wick watering system that automatically water plants based on consumption at a low operation cost.

Another object of the invention is to provide a wick automatic watering system of low investment. The invention achieves the first object by providing an automatic soak system for watering plants, the system comprising: a main water supply line with a valve; a tightly closed tank with an upper pipe connector and a lower pipe connector; pipelines; and at least a water supply set including: a spring check valve, a three gate valve set, a one-way valve; and a tray having walls higher than its bottom and at least one the control point and at least one the water receiving point; wherein the one-way valve is arranged in the line from the upper pipe connector of the tightly closed tank to the control point of the tray; the three gate valve set has a first port connecting to the outlet of the spring check valve, a second port connecting to the line that feeds water to the water receiving point of the tray and a third port connecting to the inlet of the tightly closed tank; the automatic controller control the three gate valve set on the basis of water level in the tray at the control point so that the main water supply line feeds water to the tightly closed tank via the first port and the third port while the second port closes or the tightly closed tank feeds water to the tray via the third port and the second port (V32); and

the control point is higher than the water receiving point.

The invention achieves the second object by providing a self-actuated three- port valve comprising of: a tubular case consisting of two sections in series forming a lower inlet, an upper outlet, and a horizontal gate, respectively providing a lower port, an upper port and a horizontal port; a valve needle freely moving up and down inside the tubular case; the valve needle having a cylindrical body with a lifting ring amid its length, the diameter of the lifting ring is substantially smaller than the inner diameter of the tubular case; the valve needle with the upper end and the lower end expanding to form a male face block while the upper and lower ends of the inside face of the tubular case having female faces such that the upper and lower ends of the valve needle fit to the upper and lower of the inside face of the tubular case, thereby forming a male-female sealing and making it possible to open/close the upper port, and the lower port.

Brief description of drawings

The nature and further characteristics and advantages of the present invention will be described in more detailed with reference to illustrative figures, where: Fig. 1 is a diagram showing an automatic watering system for plants in an embodiment of the invention;

Fig. 2 is a perspective view of a self-actuated three-port valve in an automatic watering system in an embodiment of the invention;

Fig. 3 is an exploded perspective view of the self-actuated three-port valve in

Fig. 2;

Fig. 4 is a cross-section view of the self-actuated three-port valve in Fig. 2;

Fig. 5 is a cross-section view of the self-actuated three-port valve in Fig. 2 at a first state;

Fig. 6 is a cross-section view of the self-actuated three-port valve in Fig. 2 at second state;

Fig. 7 is a symbol of the self-actuated three-port valve of the invention at the state shown in Fig. 5;

Fig. 8 is a symbol of the self-actuated three-port valve of the invention at the state shown in Fig. 7;

Fig. 9 is a diagram illustrating the operation of an automatic watering system for plants in an embodiment of the invention;

Fig. 10 is a perspective view of a tray in an automatic watering system in an. . embodiment of the invention;

Fig. 11 is a cross-section view showing a tray in an automatic watering system in an embodiment of the invention;

Fig. 12 is a cross-section view showing a tray in an automatic watering system in another embodiment of the invention;

Detailed description of the invention

As shown in Fig. 1, an automatic watering system for plants of the invention comprise of: a main water supply line (10) with a valve (VI); a tightly closed tank (20) with an upper pipe connector (21) and a lower pipe connector (22); pipelines; and at least a water supply set including a spring check valve (V2), a three gate valve set (V3), a one-way valve (V4); and a tray (30) having walls higher than its bottom and at least one the control point (31) and at least one the water receiving point (32); wherein the one-way valve (V4) is arranged in the line from the upper pipe connector (21) of the tightly closed tank to the control point (31) of the tray (30) the three gate valve set (V3) has a first port (V31) connecting to the outlet of the spring check valve (V2), a second port (V32) connecting to the line that feeds water to the water receiving point (32) of the tray (30) and a third port (V33) connecting to the inlet of the tightly closed tank (20); the automatic controller (38) control the three gate valve set (V3) on the basis of water level in the tray (30) at the control point (31) so thafthe main water supply line (10) feeds water to the tightly closed tank (20) via the first port (V31) and the third port (V33) while the second port (V32) closes or the tightly closed tank (20) feeds water to the tray (30) via the third port (V33) and the second port (V32); and the control point (31) is higher than the water receiving point (32).

In soak watering systems of the invention, the valve (VI) functions to open/close to carry water to the whole system.

The spring check valve (V2) functions to allow only water at a certain pressure in order to carry water from the main line (10) to the tightly closed tank (20) and prevent water from flowing in the opposite direction. The tightly closed tank (20) may have a water level gauge (40) for conveniently monitoring the leftover volume of water in the tightly closed tank (30) and making up (from a main water supply line) when needed. Further, a pump (not shown in the drawing) may be provided to create sufficient pressure to carry water up to the tank if it is elevated. During operation, there is a reduced pressure inside the tightly closed tank (20) that avoids water from freely flowing therefrom to the tray (30). The role of the oneway valve (V4) is to maintain water inside the pipeline from the tightly closed tank

(30) to the control point (31). Preferably, the type and the position of the one-way valve (V4) is chosen so that water cannot flow in the top to bottom direction and air bubbles can go through the alve in the reverse direction. Furthermore, it is easy to carry out a test to determine an appropriate angle of the pipeline from the one-way valve (V4) to the upper pipe connector (21) of the tightly closed tank (20) for air bubbles to go through it easily. In the system of the invention, there are the control point (31) and at least one water receiving point (32); wherein the control point (31) is higher than the water receiving point (32), that is the height Tl from the tray bottom to the control point

(31) is larger than the height T2 from the tray bottom to the water receiving point (32) as illustrated in Fig. 1. The three-way valve set (V3) may comprise of many controllable valves, for instance valves controllable by means of compressed air, and electro-magnetic valves well known in the art. There are many literatures describing proper operations and arrangements of valves and pipelines together with automatic controllers to achieve objectives as desired, i.e. to control the three gate valve set (V3) on the basis of the water level in the tray (30) at the control point (31) with two operation states:

(1) Water making up: the main water supply line (10) feeds water to the . tightly closed tank (20) via the first gate (V31) and the third gate (V33) while the second gate (V32) is closed; and

(2) Soak watering: the _; tightly closed tank (20) feeds water to the tray (30) via the third gate (V33) and the second gate (V32).

In fact, the control mentioned above corresponds to three branches, each of which has a pneumatically or electro-magnetically controllable valve and a controller is designed to function as follows: (1) Water making up: opening the main water supply valve, the first valve and the third valve and closing the second valve when an air bubble from the control point appears and this state is maintained until air bubble no longer appears and at that time, the system shifts to the second state; (2) Soak watering: closing the first valve and opening the second valve and the third valve.

The automatic controller (38) can also control the valve (VI) of the main water supply line (10).

In the state of water making up, the valve (VI) (and a pump, if needed) is opened, water from the main water supply line (10) flows through the one-way spring valve (V2) and the first gate (V31) to the tightly closed tank (20) until the tightly closed tank (20) is full then water supply is stopped, that is the valve (VI) is closed.

In the state of soak watering, the tightly closed tank (20) carries water to the tray (30) via the third gate (V33) and the second gate (V32), that means the second gate (V32) and the third gate (V33) are opened, while the first gate (V31) can be optionally closed or opened because the downflow water is stopped by the one-way spring valve (V2).

Nevertheless, due to the reduced pressure inside the tightly closed tank (20) and the water inside the pipeline from the tightly closed tank (30) to the control point (31) as well, whereas the water receiving point (32) is lower than the control point (31), water cannot freely flow through the third gate (V33) and the second gate (V32). Only when the water level in the tray (30) is lower than the control point (31), the air can enter the control point (31) to make air bubbles.

Since one-way valve (V4) is properly arranged, air bubbles can easily go through the vertical pipe section (as air is lighter than water), and through the horizontal pipe section (thank to the reduced pressure in the tightly closed tank (20)) of the pipeline from the one-way valve (V4) to the upper pipe connector (21) and eventually enter the tightly closed tank (30), thereby increasing the pressure (i.e., decreasing the reduced pressure) inside the tightly closed tank (20), and allowing some water flows in the lower connecting pipe (22) via the third gate (V33) and the second gate (V32) to the water receiving point (32) and into the tray (30). The water entering the tray (30) increases the water level therein and that process continues until the water level in the tray (30) higher than the control point (31). At that time, air bubbles can no longer enter the control point (31), thereby the reduced pressure formed inside the tightly closed tank (20) keep water not flow down from the tightly closed tank (20). Because the system supplies water on the basis of the principle of communicating vessels, variations of water levels in the tightly closed tank (20) and the tray (30) are self stabilized. As a result, the supply of water from the tightly closed tank (20) to the tray (30) is stable.

In the watering system of the invention, T1-T2 is the stable volume of water in the tray (30) and thank to it, water is supplied based on consumption, which includes use by plants and loss due to evaporation.

It is apparent that the soak watering of the invention works based on the principle of communicating vessels, and it is therefore possible to properly arrange a single main water supply line (10) to carry water to a plurality of tightly closed tanks (20), and each tightly closed tank (20) can supply water for many trays (30). In this variation, it is noteworthy to arrange the trays at substantially equal elevations.

Furthermore, depending on the nature of plants and climate, it is possible to calculate and arrange tightly closed tank(s) of appropriate capacity.

An advantage of the soak watering system for plants of the invention is that it needs not to keep constant pressure in the water supply pipeline, and therefore, it needs not specialized pipes and pumps and its operation is cost-effective.

Furthermore, the main water supply line (10) can carry water to many tightly closed tanks (20), and one tightly closed tank (20) can also feed water to many trays (30) when proper T-connectors are used, preferably the T-connectors mentioned in the Vietnamese patent application numbered 1-2014-02490 of the same author of this invention. By arranging many tightly closed tanks (20) and or many trays (20) as mentioned in the above embodiments, it is possible to cut down part of investment. Nevertheless, that fails to remedy the drawback as the controller (38) and controllable valves of the three gate valve set (V3) are expensive. Therefore, the invention provides a self-actuated three-port valve (50) as illustrated in Figs. 2 to 4. The self-actuated three-port valve in a preferred embodiment of the invention comprises of: a tubular case (500) consisting of two sections (501, 502) in series forming a lower inlet (501), an upper, outlet (502), and a horizontal gate (503), respectively providing a lower port (51), an upper port (52) and a horizontal port (53); a valve needle (54) freely moving up and down inside the tubular case (500); the valve needle (54) having a cylindrical body (541) with a lifting ring (544) amid its length, the diameter of the lifting ring is substantially smaller than the inner diameter of the tubular case (500); the valve needle (54) with the upper end and the lower end (542, 543) expanding to form a male face block while the upper and lower ends of the inside face of the tubular case having female faces such that the upper and lower ends of the valve needle (54) fit to the upper and lower of the inside face of the tubular case (500), thereby forming a male-female sealing and making it possible to open/close the upper port (52), and the lower port (51).

The self-actuated three-port valve of the invention can be made from well known plastic materials, preferably by molding. Since the tubular case (500) comprises of two sections, it is easy to mount the valve needle (54) inside it. The two sections (501, 502) can be fixed to each other by well known methods such as adhesion with an adhesive, thermal adhesion, or fabrication with a tenon-slot structure in order to fix by pressure, or threading, etc. to ensure the tightness of the tubular case (500).

The term "male - female sealing" means that two faces that can press tightly to each other and stop the passage through the valve. The male - female sealing may be a planar, spherical, conical, or truncated conical surface, preferably a conical surface of the upper end of the valve needle (54) and/or the reverse truncated conical surface of the lower end of the valve needle (54) as shown in drawings.

The mode of operation of the self-actuated three-port valve (50) of the invention is illustrated in Figs. 5 and 6, corresponding with the symbols in Figs. 7 and 8, with details as follows:

In the first state as illustrated in Fig. 5, when water is pumped through the lower gate the lower gate (51), the pressure of water together with the resistance of the lifting ring (544) push up the valve needle (54), thereby the upper end of the valve needle (54) presses to the inner surface of the upper end of the tubular case (500), forming a male - female sealing that tightly closes the upper gate (52), then water runs out through the horizontal gate (53). This state corresponds to the symbol in Fig. 7 with the white-head arrow indicating the direction of the water flow through the valve, i.e. from the lower gate (PI) to the horizontal gate (P2). In the second state, since there is a flow of water from the horizontal gate (53), gravity effectuates the valve needle (54) and together with water pressure, it pushes down the valve needle (54), thereby the lower end of the valve needle (54) presses to the inner surface of the lower end of the tubular case (500), forming a male - female sealing that closes the lower gate (52), and water therefore flows out via the upper gate (52). This state corresponds to the symbol in Fig. 8 with the white-head arrow indicating the direction of the water flow through the valve, i.e. from the horizontal gate (P2) to the upper gate (P3)

Thus, the self-actuated three-port valve (50) of the invention works based on gravity and water flowing through it without devices, fittings or pneumatic or electro- magnetic controllers. That is an advantage of the invention, and also the background for designing, manufacturing and assembling automatic watering systems of low investment and operation costs.

Thanks to the structure and mode operation described above, it is clear that the self-actuated three-port valve of the invention should be arranged substantially vertical. Another advantage of the self-actuated three-port valve of the invention is that it is easily arranged in the basically vertical water supply line from the valve (VI) of the main water supply line (10) to the tightly closed tank (20).

Furthermore, the self-actuated three-port valve (50) of the invention is a perfect substitution for the three gate valve set (V3) in the automatic soak system for watering plants of the invention.

Fig. 9 illustrates an automatic soak system for watering plants where the self- actuated three-port valve of the invention is incorporated.

It is apparent that this system functions in a manner entirely similar with the system with the three gate valve set, i.e. in two states as follows: (1) Water making up: the main water supply line (10) supplies water for the tightly closed tank (20) via the lower gate (PI) and the horizontal gate (P3) while the upper gate (P2) closes; and

(2) Soak watering: the tightly closed tank (20) carries water to the tray (30) via the horizontal gate (P2) and the upper gate (P3). The first state is shown with a white-head arrow and a continuous line shaft and the second with a white-head arrow and a discontinuous line shaft.

An advantage of the system is the self-actuation property of the self-actuated three-port valve (50). By the functions of the self-actuated three-port valve (50), the gates can open or close correspondingly with the states of the system without any more controllers or sensors.

The watering system of the invention therefore requires neither continuous water supply nor complicated control over water supply. In fact, the operation is extremely simple, that is to open the valve (VI) until the tightly closed water (20) is full, then to close the valve (VI) for the system to automatically water plants based on consumption.

The watering system of the invention inherits all advantages of the soak watering method, which can avoid of waste water due to drip and drop or evaporation from the soil surface that means excellent saving of water. This is exceptionally important in agriculture, particularly in conditions of climate change when long lasting draughts appear in many regions, or in the regions where the development of industrial plants leads to overexploitation of underground water.

As illustrated in Fig. 10, in an alternative embodiment of the invention, the tray (30) further has slots (33). An advantage of this embodiment is that water from slots (33) can gradually soak to the soil or growing medium, avoiding of root rot when roots are entirely submerged in water.

One, two or more slots (33) can be provided. For a tray (33) with a limited width, two slots are enough for water to be distributed evenly on the tray bottom, and soaking to the soil or growing medium. In another embodiment as illustrated in Fig. 11, the tray (30) further has a wick material sheet (34) placed over the slots (33).

The term "wick material" means any material that can well soak and transfer water, for instance, sponge, coconut fiber, porous ceramic, etc.

The term "wick material sheet" means a wick material after processing, for instance, by cutting, compacting, covering in a net, etc. to produce a sheet that basically inherits the properties of good soak and transfer of water.

This embodiment enables to expand the scope of soak watering of the tray (30) since the wick material is capable of watering for the soil or growing medium not only above but also around it. The system is effective with the cooperation of slots (33) and the wick material sheet (34), preferably sponge.

In another embodiment, the automatic soak watering of the invention further has a net layer (35) below the wick material sheet (34), i.e. right above the bottom of the tray (30) as illustrated in Fig. 11. An advantage of this embodiment is that the net layer (35) covers the slots (33), and avoid wick materials, such as coconut fiber, from falling into slots (33), or avoid the wick material sheet (34), such as the sponge, from overly deformation and causation of a pressure on slots (33), thereby water flowing in slots (33) is not obstructed, that is water can be distributed evenly for soaking to the soil or growing medium. Dependent upon water consumption, i.e. dependent upon the nature of plants and weather conditions, it is allowed to adjust the elevation of the control point (36) to ensure that moisture is kept stable. Therefore, in another embodiment of the invention, the tray (30) further has a device to fix the control point (36) at one of its wall (37). In practice, the device (36) may be simply a pipe section fixed to the wall (37) of the tray (30) so as an end of the water supply pipeline can be inserted there through and fixed therein as shown in Figs. 10 to Fig. 12. In a preferred embodiment, the device fixing the control point is a bar, which has equally spaced markings along its length for easy adjustment and a clip for fixing the end of the water supply pipeline from the one-way valve (V4) to the tray (30).

In this specification, the term "the tray" indicates a flat, shallow object container with a raised rim, thereby capable of containing a certain amount of water for soaking to the soil or growing medium. Therefore, the face of tray (30) may be a rectangle, a diamond, a square, a semi-circle, an annulus or an arc as illustrated in Fig. 12. It is an advantage of the annular embodiment that the tray (30) can surround a plant and the system causes no bad impact on the growth of the plant.

A person skilled in the art can design and arrange a tray (30) compatible to pots for growing flowers, decorative plants, vegetable, and fruit trees, etc., to holes for planting perennial trees or industrial trees before planting same in the pots or holes. Alternatively, it is possible to arrange a tray (30) for watering available plants, i.e. by digging a suitable hole, placing the tray (30) around the plant root.

As such, the soak automatic watering system of the invention has a very broad scope of application. It allows designing and building up cultivation systems of various models. Advantages

The automatic soak watering systems of the invention have outstanding features such as simple parts easily produced and assembled at a low cost, simple operation, preferably the systems that incorporate self-actuated three-port valves of the invention are able to water plants in a stable manner with low investment and operation expenses. Therefore, such systems can apply broadly to agriculture, particularly in the regions where water resources are scarce.

An excellent effect of the systems of the invention is its help develop cultivation with effective use of water. That is very meaningful in the present context of climate change and increasingly scarcer resources of fresh water.

Other embodiments

It is noted that the embodiments described above are illustrative only for better understanding of the nature and scope of the invention, based on which, a person skilled in the art can make various modifications, for instance, changes in shape of parts, matters of construction, or components or parts in the system with matters of construction, components or parts of the same functions, for instance one-way pressure valve or horizontal ^, one-way valve, etc. Those embodiments are within the scope of the invention.