Portable irrigation device

Abstract

The invention provides a portable irrigation device for dispensing irrigation liquid from a container to a target plant holder substrate area. The device comprises a dispensing unit which is releasably attached to the container, a control unit for activating or deactivating the dispensing unit, and a discharge tube in fluid communication with the dispensing unit through which discharged irrigation flows. Irrigation liquid is discharged from the container as a result of pressurized air which is generated by said control unit and injected into the container.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of Israeli Application No. PCT/IL2004/000075 filed Jan. 27, 2004, which claims priority on U.S. Provisional Patent Application No. 60/442,666 filed Jan. 27, 2003. Said applications are included herein in their entirety by reference.

FIELD OF THE INVENTION

This invention relates to the field of portable irrigation devices, particularly, though not exclusively, useful for the irrigation of plants, e.g. potted plants. A simple device is provided which is inexpensive and permits to save irrigation water.

BACKGROUND OF THE INVENTION

Small scale agricultural irrigation, for which large and complex apparatus is unnecessary, is performed either automatically or manually. Automatic apparatus consists of spray units that are fixed or displaceable and are automatically operated at fixed times. Said units may be mechanical sprayers and may direct sprays in changing directions to cover broad areas of relevant growth, or may comprise rigid or flexible conduits having openings therein the allow irrigation water to issue in drops or thin streams. Hand operated apparatus generally consist of flexible pipes which deliver water streams or sprays from their end orifices and may be carried and directed by users to project said water streams or sprays as desired. Automatic apparatus is expensive and water consuming and is not adapted individually to irrigate plants, as it is always conceived to irrigate broad areas of vegetable growth. Hand operated apparatus may be inexpensive, but is awkward to use and is wasteful and inefficient in the irrigation of individual plants, as it generates streams or broad sprays of water which always spread the water over large areas.

Recently, drip irrigation has been employed in small scale agricultural applications in order to increase water efficiency. Water is applied only to those areas where it is needed, that is, it is dripped onto the soil above a root zone, and therefore only a relatively small amount is wasted. Drip irrigation depends on a pump and other ancillary equipment to force water through perforated pipes running above ground, at rates of 1-10 liters per hour per emitter. Even though the technology is simple, drip irrigation requires careful maintenance of equipment since the emitters can become easily clogged.

Liquid chemical additives, such as fertilizers, weed killers and pesticides, are generally added to the water which is pumped to the emitters of a drip irrigation system, so that a given soil area or substrate may support increased plant growth. In order to preserve its structural integrity, a pump for delivering a corrosive fertilizer solution, for example, to a drip irrigation system, needs to be made from expensive non-corrosive material such as stainless steel. Economic considerations therefore preclude, or restrict, the use of portable irrigation devices which are based on a drip irrigation system.

Some prior art irrigation devices employ an inverted reservoir to deliver irrigation liquid to a given plant growth substrate. Although such an irrigation device is economical, the delivery rate of irrigation liquid is not controllable, and therefore an inordinate amount of liquid is improperly utilized.

It is therefore an object of the present invention to provide a portable irrigation device which delivers a controllable rate of irrigation liquid for a predetermined duration.

It is an additional object of the present invention to provide a portable irrigation device which operates intermittently at desired times and which may be started and stopped instantaneously as desired.

It is an additional object of the present invention to provide a portable irrigation device which may deliver a fertilizer solution without compromising its structural integrity.

It is an additional object of the present invention to provide a portable irrigation device which may direct irrigation liquid to any desired target, within a limited area.

It is yet an additional object of the present invention to provide a portable irrigation device which is easy to use.

It is an additional object of the present invention to provide an inexpensive portable irrigation device.

It will be understood that a device having such features permits a most efficient irrigation with the least possible amount of water, since irrigation liquid is delivered at desired times and can be directed precisely to a desired target.

Other objects and advantages of the invention will appear as the description proceeds.

SUMMARY OF THE INVENTION

The invention provides a portable irrigation device for dispensing therefrom water or an aqueous solution containing a liquid chemical additive, such as fertilizers, weed killers and pesticides—hereinafter referred to as an “irrigation liquid”—, which increases the capability of given soil area or substrate to support plant growth.

The irrigation device comprises a container for irrigation liquid; a dispensing unit releasably attached to the container; a control unit for activating or deactivating said dispensing unit; and a discharge tube in fluid communication with said dispensing unit through which irrigation liquid is discharged from the container by means of pressurized air injected into said container, said pressurized air being generated by said control unit.

Following sustained operation of the dispensing unit, a steady stream of irrigation liquid is formed in the discharge tube and a predetermined dose of irrigation liquid is thereby deliverable to a desired target in a plant holder substrate. Said steady stream continues even upon deactivation of the dispensing unit, due to a siphoning effect.

Preferably, the irrigation device comprises an abutment plate formed with a liquid passageway and an air inlet; a discharge tube in fluid communication with said passageway; means for releasably attaching the container to said abutment plate such that the container wall surrounds said liquid passageway and air inlet; means for pressurizing air and delivering the pressurized air to the container via said air inlet, said pressurized air forcing irrigation liquid to flow through said liquid passageway and discharge tube; and control means for governing operation of said pressurizing means, said pressurizing means and control means being housed by a dispensing unit formed with said abutment plate. The expression “abutment plate”, whenever used, is not intended to limit the structure of the element to which it refers, which may have any convenient shape and need not be flat or thin or have any other specific structure: it need only be formed with a liquid passageway and an air inlet, and be such that it may perform the functions hereinafter described.

In a preferred embodiment of the invention, the pressurizing means comprises an air pump and a motor in driving engagement therewith.

Preferably:

Pressurized air generated by the air pump is delivered to the container via an air tube and the air inlet.

The container has a spout and the attaching means are standard, outer threads formed around the spout which are threadedly engageable with complementary inner threads formed in the underside of the abutment surface.

The container is a commercial container made for other purposes and previously used, as is the case of standard bottles of mineral water or soft drinks. The container is preferably a used container for water of soft drinks, which normally would be discarded after use and therefore has no cost or almost no cost. However, a specific container may be provided for the purposes of the invention, and the “standard threads” will be those defined about the spout of said specific container.

The device further comprises a conduit insertable within the container and in fluid communication with said passageway, said conduit reaching into the irrigation liquid as close as practical to the bottom of the container, while not coming into contact with it, to allow as much irrigation liquid as possible to flow out of the container through said conduit.

The conduit is supported by a sleeve downwardly extending from the abutment surface and in fluid communication with the passageway.

The container, conduit, passageway and discharge tube are made of a material stable in both acidic and alkaline environments.

A check valve is in fluid communication with the passageway for discharging irrigation fluid remaining in the discharge tube following deactivation of the air pump motor, said check valve preventing egress of irrigation liquid from the passageway and permitting ingress of air.

The motor is powered by batteries.

The discharge tube is flexible and is provided with an orifice for directing irrigation liquid drawn from the container to a desired target.

A dispensing unit is attachable to each of a plurality of containers, so that any desired irrigation liquid contained in a corresponding container may be dispensed to a target.

Each dispensing unit is programmed to operate according to a specific irrigation cycle.

The control unit comprises a central processing unit (CPU), memory means, such as a programmable read-only memory (PROM), a power source, an activation device, and optionally a selector, said CPU suitable for governing operation of the rotor of the air pump motor according to a selected irrigation cycle programmed into said memory means and at a predetermined time following the operation of said activation device.

In one aspect, the air pump is a bellows. The rotor of the motor is connected to a shaft which drives a cam, said cam being connected to the bellows by means of an eccentric pin protruding from said cam and imparting reciprocating motion to the bellows, thereby generating bursts of air.

In another aspect, the air pump is a piston pump. The rotor of the motor is connected to a shaft which drives the piston pump by means of a gear train, thereby imparting reciprocating motion to a piston axially displaceable within said pump and generating bursts of air.

The major advantages of this device are: It is portable; it can operate without supervision; itreliably and efficiently dispenses a predetermined dose of irrigation liquid to a target of a desired plant holder substrate at a predetermined time; it releases the irrigation liquid at a relatively uniform rate; it can use readily available irrigation liquid and soft drink containers; its performance is not affected by the selected type of irrigation liquid; it is simple to install and operate; and it is inexpensive to manufacture.

Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the preferred embodiment of the device, in which water is drawn from the container by means of air pressure.

FIG. 1 is a schematic, front view of an exemplary irrigation device, according to the present invention;

FIG. 2 is a partial, cross-sectional view of the housing of a dispensing unit, showing the fluid communication between a conduit placed in a container and a passageway which discharges irrigation liquid from the container to a target area;

FIG. 3 is a schematic plan view from above of an embodiment of the dispensing unit, its cover being removed;

FIG. 4 is a schematic, exploded, perspective plan view of another embodiment of the dispensing unit;

FIG. 5 is a plan view from above of the dispensing unit of FIG. 4, its cover being removed;

FIGS. 6 and 7 schematically illustrate the dispensing of irrigation liquid from a conventional, commercially available container to plant holder substrates;

FIG. 8 schematically illustrates the dispensing of irrigation liquid from a reservoir of irrigation liquid contained within a plant holder; and

FIG. 9 is a block diagram illustrating the control unit.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention relates to an unattended portable irrigation device which dispenses a controllable dose of irrigation liquid from a sealed container by means of bursts of air delivered into the container, which force the irrigation liquid to be discharged from the container via a conduit disposed therein.

FIG. 1 illustrates an exemplary irrigation device according to the present invention, and is generally indicated at 1. Irrigation device 1 comprises dispensing unit 5, container 10 threadedly enageable therewith, conduit 12 in fluid communication with the container and with the dispensing unit, discharge tube 30, and a control unit, which is schematically designated by numeral 35 and is illustrated in FIG. 9. Container 10, which is preferably a standard transparent or translucent bottle for soft drinks, as shown, having a volume of e.g. one or two liters, is partially filled with irrigation liquid as indicated at 11. Conduit 12 is disposed within the container and reaches near, but not to, the bottom of the container, as indicated at 13. All components of the irrigation device are advantageously made from readily available and inexpensive plastic material, such as polycarbonate, polypropylene and polyethylene, which are stable in both acidic and basic environments, over a wide range of pH values, and are therefore suitable for the dispensing of any irrigation liquid. The irrigation device is operated by depressing button 17 in conjunction with control unit 35, as will be described hereinafter.

Housing 9 of the dispensing unit is shown in FIG. 2. Housing 9 comprises a planar, housing bottom 14, curvilinear wall 15 encircling said housing bottom, and neck 16 curving upwardly from wall 15 for receiving a complementary housing cover 57 (FIG. 4). Battery compartment 21, motor compartment 23, and air pump compartment 45 (FIG. 3) extend upwardly from housing bottom 14. Housing bottom 14 is centrally recessed, forming substantially cylindrical wall 22 and top, abutment plate 25. Abutment plate 25 contacts top 27 of the spout of container 10, when said container (which is partially shown) is engaged with housing 9 to a maximum extent by means of complementary inner and outer threads formed in said wall 22 and in the container spout, respectively, and indicated together at 28a and 28b.

Conduit 12 is supported by sleeve 29, which downwardly extends from abutment plate 25. Sleeve 29 is provided with shoulder 33, which downwardly extends from abutment surface 25, for facilitating placement of conduit 12 about the sleeve. Aperture 34 is formed in abutment plate 25 between shoulder 33 and threading 28b, and serves as an inlet to the container for the bursts of air generated by the pressurizing means, which will be described hereinafter. As the air pressure within container 10 rises, irrigation liquid is forced to flow through conduit 12, sleeve 29, passageway 37 (also shown in FIG. 3), which extends upwardly and outwardly from abutment surface 25, and discharge tube 30 (FIG. 1) insertable and resiliently retainable within the passageway.

One embodiment of dispensing unit 5 is shown in more detail in FIG. 3. Motor 42, e.g. a direct-current stepping motor, which is retained by compartment 23, is powered by batteries, or any other convenient power source, housed in compartment 21. The rotor of motor 42 is connected to a shaft 44 which drives cam 48. Cam 48 in turn is connected to bellows 51 by means of eccentric pin 54 which protrudes from cam 48. Pin 54 thereby imparts reciprocating motion to bellows 51, causing the latter to be sequentially axially extended and compressed. Following each rotation of cam 48, a burst of air of approximately 1.5 atmospheres, the pressure of which being dependant on the rotational speed of motor 42, is generated by bellows 51 and is delivered to the container via air tube 55 and aperture 34 (FIG. 2). The device dispenses irrigation liquid through the discharge tube as long as motor 42 continues to be actuated.

FIGS. 4 and 5 show, in perspective view and plan view, respectively, another embodiment of the dispensing unit 5. In this embodiment the air pump is a piston pump. Motor 65, which is powered by battery 73, is retained by compartment 63 and drives piston pump 59 by means of a gear train generally indicated at 56, which imparts reciprocating motion to a piston (not shown) so that bursts of pressurized air may be generated thereby. Exemplary gear train 56 comprises pinion 61 mounted on the shaft of motor 65, bevel gear 67 which meshes with pinion 61 and carries concentric smaller spur gear 68, and larger spur gear 69 which is driven by smaller spur gear 68. Larger spur gear 69 carries rod 71 formed with a circular head 70. Circular head 70 is eccentrically connected to larger spur gear 69 and has an axis parallel to the axis of rotation of larger spur gear 69, and rod 71 is pivoted to the piston of pump 59. While head 70 is displaced along an eccentric, circular path of motion, rod 71 is guided in rectilinear motion by the casing of pump 59. Pressurized air exits piston pump 59 and is delivered to the container via air tube 55 and aperture 34 (FIG. 2). The device dispenses irrigation liquid through the discharge tube as long as motor 65 continues to be actuated.

Operationally, as shown in FIG. 6, irrigation device 1 is placed next to plant holder 75, such as a planter or a pot, while orifice 74 of discharge tube 30 is positioned proximate to a selected target of substrate 77 contained within the plant holder, so that irrigation liquid may be dispensed to said target. Orifice 74 may be imbedded within substrate 77, or otherwise fixed in position, to ensure that irrigation liquid is discharge to a desired target. Irrigation device 1 may be advantageously placed in an unobtrusive location relative to plant holder 75, in contrast to prior art unattended irrigation devices which are necessarily positioned directly over a target, whether in an upright or inverted orientation, compromising the esthetic presentation of the room in which the plant holder is located. If so desired, as shown in FIG. 7, irrigation device 1 may concurrently dispense irrigation liquid to multiple plant holders, e.g. planter 83 and pot 84, by means of bifurcation 86.

Alternatively, as shown in FIG. 8, unattended irrigation may be carried out with use of plant holder 89 containing reservoir 78 for body of irrigation liquid 81, as well as substrate 77 in which plant 82 is grown. Partition 88 separates liquid body 81 from substrate 77. After a sufficient amount of irrigation liquid is introduced to reservoir 78 via cap 85, dispensing unit 5 is releasably attached to a top of the reservoir, with conduit 12 extending downwardly from the dispensing unit to slightly above the bottom of the reservoir.

Upon depressing button 17 (FIG. 1), or any other convenient activation device, the air pump motor is set to a standby mode. The motor is maintained in a standby mode until the predetermined irrigation time, whereupon it is activated, operating according to a programmed cycle, including rotational velocity of the motor, time of operation and duration of operation. After each rotation of the rotor of the air pump motor, a burst of air is generated by the air pump and is injected into container 10. Injection of successive bursts of air into the container, due to sustained operation of the motor, increases the air pressure within the container above the irrigation liquid. Due to the pressure differential inside and outside of the container, irrigation liquid is forced to flow through conduit 12 and then through discharge tube 30, which is in fluid communication with the conduit. At first, irrigation liquid rises and descends within discharge tube 30, unable to rise above summit 79 (see FIG. 6) thereof. As the pressurized air applies a greater force onto the irrigation liquid, the latter is subjected to a pressure sufficient to cause it to rise above summit 79 and to continue to flow to the target by a siphoning effect, despite deactivation of the motor.

Irrigation liquid continues to be discharged from orifice 74 after deactivation of the motor until the pressure within container reaches atmospheric pressure, or shortly thereafter, depending on the depth of the remaining irrigation liquid within the container and the difference in height between orifice 74 and the free surface of the irrigation liquid. Without a pressure differential inside and outside of the container, irrigation liquid remains in discharge tube 30 since the pressure of the irrigation liquid remaining in the discharge tube is below atmospheric pressure, as well known to those skilled in the art. Although the components of most irrigation liquids remain in liquid form during extended periods of time, some, such as a calcium hydrogen phosphate solution, may precipitate as insoluble calcium phosphate, especially following exposure to the sun, and may be liable to clog the discharge tube.

In order to discharge all of the irrigation liquid from the discharge tube, the device of the invention may be provided with check valve 47 (FIG. 3), which is positioned above, and in fluid communication with, passageway 37. Check valve 47 has an inlet port 49 which allows ingress of air from the interior of the dispensing unit to passageway 37, but prevents egress of fluid from the passageway to port 49. Consequently, irrigation liquid, when flowing through passageway 37, will not be discharged from port 49. To prevent irrigation liquid from remaining in discharge tube 30 when there is no pressure differential inside and outside of the container, atmospheric-pressure air enters passageway 37 via port 49 and acts on the irrigation liquid, causing the latter to be discharged from orifice 74 by gravity.

Referring now to FIG. 9, control unit 35 comprises central processing unit (CPU) 91 preferably embodied by a microprocessor electrically connected to an integrated circuit, memory means 93, such as a programmable read-only memory (PROM), power source 95, which is preferably a battery, and activation device 96. Before initiating an unattended irrigation operation, a user selects a dispensing unit whose memory means was programmed with a desired irrigation cycle, attaches conduit 12 to sleeve 29 (FIG. 2), and threadedly engages said dispensing unit with container 10. A plurality of dispensing units may be advantageously hung by a corresponding aperture 3 (FIG. 1) formed in the dispensing unit housing in order to increase accessibility of each dispensing unit and to facilitate selection thereof. After activation device 96 is operated, power source 95 provides sufficient power for the operation of both CPU 91 and memory means 93. CPU 91 then operates rotor 97 of the air pump motor according to the selected irrigation cycle which was programmed into memory means 93. The rotor is activated at a predetermined time following the operation of activation device 96, as monitored by an internal timer of CPU 91, and operates for a predetermined duration at a predetermined rotational velocity. A predetermined dose of irrigation liquid is therefore dispensed to a target of a desired plant holder substrate.

Optionally, the control unit may further comprise selector 98, for selecting one specific irrigation cycle. Selector 98 is preferably a potentiometer, which may be actuated by a selector switch or by means of screws, as well known to those skilled in the art.

As described hereinabove, the irrigation device of the present invention is an economical and easily operable device, which is suitable for reliable, unattended dispensing of irrigation liquid onto a defined area of a plant holder substrate.

While embodiments of the invention have been described and illustrated, they constitute only examples and the invention can be implemented with many variations, adaptations and modifications, without exceeding the scope of the claims.

Claims

1. Portable irrigation device, comprising

a) a container for irrigation liquid;

b) a dispensing unit releasably attached to the container, for delivering a predetermined dose of said irrigation liquid;

c) a programmable control unit for activating or deactivating said dispensing unit; and

d) a discharge tube in fluid communication with said dispensing unit through which said predetermined dose of irrigation liquid is discharged from the container by means of pressurized atmospheric air injected into said container, said pressurized air being generated by said dispensing unit in accordance with a cycle governed by said control unit.

2. Device according to claim 1, which comprises:

a) an abutment plate formed with a liquid passageway and an air inlet;

b) a discharge tube in fluid communication with said passageway;

c) means for releasably attaching the container to said abutment plate such that the container wall surrounds said liquid passageway and air inlet;

d) means for pressurizing air and delivering the pressurized air to the container via said air inlet, said pressurized air forcing irrigation liquid to flow through said liquid passageway and discharge tube; and

e) control means for governing operation of said pressurizing means, said pressurizing means and control means being housed by a dispensing unit formed with said abutment plate.

3. Device according to claim 1, wherein the dispensing unit is releasably attached to the container through matching screw threads formed in said dispensing unit and in said container respectively.

4. Device according to claim 1, wherein the dispensing unit comprises an air pump for generating the pressurized air and a motor for driving said pump.

5. Device according to claim 4, wherein pressurized air generated by the air pump is delivered to the container via an air tube and an air inlet.

6. Device according to claim 3, wherein the container has a spout and the screw threads formed in the container are outer threads formed around the spout and the screw threads formed in the dispensing unit are threadedly complementary inner screw threads.

7. Device according to claim 6, wherein the dispensing unit comprises an abutment plate formed with a liquid passageway and an air inlet, and complementary inner screw threads are formed in the underside of the abutment plate.

8. Device according to claim 1, wherein the container is a commercial, discardable container.

9. Device according to claim 2, further comprising a conduit insertable within the container and in fluid communication with the passageway, said conduit reaching into the irrigation liquid as close as practical to the bottom of the container, while not coming into contact with it, to allow as much irrigation liquid as possible to flow out of the container through said conduit.

10. Device according to claim 9, wherein the conduit is supported by a sleeve downwardly extending from the abutment surface and in fluid communication with the passageway.

11. Device according to claim 9, wherein the container, the conduit, the passageway and the discharge tube are made of a material stable in acidic and/or alkaline environments.

12. Device according to claim 4, further comprising a check valve in fluid communication with the passageway for discharging irrigation fluid remaining in the discharge tube following deactivation of the air pump motor, said check valve preventing egress of irrigation liquid from the passageway and permitting ingress of air.

13. Device according to claim 4, wherein the motor is powered by batteries.

14. Device according to claim 2, wherein the discharge tube is flexible and is provided with an orifice for directing irrigation liquid drawn from the container to a desired target.

15. Device according to claim 1, wherein the dispensing unit is attachable to each of a plurality of containers, so that any desired irrigation liquid contained in a corresponding container may be dispensed to a target.

16. Device according to claim 1, wherein the control unit comprises a central processing unit (CPU), memory means, a power source, an activation device, and optionally a selector, said CPU suitable for governing operation of the rotor of the air pump motor according to a selected irrigation cycle programmed into said memory means and at a predetermined time following the operation of said activation device.

17. Device according to claim 16, wherein the memory means is a programmable read-only memory (PROM).

18. Device according to claim 4, wherein the air pump is a bellows.

19. Device according to claim 3, wherein the air pump is a piston pump.

20. Device according to claim 16, wherein the selected irrigation cycle defines a predetermined duration of operation.