U.S. patent application number 10/543722 was filed with the patent office on 2006-11-16 for portable irrigation device.
This patent application is currently assigned to EVERLASTING GLORY LIMITED. Invention is credited to Simon Dotan.
Application Number | 20060255172 10/543722 |
Document ID | / |
Family ID | 32850757 |
Filed Date | 2006-11-16 |
United States Patent
Application |
20060255172 |
Kind Code |
A1 |
Dotan; Simon |
November 16, 2006 |
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.
Inventors: |
Dotan; Simon; (Netanya,
IL) |
Correspondence
Address: |
ARENT FOX PLLC
1675 BROADWAY
NEW YORK
NY
10019
US
|
Assignee: |
EVERLASTING GLORY LIMITED
28/F, BEA HARBOUR VIEW CENTRE 56 GLOUCESTER ROAD
WANCHAI
HK
|
Family ID: |
32850757 |
Appl. No.: |
10/543722 |
Filed: |
January 27, 2004 |
PCT Filed: |
January 27, 2004 |
PCT NO: |
PCT/IL04/00075 |
371 Date: |
May 8, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60442666 |
Jan 27, 2003 |
|
|
|
Current U.S.
Class: |
239/69 ;
239/337 |
Current CPC
Class: |
A01G 27/005 20130101;
A01G 25/14 20130101; A01G 27/02 20130101 |
Class at
Publication: |
239/069 ;
239/337 |
International
Class: |
F23D 14/28 20060101
F23D014/28 |
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.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] 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
[0002] 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
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] It is yet an additional object of the present invention to
provide a portable irrigation device which is easy to use.
[0012] It is an additional object of the present invention to
provide an inexpensive portable irrigation device.
[0013] 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.
[0014] Other objects and advantages of the invention will appear as
the description proceeds.
SUMMARY OF THE INVENTION
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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.
[0019] In a preferred embodiment of the invention, the pressurizing
means comprises an air pump and a motor in driving engagement
therewith.
[0020] Preferably:
Pressurized air generated by the air pump is delivered to the
container via an air tube and the air inlet.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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.
[0026] The motor is powered by batteries.
[0027] The discharge tube is flexible and is provided with an
orifice for directing irrigation liquid drawn from the container to
a desired target.
[0028] 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.
[0029] Each dispensing unit is programmed to operate according to a
specific irrigation cycle.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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
[0035] The drawings illustrate the preferred embodiment of the
device, in which water is drawn from the container by means of air
pressure.
[0036] FIG. 1 is a schematic, front view of an exemplary irrigation
device, according to the present invention;
[0037] 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;
[0038] FIG. 3 is a schematic plan view from above of an embodiment
of the dispensing unit, its cover being removed;
[0039] FIG. 4 is a schematic, exploded, perspective plan view of
another embodiment of the dispensing unit;
[0040] FIG. 5 is a plan view from above of the dispensing unit of
FIG. 4, its cover being removed;
[0041] FIGS. 6 and 7 schematically illustrate the dispensing of
irrigation liquid from a conventional, commercially available
container to plant holder substrates;
[0042] FIG. 8 schematically illustrates the dispensing of
irrigation liquid from a reservoir of irrigation liquid contained
within a plant holder; and
[0043] FIG. 9 is a block diagram illustrating the control unit.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0044] 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.
[0045] 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.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] 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.
[0050] 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.
[0051] 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.
[0052] 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.
[0053] 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.
[0054] 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.
[0055] 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.
[0056] 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.
[0057] 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.
[0058] 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.
* * * * *