Note: Descriptions are shown in the official language in which they were submitted.
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Background of the invention
Field of the invention:
The present invention relates to automatic irrigation with humidity sensors,
and
more specifically to a system and method for more efficient automatic
irrigation based
on a large number of cheap humidity sensors and cheap automatic faucets, which
can
optimize the use of water so that less water is wasted and each plant or group
of plants
can get the optimal amount of water that it needs. Various solutions shown in
the
patent can be used for example for gardens, agriculture, and flowerpots (for
example
at homes or in plant nurseries).
Background
The most efficient water irrigation systems today for gardens and/or fields
typically
use dripping systems that release drops of water at certain distance intervals
for
example for about 30-60 minutes per day (for example every 30-100 cm of the
pipe
there is dropper that releases typically 2 litters of water per hour) and are
typically
controlled by timers that start or stop the water in the main pipes. However,
although
this is in general more efficient than systems that do not use droppers, this
can still be
far from optimal since it does not take into account different needs for each
area,
depending for example on the individual needs of each plant, heterogeneity of
soil
type, different amount of Sun or shade in each part of the garden or field,
different
number of plants in each area, etc. In other words, irngation systems based on
pipes
with droppers, typically controlled only with a timer, which are the most
common
form of irrigation used today, suffer from one very basic weakness, which is
that they
have no feedback, so they are in essence working blindly. Another problem,
which is
related to the above lack of feedback, is that there is no efficient way of
self
monitoring, so typically, since the system is not aware of its own condition,
it also
cannot report problems, such as for example breach of main pipes that can
cause
flooding, or, in the other direction, various pipes or side-channels becoming
blocked.
Therefore, these systems typically can still waste a lot of water on the one
hand and
neglect many plants on the other hand, so that some plants get too much water
and
others get too little water. For example, a raspberry plant or a weeping
willow tree
typically needs much more water than other plants. Similarly, to the best of
our
knowledge, there is no simple solution for efficient cheap automatic
irrigation of
plants in multiple flowerpots that can be used easily with ordinary
flowerpots, for
example in homes and in plant nurseries that sell plants, except for inserting
a pipe in
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each flowerpot and opening and closing large groups of them by time control,
which
suffers from all the drawbacks described above. British patent 2281182
describes a
closed container of water covered with a capillary mat on its top on which
flowerpots
are placed. However, this can reduce the efficiency of water uptake compared
to
placing the flowerpots directly in a water-filled bottom dish, and also the
container is
filled manually. Many patents describe the use of a water container coupled to
a
flowerpot that automatically lets the flowerpot draw water when needed, but
only few
of them, such as US patents 5918415, 4083147, 4546571, and 4557071 describe a
truly automatic refilling of the container. However, even those typically use
a
complex configuration that can't be used with normal flowerpots or requires a
complex control valve. Anyway, in practice in homes and even in many plant
nurseries the plants are still typically watered manually. Therefore, many
plants either
get too much water, or are neglected and dry out.
Saving water is very important, since according to the World Watch 2000 report
we
are depleting the planet's water resources at the rate of 109 billion gallons
of water
per day. Many areas in the world already suffer shortages of water, and others
will
suffer from it in the coming years. Israel, for example, is now in a critical
stage of
water shortage, with the Kineret sea's water level already at a critically low
level.
Therefore, in addition to more desalination of water, more efficient irngation
systems
are essential for our survival on this planet.
In order to improve the efficiency of the automatic irngation systems,
humidity
sensors are needed, however, although many types of humidity sensors exist,
they are
typically quite expensive (typically between $150 to even thousands of
dollars), and
automatic faucets are also typically relatively expensive (costing typically
at least a
few dozens of dollars each, since they typically contain an electric motor,
good
insulation between the water and the electrical parts, etc.), so they are not
used for
controlling more optimally the amount of water for each individual plant or
for each
small group of plants or small area. Also, many of the known methods for
humidity
sensing suffer from various limitations, such as for example limited range of
response,
sensitivity to changes in the salinity of the ground, sensitivity to changes
in
temperature of the ground, etc. So clearly cheaper good sensors and cheaper
automatic valves are needed. Such a cheap solution would also be very
attractive to
customers and encourage them to use it, since a cheap enough system that saves
a lot.
of money on watering per month while also improving plant growth, can
preferably
pay itself back in a few months or even less and start actually saving money
for the
customer.
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Summary of the invention
The present invention tries to solve the above problems by providing much
cheaper
humidity sensors that are still quite reliable and also much cheaper automatic
faucets,
so that preferably each plant or (preferably small) group of plants can be
automatically watered by an individual set of moisture sensor and automatic
faucet.
The attainment of cheaper but reliable humidity sensors is preferably done by
using
durable cheap sensors that do not degrade quickly and are preferably immune to
or
able to cheaply compensate for changes in temperature and in salinity. The
attainment
of cheap automatic faucets is preferably done by using at the end nodes of the
system
low water pressure, so that much less force is needed to open and close the
local
waterway, and then either using much simpler electrical valves that do not
require
engines, or circumventing the need for electrical valves altogether, by using
mechanical sensors that control a mechanical valve or directly exert pressure
on a
flexible pipe, as explained below. Another possible variation, instead of
mechanical
sensors and valves, is to use for example some chemical control that takes
advantage
of the behavioral tendency of the water itself, so that for example the water
is supplied
by a device similar to a plant's roots, except that it works in reverse, so
that water is
supplied at low pressure to the artificial "root" from above, and the "root"
adds water
to the earth instead of absorbing it, and stops supplying the water to the
earth when
the earth has reached a certain humidity level, which automatically creates an
equilibrium for example in osmotic pressure between the artificial root and
the earth.
A similar variation of this is adding a preferably synthetic material that
tends to
behave like a normal root preferably at the edge of each side channel (and/or
in other
places), so that the "root" counter-balances the water supply and reaches
equilibrium
with it when the soil becomes wet enough, based preferably on asymmetric
capillary
material or materials, as shown for example in Fig. 6. Another possible
variation is to
use for many plants or at least for each sub-group of them a common water tank
like a
Niagara, but air-tight, and one or more pipe leads from the common tank to the
plants
where preferably each side branch for example goes preferably more or less
vertically
into the soil in a flowerpot or (if it is in a garden or field) into the soil
near one or
more plants, so that each such side-branch has a humidity control based on air
passage, as explained in Fig. 7.
The solution for flowerpots is similar, except that the sensing can be done
even
more efficiently and even more cheaply, and also the control of the watering
itself can
be done more efficiently and more cheaply, by taking advantage of certain
features of
flowerpots, as explained below. Therefore, the solution or flowerpots can be
regarded
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also as a smart-home gadget, since it uses smart and cheap automation to both
save
work and time and to save water.
In gardens and agricultural fields preferably one or more main pipes are used
with
sufficient water pressure of for example 1 or more atmospheres, and each pipe
preferably extends into smaller channels that go for example sideways, each
preferably with a much lower pressure. This way, the valve that is needed to
control
each of these small channels needs much less force and therefore can be much
cheaper than an ordinary electronic faucet. The reduced pressure can be
created for
example by using long twisted small conduits at or before each side-channel
that
easily lower the water flow (such as for example in the pipes by Queen-Gil),
which is
very cheap and efficient. Another possible variation is using for example a
set of
preferably small water collectors that work like a toilet's Niagara
(preferably one for
each side channel), or using mechanical pressure reducers (however these last
2
options are less efficient). This general configuration is shown in Figs. 1 &
la-b. The
sensing can be for example mechanical, so that for example a sponge or wood or
hair
(or other material that changes it shape when it becomes wetter or drier)
closes or
opens a valve for example directly by its own mechanical change of shape or
indirectly through activating an electrical element (Preferable solutions for
this are
shown for example in Figs. 2a-i), or the sensing and control can be done
electrically,
but preferably in very cheap and efficient ways, as described below
(Preferable
solutions for this are shown for example Fig. 3a-d & 4a-c), or the sensing and
control
can be based on physical and/or chemical tendencies of the water itself,
preferably by
using asymmetric and/or irregular and/or strong capillary material or
materials, as
explained above and in Fig. 6.
In flowerpots (plant pots), the solution can be even more efficient, because
of the
very fact that the plant and its earth are isolated and typically placed over
a bottom
dish that prevents excess water from running away. This opens up a few
interesting
possibilities that are harder to accomplish in gardens and fields: The sensor
can be
placed preferably on the bottom of the bottom dish, so that it merely has to
sense if it
is in water or in the air, which is much easier than sensing the level of
humidity in the
earth, since it does not have to face all the problems described above. This
can be
done for example by a simple electrical circuit that is closed when it is in
water, or for
example by a simple preferably small element with a floating part, that
preferably
moves up when there is water in the dish and down when there is no water or
less
water and opens or closes a valve mechanically or electrically. This on/off
method is
free of all the problems described above, and also is optimal in the sense
that the earth
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in the flowerpot is always kept at more or less maximum humidity, and yet it
is very
efficiently since the reserve water is always kept at the bottom dish, instead
of going
down deeper into the ground, as it would do in a garden or in a field. The
actual
watering of the flowerpot is preferably done by letting the sensor control a
valve on a
pipe that enters or comes near to the flowerpot soil from above. This ensures
that the
water will go through the soil from the top down before it reaches the dish.
Another
possible variation is that the water pipe drops water for example directly
into the
bottom dish, which has the advantage of making the device even simpler, and
due to
capillary action, the water is absorbed in the soil anyway even if it comes
only from
below. However in this case, preferably there are more holes and/or larger
holes at the
bottom of the flowerpot. Another possible variation is the use these features
in
combination with using each dish in sharing with more than one flowerpot, for
example by creating a round or square large area (for example like a large
bath) in
which the flowerpots are together side by side, or for example using an
elongated dish
that supports many flowerpot next to each other in a line. In these variations
preferably the dish is balanced horizontally, so that the water is more or
less evenly
spread around it. This way, preferably one sensor is enough for the entire
dish, and if
the variation of watering the dish directly is used, than also preferably only
one water
supply and one valve is needed for the dish. This way automatically each plant
that
needs more water absorbs more water from the common pool into itself and
therefore
into its soil, and as long as there is sufficient water in the common dish and
yet the
water does not overflow, no plant is underwatered and no plant is overwatered,
even
for different types and sizes of plants, different soil types, etc. Also, this
can lead to
much more optimal conditions for plant growth, so plant nurseries can make
more
money because the plants grow bigger and faster, so by the time they sell them
they
can get a better price for them. The elongated dish variation has the
advantage that it's
more practical and more easy to balance, and also allows easy access to every
plant,
whereas a dish extended in two dimensions would make it hard to access the
inner
flowerpots without stepping into the dish. This can be used very easily for
example in
balconies in homes, or in plant nurseries. An array of such large mufti-plant
dish rows
in a plant nursery is shown for example in Fig. Sf. Another possible variation
is to use
for example dishes that are closed on the top and have for example holes in
the top
part for inserting the flowerpots. This has the further advantage that less
water is lost
due to evaporation directly from the dish. This is a major advance over the
current
state-of the art of methods of irrigating plants in flowerpots. Another
possible
variation is to connect a number of such preferably elongated bottom dishes
for
example with side pipes, so that one set of sensor and water supply can take
care of
more than one dish. Another possible variation is to combine the above for
example
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with time control, so that for example the dishes are kept with water in them
only for
example for a few hours each day. This gives more flexibility in the moisture
content
in the soils, so that lower moisture levels can also be used. Another possible
variation
is to use these mufti-flowerpot dishes in any of the above configuration with
manual
filling of water in the dish, which is of course less efficient then automatic
control, but
still, if for example a plant nursery is divided into a number of rows, each
with an
elongated dish that serves for example dozens of plants, this is already much
more
efficient than the current state of the art, since all the workers have to do
is water each
of the elongated dishes, which is much more efficient and easy than having to
water
each individual plant, and yet each individual plants gets more optimal
conditions
than by the normal method of watering each plant individually. Of course,
various
combinations of the above and other variations can also be used. Preferable
variations
of these solutions are shown for example in Figs. Sa-g. Also, the same methods
or
principles described for gardens and fields can be also used with flowerpots,
however
that could be less efficient, except in the case of asymmetric capillary
materials,
which might be the best method also for flowerpots.
Another possible variation is to use similar principles like those of the
solutions for
the flowerpots - also for gardens and/or fields, for example by inserting
(preferably
more or less horizontally) a water-blocking material (such as for example a
preferably
strong plastic or nylon) below the plants, for example by removing 1-2 meters
of
earth, adding the material, and adding back the earth on top, preferably
before
planting the plants. The blocking material is preferably also hard enough so
as not to
be distorted in shape too much by the pressure from above and by the contours
of land
and rocks below, and preferably has also for example vertical walls around
itself, so
as to create one or more large pool isolating the earth with the plants above
that pool
from the rest of the earth below and around. This way, although the humidity
sensors
have to work more like in the solutions described above for gardens and fields
than
the special solutions that can work with water dishes with flowerpots, still
the usage
of water can be much more efficient since the earth in the area of the plants
can be
kept at higher humidity levels with less water than in a normal garden or
field where
excess water can always escape further below into the ground. This can work
even if
the blocking material does not seal the area hermetically but only
significantly
reduces the rate in which water can escape away downwards. Like with the
flowerpot
dishes, the water blocking material can also be for example based on an array
of
elongated structures that look like bottom-halves of large pipes, that are
inserted into
the ground and covered with a layer of earth upon which for example vegetables
or
other agricultural products can be grown more efficiently.
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Another possible variation, which can be applied in combination with any of
the
other variations, is to supply the plants with the same water supply system,
also with
other nutrients in addition to the water, such as for example liquid
fertilizers andlor
minerals, and/or for example air or C02 or oxygen (for example by using Soda
water
with various degrees of C02 melted in the water) in order to further help
stimulate the
plant's growth. Such additional materials can be added for example all the
time in the
desired quantities as a certain percent of the water, and/or part of the time
with the aid
of an automatic time schedule, and/or together with additional sensing (for
example
when the naturally occurring electrical potential in the earth indicates too
low salinity,
or when there is indication of too little air in the ground, and/or for
example
depending on the level of humidity, etc.). The addition of air or C02 or other
gases is
especially important, since, apart from speeding up plant growth, it can also
protect its
roots from rotting, since he main cause for rotting in roots is the lack of
air when they
are immersed too much in water. This addition of gases such as for example air
or
Oxygen or C02 can be used also in combination with hydrophonic or hydrostatic
irrigation methods, since the main problem that limits the use of such methods
to only
a limited variety of plants is that in many plants the roots rot under such
conditions
due to lack of air. However, adding for example air or Oxygen instead of C02
is more
preferable, since the absorption of C02 in water makes them acidic. Since
(unlike
leafs) the roots need Oxygen, adding Oxygen to the water supply can help the
plant
thrive even at levels of 100% humidity.
Another possible variation, which can be applied in combination with any of
the
other variations, is adding a feedback system for automatically reporting
problems for
example to a central control unit, such as for example flooding or blockages.
One way
of accomplishing this is by allowing for example each valve or sensor at the
side
channels to report back the approximate amount of water passed by it and/or
the
percent of time it remained open and/or for example to report significant
changes in
conditions, such as for example suddenly finding much more humidity in a
certain
area, or finding that the area remains dry despite the attempts of the sensor
to open the
valve. (However, increase in humidity can also be caused by rain for example
so this
is preferably reported to the user by the central control only if it deviates
significantly
from other sub-areas). However this can make the system a little more
expensive.
Another possible variation is to use a hierarchy of more than 2 levels, so
that there are
not only main pipes and side channels but also one or more intermediary
levels, and
preferably intermediary junctures are responsible for indication and/or
reporting of
such problems, which is cheaper to implement, since in this case only these
junctures
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have to be smarter. For these junctures the more preferred variation is that
they simply
have a cheap water-meter and report back to the center and/or to the main
supply of
each main pipe the approximate amount of water consumed per time period,
and/or
each main pipe for example has its own water-meter and reports this, and then
either
the human operator or a preferably cheap processor at the center can easily
notice if
there are significant deviations.
Brief description of the drawings
Fig. 1 is a top-view illustration of a preferable general configuration of a
main pipe
with sufficient water pressure which extends into smaller channels with a
preferably
much lower pressure that are preferably each controlled by its own cheap
humidity
sensor and cheap valve.
Figs. la-b show a few preferable variations of methods for lowering the
pressure at
the side channels.
Figs. 2a-i show a few preferable examples of mechanical sensing based on
materials
that change their shape when they become wetter or drier and thus efficiently
close or
open or gradually move a cheap and efficient valve electrically or
mechanically
and/or exert pressure for example on a flexible pipe.
Figs. 3a-d show a preferable example of a cheap and efficient electrical
moisture
sensor that is both reliable and durable and preferably is not misguided by
changes in
temperature and/or salinity of the soil.
Figs. 4a-c show a few examples of cheap electrical valves that preferably work
with
low water pressure.
Figs. Sa-h show a few preferable examples of cheap and efficient sensors and
water
supplies that take advantage of the bottom dishes of flowerpots.
Fig. 6 & 6b show a preferable example of using reversed capillary pressure at
the end
of the side channel, so that when the earth has reached a certain humidity
level it
automatically creates an equilibrium for example in osmotic and/or capillary
pressure
that stops the water flow until the level of humidity of the earth has
sufficiently
decrease again.
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Fig. 7 shows a preferable variation where each such side-branch has a humidity
control based on air passage, with shared or individual air-tight containers.
Important Clarification and Glossary:
All these drawings are just exemplary drawings. They should not be interpreted
as literal positioning, shapes, angles, or sizes of the various elements.
Throughout
the patent whenever variations or various solutions are mentioned, it is also
possible to use various combinations of these variations or of elements in
them,
and when combinations are used, it is also possible to use at least some
elements
in them separately or in other combinations. These variations are preferably
in
different embodiments. In other words: certain features of the invention,
which
are described in the context of separate embodiments, may also be provided in
combination in a single embodiment. Conversely, various features of the
invention, which are described in the context of a single embodiment, may also
be provided separately or in any suitable sub-combination. The word
"flowerpot" as used throughout the text, including the claims, can mean any
type
of pot or container for growing plants. The words "automatic faucet" or
"automatic valve" as used throughout the text, including the claims, can mean
generally any type of automatic control, including one with no moving parts,
such as for example when using asymmetric capillary materials.
Detailed description of the preferred embodiments
All of descriptions in this and other sections are intended to be illustrative
examples
and not limiting.
Referring to Fig. 1 & 1 a-b, we show a top-view illustration of a preferable
general
configuration of a main pipe (10) with sufficient water pressure (such as for
example
1 or a few atmospheres) which extends into smaller channels that go for
example
sideways ( 11 ) with a preferably much lower pressure that are preferably each
controlled by its own cheap humidity sensor ( 13) and cheap valve ( 12). Each
such
side-channel can go for example to an individual plant, or to a preferably
small area
surrounding a number of plants, as desired by the user. This way, the valve
(12) that is
needed to control each of these small channels ( 11 ) needs much less force
and
therefore can be much cheaper than an ordinary electronic faucet (solenoid),
which
typically contains a motor and is designed to deal with much higher pressures.
Preferably the sensors are not too close to the end of the side channel in
order to sense
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the real humidity in the near earth and not to be influenced too much by
immediate
feedback of humidity at the end of the side channel. Of course other shapes
and angles
can also be used (and the channels can for example go only to one side instead
of the
two sides), and in each garden or field preferably more than one main pipe is
used.
Another possible variation is to use for example a hierarchy of more than 2
levels, so
that between main pipes and side channels there can be also 1 or more
intermediary
level pipes, preferably with intermediate water pressure. The reduced pressure
can be
created for example by using long twisted small conduits at or before each
side-
channel that easily lower the water flow (such as for example in the Queen-Gil
pipes,
except that the side branches are preferably at larger distances from each
other than
the 10 cm interval in the Queen-Gil pipes The combination of higher pressure
in
each main pipe and much lower pressure in each side-channel also solves the
problem
of independence between the channels: This way each sensor can decide to open
or
close its valve independently of the others, without suffering from lower or
higher
pressure depending on the decisions of its neighbors, since even if all of the
sensors
open their valves at the same time and the water flow is for example 0.5
litters per
hour from each side channel, the total loss of pressure after a hundred meters
can be
for example just a few percents. Another possible variation is using for
example at or
before each smaller channel (or each group of channels) a preferably small
water
collector that works like a toilet's Niagara (except that when released the
water is
allowed to go out preferably slower than when a toilets' Niagara is flushed).
In this
case it is also possible to lower the pressure for example also at the
beginning of the
main pipe (by a similar larger Niagara type container or by other pressure-
lowering
devices) because the small collectors an also solve the problem of
independence
between different channels so that each one does not feel a different pressure
if the
others are open or closed. Fig. la shows a labyrinth of thin water conduit
before or at
each side-channel with right angles like a square wave (14 or 15), which can
extend
for example for a few dozen such cycles, like in Queen-Gil pipes (where after
every
certain distance there is a labyrinth on the side, leading to 4 small holes
beside each
other on the side, except that preferably there is only 1 exit for each such
labyrinth).
Fig. lb shows a labyrinth with much sharper angles (16), which can reduce the
water
flow with even less cycles. (As explained above in clarification section, for
example
the labyrinth with sharper angles, or any other feature in this invention, can
also be
used independently of any other features of this invention). Each valve can be
for
example attached a small pipe at the end of the labyrinth conduit, or for
example the
exit side-pipe expends to a wider pipe before the valve, in order to translate
the lower
water flow more directly into lower pressure. The sensing can be for example
mechanical, so that for example a sponge or wood or hair (or other material
that
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changes its shape when it becomes wetter or drier) closes or opens a valve for
example directly by its own mechanical change of shape or indirectly through
activating an electrical element (Preferable solutions for this are shown for
example in
Figs. 2a-i), or the sensing and control can be done electrically, but
preferably in very
cheap and efficient ways, as described below (Preferable solutions for this
are shown
for example Figs 3a-d). If the control of the valves is electrical, preferably
there is no
need for central control by a main computer, so that each sensor preferably
controls
directly the valve coupled to it, so that preferably only 2-3 power lines are
needed
along the main pipes. However, preferably the main control of each main pipe
(or
each group of main pipes, or for example any control of pipes or subgroups of
pipes
or subgroups of side-channels) can also override the individual sensors for
example
by issuing a command to force all the valves (or a large group of valves) to
close no
matter what their sensors say (for example by stopping the main water supply
and/or
by electrical command to all the valves), or forcing all the valves (or a
large group of
valves) to open (for example by increased main water pressure or by electrical
command to all the valves to open no matter what their sensors say). This can
be used
for example for creating combinations between sensor control and centrally
controlled
time schedules, which can be for example on the level of On/Off, or by
increasing or
decreasing the overall water supply. For avoiding blockings in the smaller
conduits
because of accumulating dirt, such as for example sand or other materials,
preferably
good pre-filters are used for example at the beginnings of the main pipes,
that can
remove such elements as much as possible, for example in a way similar to the
pre-
filters that are used before desalination devices. Another possible variation
is that
once in a while a significantly larger water pressure is used for a short
burst or bursts
(for example for a few minutes each day, or a few minutes or seconds each
hour), in
order to help push away such elements that might clog the small conduits or
side
channels during the slow flow. Preferably the small conduits and their valves
are
strong enough to stay intact even with the stronger pressure, and preferably
during
this pressure bursts all the valves become open even if their sensor did not
tell them to
open, so that the sensors are preferably temporarily overridden. This can be
accomplished either mechanically by the increased pressure itself, or if the
valves are
electrically controlled, by issuing a central command to all of them to open,
thus
overnding the local controllers. Another possible variation is that each
sensor and/or
valve can automatically control for example number of side channels together.
Of
course, various combinations of the above and other variations are also
possible.
Refernng to Figs. 2a-i, we show a few preferable examples of mechanical
sensing
based on materials that change their shape when they become wetter or drier
and thus
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efficiently close or open or gradually move a cheap and efficient valve
electrically or
mechanically, and/or exert pressure for example on a flexible pipe. Fig. 2a
shows one
or more absorbing materials, such as for example sponge, for example in the
shape of
a ring (22), with a hole that surrounds a flexible conducting pipe (21) (for
example
made of silicon, which has very durable elasticity, or for example made of
Latex), so
that the hole in the middle allows the preferably low pressure water (20) to
flow freely
until absorbed into the absorbing material, and then when the absorbing
material
expands (or for example vice versa - when it contracts) it closes the hole in
the
middle by mechanical pressure. Preferably the pipe is narrow and with
preferably thin
walls that don't require a large force to squeeze. If it is based on
expansion, then
preferably the changing ring is closely encased is an external ring (or other
shape) of
solid material, so that when the material expends it exerts pressure on the
internal
hole. And when the amount of water is reduced again the material relaxes again
and
releases the pressure. Preferably the absorbing material touches the soil next
to it and
preferably there is some distance between the exit point of the water and the
absorbing material, so that it is not too directly affected by the water but
instead is
affected by the conditions in the general soil next to it. However, for
example,
different such distances can be used for different sensitivity, and one
possible
variation is that the user himself can easily move the position of the
absorbing
material for changing the sensitivity. Adding for example more rings (next to
each
other or for example with certain intervals between them) and/or for example
making
the hole smaller, can make the system more strongly responsive to changes in
humidity. Another possible variation is to use for example water absorbing
Crystals or
Polymers, preferably slightly cross-linked polymers, or Gel, that considerably
swell
when absorbing water, such as for example Sacharidic polymers that can expand
for
example 2.5 times their size when absorbing water, or Silica Gel, or for
example any
of the materials used in Tampons or in diapers. Preferably these materials are
in a
shape of one or more lumps but smaller grains may also be used, for example
within a
one or more solid mesh and/or ring and/or membrane so that preferably water
can
freely enter or exit but the water-swellable material or earth cannot) that
preferably
surrounds at least one part of the pipe. Another possible variation is to add
some
preferably more solid material between the swelling material and the pipe in
order to
concentrate the pressure more strongly on the pipe. Another possible variation
is that
these polymers are manufactured directly in the shape of a ring, which can
then
preferably be fitted for example within an external solid mesh, so that their
expansion
directly presses a flexible pipe that goes through the ring, and the mesh
allows
maximum surface interface with the surrounding moisture. However many other
shapes can also be used, such as for example polymers in the shape of multiple
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needles, so that they have maximum surface exposure to the water, preferably
based
on inserting pressure on a flexible pipe. The needles can be for example each
in a
preferably rigid mesh-like tunnel, or for example they are rigid enough to
work for
example in parallel without a mesh, and preferably push together for example a
solid
object which concentrates their force preferably on a small section of the
pipe. Of
course a mixture of more than one such material can also be used. According to
US
patent 4,655,076, issued on April 7, 1987 to Weihe et. al., there is a large
group of
water-swellable polymers which can be cross-linked as required to have the
desired
degree of stability in water and the desired amount of swelling, with good
hydration-
dehydration reversibility, without hysteresis, and with a response range at
the most
important range of humidity - between 0 to -15 bars. In fact, Weihe also
quotes US
patent 4,182,357, issued on Jan. 8, 1980 to Ornstein, which describes the use
of a
water-swellable cross-linked gel in a similar way to automatically regulate a
flexible
pipe or membrane with the aid of a piston that concentrates the force of the
expanding
gel on a smaller area of the pipe. However, according to the descriptions at
http://www.pipeline.com/~lenornstJIrristat.html, which refer to the above
patent, it
seems like the response time of this device can be at least in certain aspects
quite
slow, requiring for example 24 hours saturation at the start in order to be
sure that the
device starts in a closed position. Therefore, preferably other polymers are
used which
have a much faster response time (for example the materials used in diapers
typically
expand in seconds, although they are designed to keep the water instead of
releasing it
easily). Another possible variation is that for faster response the water-
swellable
material is shaped like a thin folded plate (for example like a heat radiator)
so that it
has maximum surface connection with the surroundings. Also, preferably the
sensors-
regulators are used in low-pressure side channels, preferably after using for
example
the labyrinth structures or other dripper devices or capillary link for
considerably
reducing the water pressure, since this requires much less pressure to control
the pipe
and therefore preferably cheap miniature devices can be mass-produced and
integrated preferably each with one side channel. Another possible variation
is to use
one or more hydraulic and/or mechanical levers to change the force and/or
displacement factor of the expanding material. Another possible variation is
that the
solid surrounding material is divided into two or more cells with a movable
preferably
solid border between them, so that when it is moved by the swelling material
it
presses the pipe. Another possible variation is to use for example one or more
strings
from a horsetail hair or other types of hair (or any other organic or
synthetic material
with similar qualities, such as for example strong sponge is the shape or a
string),
which expands or contracts according to its wetness, and this string or
strings can for
example push or pull a lever (Of course the lever can be designed for example
so that
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a small movement translates to larger movement). Fig. 2b shows another
possible
variation where the absorbing material (22) pushes or pulls a lever (26) for
example
with a ball at its end, which closes or opens for example a flow hole (24)
above it.
Preferably, again, the water does not flow directly over the absorbing
material, but
goes outside into the soil for example sideways through sideways conduits
(27). Of
course, various combinations of the above and other variations are also
possible. Fig.
2c shows for example a preferably solid material (22), such as for example
wood or
another material or for example bi-material that changes its shape according
to its
level of wetness. This solid material is for example in the shape of a "V" or
a "U" and
when it is wet it tends to become more straight due to the capillary action of
the water,
and then its movement can for example move a lever (26) that closes or opens a
hole
(24) or can for example directly exert more or less pressure on a for example
silicon
pipe (21) (or for example it can be more straight when dry and become more
bent
when wet). A Bi-material made for example of two parallel attached preferably
thin
stripes of materials, preferably one that expands when wet and another that
contracts
when wet (such as for example leather and wood), has the advantage that its
side-
movement can be more conspicuous than the percent of lengthening or shortening
of
the stripes, like in a bi-metal, which bends or straightens sideways as
temperature
changes much more than the visible expansion or contraction of an ordinary
metal by
changes in heat (of course more than two materials may also be used). Of
course this
can also have the advantage of concentrating the movement in one direction and
if
thin stripes are used then also it has better surface contact with the water
and can also
respond faster since water does not have to move deeply in or out. However,
since
materials such as wood or leather have poor repeatability and tend to degrade
over
time, preferably synthetic polymers are used, such as for example a
considerably
expanding polymer side-by-side with a polymer that does not expand or for
example
expands less or for example with a preferably thin sheet of a strong and
flexible
material (Of course it could be also for example two or more materials that
contract
when wet, wherein one contracts less than the other, but such materials are
much less
likely to be available). Preferably two or more materials with similar thermal
expansion coefficient are used, since otherwise they would change their shape
also as
a result of temperature changes. For example two or more polymers (As
explained
above, preferably in the shape of the two or more preferably thin, preferably
solid
stripes) of the same type can be used, for example with different levels of
cross-
linking. (Of course if more than two types of materials with different
expansions are
formed this is actually a mufti-material and not bi-material). Of course, like
other
features of this invention, this can be used also independently of any other
features of
this invention, so this can be used also for example for creating better
hygroscopes,
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and in that case the bi-material can for example move a dial mechanically or
for
example affect an electrical circuit for example by moving an element that
changes
capacity and/or an electromagnetic field and/or is detected for example
optically.
Another possible variation is to use for example a complex material that
contains
capillary or water-swellable material mixed with stronger non-capillary or non
swellable material, such as for example two woven fiberglass cloths with
capillary
materials sewn between them, or for example 2 sheets of a preferably low
friction and
flexible material such as for example Teflon with a water-swellable polymer
between
them. Preferably the sheets are perforated with a lot of holes so that water
can freely
access the polymer. Another possible variation is that the two sheets can be
for
example rolled like a rollada, with the inner part for example attached to an
internal
hinge, and the outer part to a tube in which the rollada can rotate so that
swelling or
contraction causes for example a rotation of the hinge (for example in a way
similar to
a pressure gauge). Another possible variation is that the rollada is for
example based
on rolling one or more preferably thin preferably long water-swellable
polymers, for
example in the shape of a rolled needles, preferably connected at one end to
the
internal hinge and at the other end to a tube in which the rollada can rotate.
The rolled
sheet or needle can be for example contained within a mesh that is rolled with
it, or is
rolled freely for example with a tube. Another possible variation is that the
rollada is
in the shape of a spiral or helix. In other words, preferably a bi-material
(preferably as
explained above composed of two or more preferably thin, preferably solid
stripes,
coupled to each other, in which one of the materials expands more than the
other
when it gets wet) is rolled in the shape of a helix, and preferably the helix
is bent for
example into a shape of half a circle. This has the advantage that more choice
of
preferably sufficiently solid materials is available, since this way even a
smaller
difference in the expansions can cause sufficient movement of the half circle.
This
complex material can be easily formed for example by extrusion of the two or
more
stripes together and then twisting them into the desired shape while they are
still
malleable. This can work similarly to the Helimorph of 1 Ltd
(http://www.llimited.comltech/helimorphlindex.htn~l), shown in Fig. 2e, which
is a
bent helix of two or more Piezoelectric materials that are surrounded and
separated by
conductive electrodes and translates bending caused by applying an electric
field into
a linear movement of one end of the half circle up or down (when the half
circle is
lying horizontally and the other end is anchored). Fig 2e shows a few
Helimorphs of a
few various sizes (both in terms of the diameter of the helix and the diameter
of the
half circle). However the Helimorph translates electric field into linear
movement,
whereas in this case the bi-material helix works on the principle of different
response
to water. This mechanical movement of the half circle can be used in various
ways for
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example to push or pull a lever or to exert pressure on a preferably small
flexible low-
pressure pipe (for example made of silicon or latex, like in other above
similar
variations). For example, in Fig. 2f, the flexible pipe (21 ) can be held
against a solid
frame (29), and when the free end of the half circle moves down it puts
pressure on
the pipe until it closes it and when it moves up it releases the pressure and
the water
can flow again. Another possible variation, shown in Fig. 2g, it that for
example two
such half circles (22a & 22b) which are designed to work in the opposite
direction
(i.e. the bi-material spirals are for example like mirror images of each
other), hold the
flexible pipe (21 ) against each other, and for example when the humidity
increases,
the free end of half circle 22a goes down and the free end of half circle 22b
goes up.
Fig 2h shows two such half circles (22a & 22b) of which one is simply
connected in
reverse to work in the opposite direction. Preferably at the other end the two
half
circles are connected together, for example with a preferably solid ring (22c)
that fits
around the flexible pipe, in order to keep this "clips" in position (Of course
similar
designs of the contact between the biomaterial and the flexible pipe can be
used also
with bi-materials which are not based on a bent Helix, but as explained above
the
increased effect of this shape allows a wider choice of matrials). Another
possible
variation is to insert for example the flexible pipe within the helix, like a
sleeve, as
shown in Fig. 2i, so that when the helix bends it preferably causes the pipe
to bend
sufficiently to become closed. In this case the helix can be for example also
in the
shape of half a circle or in other shapes that are most appropriate for this.
Another
possible variation in that the flexible pipe is threaded for example through
two such
helixes, which are preferably mirror images of each other and are for example
next to
each other or twisted one within the other, thus exerting opposite forces on
the pipe.
Another possible variation is to use for example bi-material stripes or plates
which are
shaped like fractals, thus increasing to the maximum their surface area, or
for example
shaped like triangles. (Creating for example a Piezo-electric bi-material as a
fractile-
like plate, for example like the shape of a snow-flake, instead of a bent
Helix, might
for example create an interesting speaker which automatically vibrates in
multiple
frequencies and which automatically stops when the voltage becomes constant.
The
plate itself might then vibrate sufficiently even like this, or with
additional connected
or independent similar fractal plates of different sizes, and/or the plates
themselves or
at least some of them can also be actuated for example by a Helimorph. Another
possible variation is for example to shape the vibrated one or more plate like
a
triangle, for example with a straight profile on each side or for example with
at least
one side for example with for example a parabolic or hyperbolic or other
appropriate
profile, so that each cross-section is most fit for a different frequency. In
this case the
plate is preferably for example actuated by a Helimorph and the plate itself
is for
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example made of a normal solid material or of a Piezo-electric bi-material.
Also the
plate might be made for example thicker at the sections where the cross-
section is
wider in order to allow it to vibrate with more energy. Of course, if a
fractal is used,
the fractal itself might contain for example similar triangular shapes). Of
course these
are just examples and other configurations with such twisted spirals are also
possible,
and also the spiral can be bent also in to other shapes than half a circle -
for example
in a shape of a snail's shell, in order to even further increase the linear
movement
effect. Of course, like other features of this invention, this can be used
also
independently of any other features of this invention, so for example this
bent helix
can be used also as explained above for creating for example an exact
hygroscope that
uses such a direct humidity sensor and displays the reading for example by
moving a
mechanical arm or by any other electronic display (For example by sensing the
amount of movement of the free end of the half circle, for example optically
and/or
for example by change capacitance and/or for example electromagnetically - for
example by adding a magnet to the moving end and using a sensing coil, etc).
Another
possible variation is to use indeed the Helimorph of lLtd (or similar
structures) for
pushing or pulling a valve or exerting pressure in a flexible pipe, and
activate it by
electrical humidity sensors, but that is less efficient than the above direct
sensing of
humidity, since is requires a power source and since, as explained above,
electronic
humidity sensors are much more problematic). As explained above, preferably
the
flexible pipes (21) are side pipes that come out of a main pipe, preferably
after
reducing the pressure for example by the cheap labyrinths as explained in
Figs. 1-lb.
However since these flexible side pipes with the twisted spirals (or any of
the other
automatic sensors-controllers described above) can live longer than a cheap
main pipe
with labyrinths, and since as explained elsewhere in this application there
are
preferably different units available for different levels of desired water
saturation,
preferably the main pipe comes with a preferably rigid small protrusion where
each
small pipe can fit, and by default the small protrusion is preferably covered
with a
small closed pipe or cover which keeps it closed, and thus in places where the
user
wants to connect these smart side-pipes he simply removes the cup and
preferably fits
the end of the flexible pipe over the small protrusion. This has the advantage
that
unlike normal cheap main pipes with the water pressure reducing labyrinths,
the user
can chose to use the outlets only where he needs them. Another possible
variation is
that the main pipe does not come with its own labyrinths or other water
reducing
elements, and instead the flexible side-pipes come with their own labyrinth or
other
type of water-pressure-reducing element (for example like in a normal dripper
button), and is inserted in any desired place into the main pipe like a normal
dripper
button, except that after the water pressure reduction the water goes through
the
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section that is controlled by the bi-material smart sensors-controllers.
Although this
might be a little more expensive than a normal dripper, it can save the cost
of buying a
computer that controls the times when the watering is activated, and of course
the
plants become watered much more optimally, and thus can grow better and
quickly
bring a return on the investment. Anyway, the material that changes its shape
according to wetness preferably absorbs water fast, preferably changes
significantly
between its wet and dry states, and preferably has high homeostatic balance
with the
earth, so that it becomes with the same wetness of the earth. This is one of
the reasons
why the two stripes are preferably thin, since this allows them to respond
much more
quickly to changes in humidity. (Another possible variation is to use such
materials
for example to help open clogged arteries and/or for example clogged urinary
tracts
and/or for example various types of clogged pipes, and/or for example increase
the
blood flow into the appropriate blood vessels for people who have erection
problems.
In this use for example miniatures of the two half circles (or other
convenient shapes)
shown in Figs. 2g-2h are preferably connected similarly to move away from each
other when there is a clogging (except that in this case the force is exerted
from within
on the internal walls of the for example urinary tract or blood vessel) or for
example
to move in the opposite way so that when wet the free ends of each move away
from
each other, and thus increase further the flow of liquid. Preferably the free
ends are
encased for example in some soft material, for example a silicon ball, in
order to
prevent it from injuring the walls of the blood or urinary vessels. Also, the
maximum
linear movement is preferably designed in advance so that it does not exert
too much
force on the walls of the vessels. Another possible variation is to use for
example
Piezoelectric Helimorphs for example within such blood vessels, which are for
example controlled electronically and/or remote-controlled). Another possible
variation is to use for example a capillary material that becomes heavier when
it
absorbs water from the earth, which has preferably enough free movement to
affect
for example a scale or a lever, which then for example moves a valve or exerts
pressure directly on a preferably thin low pressure flexible pipe. This can be
accomplished for example by letting a free rope of the capillary material hang
from a
lever and freely touch the ground with its bottom part. Preferably any of the
above
solutions can be mass-produced as miniature versions that are integrated on a
small
section of the small flexible side pipes, so that the total cost is relatively
cheap.
Preferably the user can choose from a number of end-unit types - each one
fitted for a
different desired level of humidity, or for example turning some screw can
change the
range of response, for example by narrowing or widening the space where the
water-
swellable material can expand. Fig. 2d shows another variation where the side-
pipe
(21) terminates like a widening cone with a closed bottom with holes or slits
around
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it, and a capillary material that expends when its wet, such as for example
sponge or
rope (22) fills up the cone when its wet, thus both decreasing the water flow
from the
side holes or slits and also pushing up for example a rubber diaphragm (26)
that is
wider than the pipe, which seals off the passage even more strongly. Although
such
mechanical sensors may sound primitive, they can be very cheap and efficient,
and
they have the advantage that they measure humidity directly and therefore do
not
suffer from all the problems that electrical sensors have because they by
definition
measure humidity only indirectly. Of course, various combinations of the above
and
other variations can also be used.
Refernng to Figs. 3a-d, we show a preferable example of a cheap and efficient
electrical moisture sensor that is both reliable and durable and preferably is
not
misguided by changes in temperature and/or salinity of the soil. The sensor
uses for
example two or more electrodes (32,33) on an electrically insulating element
(31) that
is inserted into the ground for testing directly the electrical resistance of
the ground,
which is more or less the cheapest electrical method. The shape of the sensor
can be
for example like a small dish with two round plate electrodes, one at each
side, as
shown in Fig. 3a. This dish is preferably small, for example the size of a
large coin,
and preferably has all the electronics in a printed circuit inside the dish,
or for
example in the shape of a pole with 2 or more ring electrodes attached to it,
as shown
in Fig. 3b (however, preferably each such ring is more elongated so that it
covers a
larger section of the pole), but many other forms can also be used, such as
for
example a table fork, or many other shapes. On the other hands, the electrodes
are
preferably large and massive enough so as to be more durable and also
preferably
have sufficient surface contact with the soil. However, it uses a few smart
improvements to overcome the normal problems of simple electronic devices that
measure electric resistance: The need to avoid fast degradation of the
electrodes, the
need to take into account changes in salinity, and the need to take into
account
changes in temperature. This is preferably done by using for example for the
two
electrodes different materials (such as for example zinc and copper, or
preferably
another more chemically-resistant or corrosion-resistant pair of metals or
other
conducting materials, such as for example silver, chrome, stainless steel,
carbon,
electrically conducting plastics, silicon with p and n impurities, etc.) and
testing (or
sensing) both the naturally occurring electrical potential between them, AND
then
preferably the reduction in current when a current is run through them, so
that the
potential, which is much more effected by the salinity than by the humidity,
shows the
level of salinity and can be used to correct the estimate of humidity
accordingly. In
order to avoid corrosion to the electrodes preferably this is done in short
pulses so that
for example first the electrical potential is sensed, and then the circuit is
reversed and
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the resistance to the current is measured by actively applying a short DC
current in the
opposite +/- direction, so that during this measurement the electrodes are
also
automatically compensated for the small degradation caused by naturally
occurring
potential when the electrodes are near each other the earth (like in a
battery's
dielectric). The duration of the two opposite states does not have to be the
same, and
also the intervals between them can be for example short (such as for example
a few
seconds or less) or long (such as for example a few minutes), however the
counter-
current is preferably designed by strength and duration to take into account
the time
that elapsed from the previous pulse, so as to compensate more or less
correctly for
the loss of ions caused by the naturally occurring potential. If for example
one
electrode is of carbon and the second of silver, the carbon electrode is not
sensitive to
aggressive chemicals, but after a long time the silver electrode could still
be eaten
away, so in the reverse pulses by connecting the silver electrode to the
positive and
the carbon to the negative, the silver particles that separated will return to
the silver
electrode according the electrolytic principles and this repairs partly the
electrodes.
Such electrodes will have of course a considerably lower potential than for
example
copper and zinc, but it can still be detected with a more sensitive sensor,
and what
matters is the changes in the potential. In order to take into account also
changes in
temperature, preferably a small thermometer, such as for example a
thermocoupler, is
added or integrated into the circuit, or for example one of the electrodes is
itself used
together with another metal as part of a thermocoupler. Another possible
variation is
to include for example in the circuit that measures the electrical resistance
also for
example a PTC (Positive Temperature Coefficient) thermistor with appropriate
parameters, so that it automatically increases the resistance when the
temperature
rises, in an amount that more or less compensates for the natural reduction in
the
earth's electrical resistance as the temperature rises. Another possible
variation is
using for example a leaking diode in which the amount of leaking in the
opposite
direction is affected by the temperature. Another possible variation is to add
for
example to each valve a manual switch of preferably more than 2 states, so
that the
user can overnde the system for individual plants (or areas) and indicate that
certain
sensors or valves should be more generous or less generous with their water
supply
(which can be accomplished for example by releasing more or less water for
each
given level of humidity, or for example by changing the threshold of humidity
that is
considered sufficient, or any combination of these). A good example would be
again a
raspberry bush, which if watered optimally could easily spread very fast into
many
other places. So, if watered optimally it might take over other plants, so a
user might
want to restrain it on purpose by limiting its water supply for example to
less than
optimal. This manual setting can preferably done also if mechanical sensors
are used.
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Another variation is to use central control over individual plants or areas,
but that is
less desirable since it is more expensive, and also might require more power
lines,
unless a smarter and more expensive device is used for each controller so that
they
can identify for example a given code and respond only if their individual
code was
named. Like with the mechanical sensors, preferably there is some distance
between
the sensor and the actual point where the water is released. The output of the
sensor
can be for example an on/off command, based on some predefined or user-
adjustable
threshold, or a more exact value, for example in a number representing percent
of
humidity, or for example some scale, and it can be either in the form of an
analogue
signal or for example a digital signal. A digital signal for example can be
used more
easily by a processor or circuit in the valve, but also involves more
electronics in the
sensor itself. Another possible variation is that the sensor control and valve
control are
integrated into the same circuit (however, they are still preferably distant
enough from
each other.
We describe below in more detail an example of using a digital output for
example
with the device shown in Fig. 3a: The sensor can be for example a sandwich of
2 non-
oxidizing metals separated by a plastic or PVC plate, and in the plate are the
electronics of measuring and transmitting of the humidity impedance. There are
2
wires that are hermetically connected. The sensor is preferably inside the
soil,
preferably in nearly the same depth as the roots of the plant. The electronics
creates
for example a 16-bit BCD code that changes according the humidity, or any
other
convenient coding. If needed, for example 8 bits can be used for
identification and 8
for measurement (if more that 1 sensor can be accessed for example from a
central
control or from an intermediary branch on the hierarchy). If there is no need
for
identification, a total of 5 bits is good for representing 16 levels of
measurement. The
wires of the sensor are connected to the electronics of the solenoid that
supplies the
water to the plant. The electronics can be for example connected to a total of
4 wires:
2 sensor wires that connect between the sensor and the valve that it controls,
and 2
energy supply wires that come for example along the main pipe from a
transformer
connected to the electrical network. Preferably, the same power lines are
connected to
all the sensors and valves that go out from each main pipe. Another possible
variation
in that each sensor or some sensors can control more than one valve. Another
possible
variation is to add for example also 1 or 2 additional lines for central
control, for
example for creating the ability to override all (or some of) the individual
sensors by a
general "On" command or "Off ' command. Another possible variation is that
such
control command can be transmitted over the power lines themselves, for
example by
superimposing an RS485 or other data transfer protocol over the power lines
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themselves. Another possible variation is that the electrical wires are part
of the pipe,
for example integrated within an intermediate layer in the body of the pipe.
Another
possible variation is that the sensor and the valve are for example integrated
into one
circuit or component, but in that case preferably the electrodes of the sensor
extend to
an area somewhat away from the valve, or the valve controls the low pressure
side-
channel at some distance from the actual edge where the water is actually
released, so
that the sensor measures the earth in that general area and is not affected
too much by
immediate feedback from the water as it exits the side-channel. Of course,
various
combinations of the above and other variations can also be used.
Referring to Figs. 4a-c, we show a few examples of cheap electrical valves
that
preferably work with low water pressure. Fig. 4a shows for example a water
solenoid
based on a rotating element (42) that is divided into for example a few cells
(43a-43d)
and preferably is limited for example by internal valves to rotating only in
the desired
direction. When the valve gets a command to release water, for example an
electromagnet (41 ) pulls a lever (44) that connects to teeth in the rotating
element and
causes the rotating element to advance one or more steps. For every pulse, the
drum in
this example turns for example 90 degrees (or any other convenient angle) and
the
water (20) that comes from the pipe (21 ) above is released into the outlet.
Of course
this is just one example and many variations are possible and of course for
example
more or less cells can be used. This has the advantage that every pulse can
release a
clear amount of water, so that for example if water pulses are counted then
the amount
of water that was released can be easily computed. However, such a solenoid
might
still be not cheap enough. Fig. 4b shows an even simpler and cheaper valve,
based for
example on an electromagnet (41) that pulls or pushes a lever (44) that for
example
encircles a flexible pipe (21) (for example made of silicon at least at the
position of
the valve) and directly presses the pipe for example against a solid contra-
wall (48).
Preferably the lever (44) has a tendency to remain in either the closed or the
open
position even when electric force is not used, for example by teeth that snap
into
position when it is in one of the stable positions. Another possible variation
is that the
electromagnet works for example with a spring and force is needed for example
to
keep the valve open. This has the advantage that in case of electric failure
the valves
will automatically close. Another possible variation is that for example that
the valves
of the side channels lock into position without the need for force, but for
example the
main faucet is designed to automatically remain closed (or in another
variation - open)
when power fails. Another possible variation is that for example more than 2
states
can be used, so that the valve can exert also intermediate levels of pressure
depending
on the humidity reading of the sensors. Fig. 4c shows another variation where
the
element (44) that closes or opens the water passage by exerting pressure on
the pipe
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(21 ) for example rotates slightly around a hinge (49). Again, preferably, it
automatically locks into one or more desired position. Of course, various
combinations of the above and other variations can also be used.
Referring to Figs. Sa-h, we show a few preferable examples of cheap and
efficient
sensor (SS) and water supply (54) that take advantage of the bottom dish (52)
of one
or more flowerpots (53). The sensor can be placed preferably on the bottom of
the
dish, so that it merely has to sense if it is in water or not, which is much
easier then
sensing the level of humidity in the earth, since it does not have to face all
the
problems described above. This can be done for example by a simple electric
circuit
that is closed when it is in water or for example by a simple preferably small
element
with a floating part, that preferably moves up when there is water in the dish
and
down when there is no water or less water and opens or closes a valve
mechanically
or electrically. However, for this valve to be cheap and reliable preferably
it works on
reduced-pressure water, like in the solutions described above for gardens and
fields,
so that preferably only the main pipe or pipes has higher pressure and each
side
branch that goes into a bottom dish preferably works with much smaller
pressure,
accomplished for example by the labyrinths method. This on/off method is free
of all
the problems described above, and also is optimal in the sense that the earth
in the
flowerpot can always be kept even at more or less maximum humidity, and yet it
is
very efficiently since the reserve water is always kept at the bottom dish,
instead of
going down deeper into the ground, as it would do in a garden or in a field.
The actual
watering of the flowerpot is preferably done by letting the sensor control
directly an
adjacent valve on a pipe that enters or comes near to the flowerpot soil from
above.
This ensures that the water will go through the soil from the top down before
it
reaches the dish. Another possible variation, shown in Fig. Sb, is that the
water pipe
(54) drops water for example directly into the bottom dish, which has the
advantage
of making the device even simpler, and due to capillary action, the water is
absorbed
in the soil anyway even if it comes only from below. This has the further
advantage
that especially in this case the valve control can be even more easily done
mechanically for example with a small mechanical sensor with a preferably
small
floating element connected to a preferably small arm like a miniature floating
arm of a
Toilet's Niagara that directly moves a mechanical valve or exerts pressure on
a
flexible (for example silicon) pipe when it floats up, since this can be
extremely
cheap, and also, unlike in the soil, there is no need in this case to keep the
sensor at a
distance from the valve, since when directly inside the water there is no
problem of
propagation. Another possible variation is that in this case preferably there
are more
holes and/or larger holes at the bottom of the flowerpot in order to allow the
water
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more easily to enter the soil from below. Another possible variation is that
the bottom
of the flowerpot and/or part of it and/or part of its lower side walls is made
of a fine
mesh instead of plastic (such as for example like in a fine flour sieve) or
some other
preferably fine porous material, in order to further increase the ability of
the water to
easily climb from the bottom up into the soil, while preferably blocking the
soil from
entering the water pool below. Another possible variation is adding for
example
preferably sturdy vertical capillary protrusions to the bottom dish so that
they are
stuck into at least some of the holes at the bottom of the flowerpot and go up
into its
soil in order to even further facilitate the absorption of the water from
below. In the
version where the water is entered directly into the soil from above trough
pipe 54, the
control can either be done for example with an electrical valve like those
described in
Figs 3.a-c (for example with a mechanical sensor (55) like the small arm
described
above, but in this case affecting an electrical switch, or with a simple
electrical circuit
that becomes closed when water is present), or mechanically, for example by
letting
the arm of the sensor for example move a metal wire within a hard preferably
flexible
sleeve that is coupled to the water pipe that reaches the soils from above,
similar for
example to the way that breaks or gear are controlled from away in bicycles.
Another
possible variation is that in this case the mechanical sensor (55) for example
controls
a valve or exerts pressure directly on the part of the pipe (54) that passes
next to it,
before the pipe bends to go up into the flowerpot from above, as shown in Fig.
Sh.
Another possible variation, shown in Figs. Sc-d, is to use these features in
combination with using each dish in sharing with more than one flowerpot, for
example by creating a round or square large area in which the flowerpots are
together
side by side, or for example using an elongated dish that supports many
flowerpots
next to each other in a line (for simplicity only 5 flowerpots are shown, but
preferably a much more elongated dish is used with a much larger number of
pots). In
these variations preferably the dish is balanced horizontally, so that the
water is more
or less evenly spread around it. Preferably, the dish has higher walls than
normal
flowerpot dishes, since a very long dish is more sensitive to slight
deviations from
horizontal balance, and also this enables more flexibility in the speed of the
water
supply by creating a larger common pool. This way, preferably one sensor is
enough
for the entire dish. In this case, if the variation of entering the water
directly into the
soil from above is used, then preferably each flowerpot (53) gets its own
water
supply, however this has the disadvantage that it can for example force more
water to
run also though the soils of plants that need less water, thus causing
unnecessary
erosion of their soil. If the variation of watering the dish directly is used,
than also
preferably only one water supply and one valve is needed for the dish. This
has the
further advantage that this way automatically each plant that needs more water
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absorbs more water from the common pool into itself and therefore into its
soil, and as
long as there is sufficient water in the common dish and yet the water does
not
overflow, no plant is underwatered and no plant is overwatered, even for
different
types and sizes of plants, different soil types, etc. The elongated dish
variation has the
advantage that it is more practical and more easy to balance, and also allows
easy
access to every plant, whereas a dish extended in two dimensions would make it
hard
to access the inner flowerpots without stepping into the dish. This can be
used very
easily for example in balconies, homes, offices, or plant nurseries. An array
of multi-
pot (53) elongated dishes (52), each dish with its single water supply (54),
preferably
with the simple mechanical water sensor and valve at the end of the pipe at
the bottom
of the dish, which can be used for example in a plant nursery, is shown for
example in
Fig. Sg. Another possible variation, shown in Fig. Se, is to use for example
dishes that
are covered on the top and have for example holes in the top part for
inserting the
flowerpots (for simplicity only 3 holes are shown, but preferably a much more
elongated dish is used with much more holes). This has the further advantage
that less
water is lost due to evaporation directly from the dish (of course, the holes
can be also
closer to each other, or for example more than one row per dish may be used).
Various hole sizes can be used, or the cover can be for example from nylon and
for
example the holes can be easily enlarged as needed by pressure for larger
flowerpots).
Preferably the flowerpots touch the floor of the dish. Another possible
variation is that
they are held a little above the bottom for example by using smaller holes
that hold
the flowerpots a little higher or by using for example additional internal
smaller walls
inside the dish - in order to make it even easier for water to enter the soil
from below,
however this is not necessary since typically flowerpots have small
protrusions on
their bottom in order to lift their holes a little above the bottom of the
dish. The cover
can be supported for example by the external walls of the dish, or for example
also by
internal walls (56) at various places. Another possible variation is to
connect a
number of such preferably elongated bottom dishes for example with side pipes
(for
example with one or more side-pipes connecting between each two dishes), so
that
one set of sensor and water supply can take care of more than one dish. In
this case
preferably the connected dishes are more or less at the same vertical level.
Another
possible variation, shown in Fig. Sf is to use for example a water absorbing
material,
such as for example one or more ropes or sponge between each two dishes, to
transfer
water by capillary action even between dishes that are not at the same level,
since the
capillary action works two-ways based on the surface tension of the water,
even
opposite to gravity. Another possible variation is to combine the above for
example
with time control, so that for example the dishes are kept with water in them
only for
example for a few hours each day. This gives more flexibility in setting the
moisture
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content in the soils, so that lower moisture levels can also be used. The
above
variations are a major advance over the current state-of the art of methods of
irngating plants in flowerpots. Another possible variation is to use these
multi-
flowerpot dishes in any of the above configurations with manual filling of
water in the
dish, which is of course less efficient then automatic control, but still, if
for example a
plant nursery is divided into a number of rows, each with an elongated dish
that serves
for example dozens of plants, this is already much more efficient than the
current state
of the art, since all the workers have to do is water each of the elongated
dishes,
which is much more efficient and easy than having to water each individual
plant, and
yet each individual plants gets more optimal conditions than by the normal
method of
watering each plant individually. Of course, various combinations of the above
and
other variations can also be used. Also, the same methods described for
gardens and
fields can be also used with flowerpots, however some of them would be less
efficient.
Referring to Figs. 6 & 6b, in Fig. 6, we show a top view of a preferable
example of
using reversed capillary pressure at the end of the side channel, so that when
the earth
has reached a certain humidity level it automatically creates an equilibrium
for
example in osmotic and/or capillary pressure and/or any other type of counter-
balancing force that stops the water flow until the level of humidity of the
earth has
sufficiently decreased again. This can be accomplished for example by adding a
water
absorbing material with minute capillary pores (61 ) coupled to each side
channel ( 11 )
(preferably at its edge that touches the soil), with a pore size small enough
as to make
the capillary action stronger than the water pressure itself, so that a
balance of
capillary pressures can be quickly reached when the earth become wet enough.
This
capillary material preferably does not change its shape when it becomes wet,
such as
for example Tuff stones. Another possible variation is to preferably design
the pores
to be asymmetrical, so that they are for example narrower at the side of the
water
supply than at the side of the soil, so that the capillary action tends to
come for
example more from the earth into the side channel, so when the earth becomes
filled
enough with water, the force drawing back water from the earth balances the
force
supplying the water. Another way to explain this is that if we use normal
symmetric
capillary materials, then as long as there is even low water pressure in the
pipe, water
will keep always flowing into the earth, since the water in the pipe is always
more
moist than the earth. If we used for example a completely one-directional
valve or
capillary material that counteracts the water pressure, then water would never
flow.
But when we use asymmetric capillary material or materials, somewhere between
these two extremes, than there will always be a certain level of humidity of
the earth
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where equilibrium is reached, depending on the level (or on the gradient) of
asymmetry of the asymmetric capillary material and on the water pressure in
the
pipes. When the plant (or plants) in the given areas sucks up the water it
needs, the
earth's level of humidity becomes again below the level of equilibrium, and
thus
water is added again. Of course, this principle of reaching the desired
equilibrium by
using asymmetric capillary materials can be used also independently of any
other
features of this invention. (It might be used also in other areas apart from
irngation,
such as for example in medicine, for example for creating an artificial heart
with input
and output tubes based on asymmetric capillary material, for increasing
efficiency).
One way of accomplishing this is by using for example asymmetric carbon
capillary
membranes, which already exist, or similar materials which already exist, such
as for
example asymmetric polysulfone membranes or asymmetric ceramic membranes,
which have funnel shaped pores, that can vary for example between 0.2 to 20
micron
or over a smaller range. Another way is to use for example small capillary
tubes
which are preferably narrower on the side of the water supply. Another
possible
variation is to use for example static negative charge and/or materials that
contain
more Oxygen on the side of the water supply, since water is attracted more to
negative
charge and to materials containing Oxygen. Another possible variation is to
use other
forms of asymmetric pores, such as for example V-shaped pores. Another
possible
variation is to use for example a gradient of different materials, so that the
materials
closer to the side of the water supply have higher capillarity. Another
possible
variation is to use for example membranes or materials which are more
hydrophilic on
the side of the earth and more hydrophobic on the side of the water supply,
like in
normal roots. This is actually more like adding a normal root of exactly
desired
parameters at the end of each side channel, except that it is preferably
synthetic, since
adding for example a real root or part of a root would cause the root to start
to grow
into the side channel and thus block it permanently. Another possible
variation is that
preferably this capillary material is shaped like a root with branches, so
that it senses
and interacts with the soil's moisture in a larger area. Additional
adjustments can
preferably be done by changing the water pressure at the side channels (for
example
by changing a local switch manually or by changing the water pressure in the
main
pipe), since different levels of pressure will reach equilibrium at different
levels of
humidity of the soil, and/or by letting the user for example choose between a
number
of such asymmetric capillary materials with a different gradient or
coefficient of
asymmetry, so that for example various choices are used for various desired
levels or
percents of humidity. For example, there might be asymmetric side branches for
reaching for example 25% humidity in the earth, other types of asymmetric
branches
for reaching for example 50% humidity in the earth, other types of asymmetric
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branches for reaching for example 75% humidity in the earth, and other types
of
asymmetric branches for reaching for example 100% humidity in the earth.
Another
possible variation is that this capillary material (preferably in the shape of
a root) is
itself also used to sufficiently lower the water pressure at the side
channels, so no
other device such as for example the labyrinths are needed, and the only
control
needed for the water pressure is for example in the main pipe or in other
levels in the
hierarchy, if there are more than 2 levels. Another possible variation is that
when the
earth is wet the artificial root sucks up water like a plant into some
container that
becomes filled with water for example like a thick leaf, and when the earth is
dry the
water level in the container drops, and the sensing of humidity is preferably
done by
an element that can sense when it is in water, like for example in the
variations
described for flowerpots. This sensor preferably affects the water flow in
that area for
example mechanically or electronically. Another possible variation, shown in
Fig. 6b
in a side-view, is that the low pressure side pipe (54) enters the earth
preferably more
or less vertically and ends for example in a preferably widening cone shape
(57) and a
closed bottom, and for example a rubber ball filled with air (55) or similar
floating
object, which is wider than the pipe, acts as a very cheap valve, or for
example any
other type of preferably cheap Niagara-like container with floating valve can
be used.
These containers can be for example closed to the outside air, which can add
the
balancing force of vacuum, or for example with a pipe allowing air to enter.
Out of
preferably small holes at the sides of the cone (57), capillary materials,
such as for
example strands of rope that look like roots (56), are in contact with the
ground. At
first the water fills the cone until the ball floats and blocks it, and then
as the earth
absorbs water from the capillary materials they remove water from the cone
until the
ball drops down again and allows more water to come in. When the earth is wet
the
water comes out more slowly from the capillary materials, and also they start
acting
also like a normal root since the capillary force works in both directions.
Another
possible variation is that these root-like structures (56) go mainly in a
direction
upwards from the cone, so that the water has to climb up in them against the
direction
of gravity, and thus gravity acts as the counter-balancing force. In this
case, preferably
at least part of the capillary material that is going up is covered with a non-
porous
material along the way, such as for example nylon or plastic tube, so that the
water
indeed has to climb up first without being sucked by the earth along the way.
Preferably the container is for example cone shaped and preferably becomes
elongated again at least on its bottom part, so that the bottom has preferably
a more or
less sharp edge and can be easily inserted into the ground. Of course, each
container
can be used for example for one plant or for many plants, so that there can be
preferably smaller containers for single plants or larger containers,
preferably with a
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large spread of capillary branches, for multiple plants. In this case another
possible
variation is that various end-units are available for various levels or
percents of
desired humidity of the earth, so that for example end-units where the
capillary
material climbs higher and/or has weaker capillary strength are used for lower
levels
of desired humidity. Like in fig. 7, preferably the valve does not open all
the time
after the water in the container has gone down a little bit, but only after
the water has
gone down by at least a certain desired amount. This helps the device live
longer, and
is especially important in case vacuum is used, since if the valve would open
every
time the water goes down by even a very little amount, then it would be almost
like
constant flow and there would practically be almost no time when the vacuum
actually exists. Also, preferably, while the valve allows refilling, the water
is blocked
from going out through the capillary openings, like in the variations of Fig.
7.
However, like in one of the variations described in the ref. to Fig. 7,
another possible
variation is that when the valve allows refilling it opens for only a very
short time and
the container is refilled quickly, in which case there is no problem since the
water
moves much slower through the capillary exits. This can be accomplished for
example by using a vertical element (for example a rod) with two wider parts
at its
ends, with a floating element for example around the central rod, so that the
floating
element changes the position of the vertical element only when it reaches one
of the
two extremes. Another similar variation is for example using an external
moving part
that affects the water supply with top and bottom arms (for example in the
shape of a
horizontally rotated V), so that a floating element affects the bottom arm
only below a
certain water level and the top arm only above a certain water level. Another
possible
variation is that this is accomplished for example by using two Niagara-like
containers for each side branch - a main container with the vacuum and
capillary exits
to the ground, and an auxiliary supply tank that just is ready all the time
with water,
and when the water has gone down sufficiently in the main tank, it releases
the water
in the supply tank to quickly refill the main tank. Another possible variation
is that
various types of main tanks are available for various levels of desired
percent or level
of humidity in the ground, so that for example tanks where the vacuum force is
stronger are used for lower humidity and tanks with weaker vacuum force are
used for
higher humidity. The vacuum force can be controlled for example by changing
the
height of the tank and/or the amount of water in it and/or the height or
percent that the
water in the tank is allowed to go down before the refill valve is released.
These tanks
are preferably small and very cheap since they preferably work on low-pressure
water
supply. Another possible variation is that this can work even without the
floating
valve (and then many other shapes of the container can also be used), since if
the side
holes are small enough the rate of absorption by the earth will depend mainly
on
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capillary forces and thus on the wetness of the soil. Another possible
variation is to
combine this for example with a time schedule, so that the device is activated
for
example only for a few hours each day, and during its operation the earth's
wetness
determines the amount of water released. Another possible variation is to use
a very
strong capillary element that has capillary strength much higher than the
earth, such as
for example at least two pieces of glass or plastic or other suitable
materials that are
parallel to each other at a very close distance (for example plates a few nano
or
dozens of nano meters apart), or for example a paper rope with pressure on it,
with or
without capillary asymmetry, so that the very strong capillary material tends
to suck
water off the earth more than give it to it. This material can be either
straight or for
example spiral shaped, and preferably relatively long, so that the water has a
longer
passage between the water supply and the earth, thus making the capillary
forces more
dominant. If a spiral is used, it can be for example in a direction opposite
to the
normal direction of a water vortex (such as for example is created when water
exists a
bath sink) on that side of the planet, thus adding an additional counter-
balancing
force), or for example in the same direction. Another possible variation is to
use an
irregular capillary material, so that at least one part of the capillary
material is
preferably with considerably stronger capillary strength, as shown for example
in the
example below. Of course, various combinations of the above and other
variations are
also possible. These variations can of course be used also with flowerpots.
The above
methods can be defined in general as chemical or structural methods, as
compared
with mechanical or electronic methods of sensing and control. Another possible
variation is using such asymmetric capillary materials also inside plants that
need
them, such as for example twigs, so that for example if a branch (or other
part) of a
plant or tree is cut and inserted into the ground or for example into water
for
developing its own roots, the asymmetric capillary material can be inserted
for
example at the bottom of the branch (preferably by using a narrow edge like a
needle),
and thus act as an artificial root, helping to nourish it until it develops
its own real
roots, at which point the artificial root may be for example removed.
A few of the possible ways of manufacturing such asymmetric and/or irregular
capillary materials are for example:
a. Creating for example a glass or plastic rod with multiple holes like in an
optic holofiber with multiple holes, and then stretching the tube with
asymmetric
pressure for example so that at one end is only pulled away from the other end
and at
the other end it is also pulled sideways so that it becomes wider than at the
other end
and thus the holes are also cone-shaped with one side wider than the other.
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b. Creating for example a sponge-like material, for example by baking it in a
tube with one or more gas-releasing substances for creating the airy
structure, and
then using for example centrifuge for condensing gradually more solid material
at the
edge of the centrifuge and more airy material at the center.
c. Starting with a central grain and for example dipping it in a material
(preferably liquid) with small holes (or bubbles) that condenses around it,
and then
after it solidifies, dipping in a material with larger holes or bubbles, and
so on (or vice
versa - in the order of decreasing hole sizes), and then cutting it into
stripes so that
each stripe is a cross section of many layers.
d. Baking for example a sponge-like material at a certain mechanical pressure
or with a certain pressure of air-producing substances, letting it cool a bit,
baking it
again inside a similar material with less pressure or less air producing
substances, and
so on in a number of stages (or in the opposite order). This can be done for
example in
a tube, so that the first material inserted is at higher pressure and the
final material
inserted is at lower pressure.
e. Drilling or boring for example cone-shaped (or other types of
asymmetrically
shaped) holes or tunnels for example into a sponge-like or rubber or plastic
material,
or other type of capillary material.
~ Using one or more molds for casting for example sponge-like or rubber or
plastic material (or other type of capillary material) into the desired shape,
preferably
with cone shaped holes or tunnels (or other types of asymmetric tunnels).
g. Using for example an ordinary absorbing rag (or other flexible capillary
material) which is preferably squeezed in a gradient, for example by pushing
it into a
narrowing tunnel, for example a cone-shaped solid tube (for example made of
hollow
metal or plastic) or for example two close plates at an angle, for example of
glass or
plastic, so that the pores within the sponge become gradually smaller as the
tunnel
becomes narrower (This has the further advantage that if for example the
tunnel's
gradient can be changed mechanically, the user might have further manual
control of
the level of asymmetry, without having to switch to a different part).
h. Using a gradient created by putting closely together at least two solid
preferably elongated plates of material such as for example glass or plastic,
so that at
one end they are closer than at the other end, preferably with some solid
obstacle that
keeps them apart at each end, and preferably covering the sideways sides for
example
with Glue (such as for example Silicon or Epoxy) or gluing or soldering two
side
walls. These plates can be used for example with or without putting additional
capillary material between them.
i. Using a preferably soft and flexible capillary material, such as for
example
paper or absorbing rag, preferably in the shape of a rope, in which at least
one part is
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pressed into a lower diameter, for example in the shape of one or more rings
along the
way. Of course many additional configurations can be used for reaching similar
results, and various materials instead of or in addition to paper or absorbing
rugs can
be used, and/or various pressures in the one or more rings (or in other
shapes) can be
used and/or various ratios between the compressed and uncompressed parts of
the
capillary material, and/or various directions or orientations or shapes of the
capillary
materials. Preferably any of the above parameters and/or various pressures of
the
water supply can be used for reaching various desired levels of wetness of the
earth.
Another possible variation is allowing the user for example to turn a screw in
order to
create various levels of pressure on the compressed part or parts of the
capillary
material. (Also, as explained above, even if 100% humidity is used, another
possible
variation is to combine this for example with a time schedule and/or for
example to
add air with the water supply in order to reduce the risk of roots rotting).
Of course, various combinations of the above are also possible.
Referring to Fig. 7, we show a preferable variation where a number of plants
in a
garden or field or in flowerpots (or many plants) are irrigated using for many
plants or
at least for each sub-group of them a common water tank like a Niagara (71 ),
but air-
tight. This example shows flowerpots (53a-53e) but it can be used similarly
also in
gardens and fields. The Niagara-like container preferably has a water supply
(72) and
water level sensor (73), so that preferably after the water has gone below a
certain
level the tank is automatically refilled. Preferably, while refilling, another
valve (75 )
at the exit pipe (54) automatically closes, otherwise the water would keep
flowing out
while refilling. One or more exit pipe (54) leads from the common tank (71 )
to the
plants, where preferably each side branch (54a-54e) for example goes
preferably more
or less vertically into the soil in a flowerpot (53a-53e) or (if it is in a
garden or field)
into the soil near one or more plants (however other angles are also possible
such as
for example a diagonal or even more horizontal direction), so that each such
side-
branch has a humidity control based on air, as explained below. In the case of
flowerpots, preferably each side branch goes down to a little above the bottom
of the
flowerpot, for example into a depth of 1 cm above the floor of the flowerpot
and so
water starts dripping into each flowerpot until the water reaches the bottom
of the
preferably vertical side-pipe (51 a-54e), and then stops since the air cannot
enter the
side pipe anymore, so any further water coming from the common tank (71 )
would
create a vacuum in the tank. When the earth becomes drier and absorbs more
water
from below the pipe, air can again enter, so new water is released again into
the
flowerpot from the common tank. However, the main problem with this
configuration
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is that if even one of the flowerpots is for example in a higher position than
the others
or even one of the side pipes for example has been inserted to a depth for
example of
only 3 cm above the bottom instead of 1 cm above the bottom, then the law of
combined vessels will cause that flowerpot to flood the other flowerpots.
Therefore,
preferably each of the side pipes (54a-54e) has also a unidirectional no-
return valve
(74a-74e), so that no water can go back up in it, however air can go up (this
can be
accomplished for example by using a floating ball that goes up if the water
tries to go
up the side-pipe, but allows air to go through). However, in this method, if
the
flowerpots are together in a common bottom dish, that would still cause
flooding of
the others if even one of the vertical pipes ends too high in the pot, so the
no-return
valve would still not solve the problem, so care must still be taken that the
pipe is
deep enough in each of the pots. So preferably in this case each pipe is with
its own
dish, but, still, if the pipe is not deep enough and its bottom end is above
the height of
the bottom dish's walls, the bottom dish will still overflow. So in fact, this
can work
even better if the flowerpot has no hole in the bottom and is used without a
bottom
dish at all. A more preferable variation is that instead of flooding for
example the
bottom of the flowerpot (for example the bottom 1 cm of it), the bottom of the
preferably vertical side pipe (54a-54e) is preferably closed and preferably
there are
holes or slits on the sides of it and preferably a capillary material such as
for example
sponge is inserted into the bottom of the side pipe, so that it touches the
soil though
the side holes or side slits of the vertical pipe. This way it can work even
without
regard to the bottom of the flowerpot, and therefore this can be used also in
fields and
gardens, where there is no "bottom". Another possible variation is to use this
together
with the variation of inserting a "bottom" of for example plastic or nylon
below the
earth in a garden or a field. Another possible variation is to use for example
just a
capillary material at the end of the pipe, such as for example sponge or
ceramic
substance that can let both water and air path through it but preferably
blocks the
earth from entering it. This porous material preferably allows air to enter
into the side
pipe only when the earth near it is not wet. For different levels of
sensitivity
preferably the user can choose for example between a number of side-pipes, so
that
for example for achieving higher humidity a side-pipe with a sponge of bigger
holes is
used. These variations where the vertical pipe does not flood the bottom of
the
flowerpot are therefore more preferable, since they can be used also in fields
and
gardens, and since they are based on blocking the air passage when the soil is
wet
without the need for it to be flooded, so they don't have the problem of
flooding the
bottom dishes in flowerpots if the pipe is not deep enough. The idea of using
humidity
controls based on air passage is not new and started already from US patent
3758987
in 1973, however to the best of our knowledge it has not been used while
combining
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separate controls for multiple plants joined together with a single source
tank, and
also no-return valves were not used in this context since there was no need
for them,
and also to the best of out knowledge this has not been used in the context of
dropper
irrigation pipe networks. Another possible variation, for example in large
gardens or
in fields, is to use (preferably in combination with the variation of the
hierarchy of
more than two levels) more than one such common tank, so that for example
there is
one main tank, but for example there are additional intermediary junctures
that also
have such a common tank for the sub-group of areas (or plants) that they
control.
Each such tank or juncture preferably also has a no-return valve, so that
preferably for
example breaches in any side-pipe or container will preferably only have local
effects.
Another possible variation is that each side-channel has its own preferably
small or
even miniature air-tight tank (for example just the size of a small syringe or
even
smaller), each for example with it's small Niagara-like floating arm (which
for
example moves a small low-pressure valve or more preferably presses against a
flexible for example Silicon pipe), in a way similar to the variation of using
a small
Niagara-tank for each plant, except that the moisture control is based on
allowing air
to enter only when the soil is not wet. Such small tanks may be even mass-
produced
as an integrated part of the pipes. Preferably each such small-tank has also
its own no-
return valve. Such small tanks might work even without the valve (75) at the
exit of
the tank since the water flow in the exit pipe is preferably low enough that
its effect
during the refilling of the tank is negligible. In fact, these small Niagara-
like
containers can be very similar to those shown in Fig. 6b. Of course, various
combinations of the above and other variations are also possible.
While the invention has been described with respect to a limited number of
embodiments, it will be appreciated that many variations, modifications,
expansions and other applications of the invention may be made which are
included within the scope of the present invention, as would be obvious to
those
sldlled in the art.
