Note: Descriptions are shown in the official language in which they were submitted.
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Specification
This invention relates to the areas of hydroponics and automatic nutrient
feeding, and in particular, to devices which may be automatically gas-fed,
and to improved media for growth and germination of some seed.
Previously developed hydroponic devices with automatic feeding have
used techniques of top feeding the nutrient solution and bottom draining,
or bottom feeding and draining. These techniques make it difficult to
simultaneously feed units placed at different heights above ground. The
growing medium is usually light porous material, like e~panded mica, to hold
water, or heavier granular opaque non-porous siliceous material to hold the
10 plant, or a mixture of the two. Mi~es of the porous and the heavier material
provide the combination of moisture to the roots and support to the plant.
However, on repeated feeding, the lighter porous material tends to rise to
the top, and this results in the exact opposite of the optimum functional
arrangements; the plant needs support at the top of the growing medium and
moisture below. The resulting segregation may lead to damping off, or loss
of stance, and may need more frequent feeding. Also the inefficient use of
materials with respect to their functions, has an undesirable effect on at
least the weight of the unit. Certain algae and such life tend to grow in
the nutrient which are difficult to remove without disturbing the growing
20 plant. Some types of seed need light to germinate and the use of opaque
materials in the growing medium~ that reduce the light reaching the seed,
reduces the success of germination in these seed.
Therefore it is an object of the subject invention to introduce
pressurised gas as a means of nutrient feeding to allow positioning of
growing units at different levels and feeding from a single pump, to im-
prove the positioning and use of material in most growing media with regard
to function, to provide a means of accessing and servicing some of the
components of the unit, to improve the germination and growth, and/or to
optimize the use of equipment.
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By introducing pressurised gas into a space that is occupied by the
nutrient solution, so as to displace the solution into the upper regions
of a container, where the growing medium is contained, I have allowed the
feeding of nutrient. Two general principles are employed. The first
technique involves the separation of gas and nutrient by the natural
forces (surface tension, gravity) that tend to segregate them. However,
this technique introduces problems arising from the gas-nutrient interface,
with splash-back and moist gas, which may be deleterious to the pressurised
gas source and cause unnecessary evaporation, increasing the surrounding
humidity, and increasing the necessary frequency of water replenishment in
the nutrient. These problems may be serious in the long term. However,
the second technique tends to minimise the gas-nutrient interface problems.
By inflating a container whose expansion displaces the nutrient solu-
tion into the growing medium I have isolated the nutrient from the gas, and
reduced the problems associated with the gas-nutrient interface. Deflation
returns the solution to its prior abode. A means of allowing the inflating
fluid to flow essentially in one direction, into the inflatable container,
further reduces such problems. If the top portion of the inflatable container
is flexible, the collapse of this surface during deflation further reduces
such problems, partially protecting the system against accidental rupture
of the inflatable container.
I have improved the functional arrangement of the components of the
growing medium and the nutrient solution by separating them by dividers
which allow the solution to cross them but prevent some or all of the
solid material from doing so. However, the finer roots and other growing
parts, and some finer material may cross them and extend from one region
to another. This technique may be used to maintain the bulk of the heavier
(plant supporting) medium above the porous light (nutrient retaining)
material for effective functional distribution of the componen~s of the
30 growing medium. This technique may also be used with proper reinforcement
and support to maintain the growing medium above the resting nutrient, pro-
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viding effective drainage in the process, and often elimina~ing the needfor a special drainage medium and zone. For many plants, the layer of the
growing medium whicll mainly supports the plant and maintains its stance is
not very deep, and consequently this invention permits the use of relatively
little heavy plant supporting medium, and reduces the dead weight of the
unit. Of~en it also eliminates the need for the drainage zone, reducing
the total height of the unit, and reducing the pressure requirements of
the inflating system. The use of one or more fine screens in the growing
medium maybe used to give the plant additional underground support by
holding the plant root system.
The immediately preceeding invention is suitable for plants with fib-
rous roots. If, however, the plant has bulbous roots, or bulbous under-
ground stems, the growth of the bulb may be difficult without in~ury to the
divider that separates the heavy and porous material, or the bulb or both.
A compromise is reached by using heavy medium with small size and light
porous material with larger size. Mixing is permitted, and a system of
dividers may be introduced which allows the separation of the two media
during feeding, so that they may be reused.
By attaching and/or properly supporting a suitably reinforced divider
20 that is located below the growing medium (which may or may not include the
drainage medium if there is one) by a means which is detachable from the
resting nutrient solution container, I have facilitated the access to,
cleaning and servicing of some of the components of the unit 9 without sub-
stantially disturbing the plant and growing medium. Similar dividers allow
other components to be similarly accessed and serviced.
Some types of seed need some portion of the light spectrum to germinate.
I have, for use with these seed, replaced the opaque heavier material with
transparent or translucent, coloured or colourless material, to improve -
their germination.
Also it is sometimes desirable to drain off the nutrient fluid. I
have facilitated this by providing a siphon, or drainage means at the
bottom of the unit.
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Provision for artificial lighting is also made by means of holders
attached to the unit in which rods may be held upright. The lighting
fixtures may be attached to these by some movable means. These rods may
also be used to secure dev;ces that guide the plants' growth.
Another feature of the invention is the use of modular units, which
provide flexibility in germination and growth. Seeds may be germinated
in small sub-units under the proper conditions, and these sub-un;ts may
be subsequently incorporated very simply into larger units without trans-
planting. Also, the larger units may be easily added to, or removed from
the feeding unit. This permits flexibility and continuity for optimum use
of the equipment.
In drawings which illustrate embodiments of the present invention,
-Figure 1. is a sectional view of a simple unit with some of the
features of the present invention.
Figure 2. is a sectional view of another embodiment with some of
the features of the present invention.
Figure 3. is a sectional view of s~ill another embodiment showing
some of the features of the present invention.
Figure 4. is a sectional view of an embodiment of one system of
modular sub-units that does not exclude other arrangements.
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In Figure 1 a bag 1 which is inflatable, by pumping air or some suitable
gaseous fluid through the tube 7, by human means or by a suitably controlled
pressurized gas supply or by a suitably controlled pump or by some such means,
displaces the nutrient solution 2 pushing the solution into the upper regions
of the container 8. Bag 1 may be perforated above the level of the nutrient,
to allow the inflation to subside after feeding or watering is completed, or
Bag 1 may be imperforated and air tight, and deflation is allowed to proceed
by exposing the entrance to tube 7 to atmospheric pressure. Item 3 is a per-
forated sheet or gauze with perforations of such size that fibrous roots,
10 fine growing medium material and nutrient solution may cross it. However,
the bulk of heavy light permitting material 6, and the bulk of light porous
material 5, are prevented from crossing this region 3 and mixing with each
other. In this figure, material 6 is not opaque to light. Because material
6 is of higher density than material 5, if this divider 3 were not present,
repeated feeding and disturbance would tend to make material 6 move do~m
and material 5 would move upward, upsetting the functional arrangement:
the heavier granular material 6 provides support for the plant and prevents
water-logging, while the porous light material 5 retains moisture from the
feeding and gives it to the roots of the plant as they may need it. Divider
20 4 similarly separates materials 5 and 11. Material 11 may be even lighter
than material 5, and is mainly used to provide drainage. Divider 10
separates material 11 from the nutrient 2, and also provides support for
the growing medium 5 and 6 and drainage medium 11. A container 9 which
is open at the bottom and top provides a means of transferring the weight
of the growing medium to the container 8, and allows the movement of nutrient
2. Item 2S will accept a rod to which a lighting fixture and/or other
accessories are attached. The rod may be secured by tightening screw 27.
The way in which the lighting fixture or accessory is attached to the rod
is such that it can be moved up or down the rod, and/or secured. There
30 may be more than one of the items 26 and 27 depending on design. Tap 28
allows drainage of the nutrient from the container 8 without disturbing
the growing medium.
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In Figure 2 membrane 1 displaces the nutrient 2 when an inflating fluid
is introduced through inlet 7 between membrane 1 and the inner walls of the
container 2. Container 3 is perforated and contains opaque heavy material 14,
that replaces material 6 in Figure 1. Handles 12 are attached to container 3
to facilitate removal and replacement of this component of the unit. Con-
tainer 4 replaces divider 10 and contalner 9 in Figure 1. There is no
drainage medium, since material 5 which is light and porous performs this
function along with the function of retaining moisture. Handles 13 are
attached to container 4 to facilitate handling of this component. The
lo pressure of container 4 against container 8 via the membrane 1 at the lip
of container 8 effectively seals the space between membrane 1 and container
8, or the contours of the lips of containers 4 and/or 8 may be such as to
allow some leakage for deflation. Containers 3 and/or 4 may be rigid or
flexible.
In Figure 3, nutrient 2 is displaced by inflating the space between
membranes 1 and 20, via the inlet 7 which has a one-way valve attached to
it. This valve 21 or similar device allows the rate of flow into the
space between membranes 1 and 20 to be greater than the rate of flow from
this space back through inlet 7. In case membrane 1 i9 accidentally rup-
20 tured, the collapse of membrane 1 against the opening of inlet 7 tends toprevent leakage of the nutrient fluid. In addition, device 21 further pro-
tects against unwanted nu~rient leakage, until the rupture is fixed or
membrane replaced. Membranes 1 and/or 20 may be self reinforced to with-
stand the weight of nutrient and the pressure of inflation. Membrane 20
is externally reinforced by a perforated vessel 19. Vessel 19 may be per-
forated to allow easy access of inlet 7 to membrane 20, and/or to reduce
the weight of the unit, and/or sometimes to provide flexibility of the
shape of the unit. Container 4 is similar to, and performs essentially
the same functions as container 4 in Figure 2. However, there is an
30 opening 22 at the top of container 4, which permits the addition of nutrient
or water into the Ullit, and also allows the introduction of a ~ube into
the nutrient space to siphon out the nutrient. One par~ of the invention
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shown here i5 the use of germination modules 16, 17 and 18. Module 16
contains opaque material 14, module 17 contains colourless non-opaque
material 6, and module 18 contains suitably coloured non-opaque material
15. Three modules are depicted here, but this does not necessarily limit
the number of modules used, or their contents. These modules may be rigid,
or flexible by using netting for their construction. These germination
modules allow the seed to be germinated separately, under suitable condi-
tions and germination medium, and transferred to the urit in the same
module without substantially disturbing the new plant. Conventional
10 transplanting is not necessary.
In Figure 4, the inflating fluid inlet 7 has a spring loaded valve
which stays shut when no pressure is used. During inflation, the pressure
differential across the valve maintains it open. Components 28 are used to
attach handles to container 8, which is used as a feeding tank for three
growing units A, B and C.
Though this configuration was chosen for Figure 4, it by no means
implies that other configurations are not possible or included. These
units may be removed, replaced and rearranged as desired. Units A and B
are similar to units previously discussed. Unit C is specially adapted to
20 growing plants with bulbous roots or underground bulbous stems. However,
Unit C may also be used to grow plants with other underground parts.
Unit C has an outer perforated container 29 which allows the nutrient to
move in and out, but does not permit the heavier growing medium 31 to
escape, by virtue of the size of its perforations. Container 30 is also
perforated, but its perforation is such as to allow medium 31 to escape,
but does not allow the lighter porous medium 32 to escape. Medium 31 is
of finer size than medium 32. Container 30 is deep enough to contain the
majority of the root and/or stem. This configuration or similar devices
are operated as follows: The medium 32 is first made to fill the majority
300f the container 30. On top of this material 32 is placed material 31.
As repeated feeding i9 done, the heavier material 31 tends to move to the
bottom~ It is then automatically dynamically separated from material 32
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by the screenin3 action of container 30, and collects in container 29.
This screened material 31 may be reused to add to the top of layer 31.
This unit allows material in the growing medium to perform its function,
be reused, and has no part that may seriously injure the underground part
of the plant, or itself be injured. The units A, B and C are supported
on a support 25. A siphon 23 allows the nutrient to be drained. Other
numbered items in this figure perform similar functions to -items of the
same numbers in Figures 1, 2 and 3.
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In the Claims, nutrient liquid includes an aqueous solution or
suspension of nutrient salts, or both.
Automatic control of the feeding process may be achieved by con-
trolling the inflation and/or deflation. The inflating fluid may be
delivered from a pressurised store and/or from a pump. The controlling
means may be activated by time, humidity or pressure in the inflated
region and/or height of ,luid in the unit. The inflation may also be
humanly controlled, or humanly done.
The hydroponic devices to which this invention relates encompass
a wide range of possible sizes. This invention applies to small units
and to large scale applications. Large scale applications include but ~-
are not limited to automated lawn feeding, playground feeding etc., ~
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besides the usual applications of vegetable, fruit and flower cultivat;on.
Thus this invention encompasses a wide range of possible devices,
arrangements, materials and means, and includes, but is not limited to
the spec;fic descriptions employed here to describe the invention.
SUPPLEMENTARY DISCLOSURE
In additional drawings which illustrate embodiments of the present
invention,
Figure 5. is a sectional view of ano~her simple unit showing another
means by which gas pumping may be used for nutrient feeding.
Figure 6. is a sectional view of another embodiment showing some of
the features of the present invent;on.
Figure 7. is a sectional view of another embodiment of the present
invention showing some features.
In figure 5, a means of displacing the nutrient solution 2 by pumping
gas into a space previously occupied by the nutrient solutions, is shown.
The gas is pumped through tube 7 into the space in container 33. Container
33 has an open bottom and a closed top. The pressurised gas is trapped
at the top of this container and displaces the nutrient solution 2 out
under the container 33 into the growing medium which is a mixture of
heavier material 14 and light, water-holding material 5. The segregation
of material 14 to the bottom is shown. Also shown is a screen 39 whose
main function here, is to tangle with the plants' rooting system and give
the plant additional underground support. The screen may or may not have
a rigid border. One screen is shown, but this does not exclude the use of
multiple screens. These screens may be used to perform the dual function
of divider and underground support. Other numbered items perform essen-
tially the same functions as items with the same numbers in previous figures.
This embodiment of the invention can assume a variety of arrangements: Inner
container 4 can be fabricated of flexible, perforated sheet that drapes over
chamber 33 and extends upwardly along the inner walls of container 8, or
inner conta;ner 4 could be integrated into containers 8 and 33 by defining
container 4 as being formed by the inner walls and a portion of the bottom
of container 8 and the outer side walls an~ the top surface of container 33.
In these arrangements, the lower portion of the growing media 5 and 14 may
be immersed within the nutrient liquid 2 so that the media would remain
moist by capillary action. Furthermore, container 33 may be attached to
container 8 to prevent bouyancy forces generated during the intrGduction of
pressurised gas into container 33 from lifting it off the bottom of contain~
er 8. Other fabrication possibilities also arise: container 33 and the walls
of container 8 may be formed as one piece7 and the bottom of container 8
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would subsequently be at~ached by a water-tight seal, or two parallel
walls of container 8 and the two corresponding parallel walls of container
33 and the bottom of container 8 and the top of container 33 might be
formed by an extrusion or similar process and two side plates would
subsequently be attached to the two ends so as to complete the remaining
walls of containers 8 and 33. Such a fabrication procedure could also
incorporate a slit along the bottom of one of the parallel side walls of
container 33 to permit fluid communication between containers 8 and 33,
or such a slit and a connection for tube 7 could be added in a subsequent
operation, or containers 4 and 33 could be attached and formed in one piece.
In Figure 6, tube 7 enters the unit and is coiled at the bottom of
container 8 in region 34. The tube is open at both ends, but is essen-
tially intact at other points. The end near 7 is connected to a pressurised
gas supply or pump. When the pressurised gas is allowed into the tube,
it pushes nutrient solution out of the lower regions of the tube through
the submerged open end of the tube, into the growing medium. The coiled
tube 34 may or may not be used to support container 29. In this figure,
a unit which may be used to grow plants with fibrous roots and/or bulbous
underground parts is shown. Its operation is similar to that of Unit C
in Figure 4. Other numbered items perform essentially the same functions as
items with the same numbers in previous figures.
In Figure 7, the pressurised gas is introduced through inlet 7 which
forces the nutrient 2 through the tubes 41 into the growing medium. The
tubes 41 may be an integral part of container 40 which contains the grow-
ing medium, and the tubes may be of large enough diameter to allow some of
the growing medium to descend into the nutrient. This allows capillary
action to raise the nutrient into the growing medium, providing moisture
to the roots, between feedings. Device 42 may be a seal which essentially
allows the space between the containers above the nutrient, to be pressurised.
It may be of the snap-on type. In this embodiment of the invention, an
intermediate container is incorporated into the designs of the outer
container 8 and the inner container 40 by defining the intermediate
container as being formed by the inside walls of container 8 and the
outside walls and bottom surfaces of container 40 and a portion of the
supporting lip extending from container 40 to container 8. This definition
applies to other arrangements of this embodiment, some of which are
described ;n the next paragraph. Screen 39 is employed mainly for plant
support via the roots. Divider 3 may be supported by container 40 as
shown in this Figure~ rather than on the porous medium 5. This reduces the
compressive forces on medium 5, which may tend to lose porosity under com-
pression. Other numbered items perform essentially the same functions as
items with the same numbers in previous figures.
The diagram in Figure 7 serves to expla;n the principle of this facet
of the invention. However, containers 8 and 40 may be fabricated as one
piece, without device 42. It is also possible to fabricate container 40
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and the walls of container 8 in one piece, and then attach a bottom for
container 8 in a subsequent operation, so that the joint between the
bottom and walls of container 8 is watertight. If inlet 7 is omitted or
blocked, and the walls of container 8 are semi-flexible, the nutrient
solution can be fed into the growing medium by simply squeezing the walls
of container 8. On releasing the squeeze, excess nutrient solution returns
to the bottom of container 8. If a hollow pipe extends downwards from
the lip of container 40 to a level close to the bottom of tubes 41, a
nutrient level indicator can be inserted into the unit. If the end of
this pipe is located above the bottom of tubes 41, it also serves as a
gas escape device, and prevents gas from bubbling through the growing
medium, in case control of pressurisation is lost.
All the comments made about the invention in the four paragraphs
preceeding the Supplementary Disclosure are equally applicable to the
Supplementary Disclosure.
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