Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02488047 2004-11-19
CROSS- F'E hICE TO RELATED PLICAT)(ONS
This application claims the benefit of Canadian Patent Application~No,
2,450,151,
filed November 19, 2003, and US Patent Application No. 601523,099, each of
which is
incorporated herein by reference in its entirety.
FIEr.D OF THE INVENTION
The present invention relates generally to irrigation gates. More
particularly, the
present invention relates to a cost-effective, reliable water gate system t'or
controlling
water in irrigation supply canals and similar water channels through the use
of as
electronically controlled gate or gaffs.
SACKGROU~VD O$, T~IfE INVENTION
Prior art devices have been developed to control water in irrigation supply
canals
and in similar water channels. Such devices are required to manage _wator
resources
effectively.
An example of such a prior art device used to maintain a cox~staat or
predetermined
water level in as iaigatiort ditch gate as found in United States Patent
4,349,296 (referred
to as the L.~PAC patent). The gate system taught in the LOPAC patent consists
of two
opposing, vertically hinged biased gate leaves which automatically open snd
close in
response to a chango in water pressure against the upstream surihce of the
Bata leaves,
thereby maintaining a constant upstream water level in the irrigation ditch.
One disadvantage of the system presented in the LOPAC patent is 'that it is
difficult
and time consuming to 6ne-tune end place the springs neccssaty to bias the
gate leaves to
a desired position. This disadvantage is especially pronotmccd when the 'gate
leaves need
to be larger than one square meter to span an irrigation ditch.
A furthez disadvantage of the system disclosed in the LOPAC g~tent is that
since
the gate leaves are spring-actuated, the system is Limited to controlling thv
upstream water
level and does not, for example, respond to downstream conditions.
It is, therefore, desirable to provide an i.xrigation gate system. which does
not
roquire a great detail of fine tuning to achirvo the desired flow through the
irrigation gate
system and is capable of responding to and being used to cool more than
upstream
water levels. ,
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CA 02488047 2004-11-19
SUMMARY ~ TSE INVENTIOl~
It is an object of the present invention to obviate or mitigate the
disadvantages of
the prior art by providing an irrigation gate system whicb can be casx'ly and
quickly
adjusted electronically to achieve a desired flow thmugh an irrigation gate
system. It is a
further object of the present imre~ntion to control upstream water levels sad
respond to
othtr conditions (such as downstream flow) showing for further uses of the
present
invention. '
In a fast aspect, the present invention provides an irngation gate system
installed
in a ditch or canal for maintaining a desired level of water upstream from the
irrigation
gate system. The irrigation gate system includes a gate, which is operable in
either a
closed position for preventing water from flowing past tht gate or in a
plurality of open
positions for allowing variable amounts of water to flow past the getc. The
gate is
vertically hingedly connected to a pipe shaft, which is supported by a frame
installed in
the ditch or canal. A gate actuator in cooperation with the pipe shaft unoves
the gate
between its various positions upon receiving signals from an electronic
programnnable
coniroller which in turn receives signals from a level sensor (or other sensor
depending on
what is being tnomtared) which may be installed upstream from the gatte to
maintain a
desired upstream water level or downstream if something other than the desired
upstream
water level is being measured). Additionally, the gate mey be set at a
particular open
position to measuro the vohlrae or rate of flow in the ditch or channel by~
reference to the
water's height in the gate st that pre-set position. ,
Other aspects and features of the present invention will become apparent to
those
ordinarily sldllod in the art upon review of the following description of
specific
embodiments of the invention is coq~unetion with the accompanying figures.
BRI~ DE CRIP'1"ION OF ~'I~E DRAW)(~1GS '
Embodiments of the present invention will now be described, by way of example
only, with reference to the attached Figures, wherein:
Rig. 1 is a perspective view of a gate in a closed position in acaordanec with
the
present invention;
Fig. 2 is a perspective view of a plurality of gates each in a o7ased position
in
accordance with the present invention; ,
Fig. 3 is a perspective view of a gate activator in accordance; with the
present
invention;
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CA 02488047 2004-11-19
Fig. 4 is a perspective and exploded view of a plurality of gates in ~ open
position
in accordance with the present invention;
Tig. 5 is a perspective view of an alternate gate actuator in opcradoa with a
plurality of gates in accordance with the present invention;
Fig. 6 is a perspective view of an irrigation gate system used as part of a
fish
exclusion structure in accordanct with the present invention. ,
DETAILED I1ESCRIPTIQ1~
Cfencrally, the present invention provides a method and system for providing
an
irrigation gate system, which can be easily and quickly electronically
adjusted to achieve
desired water levels upstream from the gate through the intigstion ga~de
system, or to
achieve other desire water flow or water level results based upon readings
provided by a
sensor or sCnsors.
As shown in Figure 1, the preferred embodiment of the presrnt system 100
generahy includes a flame 30, which is positioned within an irrigation ditdh,
channel, weir
or other check structure. The frame 30 includes two sidewalk 31, which support
a top wall
32_ SidewaUs 3I include a pipe shaft 11, which is operatively connected to sad
forms a
vertical hinge for gate 1 o for allowing the gate I o to pivot between a
closdd position and a
plurality of open positions. If gate 10 is closed, flow through the ditch or
channel is
restricted or stopped. If gate 10 is open, flow is allowed through the ditch
or channel and
such flow depends on the ralativt openness of gate I o. Accordingly, i~'low
through the
ditch or channel (and therefore the upstream water level) is Changed by
opening or closing
the gate 10 and, if opened, flow is adjusted by opening the gate I 0 more or
less.
'fhe top wall 32 dents a recess far receiving pipe shaft 11. As sl~owa in
Figure 2,
a gate actuator 20 oa the tap wall 32 is connected to pipe shaft 11 for
rotaring pipe shaf3 l l
and consequ~tly rotating gate 10 between various positions. Gate actultor 20
may be a
screw jack, a hydraulic cylinder or another suitable eoternslly-powered
mechanism
(samples of which are shown in 1~igure 3, 4 and 5) which is is communication
with a
proy nmable controller 22. Gate actuator 20 translates electronic aign;as
received from
controller ZZ into the mechanical movement of gate 10. In ome embodim~tnt bast
shown in
Figure 3, gate activator 20 includes a lever aim 68 operatively connected to a
synchronizing roller chain 59, which in tum is connected to a hydraulic
cylindtr 60, and
limit switch harness (not shown) which collectively act as a drive train. ~,
hydraulic pump
54 may be used in this tmbodiment to provide hydraulic power to the cylinder
60. In an
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CA 02488047 2004-11-19
alternate embodiment shown is Figure 4, gate actuator 20 is a direct
mechanical cylinder
drive which may be used with a one-gate 10 embodiment or rosy, optionally,
operate two
gates. Any of the gate actuator 20 systems may be driven by a fractional
horsepower
motor (not shown).
Controller 22 provides signals to gate actuator 20 to determine the
appropriate
position of the gate 10. Controller 22 includes a reoeaver or transceiver (uot
shown) and
rnay, accordingly, receive signals from a number o~ sources including a level
sensor 24
which may be placed upstream from gate 10 to determine the water leve:.
.Alternatively,
controller 22 may be electrically connected to level sensor 24 thereby
alle°~iating the need
for controller 22 to have a receiver or transceiver. When the water level
changes, level
sensor 24, which includes a transmitter or transceiver (not shown) or which
may not
include a transmitter or transceiver if electronically connected to controller
22, but which
in any event transmits a signal to controller 22. Controller 22 then compares
the
information contained in the signal with pre-programmed infomnation un
controller 22
{namely, the desired water level) and determines if water flow should increase
or decrease
to achieve the desired result. If more flow is required, controller 22 sends a
signal which
then turns on the pump 54 to close gets 10 or opens a relief valve on the pump
54 to open
gate 10 (upstream water pressure being the driving force to open gate 10).
Level sensor 24
may be placed to measure water Ievels either above or below gate 14, depending
upon the
operator's designs.
A5 an alternative to the Ievel sensor Z4 for providing signals to the
controllar 22, a
flow mater (not shown) may be installed downstream from gate 10 for measuring
flow
which can provide signals to controher 22. In a further alternative or in
addition to the
other sensors, an enragersey high level probe (not shown) may provide an
emergency high
level override signal to controller 22 which would in taro cause gate 10 to
open
completely in the event of as undesirably high water lCVe1 occurring. Once the
watd~ IeveI
returns to an acceptable Ievel another signal may be sent to reset controller
22. Stilt
further, other sensors may provide controller 22 with signals to open or close
gate 10
based on pre-defined algorithms programmed Into controher 22. ~ In yet another
embodiment, an operator may r~notcly transmit signals to controller 22 po
control gate 10
(rather than having the gate's operation automatically controlled based on
algorithms pre-
programmed is controller 22 and signals provided from various sensors).' A
worker skilled
in the art will appreciate that a number of Sensors may be in communication
with the
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CA 02488047 2004-11-19
controller 22 to allow the algorithms pre-programmed in controller Z2 to react
to a variety
of inputs from multiple sensors.
pipe shaft 11 may also be operated using a hand cra»k (not shown) connected to
pipe shaft 11 to provide for manual operation of gate 10 far emergencies or to
perform
maintenance ox to reset the present systern_ '
Tn any of the above embodiments, power to any element requiring power, such as
a
fractional horsepower motor, level sensor 24 and controller 22 may be provided
by
connection to a deep cycle battery aperativcly connected to a solar panel or
battery
charger.
At, worker skilled in the art will appreciate that the pent invention can be
applied
in a variety of circumstances, including in irrigation check structures,
sp'llway structures
and diversion structures. Gate 10 may be constructed of various sizes to tit
the dimensions
of these various environments. '
The present invention may also be used for 8sh and other scrocni~lg structures
one
example of which is as shown in Figure d. Tn particular, structures are
sa~metimes used to
screen fish out of a diversion. Theses structures arc typically long screen
structures which
allow flow back to the main stream at the downstream end of the stttam
(typically
requiring at least 10% of the water fkowed through tht screen structure 4o be
returned to
the main stream). The gate 10 can be used to control the volume of water flow
back to the
main stream while allowing fish to pees through the gate 10,
While the embodiments o~F the present inv~tion described above include a
single
gate 10, it will be readily apparent to a worker skillod in the art that a
plurality of gates 10
and cotxespanding shafts 11 and gate actuators 20 (but not necessarily a
phuality of
controllers) would also provide Operative embodiments of the present
invention.
In a ewo-gate embodiment the irrigation gate system 100 may be used to
calculate
the flow rate of water past the gate 10, owing to the system's precise
set~ngs. That is, the
irrigation gate system 100 may serve essentially as a weir except that waa~ter
does not flow
over the weir until the gates 10 are opened. When the gates 10 are opened the
water
flowing over the weir is restricted by the gates 10 and the frame 30 and gates
l0 function
partly as an orifice of discem'blc dimensions. There are formulae and tables
lmown by
those skilled is the art for determining the rate of flow through most weirs
and or~ces
which can be used to calculate rate of flow (although as the irrigation gate
system 100 is
not definable as exactly a weir or as an orifice the irrigation gate sysxem
100 requires
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CA 02488047 2004-11-19
calibration). The width of the gate 10 opening may be calculated by
multiplying the weir
width by the angle on the gates 10. Width and depth of flow cats then be used
in a weir
formula to calculate the approximate flow rate of water. An empirical
caefl6cient is needed
to make the flow calculation accurate. The coefficient is determined by
setting up a gate
10 in a controlled situation and passing varied metered flows through the gate
10. Graphs
or charts can than be produced showing flows for various gate opening's and
depths of
flow. Flows rosy be correlated for various-sized gates 10, and various opening
configurations (gate positions).
A worker skilled in flee art will apprdciate that gate 10 and frame 30 could
he made
of a variety of materials which have high durability in an aquatic
~vi~yonment. In one
embodiment, gate 10 and frame 30 era coastt'ucted of mild steel with a~ two-
part epoxy
coating. In another embodiment, gate 10 and frame 30 are constructed of
stainless steal,
although due to the higher cost of this material, this embodiment is typically
used only in
scvcre conditions.
A worker skilled is the art will appre<:iate that controller 22, to perform
its
function, includes a circuit board, (net shown) end memory (net shown), and
programmable computing capabilities.
The above-described embodiments of the present invention are intended to be
examples only. Alterations, modfOcations and variations rnay be effected to
the particular
embodiments by those of skill in the art without departing from the scope of
the invention,
which is dc$ned solely by the claims appended hereto.
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