Note: Descriptions are shown in the official language in which they were submitted.
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ANIMAL CONTROL GATE FOR CULVERTS AND THE LIKE
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FIELD OF THE INVENTION
This invention relates to grates for a road culvert and the like and
specifically to
a control gate for keeping small animals of the water resident type from
gaining access
to culverts and the like.
BACKGROUND OF THE INVENTION
Culverts are placed under roads, embankments and the like to provide drainage
from one side of the road to the other when the road interrupts normal
drainage. The
culverts must stay clear of debris. Otherwise, they become plugged and this
can cause
l0 flooding which, if serious enough, can wash away sections of roads. Road
culverts
continually become plugged by water bearing animals such as muskrats and
beavers. The
open ended culverts are very inviting to such animals and workers must be sent
out
almost on a daily basis to plug culverts to clear them out by hand. This is a
very costly
and time consuming solution to the problem.
Numerous attempts have been made to solve the problem outlined above but, for
a variety of reasons, many of these attempts have not been successful. One
example is
shown in U.S. Patent 4,713,179 Goedderz, Sr. which discloses a removable
culvert grate
to be placed adjacent the inflow end of a culvert. It consists of a vertical
grate having a
plurality of slats to prevent the flow of beaver workings or similar debris
and the
2 0 horizontal platform which extends outwardly from the lower edge of the
vertical
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platform. The linkage bar is provided to connect the device to a power source
such as a
winch on the back of a truck. After beavers have constructed a dam or similar
debris and
is collected against the vertical grate, the unit can be lifted by the winch
carried for
example in a pick-up truck or similar vehicle, lifting the debris with the
device.
Another example is shown in Canadian Patent Application 2,140,317 published
17 August 1996. In this arrangement, a frame consists of upper and lower
crossbars
positioned at the open end of a culvert and a plurality of vertical rods are
positioned
across the frame and are supported by the crossbars. The rods are individually
movable
r to and away from the debris blocking position, each rod having a grip at its
upper end for
raising and lowering the rods relative to the frame.
Another example of the prior art is shown in Canadian Patent 1,231,063 issued
5 January 1988. This patent discloses a beaver guard which consists of a
flexible grid
formed by a plurality of transversely extending, spaced apart steel rods
welded to a pair
of spaced apart steel chains. The rods are spaced apart about 4 inches. The
chains are
brought together at their upper ends to provide a loop which may be secured to
a culvert
by hanging it over the upper edge thereof.
Other examples of the prior art may be seen in the following United States
Patents:
3,086,655 Compton 23 April 1963
2 0 4,042,506 Wilson 16 August 1977
3,955,596 Diaz 11 May 1976
4,174,913 Schliesser 20 November 1979
4,702,828 Mehmert et 27 October 1987
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Canadian application 2,016,323
published 9 November 1991
2 5 One of the objectives of the present invention is to reduce the manpower
and the
cost of keeping culverts clean. The main problem is to accomplish this task
without any
harm to the environment or to the animals in question.
The present invention addresses the problem described above by screening off
the
ends of the culvert so that an animal such as a muskrat or beaver is limited
to building
3 o a nest or the like outside the culvert and not within it. The invention
incorporates a gate
that blocks the open end of the culvert and is provided with a mechanism
which, when
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triggered, sends the gate upwards and clearing any debris that an animal might
have
brought to the mouth of the culvert as well as any debris that floats in on
its own. The
gate is then lowered back into place: The mechanism is operated, preferably,
off a
pneumatic system that requires very little maintenance or monitoring. The
minimal
attention required to operate the mechanism considerably reduces manpower and
cost.
The control gate according to the invention can also address problems with
beaver
dams. If a culvert is placed in a beaver dam at the height they want the water
to be, then
the beaver control device can be installed at the end of the culvert.
SUMMARY OF THE INVENTION
l0 The animal control gate according to the present invention operates on a
pneumatic system powered by an air piston which, in turn, raises and.lowers a
front gate
of the device to clear away debris. The air is supplied by an air tank of
suitable size, such
as a five gallon tank, that is refilled with a small air compressor. The
compressor may
be powered by a twelve volt battery which is charged throughout the day by a
five watt
solar panel or other suitable means. These components keep the control gate
running on
its own with very little monitoring.
According to a broad aspect, the invention relates to an animal control gate
for
culverts and the like to screen off the end of a culvert or a pipe to prevent
access to the
interior thereof. The control gate comprises means for positioning the gate
over the
2 0 culvert opening; means for raising and lower the gate; a comb located adj
acent the gate
for cleaning debris from the gate when the gate is being raised; a base member
for
supporting the raising and lowering means; and triggering means to actuate the
mechanism to raise and lower the gate.
When an animal such as a muskrat or beaver carries sticks or mud to the
entrance
2 5 of the culvert, it triggers the pneumatic system to raise the gate
vertically through the
associated comb and this action brushes off any debris it brings in. The gate
then slowly
lowers itself back in to the rest position.
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DESCRIPTION OF THE DRAWINGS
The invention is illustrated in the accompany drawings in which:
FIGURE 1 is a perspective view of the base of the control gate accoridng to
the
lnventlon;
FIGURE 2 is a perspective view of the control gate;
FIGURE 3 is a perspective view of the complete control gate assemlby including
lts operating mechanism;
FIGURE 4 is a schematic view of the pneumatic operating mechanism for the
control gate;
FIGURE 5 is an elevation view of the lift gate;
FIGURE 6 is an elevation view of the feeler bar;
FIGURES 7 and 8 are plan and elevation views respectively of the comb portion
of the assembly;
FIGURE 9 is an elevation view of the lifting frame;
FIGURE 10 is a plan view thereof;
FIGURE 11 is a side view thereof;
FIGURE 12 is a plan view of the base plate;
FIGURE 13 is an end elevation thereof;
FIGURE 14 is a further plan view of the base; and
2 0 FIGURE 15 is a side view thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Refernng to the drawings, and specifically to Figures 1-4, the animal control
gate
assembly is shown generally at 10 and consists of a base plate 12 which
supports the
various components of the assembly and which is suitably secured such as by
clamping
or bolting to the upper surface of a culvert 14 adjacent the open end thereof.
As an
example, the base 12 would comprise a piece of steel channel approximately 10
inches
wide and 20 inches long. A clamp 8, would be provided on the underside of the
base 12
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so that the base could slide over the open end of the culvert and the clamp 8
could be
tightened thereto. Base 12 may also be provided with a handle 13 as shown in
Figures
14 and 15.
The main functional element of the assembly 10 is the gate mechanism
illustrated
generally at 16 and comprising a comb 18 of generally rectangular
configuration, see
Figure 5, and comprising a plurality of parallel tines 20 attached to a
crossbar 22 and
joined to a guide plate 24 by means of connecting bars 26 guide plate 24 has a
pair of
spaced, parallel depending legs 28 which are coaxial with and located within a
pair of
vertically oriented guide tubes 30. It will be evident that moving the guide
plate 24 and
its associated legs 28 up and down in the guide tubes 30 affects
vertical,movement of the
comb or gate 18. Guide tubes 30 are welded or otherwise secured to a crossbar
32 which
is secured to the base member 12.
As shown in Figures 2, 7 and 8, the gate assembly 16 also includes a
stationary
cleaning bar or rake 34 mounted behind and adjacent to the comb 18 and is
provided with
a plurality of teeth 36 interspersed with the tines 20 of the comb. This bar
34 is secured,
against any movement, to the end of the base member 12 by suitable brackets
35, Figure
8, and is provided with a plurality of teeth 36 interspersed between the tines
20 of the
comb so that, when the gate 16 is raised, the teeth 36 serve to clear the comb
tines ZO of
any debris secured thereto.
2 o The means for raising and lowering the gate assembly, specifically the
gate 18
and its tines 20, is shown in Figure 3 and, schematically, in Figure 4.
The gate 18 is raised and lowered through the action of a pneumatic cylinder
38
secured at one end by a socket 37 to the base 12 (see figures 14 and 15) and
having a
reciprocal piston rod 40 with an eye 42 at the outer end thereof. A cable 44
is secured
2 5 at one end to the guide crossbar 24 and, at its other end, to a suitable
fastener 46 secured
to the base 12.
An air tank 48, filled to approximately 40 psi, is secured to the base 12 and
is
connected, as shown in Figure 4, to the pneumatic cylinder 38 through a
solenoid valve
50 having a pressure switch 52 and a micro switch 54 associated therewith.
Micro switch
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54 has a trigger lever 56 connected thereto and lever 56 is in a position to
be engagable
by gate member 18.
It will be evident from Figures 2 and 3 that when pneumatic cylinder 38 is
activated, piston rod 40 will be extended and this will raise the guide bar 24
and the legs
28 of the gate member 18 in the guide tubes 30 through the upward action of
the piston
rod 40 and its connection to the cable 44. This operation of the pneumatic
cylinder 38
is started by the micro switch 54 when it is operated by the trigger lever 56
which in turn
is operated when it is pushed with sufficient force to engage the lever 56.
This force is
w applied by the debris that is piled up against the gate by the waterborne
animals. The
micro switch 54 provides the solenoid valve 50 with a signal and it, in turn,
releases the
required amount of air, from the tank 48 to raise the piston and its rod 40 in
the
pneumatic cylinder 38. A magnet (not shown) is provided in the base of the
piston and
when this magnet comes in contact with a reed switch, it closes the contact
that sends a
further signal to the air valve to release more air from the tank to return
the piston to its
lower position. The speed of the raising and lowering of the gate is
controlled by two
mufflers 58 and 60 on the air valve 50 and illustrated in Figure 4
When pressure in the air tank 48 drops below 40 psi the pressure switch sends
a
signal to an air compressor which is activated and fills the air tank up to
the desired
pressure i.e. 40 psi. The air compressor and all other electrical devices are
run off a
2 0 twelve volt battery which is charged daily through a five watt solar
panel.
Feeler bars 62, Figure 6, may be attached to the bottom of the comb 18,
specifically by menas of sleeves 64 adjustably secured to selected tines 20 as
shown in
Figure 3, and these are used to trigger the gate if an animal such as a beaver
tries to build
out and around the culvert. They are made of plastic and do not harm the
animal when
2 5 they go up with the gate 18.
A spring mechanism keeps the gate of out reach from the limit switch. The
purpose of this is so that the water flow itself does not trigger the limit
switch. The
strength of the spring mechanism can be adjusted to coincide with the water
flow.
While the invention has been described in connection with a specific
embodiment
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thereof and in a specific use, various modifications thereof will occur to
those skilled in
the art without departing from the spirit and scope of the invention as set
forth in the
appended claims.
The terms and expressions which have been employed in this specification are
used as terms of description and not of limitations, and there is no intention
in the use of
such terms and expressions to exclude any equivalents of the features shown
and
described or portions thereof, but it is recognized that various modifications
are possible
within the scope of the invention claims.
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