Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BEAVER CONTROL DEVICE FOR USE WITH A CULVERT PIPE
FIELD OF THE INVENTION
The present invention relates to a beaver control device of the type
having a frame which is tubular and has opposing longitudinal ends which are
open
and transverse bars spanning across transversely opposing portions of an inner
surface of the frame, and more particularly the present invention relates to a
beaver
control device in which the frame has a plurality of openings spaced angularly
thereabout and the transverse bars are spaced along a longitudinal length of
the
frame and elevated relative to a bottommost edge of the frame which rests on
the
ground, the transverse bars being closer to the bottommost edge than to a
topmost
edge of the frame which is vertically opposite the bottommost edge.
BACKGROUND
Culvert pipes, which are widely used to allow water to flow beneath
roads without having to redirect it or construct a bridge to pass over the
water, present
an ideal place for beavers to construct a dam and restrict the flow of water.
A number
of previous patents have sought to deal with this problem, in which they
prevent
beavers from entering culvert pipes by physically obstructing an entrance at
an end of
the culvert pipe through the use of screens. In addition to deterring beavers
from
entering culvert pipes, it is important to deter them from building dams that
obstruct
the flow of water through the culvert pipe, too. For example, U.S. Patent Nos.
5,102,537; 6,447,206; and 7,441,989 describe cone-shaped screens that block
beavers and similarly-sized animals from entering the culvert pipe.
Furthermore, the
cone-shaped screens deter beavers from constructing dams as the beavers are
unable to properly anchor the dam. In spite of these benefits, screen-based
beaver
control devices have shortcomings. Firstly, the small debris may still gather
at the
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screen and promote clogging of the entrance of the culvert pipe. Furthermore,
these
screens inhibit passage of fish and turtles through the culvert pipe.
SUMMARY OF THE INVENTION
According to a first aspect of the invention there is provided a beaver
control device for use with a culvert pipe comprising:
a cylindrical frame comprising a plurality of longitudinally extending bars
at angularly spaced positions around a longitudinal center axis of the
cylindrical frame
and at least one peripheral bar arrangement interconnecting the longitudinal
bars so
as to define on the frame a longitudinal length between opposing longitudinal
ends
thereof, a bottom peripheral portion for resting on the ground, a top
peripheral portion
which is vertically opposite the bottom peripheral portion, a horizontal
longitudinal
= center plane containing the longitudinal center axis and a vertical
longitudinal center
plane containing the longitudinal center axis joining the bottom peripheral
portion and
the top peripheral portion;
and a plurality of transverse bars generally parallel to the horizontal
longitudinal center plane;
the plurality of transverse bars being arranged at positions spaced along
said longitudinal length of the frame;
each of the transverse bars spanning substantially straight across the
frame from a position at or adjacent the frame on a first side of the vertical
longitudinal
center plane to a position at or adjacent the frame on second opposite side of
the
vertical longitudinal center plane;
wherein the plurality of transverse bars are elevated above the bottom
peripheral portion of the frame and located at a position below the transverse
center
plane so that the transverse bars are closer to the bottom peripheral portion
than to
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the top peripheral portion.
According to a second aspect of the invention there is provided a beaver
control device for use with a culvert pipe comprising:
a cylindrical frame comprising a plurality of longitudinally extending bars
at angularly spaced positions around a longitudinal center axis of the
cylindrical frame
and at least one peripheral bar arrangement interconnecting the longitudinal
bars so
as to define on the frame a longitudinal length between opposing longitudinal
ends
thereof, a bottom peripheral portion for resting on the ground, a top
peripheral portion
which is vertically opposite the bottom peripheral portion, a horizontal
longitudinal
center plane containing the longitudinal center axis and a vertical
longitudinal center
plane containing the longitudinal center axis joining the bottom peripheral
portion and
the top peripheral portion;
and a plurality of transverse bars generally parallel to the horizontal
longitudinal center plane;
the plurality of transverse bars being arranged at positions spaced along
said longitudinal length of the frame;
each of the transverse bars being connected at a first end to a
respective first one of the longitudinally extending bars and being connected
at a
second end to a respective second one of the longitudinally extending bars and
spanning substantially straight across the frame from one side of said
vertical
longitudinal center plane to an opposed side of said vertical longitudinal
center plane;
wherein the plurality of transverse bars are elevated above the bottom
peripheral portion of the frame and located at a position below the horizontal
longitudinal center plane so that the transverse bars are closer to the bottom
peripheral portion than to the top peripheral portion.
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Preferably the transverse bars are aligned so as to lie in a common
plane parallel to the horizontal longitudinal center plane.
Preferably the peripheral bar arrangement comprises a plurality of rings
at spaced positions along the longitudinally extending bars.
Preferably there is provided a plurality of hangers attached to the frame
and extending toward the axis for supporting a pipe.
Preferably the longitudinal ends of the frame are open to allow passage
into the frame of beaver.
Preferably the transverse bars extend at right angles to the vertical
longitudinal center plane.
The embodiment as described in more detail hereinafter operates on the
principle of deterrence rather than obstruction as the prior art. Both
longitudinal
spacing of the transverse bars along the longitudinal length of the frame and
elevation
of the transverse bars relative to the bottommost edge of the frame in
proximate
distance thereto afford difficultly and discomfort when crossing the
transverse bars
that discourages the beavers from doing so. The longitudinal spacing forces a
beaver
to cross the transverse bars by inserting one foot at a time in a gap between
each pair
of adjacent transverse bars. In addition, the transverse bars are elevated at
a height
which is generally slightly larger than an average length of a leg of the
beaver, so the
elevation creates additional difficulty and discomfort. Furthermore, the
present
invention overcomes the shortcomings of the prior art in that the transverse
bars are
elevated at a height so as to allow the passage of small debris, fish, and
turtles.
Preferably, each one of the transverse bars is elevated relative to the
bottommost edge by a clearance distance which is between 1.5" and 8".
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Preferably, each one of the transverse bars is elevated relative to the
bottommost edge by a clearance distance which is between 2" and 7.5".
Preferably, each one of the transverse bars is elevated relative to the
bottommost edge by a clearance distance which is between 2.5" and 7".
5 Preferably, each pair of adjacent transverse bars has a spacing
distance
therebetween which is at least three times greater than a width of each one of
the
transverse bars.
Preferably, the transverse bars are spaced along the longitudinal length
so that each pair of adjacent transverse bars has a spacing distance
therebetween
which is between 1.5" and 7".
Preferably, the transverse bars are spaced along the longitudinal length
so that each pair of adjacent transverse bars has a spacing distance
therebetween
which is between 2" and 6.5".
Preferably, the transversely opposing portions of the inner surface,
which the transverse bars span across, are horizontally opposing portions of
the inner
surface, and each one of the transverse bars are coupled at each longitudinal
end
thereof to respective horizontally opposing portions of the inner surface.
Preferably, the transverse bars are aligned so as to lie in a common
horizontal plane.
Preferably, each one of the openings has an opening area which is less
than or equal to 150 square inches.
Preferably, each one of the openings has an opening area which is less
than or equal to 1.40 square inches.
Preferably, each one of the openings has an opening area which is less
than or equal to 135 square inches.
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=
6
Preferably, the frame further includes at least one circular ring and a
plurality of longitudinal bars which are coupled to the at least one circular
ring and
spaced angularly about the frame. Preferably, each one of the openings is
defined by
respective gaps between respective longitudinal bars within each pair of
adjacent
longitudinal bars of the frame. It is preferred that each pair of adjacent
longitudinal
bars has a gap therebetween, a width of the gap being less than or equal to
5".
Preferably, each pair of adjacent longitudinal bars has a gap therebetween, a
width of
the gap being less than or equal to 4.75". Preferably, each pair of adjacent
longitudinal bars has a gap therebetween, a width of the gap being less than
or equal
to 4.5".
Optionally, the beaver control device further includes hangers for
supporting a pipe. The hangers may be attached at respective topmost portions
of the
inner surface of the frame so as to extend downward therefrom.
One embodiment of the invention will now be described in conjunction
with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is right elevation view of a cross-section of the beaver control
device.
Figure 2 is a top plan view of another cross section of the beaver control
device in FIG. 1.
Figure 3 is an end view of a front of the beaver control device in FIG. 1.
Figure 4 is a right elevation view of the beaver control device mounted
to a culvert pipe and in an active position.
Figure 5 is a right elevation view of the beaver control device mounted
to the culvert pipe and in an inactive position.
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In the drawings like characters of reference indicate corresponding parts
in the different figures.
DETAILED DESCRIPTION
Referring to the accompanying figures, there is illustrated a beaver
control device generally indicated by reference numeral 100. The beaver
control
device is intended for use with a culvert pipe 1 by coupling to an end
thereof, so as to
prevent beavers and other similarly-sized animals from entering the culvert
pipe.
The beaver control device 100 has a frame 102 as in FIG. 1. The frame,
which is tubular, is circular cylindrical in shape and has a first open end
104 at one
longitudinal end of the frame, and a second open end 106 at an opposite
longitudinal
end of the frame. The frame comprises four circular rings which are identical
and
define a circular cross-section of the frame: a first end ring 108 is at the
first open end;
a second end ring 110 is at the second open end; and a first intermediate ring
112
and a second intermediate ring 114 are intermediate the first and second open
ends.
The first intermediate ring is adjacent the first end ring, and the second
intermediate
ring is between the first intermediate ring and the second end ring. The first
and
second intermediate rings are positioned along a longitudinal length of the
frame so
as to divide the frame into three longitudinal sections thereof, each section
being
approximately equal in longitudinal length. All four circular rings are
aligned so that an
axis of each one of the circular rings lies along an axis of the frame. An
inner diameter
of the frame, which is a measure of a width of the frame between opposing
portions of
an inner surface of the frame measured through the axis of the frame, is
arranged to
. be larger than yet proximate an outer diameter of the culvert pipe. When
the frame
comprises circular rings, the inner diameter of the frame is measured between
opposing portions of the inner surface of the first or second end rings.
Consequently,
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a rim of the second open end 106 receives a rim of the end of the culvert pipe
1 in an
active position of the device 100 when the frame 102 is substantially aligned
with the
culvert pipe end-to-end so that the axis of the frame lies along a
longitudinal axis of
the culvert pipe as shown in FIG. 4.
The frame 102 also comprises longitudinal bars 116 which span
between the first 104 and second 106 open ends and are at spaced positions
about
the frame 102. Each one of the longitudinal bars is circular cylindrical in
shape. The
longitudinal bars are arranged so that, within each pair of adjacent
longitudinal bars, a
first longitudinal bar is parallel relative to a second longitudinal bar;
furthermore, each
one of the longitudinal bars is parallel to the axis of the frame as
illustrated in FIGS. 1-
2. Each one of the longitudinal bars is coupled to each one of the circular
rings at an
inner surface thereat a longitudinal end of each one of the longitudinal bars
at the
second open end 106 is recessed from an outer edge of the second end ring 110
so
as to leave room at the second open end for the rim of the second open end to
receive the end of the culvert pipe 1 in the active positon. As such, the
first 112 and
second 114 intermediate rings add structural rigidity by providing additional
locations
along the longitudinal length of the frame for attaching the longitudinal bars
thereto. A
structure of the frame comprising circular rings and longitudinal bars as
described
reduces a mass of the beaver control device compared to using a solid type of
construction, such as a solid steel frame. The lower mass is important for
making the
device 100 easier to transport and for mounting to the end of the culvert pipe
1.
In the preferred embodiment as illustrated in FIGS. 1-5, the longitudinal
bars 116 are spaced angularly about the frame so as to form respective gaps
118
between each pair of adjacent longitudinal bars. Each one of the gaps has a
width of
4". An opening defined by each one of the gaps has an opening area of 120
square
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inches. The opening area and elongate shape of each one of the gaps are
arranged
to prevent beavers and other similarly-sized animals from passing into the
beaver
control device between any one of the pairs of adjacent longitudinal bars. The
gaps
118 may have an opening area which is less than or equal to 150 square inches.
The
opening area sized within such a range function equally well to obstruct
beaver-sized
animals when each one of the gaps are elongate as in the preferred embodiment.
Accordingly, respective gaps having an opening area equal to the maximum
thereof
would have a width of 5"; as such, a width of each one of the gaps is less
than or
equal to 5". Notwithstanding the functional equivalence, narrower gaps between
pairs
of longitudinal bars 116 necessitate more longitudinal bars about the frame
102,
thereby increasing the mass of the device 100. Also, the openings defined by
the
gaps effect flow of water and small debris into the culvert pipe through
alternative
openings in the frame other than the first open end 104, which is important in
case
that debris obstructs the first open end which is a free end of the device
when the
device is coupled to the culvert pipe 1 in the active position as shown in
FIG. 4. As
such, these openings spaced angularly about the frame reduce the likelihood of
water
levels rising due to obstructed ends of the culvert pipe.
Further to the frame 102, the beaver control device 100 also comprises
a mounting mechanism arranged for coupling to the culvert pipe 1. The mounting
mechanism comprises two lengths 120 of chain. One longitudinal end of each
length
of chain is attached proximate the second open end 106, to an uppermost
portion of
the rim of the second open end at laterally opposing points along the rim
thereof. An
opposing longitudinal end of each length of chain, which is a free end
thereof, has a
mounting portion arranged for attachment to the end of the culvert pipe. The
mounting
portion is an elongate plate 122 with holes therein for passing a bolt 124
therethrough
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to fasten the plate to the culvert pipe 1. The plate is fastened at an
uppermost portion
of an outer surface of the culvert pipe, at positions along same which are
horizontally
aligned in both longitudinal and lateral axes with respective locations of
attachment of
the lengths 120 of chain along the rim of the second open end in addition to
being
5 approximately at the same elevation as the respective locations of
attachment of the
lengths of chain. The lengths of chain are under tension in the active
position such
that the chains and a bottommost portion of the rim of the second open end 106
provide support for the device 100 against the end of the culvert pipe. in the
active
position, the beaver control device projects outwards from the end of the
culvert pipe
10 so as to resemble an extension thereof. As such, any animals that want
to access the
culvert pipe 1 have to enter the device at the first open end 104.
The mounting mechanism is arranged to facilitate motion between the
active position illustrated in FIG. 4 and an inactive position illustrated in
FIG. 5 in
which the frame 102 is not substantially aligned with the culvert pipe 1 for
purposes of
cleaning same. Accordingly, the beaver control device 100 also has a coupler
supported on the first open end 104 to facilitate connection of an actuator
126 thereto
to effect movement of the frame relative to the end of the culvert pipe
between the
working and inactive positions. More specifically, the coupler is a coupler
plate 128
which projects upward from a topmost portion of the first open end such that
opposing
surfaces of the coupler plate face in opposing transverse directions of the
frame.
Furthermore, the coupler plate has an aperture 130 for attaching an actuator
126,
such as a rope, thereto to effect pivotal-like movement thereof relative to
the end of
the culvert pipe between the working and inactive positions. In the inactive
position,
the device 100 is lifted upright so that the axis of the frame 102 forms an
angle with
the longitudinal axis of the culvert pipe 1, which affords direct access to
the culvert
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pipe for purposes such as cleaning same.
The beaver control device also includes transverse bars 132. The
transverse bars are circular cylindrical in shape and span across transversely
opposing portions of the inner surface of the frame 102. More particularly,
these
transversely opposing portions are horizontally opposing portions of the inner
surface
of the frame, and when the frame is constructed of the circular rings and
longitudinal
bars 116 as described earlier, the transverse bars span between one pair of
longitudinal bars which are located at horizontally opposing sides of the
frame as
shown in FIGS. 1-3. Arranging the transverse bars to span a full distance
between
one pair of longitudinal bars which are at a same horizontal elevation forces
a beaver
which attempts to pass through the device 100 to traverse the transverse bars,
without any way of navigating around same. The transverse bars are elevated
relative
to a bottommost edge 134 of the frame 102 so as lie in a common horizontal
plane
parallel to a horizontal longitudinal center plane H containing the axis A.
Each of the
transverse bars spans substantially straight across the frame from a position
at or
adjacent the frame on a first side of the vertical longitudinal center plane V
to a
position at or adjacent the frame on second opposite side of the vertical
longitudinal
center plane. In the preferred embodiment, the bottommost edge of the frame is
defined by one of the longitudinal bars 116; the bottommost edge of the frame
may
rest on the ground depending on a depth of a culvert. Generally speaking, the
transverse bars are elevated relative to the bottommost edge so as to be
closer to the
bottommost edge of the frame than to a topmost edge of the frame which is
vertically
opposite from the bottommost edge; however, if in an alternative embodiment
the
bottommost edge if not clearly defined, the transverse bars can be considered
to be
spaced above at least a portion of a subset of the longitudinal bars 116 that
is below a
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highest respective one of the transversely opposing longitudinal bars to which
the
transverse bars are attached. In the preferred embodiment, the horizontal
plane is
elevated relative to the bottommost edge of the frame by a clearance distance
of 5"
relative to the bottommost edge 134 of the frame. However, the clearance
distance
may be between 1.5" and 8". A minimum clearance distance of 1.5" is sufficient
to
present the transverse bars 132 as obstacles which the beaver must overcome
and to
allow fish, turtles, and small debris to pass underneath the transverse bar,
while a
maximum clearance distance of 8" ensures that an average-sized beaver cannot
pass
underneath the transverse bars. An ideal clearance distance of 5" is chosen so
as to
be larger than while still proximate a length of an average-sized beaver's
leg. In
general, the clearance distance of the transverse bars 132 creates difficulty
and
discomfort for the beaver attempting to cross over same, consequently
deterring the
beaver from passing through the device 100.
Further to the clearance distance, the transverse bars 132 are spaced
along the longitudinal length of the frame 102 which is clearly shown in FIG.
2. Each
respective transverse bar within each pair of adjacent transverse bars is
parallel
relative to one another, and each one of the transverse bars lies at a right
angle to the
axis of the frame. Each pair of adjacent transverse bars has a spacing
distance
therebetween which is between 1.5" and 7". A minimum spacing distance of 1.5"
is
sized so that an average-sized beaver's foot can fit in each gap between each
pair of
adjacent transverse bars, while a maximum spacing distance of 7" ensures that
the
beaver cannot comfortably insert more than one foot in each gap. In the
preferred
embodiment, the spacing distance is 4". Regardless of the spacing distance
that is
chosen, the spacing distance is at least three times larger than a width of
each one of
the transverse bars so that the beaver cannot walk across or slide its body
over the
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transverse bars. In general, the spacing distance of the transverse bars 132
along the
longitudinal length of the frame 102 deters the beaver attempting to cross
over the
transverse bars by forcing the beaver to insert one foot at a time in each gap
between
adjacent transverse bars which makes crossing over the transverse bars more
difficult
and uncomfortable for the beaver.
Lastly, the device 100 also includes hangers 136 for supporting a pipe 4
to drain into the culvert pipe 1 as in FIGS. 1-3. The preferred embodiment
comprises
two hangers, and each hanger has a coupling portion 138 and a receiving
portion
140. The coupling portion 138 is an elongate plate which is attached at a
topmost
portion of the inner surface of the frame 102 so as to extend downward
therefrom. As
such, a first of the two hangers is coupled to the first circular ring 108 and
a second of
the two hangers is coupled to the second intermediate ring 114 as shown in
FIGS. 1-
2. The receiving portion 140 is arranged to receive the pipe therein.
Furthermore, the
receiving portion is ring-shaped and oriented so that an axis of the receiving
portion is
parallel to the axis of the frame. Also, the receiving portion is enclosed so
that the
receiving portion receives the pipe 4 by passing same through the receiving
portion in
a direction along an axis which is parallel to the axis of the frame. The
bottommost
portion of the receiving portion is spaced above the transverse bars 132 to be
sufficiently elevated so that the beaver is unable to engage the hanger 136 or
the pipe
4 received therein. As illustrated in FIG. 4, the pipe supported by the
hangers will
have opposing longitudinal ends thereof which ideally extend beyond the first
104 and
second 106 open ends of the beaver control device 100. Extension beyond the
first
open end is important both to effect the flow of water over a beaver dam built
in front
of the first open end which may be obstructing same and to provide a physical
obstacle that deters the beavers from building a taller dam that may engage
the pipe.
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Prior to use, the beaver control device 100 is manufactured according to
the diameter of the culvert pipe 1 with which it will be used in conjunction.
Once
manufactured, the device is transported to a site where it is to be mounted to
the end
of the culvert pipe. The device is first aligned with the culvert pipe so that
the rim of
the second open end 106 receives the rim of the end of the culvert pipe. Once
the
device is aligned with the culvert pipe, the lengths 120 of chain which are
the
mounting mechanism are stretched longitudinally away from the frame 102 so as
to
exert maximum tension therein, and then the elongate plates 122 at the ends of
the
lengths of chain are fastened with bolts 124 to the uppermost portion of the
outer
surface of the culvert pipe. Normally, the device is in the active position
illustrated in
FIG. 4 once the device has been mounted to the end of the culvert pipe. The
mounting mechanism has to be able to support any downward torque exerted on
the
frame 102 as a result of a beaver attempting to pass through the beaver
control
device or due to the weight of the pipe 4 supported by the hangers 136.
In use, a beaver that attempts to pass through the beaver control device
100 engages the transverse bars 132. If the beaver chooses to overcome a first
transverse bar, the beaver must insert one foot at a time in the gap between
the first
transverse bar and a second transverse bar which is adjacent thereto. The
device
deters the beaver from continuing further as the clearance and spacing
distances of
the transverse bars 132 makes passing over same difficult and uncomfortable.
As
such, the beaver will tend to exit the beaver control device by returning to
the first
open end 104 and exiting same.
For periodic cleaning of the culvert pipe 1, the actuator 126 attached to
the coupler plate. 128 is used to raise the device frame 102 into the inactive
position
as illustrated in FIG. 5. The pipe 4 may be removed from receiving portions
136 of the
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hangers 136 prior to moving the device into the inactive position so as to
prevent the
pipe from sliding out of the receiving portions downwards and into the water
of a
culvert.
Since various modifications can be made in my invention as herein
5 above described, and many apparently widely different embodiments of
same made,
it is intended that all matter contained in the accompanying specification
shall be
interpreted as illustrative only and not in a limiting sense.
