Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a culvert end structure,
and in particular to a float operated valve for use on a culvert
end.
A common problem in northern locals is the damming
of culverts by beavers. Culverts extending through mounds of
earth or other structures such as beaver dams usually carry small
quantities of water, i.e. dribbles. It is usual for a beaver to
block the culvert to prevent the flow of dribbles. One solution
to the problem is to provide grates over the ends of the culverts.
However, when grates are used, it is necessary to maintain the
culverts on a more or less constant basis, i.e. frequently to
remove debris from the ends of the culvert.
The object of the present invention is to overcome the
above stated disadvantage of existing culvert guards by providing
a relatively simple culvert end structure which prevents dribbling
and which renders a culvert less likely to damming by a beaver.
Accordingly, the present invention relates to a culvert
end structure comprising casing means for mounting on an inlet
end of a culvert pipe so that said casing extends vertically
upwardly from the inlet end of the culvert pipe, inlet means in one
side of said casing means for admitting water into said pipe means
for discharge through the culvert pipe; valve means slidable in
said casing means normally closing said inlet means; float means
connected to said valve means for lifting said valve means when
the water at the inlet end of the culvert pipe rises above a
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predetermined level, whereby water is discharged from the culvert
pipe at intervals in relatively large quantities rather than
frequently in small quantities.
The invention will now be described in greater detail
with reference to the accompanying drawings, which illustrate
preferred embodiments of the invention, and wherein:
Figure 1 is a schematic side elevation view of a culvert
end structure in accordance with the present invention mounted on
a culvert;
Figure 2 is a side elevation view of the structure
of Fig. 1, with parts removed;
Figure 3 is a cross section taken generally along
line III-III of Fig. 2;
Figure 4 is a cross section taken generally along line
IV-IV of Fig. 2; and
Figure 5 is a sche~atic perspective view of a poxtion of a
second embodiment of the invention.
With reference to Figs. 1 to 4, a culvert end structure
in accordance with the present invention generally indicated at
1 is intended for use on one end 2 of a culvert 3 extending through
a beaver dam 4 or other mound. The structure 1 includes a
generally L-shaped casing 5. The horizontal arm 6 of the casing 5
is connected to the end 2 of the culvert 3 by a coupler 7. The
coupler 7 i5 defined by a pair of C-sections pivotally interconnected
at the bot~om by a hinge (not shown). The top end of each C-section
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includes a flange 8 for receiving bolts or screws (not shown)
for connecting the sections together. The C-sections are ru~ber
lined to provide a watertight seal between the culvert 3 and the
end structure 1. The end structure 1 is supported above the
bottom 10 of a beaver or other pond 11 by a post 12 and a bracket
13 similar in structure to the connector 8.
The vertical arm 15 of the casing S has an open top
end, which is closed by a flange cover 16. An inlet opening 17
is provided in one side of the casing for admitting water into
the casing from the pond 11. A cowl 18 protects the opening 17,
preventing the entry of debris into the opening 17. The opening
17 is normally closed by a valve 19. The valve 19 is mounted on
the bottom end of a tubular rod 20 for slidable movement in the
vertical arm 15 of the casing. The rod 20 extends upwardly through
an opening in the cover 16. Thus, the cover 16 acts as a guide
to ensure that the valve 19 remains centralized in the vertical
arm 15 of the casing. The lower limit of valve travel is deter-
mined by an annular, radially inwardly extending flange 22 near
the bottom end of the vertical arm 15 of the casing. The bottom
end 24 of the valve 19 is hemispherical for seating centrally on
the flange 22. Vertical movement of the valve 19 in the casing
is controlled by a pair of floats 25. The floats 25 are mounted
on the outer ends of arms 26, which extend outwardly and
downwardly from opposite sides of the rod 20 above the valve 19.
The arms 26 project outwardly through longitudinally extending
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slots 28 in the casing 5 so that the arms are free to move ver-
tically in the casing.
With reference to Fig. 5, the second embodiment of the
invention is similar to the first embodiment, and accordingly only
the valve and float portions are shown. The device of Fig. 5 is
intended for mounting in the vertical arm 15 of a casing of the
type shown in Figs. 1 and 4.
The device of Fig. 5 includes a valve 30 mounted on the
bottom end of a tubular rod 31. The rod 31 extends upwardly through
a rectangular block 33, which is held in one position on the rod
by a set screw (not shown). Similar, generally U-shaped brackets
34 are pivotally mounted on opposite sides of the block 33 for
supporting arms 36 and floats 37. The inner ends 38 of the sides
of the brackets 34 extend downwardly beyond the pivot points 40
of such brackets. A helical spring 41 extends between the bottom
end of each pair of bracket sides on opposite sides of the block
33. Thus, the spring 41 controls rotation of the brackets 34
and the arms 36 around the pivot points 40, i.e. the springs 41
have a direct effect on the water level required to cause the
floats 37 to rise. Whlle it is not readily apparent from
Fig. 5, the valve 30 is larger in diameter than the block 33 and
the brackets 34, so that the valve can slide freely in the
casing 5.
The operation of the structure will be described with
reference first to Figs. 1 to 4. When the water level in the pond
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11 is sufficiently low, the valve 19 remains in the closed position
(Fig. 3) blocking the inlet opening 17. When the water level
rises sufficiently, the floats 25 cause the rod 20 and the valve
19 to move upwardly which permits the escape of water from the
pond 11 through the opening 17, the horizontal arm 6 of the casing
5 and the culvert 3. The same action occurs with the embodiment
of the invention illustrated in Fig. 5, the springs 41 retarding
upward movement of the block 33, the rod 31 and the float 30.
It has been found that beavers tend to block small
flows through culverts of the dribble-type, i.e. frequent or
constant flows of small volumes of water more readily than large,
infrequent flows of large quantities or slugs of water. Thus,
by providing a culvert end structure which causes only the
infrequent discharge of relatively large quantities of water,
the likelihood of culvert damming is reduced or eliminated.
