Patent Application
20070059101
This invention relates generally to a cone-shaped screen for attachment to an end of a culvert pipe for preventing beavers from building a dam to block the flow of water. More particularly, the present invention relates to a cone-shaped screen having an apex portion for selective connection to a drainage pipe arranged to drain into or pass through the culvert pipe.
Culvert pipes are widely used to allow water to flow beneath roads without having to redirect it or construct a bridge to pass over the stream. Unfortunately, such pipes represent an ideal place for beavers to construct a damn and restrict the flow of water. These damns can quickly cause flooding and washouts when water levels are elevated, for example, by heavy rains or melting snow. Vertical screens or grates have been used to prevent beavers from entering culverts, but such devices do not discourage beavers from building dams at the ends of a culvert pipe. Also, water flows tend to deposit debris at such barriers which builds up over time and restricts flow through the culvert.
U.S. Pat. Nos. 5,102,537 and 6,447,206 disclose cone-shaped screens that were intended to overcome the limitations of the flat designs discussed above. A base end of the screen attached to the end of the culvert has a series of rods extending outward from the culvert to an apex end. The rods are spaced by a distance that allows small debris to pass through without clogging the culvert while preventing entry by beavers and similarly sized animals. The beavers cannot construct an ideal damn at the opening of the culvert as they cannot properly anchor the structure.
As a result of limiting access to the culvert by beavers, the prior art also limits access to the culvert pipe by others. For example, it may be useful to connect other drainage systems, such as weeping tile, to existing culvert pipes. The combination of such systems is often ideal as it eliminates the need for separate piping systems and thus reduces cost and environmental interference. In addition, large culverts require correspondingly large screens that are difficult and costly to transport due to their dimensions. As a result, there is a desire for a beaver control device that is easy to transport and prevents dam construction and debris buildup at the end of a culvert pipe while allowing the connection of other drainage sources to the culvert.
According to a first aspect of the invention there is provided a combination of a beaver control device, a culvert pipe and a drainage pipe, said combination comprising:
a generally conical screen having opposite first and second ends, said generally conical screen comprising:
The present invention overcomes the shortcomings of the prior art by providing an apex portion that is arranged to selectively couple with a drainage pipe such as those found in a weeping tile drainage system. A retaining member is provided to ensure that the drainage pipe is held in place when connected to the beaver control device so that animals cannot dislodge the drainage pipe from the desired position in which it drains into the culvert pipe. The rods extending between the base and apex portions prevent beavers from approaching the end of the culvert pipe while allowing small debris to flow through the openings between them.
Preferably the retaining member is supported on the apex portion and comprises a pin movable between an open position and a closed position. Preferably, the pin extends across the opening of the apex portion in the closed position, thereby blocking a portion of said opening, and does not extend across said opening in the open position, thereby leaving said opening substantially unobstructed. Preferably, the pin is arranged to pass through at least one hole in the drainage pipe during movement from the open position to the closed position if said drainage pipe has been received in said opening, thereby securing said drainage pipe to the apex portion. So when a drainage pipe is not connected to the apex end of the device, the pin is placed in the closed position to block off the opening to prevent beavers from entering the screen. When a drainage pipe is connected, the pin is used to lock the pipe in place so that the beavers cannot knock it free from the screen.
Preferably the base portion comprises mounting elements for connecting the generally conical screen to the end of the culvert pipe for motion between a lowered position in which said screen substantially blocks the end of the culvert pipe and a raised position in which said screen does not substantially block at least a portion of said end of said culvert pipe. The raised position allows for easier cleaning of the device to remove any build up of debris.
Preferably each mounting element comprises a length of chain attached at opposite ends thereof to the base portion of the generally conical screen and the end of the culvert pipe.
Preferably there is provided a coupler supported on the apex portion.
There may be provided an actuator for moving the generally conical screen between the lowered and raised positions. In this case, preferably the actuator comprises a flexible longitudinal member attached to the apex portion and extending toward the base portion such that pulling said longitudinal member away from the apex portion causes the generally conical screen to pivot about the end of the culvert pipe from the lowered position to the raised position. The use of such a flexible longitudinal member, like a rope or chain, allows the device to be easily raised and lowered for occasional cleaning.
The base and apex portions may comprise a plurality of base members and apex members respectively, each base member being connected to a respective apex member by respective ones of the plurality of rods. In this case, preferably adjacent base members are coupled together and adjacent apex members are coupled together. Preferably the adjacent members are detachably coupled by bolts at flanges provided at opposite ends of each member. This allows the device to be partially assembled on-site from multiple pieces which can be transported with less hassle and lower costs.
According to a second aspect of the invention there is provided a combination of a beaver control device and a culvert pipe, said combination comprising:
a generally conical screen having opposite first and second ends, said generally conical screen comprising:
the base and apex portions comprising a plurality of base members and apex members respectively, each base member being connected to a respective apex member by respective ones of the plurality of rods;
adjacent base members being coupled together such that the base members collectively define a base rim having an opening therein for receiving an end of the culvert pipe; and
adjacent apex members being coupled together.
In the accompanying drawings, which illustrate exemplary embodiments of the present invention:
Supported on the rim 46 of the apex portion 44 is a coupler in the form of a vertically extending hook 48, the purpose of which will be explained in conjunction with the limited motion allowed by the chains 38 below. The screen 30 also includes a retaining member in the form of a pin 50 which passes through aligned holes 51 in the apex rim 46. The purpose of the pin 50 is twofold. Firstly, the pin 50 serves to lock the weeping tile pipe 20 in place as shown in
In the one piece construction of the first embodiment, the rims 34 and 46 of the base portion 32 and apex portion 44 are flat bars of generally circular shape. In the two piece construction, flat bars are again used for the base and apex members but are semicircular in shape. The flanges 52 are created by welding angle iron across the bars to create a radially outward extending piece along the width of the rim. It should be appreciated that these components can be made using alternate materials and processes known to those of skill in the art to obtain the same effect.
Similarly, means of mounting the screen 30 on the culvert 10 for the relative motion between the lowered and raised positions described above other than the combination of chains 38 and bolts 36 and 40 are known to those of skill in the art. For example, the chains 38 could be wrapped around the rim 34 and reattached to themselves instead of being bolted, or a hinge mechanism could be provided in place of the chains 38. Also, the rope 58 used as an actuator for movement of the screen 30 can be replaced by any number of suitable actuators known to those of skill in the art. Another example of a manually operated, flexible longitudinal member would be a chain. Another alternative is to mechanize the lifting process with a lifting apparatus, for example, using cylinders.
While the above embodiments have been described for use on a culvert pipe 10 in order to allow the possibility of running weeping tile pipe 20 through the screen 30 for draining into the culvert 10, it should be appreciated that pipes other than those used in weeping tile systems can be received in the opening 56 of the rim 46 of the apex portion 44. The device 1 can be easily modified to accept various tubes, pipes or conduits that drain into or pass through a culvert 10 having a screen 30. Furthermore, the shape of the screen 30 does not have to be a perfect conical portion and can be somewhat varied while still retaining the desired effect of narrowing from a larger end at the base to a smaller end at the apex. In cases where the culvert 10 is damaged and cannot properly support the device 1, a screen 30 with a base rim 34 having a diameter less than that of the culvert 10 may be installed by mounting the base portion 32 within the end of the culvert 10. Finally, while the second embodiment has the screen 30 divided into two separate halves 60 and 62 that are held together by bolts 54, it is also possible to further divide the screen 30 into additional pieces, such as quarters, to facilitate transport of very large beaver control devices. In addition, the pieces can be attached by means other than bolts, including more permanent fastening methods. While detachably coupling the pieces with bolts allows for easy removal, disassembly and transport at a later date, welding or other methods known to those of skill in the art can be used to permanently attached the pieces of the screen should it be desirable to do so.
Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.
