Patent Application
20070069191
Silt fences prevent sediment carried by sheet flow from leaving a construction site and entering natural drainage ways or storm drainage systems by slowing storm water runoff and causing the deposition of sediment at the structure. Silt fencing encourages sheet flow and reduces the potential for development of rills and gullies. Silt fencing should be installed where sheet flow runoff can be stored behind the barrier without damaging the barrier or the submerged area behind the barrier. Silt fencing is generally located at the topographically lowest portions of the site where silt migrates during rain events.
Visual fence is placed just inside the clearing boundaries to define the limits of clearing. This is necessary to prevent the overclearing of trees, brush, etc., and to visually identify the clearing limits. Many local ordinances require that the visual fence have certain minimum visibility requirements.
Conventional fence systems are installed by first digging a narrow shallow trench the length that the fence is to be run. The stakes are set into the ground in the trench at a specific distance apart. Typically, a wire backing is attached to the stakes using fasteners. The wire backing lends support and strength to the fence and, in particular, to the fabric. The wire backing extends from down in the trench to above the ground level, generally up to at least a portion of the height of the fence material. The fence material, typically a synthetic fabric or mesh, is attached to the stakes using fasteners such that the lower portion of the fabric overlaps the wire backing. The trench is backfilled to secure the fence in the ground. In use, the silt fence blocks silt runoff while permitting water to pass through the fence mesh.
By the time the construction is completed to the point where the fence is no longer needed, the fence material has often degraded or is otherwise unusable in another application. However, the fence must still be removed by construction crews and either recycled or dumped in the garbage or landfill.
Currently, at least one line, and often two lines, of silt fence are separately installed and used to prevent silt runoff and a separate line of visual fence is used to provide a visual indication of tree save or other marked area. Each line must ordinarily be manually installed by workers. Often, wire ties are used to attach the fence to the stakes, with each tie taking time to feed through the fabric, around the stake and twisted off. This results in significant time being required to install and later uninstall these fences, increased waste product as the fences are often unreusable after the first use, and increased cost. It would be desirable to have a single fence which could provide a silt barrier yet also serve as a visual fence. It would also be desirable to have fence system that is easier and take less time to install, while reducing the quantity of fence required.
Generally described, the present invention provides in a first exemplary embodiment a novel combination of a silt and visual fence to prevent sedimentation from leaving the limits of construction and the visual impact of a clearing tree save fence to define the limits of project clearing. The silt/visual fence combination reduces the need for two separate material and installation processes and will allow for one product and one installation. More particularly, the present invention provides, in one exemplary embodiment, a silt/visual fence comprising a plurality of stakes, each stake comprising, a generally flat surface having a plurality of holes defined therein and spaced along at least a portion of the flat surface, a strip of fabric, comprising, a lower portion having a first visual indicia associated therewith, an upper portion having a second visual indicia associated therewith distinct from the color of the first portion, the upper and lower portions being connected; and, a plurality of fasteners for fastening the strip of fabric to the plurality of stakes. The fence preferably also includes, where use so requires, a wire grid or mesh backing to provide additional strength and support to the lower portion fabric. For certain applications a wire grid or mesh backing is not required.
Other features and advantages of the present invention will become apparent upon reading the following detailed description of embodiments of the invention, when taken in conjunction with the appended claims.
The invention is illustrated in the drawings in which like reference characters designate the same or similar parts throughout the figures of which:
The present invention provides a silt fence to prevent sediment from leaving a site with a visual fence to define the limits of project clearing or a protected tree save area. In one exemplary embodiment a silt fence 10 is shown in
The stake 12 is preferably formed of a durable generally rigid material, such as, but not limited to, metal, wood, plastic, combinations of the foregoing, and the like. In a preferred embodiment the stake is made of wood or steel. The lower end of the stake 12 preferably, though not mandatorily, terminates in a tapered tip for easier insertion into the ground. The stake 12 preferably has a generally flat portion 16 (although a curved portion, or even a cylindrical shaped stake 12 are contemplated as being within the scope of the present invention). Preferably, though not mandatorily, the stake has a reinforcing portion 18, which can be formed as an L-shaped or T-shaped (as shown in
The fabric 14 can be any suitable fluid porous material which can also retain a substantial portion of sedimentous material, such as, but not limited to, silt, topsoil, rocks, branches, leaves, and the like. In one exemplary embodiment the fabric 14 is made of polypropylene, available commercially from a number of manufacturers. The fabric 14 is preferably made of a first horizontal strip 30 and a second horizontal strip 32. The first and second strips 30, 32 are joined together, such as by adhesive, fusing or other technique known in the art, with the seam 33 shown in the drawing. Alternatively, the first and second strips 30, 32 can be part of a single strip of fabric 14.
The first strip 30 is preferably located above the top edge of the second strip 32. The first strip 30 has a first unique visual indicia associated therewith and the second strip 32 preferably has a second unique visual indicia associated therewith. The visual indicia can be any visually distinctive indicator, such as, but not limited to, color, pattern, words, symbols, combinations of the foregoing, or the like. In one preferred embodiment the first strip 30 has an orange color and the second strip 32 has a black color. Preferably, the fabric itself is made of the colored material; alternatively, the color can be applied to the fabric using any suitable technique.
In one exemplary embodiment, the fence 10 also includes a wire backing 34 as a support and strength adjunct to the fabric 14. The wire backing 34 preferably has a curved portion 36 at its lower end so as to conform to the shape of a trench into which the wire backing is maintained, as described in greater detail hereinbelow. The wire backing 34 preferably extends upward from the lower portion of the stake 12 to at least a portion of the stake 12 aboveground when installed. The wire backing 34 is preferably made of metal, plastic or other durable strong material. A primary purpose of the wire backing 34 is to provide additional strength to the fabric 14 when silt accumulates behind the fabric 14 and to resist deformation or ripping of the fabric 14.
The fabric 14 is preferably attached to the stake 12 using a number of fasteners 38. The fastener 38 has a shank 40 which is pushed through the fabric 14 and force fit into one of the holes 20 in the stake 12 (see
By spacing the stakes 12 a desired distance apart (usually mandated by state or local regulation) the fabric 14 can be stretched between the stakes 12 and secured in place using the fasteners 38. A portion of the fabric 14 is placed in a trench in the ground (as discussed above, this is usually mandated by state or local regulation) and soil placed over that portion to maintain the fabric 14 in place and to prevent silt and other nonfluid runoff from passing under the fabric 14.
An advantage of the present invention is that the two color fabric 14 eliminates the need for separate silt and visual fences as are conventionally used; i.e., one black fence and one orange fence. The elimination of one fence reduces time and cost of installation and subsequent removal of the fence once construction has ended. The present invention also reduces landfill impacts or the need to recycle one fence.
In another aspect of the present invention, a novel fastener is provided for use with the fence system 10.
It is to be understood that the caps 52 and 72 of the fasteners 50 and 70, respectively, may be constructed with different shapes, such as, but not limited to, circular, rectangular, rhomboid, elliptical, oval, hemispherical, square, wedge, asymmetric or other regular or irregular shape.
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. It should further be noted that any patents, applications and publications referred to herein are incorporated by reference in their entirety.
