Patent Abstract:
A fence for retaining silt and providing a visual marker 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 a wire grid or mesh backing to provide additional strength and support to the lower portion fabric.

Full Description:
BACKGROUND OF THE INVENTION  
       [0001]     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.  
         [0002]     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.  
         [0003]     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.  
         [0004]     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.  
         [0005]     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.  
       SUMMARY OF THE INVENTION  
       [0006]     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.  
         [0007]     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. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The invention is illustrated in the drawings in which like reference characters designate the same or similar parts throughout the figures of which:  
         [0009]      FIG. 1  is a perspective view of one exemplary embodiment of the present invention.  
         [0010]      FIG. 2  is a detailed view of the stake according to one exemplary embodiment of the present invention.  
         [0011]      FIG. 3  is a top schematic view of a stake with a fastener inserted through the wire back and fabric.  
         [0012]      FIG. 4  is a bottom plan view of a fabric fastener according to one exemplary embodiment of the present invention.  
         [0013]      FIG. 5  is a side view of the fabric fastener of  FIG. 4 , shown in position in the fence.  
         [0014]      FIG. 6  is a bottom plan view of a wire back fastener according to one exemplary embodiment of the present invention.  
         [0015]      FIG. 7  is a side view of a fastener inserted into a fence system. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0016]     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  FIG. 1  and generally comprises a plurality of stakes  12  and a strip of fabric  14 .  
         [0017]     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  FIG. 1 ) part of the stake. The flat portion  16  has a series of space apart holes  20  along at least a portion of the length of the flat portion  16 . Optionally, there are a series of tabs or protrusions  22  extending generally outward from the flat portion  16 . In one exemplary embodiment, shown in  FIG. 1 , the flat portion  16  has a generally vertical line of holes  20  on both left and right sides and a series of tabs  22  between the sets of holes  20 .  
         [0018]     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 .  
         [0019]     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.  
         [0020]     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 .  
         [0021]     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  FIG. 3 ). In one exemplary embodiment the fastener  38  can be either a fabric fastener  42  or a wire backing fastener  44 . The fabric fastener  42  may have a circular head. The wire backing fastener  44  may have a rectangular head. The fasteners  42  or  44  preferably have at least one, and more preferably, a plurality of annular barbs to restrict unintentional removal of the fastener. It is to be understood that other fasteners  38  can be used with the present invention, and may include, but are not limited to, wire or plastic ties or wraps, staples, nails, hook and loop fasteners, screws, clips, combinations of the foregoing or the like. A novel fastener is described in detail herein below.  
         [0022]     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 .  
         [0023]     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.  
         [0024]     In another aspect of the present invention, a novel fastener is provided for use with the fence system  10 .  FIGS. 4 and 5  show an exemplary embodiment of a fabric fastener  50  having a head or cap  52  and a shank  54 . The fabric fastener  50  is preferably made of plastic, but can also be made of metal or other material that preferably can be struck without substantial deformation yet be resistant to weathering. The surface of the cap  52  can be rounded or flat. The cap can be circular in circumference or of other shape. The cap  52  has a plurality of ribs  56  or barbs, teeth, fins or the like that protrude from preferably the back side (i.e., the side with the shank extending therefrom) of the cap  52 . The ribs  56  are preferably arranged is a series of concentric circles (with each rib being straight, curved, jagged, or other shape), as shown in  FIGS. 4 and 5 . It is to be understood that other regular or irregular arrangements, e.g., grid, spiral, radial, random and the like, are contemplated as being possible. The ribs  56  can be the same height, or can be of different heights above the back of the cap  52 . A purpose of the ribs  56  are to increase the gripping strength of the fabric fastener  50  to the fabric  32  when installed. When the fabric  32  is installed against the support  12 , the shank  54 , which preferably has a pointed tip  58  and a series of protrusions  60  or threads, passes through the fabric  32  and is retained in one of the holes  20 . The ribs  56  are pushed towards and/or into the fabric  32  and preferably engage the fabric fibers. This multiple-point engagement helps to retain the fabric  32  in place and reduce the tendency to rip during extended use. In one exemplary embodiment it is possible for the ribs  56  to be the result of piercing the front of the cap  52  and creating a protrusion of material extending out of the back of the cap  52 .  
         [0025]      FIG. 6  shows an alternative embodiment of a fastener, namely a wire backing fastener  70 , similar in material construction to the fabric fastener  50 , but preferably having a generally rectangular shaped cap  72 . The surface of the cap  72  can be rounded or flat. The ribs  74  are preferably arranged horizontally in rows so as to improve engagement and retention of the wire  34 . The wire backing fastener  70  has a shank  76  similar to the shank  54 .  FIG. 7  shows a wire backing fastener  70  installed in a fence system. The shank  76  of the wire backing fastener  70  is inserted through the hole  20  in the support  12 , with at least one row of ribs  74  being below the wire  34 . Preferably, at least one row of ribs  74  is above the wire  34 . In this manner the ribs assist in supporting the wire  34  and maintaining it in position with respect to the support  12 .  
         [0026]     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.  
         [0027]     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.

Technology Classification (CPC): 4