Abstract:
A portable rock filter is described as a tool for use in erosion control and inlet protection. The filter is comprised of a double wrap of PVC coated wire mesh around a core of graded rocks. The portable rock filter may be used for inlet protection.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates generally to tools and methods used to prevent erosion and to prevent sediment from entering drainage systems. 
         [0003]    2. Description of Related Art 
         [0004]    During construction or after earth moving projects the ground can be susceptible to erosion and runoff can carry large amounts of sediment. That erosion can damage a site and the sediment can clog drainage systems. Complex systems are often required to keep sediment out of drainage systems. 
         [0005]    Currently fences are often used to filter run-off and numerous inlet protection devices are employed with varying results. 
         [0006]    A need exists, therefore, for a versatile tool and method for filtering run-off and protecting inlets from sediment intrusion. 
         [0007]    All references cited herein are incorporated by reference to the maximum extent allowable by law. To the extent a reference may not be fully incorporated herein, it is incorporated by reference for background purposes and indicative of the knowledge of one of ordinary skill in the art. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    The problems presented in the art are addressed by a portable rock filter; the filter comprising graded stone and wire mesh wrapped around the graded stone. The wire mesh may be double wrapped around the graded stone. The wire mesh is PVC coated. The portable rock filter may have at least one handle attached to the wire mesh. 
         [0009]    The problems presented in the art are addressed by an inlet protection system comprised of a wire grid formed to have a flat section, a vertical section and a cover section and a plurality of portable rock filters placed on the flat section, each rock filter comprising graded stone; and wire mesh wrapped around the graded stone. The wire mesh may be double wrapped around the graded stone. The wire mesh is PVC coated. The portable rock filters may have at least one handle attached to the wire mesh. 
         [0010]    Other objects, features, and advantages of the present invention will become apparent with reference to the drawings and detailed description that follow. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a plan view of a portable rock filter; 
           [0012]      FIG. 2  is a sectional view of the portable rock filter from  FIG. 1 ; 
           [0013]      FIG. 3  is a plan view of two portable rock filters being used for inlet protection; and 
           [0014]      FIG. 4  is a sectional view of the inlet protection shown in  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    All references cited herein are incorporated by reference to the maximum extent allowable by law. To the extent a reference may not be fully incorporated herein, it is incorporated by reference for background purposes and indicative of the knowledge of one of ordinary skill in the art. 
         [0016]    In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical mechanical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. 
         [0017]      FIG. 1  is a plan view of a portable rock filter  10  having a body  12  and handles  14 . Body  12  is formed of a double wrap of PVC coated wire mesh  16  filled with graded filter stone  18 . It is typical for the coated wire mesh  16  to have an opening size of about one inch and the graded stone  18  to be about 1.5″ to 2″ in size. Wire ties  20  are spaced along the portable rock filter  10  to secure the mesh  16  about the stone  18 . For uses where a larger stone  18  is desired the mesh  16  opening size would be larger. For uses where a smaller stone  18  size is desired a smaller mesh  16  opening size would be used. Combined, the mesh  16  and stone  18  act to reduce the run-off speed of water flowing through them and to thereby trap or filter out some of the sediment in the run-off. 
         [0018]      FIG. 2  is a sectional view of the portable rock filter  10  from  FIG. 1  showing a handle  14  being comprised of a wire loop  22  and a grip  24  along the wire loop  22 . Also shown from this sectional view are the wire mesh  16  and the rock  18 . The wires mesh  16  is formed to give the filter  10  a somewhat squared profile which makes for secure placement on flat surfaces, such as roads or sidewalks. 
         [0019]      FIG. 3  is a plan view of two portable rock filters  10  being used for inlet protection at a typical curb inlet  26 . A stiff wire grid  28  is first placed to cover the inlet  26  so that large items, such as the portable filter  10  are not allowed into the inlet  28 . The grid should be shaped so that a portion is laid out in front of the inlet, and another portion covers the inlet and a third portion extends over the top of the inlet. The filters  10  are placed on the portion of the grid  28  extending in front of the inlet  26  and act to secure the grid  28  in place. In this example two filters  10  are being used together to extend beyond the opening width of inlet  26 . Typically the filters  10  should extend at least a foot beyond the inlet  26 . 
         [0020]      FIG. 4  is a sectional view of the inlet protection shown in  FIG. 3  and clearly shows the grid  28  extending under the filters  10  and then up behind the filters  10  and over the top of the inlet  26 . The grid  28  allows the filters  10  to be sized so that the tops of the filters  10  are about two inches below the top of the inlet  26  opening. This allows for water to go over the filters  10  in very high run-off volume situations where drainage may be more critical than sediment control. 
         [0021]    In all of the above applications the wire mesh  16  is double wrapped to provide a secure enclosure around the graded stone  18 . The wire mesh  16  is preferably a coated wire mesh  16 , such as PVC coated wire mesh commercially available. The PVC coated wire mesh  16  has been found to have surprising benefits in this application over both galvanized wire mesh  16  and untreated wire mesh  16 . Using coated wire mesh  16  reduces rusting, reduces tears, provides a lightweight structure, is aesthetically more pleasing and holds the stone  18  within the filter  10  better. The PVC coated mesh  16  makes the portable filters  10  actually portable in that they may be emptied of the stone  18  and stored for later reuse without worry about structural damage or decay during storage. Also, the PVC coated wire mesh  16  is easier to inspect when the filters  10  are being cleaned or emptied so that damage may be addressed. 
         [0022]    It should be apparent from the foregoing that an invention having significant advantages has been provided. While the invention is shown in only a few of its forms, it is not just limited but is susceptible to various changes and modifications without departing from the spirit thereof.