Abstract:
A filter assembly ( 20 ) for a drainage basin ( 22 ) is disclosed. The filter assembly includes a filter ( 28 ), a liquid director ( 32 ) adapted to guide liquid into the filter. The filter assembly also includes an attachment assembly ( 30 ) fastened to the filter. The attachment assembly adapted to selectively attach the filter to the drainage basin.

Description:
RELATED APPLICATION 
     This application claims priority of the earlier filing date from Provisional Application No. 60/212,098, filed on Jun. 15, 2000, the disclosure of which is expressly incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to drainage basin filters and, more particularly to a removable filter for drainage basins. 
     BACKGROUND OF THE INVENTION 
     Drainage basins collect storm water from rain fall or melting snow. City sidewalks, streets, and roads are constructed such that surface water flows to strategically placed drainage basins. Typically, water collected by a drainage basin flows directly into the local sewer system, where it is channeled to a waste water treatment facility by a sewer line. As a result, water entering the sewer line should be free from solids and other debris that may cause clogging. 
     Many conventional sewer filters are located at or above the grade level of the roadway. As located, such filters remove solids from drainage water before it flows into the drainage basin. These filters may be placed horizontally on top of the grate, or are vertically disposed in a circle above the grade level surrounding the grate. Over time, solids can clog such conventional filters and impede the flow of water, thereby resulting in flooding of the surrounding area. Moreover, locating conventional sewer filters at grade level makes it difficult to drive or walk over the top of the drainage basin without damaging the filter. 
     Other existing drainage basin filters, known as below-grade drainage basin filters, are located below grade level. When such filters are full, they are too heavy to be removed by one person. Many parts of these below-grade drainage basin filters are not replaceable, thereby making them more expensive to maintain over time. Moreover, such below-grade filters can not be custom tailored to meet changing engineering specifications. 
     Prior to applying a layer of asphalt to the road, runoff typically pools around the drainage basin&#39;s grate due to an inability to enter the drainage basin at an area below the grate. The present invention offers a solution to this problem by positioning an inlet at a predetermined level below the drainage basin grate and outside of the cavity defined by the rim of the drainage basin. 
     For each of the foregoing reasons, there is a need for a below-grade drainage basin filter able to filter solids without impeding the free flow of water and adapted for easy removal, and maintenance. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a filter assembly for a drainage basin is provided. The filter assembly includes a filter, a liquid director adapted to guide liquid into the filter, and an attachment assembly fastened to the filter. The attachment assembly is adapted to selectively attach the filter to the drainage basin. In certain embodiments, the attachment assembly includes a support member attached to a first end of the filter and a hanger assembly adapted to selectively attach the filter assembly to a portion of the drainage basin. 
     In accordance with further aspects of this invention, the hanger assembly includes one end fastened to the support member. A second end of the hanger assembly is adapted to be coupled to the drainage basin to hang the filter at a predetermined location within the drainage basin and collect liquid from the liquid connector. The hanger assembly includes three support rods having first and second ends, wherein each support rod is adapted to be placed in one of three holes of the support member at the first end and sharing a common connecting point at the second end. The attachment assembly also includes a hanger arm extending from the common connecting point and adapted to be selectively affixed to the drainage basin by connecting means. 
     In accordance with other aspects of this invention, the liquid director is a conduit extending between the filter and the drainage basin to collect liquid and channel the liquid into the filter. 
     In accordance with still yet other aspects of this invention, the liquid director is adapted to substantially seal the drainage basin to channel liquid passing through the drainage basin into the filter. 
     A filter assembly formed in accordance with the present invention has several advantages over currently available filters. First, such filters are more environmentally reliable than existing filters because they are selectively attachable to the drainage basin, thereby minimizing the risk of dropping the filter or its contents into the drainage basin during cleaning. Second, because the liquid director physically channels fluids into the filter, such a filter is more effective at filtering waste water. Finally, because the filter is selectively attachable to the drainage basin, it is easier by a single person to clean or replace. 
     Thus, a filter assembly for a drainage basin formed in accordance with the present invention is environmentally reliable and efficient, and is easily maintained and replaced by a single operator. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing aspects and many of the attendant advantages of this invention will become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of a drainage basin filter constructed in accordance with one embodiment of the present invention showing the drainage basin filter selectively attached to a drainage basin; 
     FIG. 2 is a side planar view of a drainage basin filter constructed in accordance with one embodiment of the present invention showing the drainage basin filter selectively attached to a drainage basin; 
     FIG. 3 is a partial planar side view of a drainage basin filter constructed in accordance with one embodiment of the present invention showing the drainage basin filter selectively attached to a drainage basin; 
     FIG. 4 is a side planar view of a filter assembly for a drainage basin filter formed in accordance with one embodiment of the present invention; and 
     FIG. 5 is a perspective view of a drainage basin filter constructed in accordance with a second embodiment of the present invention showing the drainage basin filter selectively attached to a drainage basin. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1-4 illustrate a filter assembly  20  constructed in accordance with one embodiment of the present invention. The filter assembly  20  is illustrated as being selectively attached to a drainage basin  22  disposed within a roadway (not shown). It should be apparent that the filter assembly  20  may be disposed within the drainage basin  22  either before a layer of asphalt is applied to the roadway, or after the roadway has been sealed by asphalt. 
     The drainage basin  22  is a substantially rectangular member and is suitably formed from a high strength material, such as concrete. The drainage basin  22  includes an inlet  24  and outlet  26  extending through sidewalls  27  of the drainage basin. The inlet  24  is a bore located near the top end of the drainage basin  22 . Similarly, the outlet  26  is a bore extending through the at least one sidewall  27  of the drainage basin  22  and is suitably located near the bottom of the drainage basin  22 . 
     As best seen by referring to FIG. 2, the filter assembly  20  includes a filter  28 , a support assembly  30 , and a liquid director  32 . The filter  28  includes a support member  34  and a filter material  36 . The support member  34  is suitably formed from woven fabric, or a comparable material. Such comparable materials include nonwoven fabrics, punctured burlap or hemp, woven cotton, punctured plastic, plastic mesh, woven steel mesh, punctured aluminum mesh, drilled stainless steel, or wire mesh. The filter material  36  is preferably tapered from an upper end to its lower end, such that it has a substantially inverted triangular shape. Although such a tapered shape is not required for the invention, it is advantageous to have such a shape to allow liquid to pass through the drainage basin  22  unimpeded by the filter material  36 . 
     The support member  34  is suitably an annular member formed from polypropylene or a comparable material, such as aluminum, steel, stainless steel, copper, or wood. Although an annular support member  34  is preferred, it should be apparent that other shapes, such as rectangular or square, are also within the scope of the present invention. 
     Referring to FIG. 3, the support assembly  30  will now be described in greater detail. The support assembly  30  includes a three-pronged support bracket  38 , a connecting point  40 , and an attaching cord  42 . The three-pronged support bracket  38  extends from the common connecting point  40  and is adapted to be placed inside support ring holes  44  located in the support member  34 . The three-pronged support bracket  38  may be formed from nylon or a comparable material, such as cable, wire, plastic, chain, aluminum, copper, steel, rope, cotton, dagron, polyester, Gore-Tex™, or rubber. 
     The connecting point  40  may be formed from steel or a comparable material such as aluminum, brass, zinc, gold, silver, platinum, rubber, plastic, stainless steel, nickel, or titanium. Such a connecting point  40  may be a well known caribeiner. The three-pronged support bracket  38  and the connecting point  40  are attached to an attaching member  42  extending between the connecting point  40  and a grate  46  of the drainage basin  22 . The support bracket  38  is coupled to the grate  46  by a loop  48  or other suitable connecting apparatus. 
     The attaching cord  42  is suitably formed from nylon or a comparable material, such as cable, wire, plastic, chain, aluminum, copper, steel, rope, cotton, dagron, polyester, Gore-Tex™, or rubber. The attaching cord  42 , connecting point  40 , and three-pronged support bracket  38  may be fastened together by compression clamps. 
     Still referring to FIG. 3, external fluids are directed into the filter  28  by the liquid director  32 . The liquid director  32  is suitably a tubular structure formed from ABS plastic or HDPP, vinyl, rubber, plastic, aluminum, steel, fiberglass, copper or nylon. Such external fluids may be directed into the liquid director  32  by the slope of the roadway or other surface in which drainage basin  22  is mounted. 
     The material from which the filter material  36  is constructed should be adapted to allow the free flow of water and the capture of solids such as silt. The filter  28  is emptied by lifting and emptying the contents, and then reinstalling it in the drainage basin. 
     As seen best in FIG. 4, the filter  28  is constructed by placing the filter material  36  around the circumference of the support member  34  and placing a fastening cord  50  around the support member  34  and tightening the fastening cord  50 , such that both the fastening cord  50  and filter material  36  rest firmly in groove  52 . The fastening cord  50  is made of nylon, steel, cable, rubber, plastic, chain, aluminum, hemp or copper. 
     Referring now to FIG. 5, a filter assembly  120  constructed in accordance with another embodiment of the present invention will now be described in greater detail. As a non-limiting example, this alternate embodiment is suitably used when a final layer of asphalt has been applied to the roadway, or when the ground grade meets the top of the drainage basin  122 . The filter assembly  120  is substantially identical in materials and operation to the filter assembly  20  described above, except that the liquid director  32  is replaced by a substantially planar liquid director  132 . 
     Instead of a tubular structure, the liquid director  132  is suitably a planar member, such as a tray. The liquid director  132  is adapted to be placed between the grate  146  and sidewalls  127  of the drainage basin  122 , such that the liquid director  132  substantially seals the upper end of the drainage basin  122  to channel liquid passing through the grate  146  into the filter assembly  120 . To facilitate channeling of liquid into the filter assembly  122 , a portion of the liquid director  132  has been cut away to form an opening  129  in one of the corners of the liquid director  132 . Although it is preferred that the opening  129  be formed in a corner of the liquid director  132 , other positions of the opening  129 , such as a centrally located opening, are also within the scope of the present invention. 
     The liquid director  132  is suitably constructed from plastic or a comparable material, such as woven fabrics, nonwoven fabrics, geotextile fabrics, rubber, steel, stainless steel, aluminum, copper, Teflon®, foil, wood, injection-molded plastic, or fiberglass. A filter assembly  120  formed in accordance with the alternate embodiment includes the same filter  128  and support assembly  130  as described above for the first embodiment (FIGS.  1 - 4 ). 
     Silt catchers formed in accordance with the present invention have several advantages over those currently available in the art. First, such catchers are easier to remove and clean by one person. Second, a catcher of the present invention has reusable parts, and therefore, is cost efficient. Finally, a silt catcher of the present invention may be custom tailored to meet engineering specifications. 
     While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.