Abstract:
A curb inlet filter for filtering out sediments and the like flowing into a curb inlet, includes a filter body, including a water permeable, substantially rigid, elongated frame having an upstream side and a downstream side thereof, and an elongated filter cover formed around at least one of the sides of the frame. The filter cover is formed of a filtration material to filter out sediments and the like. Further, a weight support attached to a bottom of said filter body for supporting a weight, and a support strap connects the weight support to an upper portion of the filter body.

Description:
FIELD OF THE INVENTION  
       [0001]     The instant invention is directed to a curb inlet filter, and more particularly to a curb inlet filter for filtering out sediments and the like flowing into a curb inlet.  
       RELATED ART  
       [0002]     Ground water from heavy rains or melted snow is normally collected in a storm sewer or in a curb inlet and then flows into an underground storm sewer line. Water flows into the basin through openings in a grate on top of the basin, or into a curb inlet through an opening along the vertical portion of the curb.  
         [0003]     It is important that water entering a sewer line should be free of suspended solids, such as sediments, debris or the like. If stormwater, for example, flows into a curb inlet, in a construction site where soil has been disturbed, a great deal of sediment or other solids (including debris) may flow into the curb inlet and thus, into the storm sewer lines. When too much sediment or solid materials flow into the storm sewer lines, they become clogged.  
         [0004]     Accordingly, in the past, numerous products have been used to prevent sediment or other solids from flowing into curb inlet storm drains. Products such as straw wattles have been used to filter out sediment and other solids flowing into a curb inlet storm drain. Hay bails have also been used to filter out sediment and other solids from stormwater flowing into a curb inlet. Additionally, stones have been wrapped in chicken wire and placed in front of a curb inlet type storm drain. The straw wattle and hay bail type of sediment filters often get clogged and are often not reusable. Also, they may decompose and slip into the storm drain. This could cause further clogging. Furthermore, the method using stones and chicken wire (stone bundles) does not filter out as large amount of sediment and other solids as do other methods. Also, these stone bundles break and fall into the drains, and can also be a safety hazard for children.  
       SUMMARY OF THE INVENTION  
       [0005]     The instant invention is a curb inlet filter for filtering out sediments, solids and the like flowing into a curb inlet type of storm drain. Generally, the term sediment, when used in connection in this application refers to solid particles that are suspended in water flowing into a curb inlet. Sediment may originate from earth, grass, and other sources, and any other type of material suspended in water flowing into a curb inlet. Generally, a curb inlet refers to an opening in a vertical face of a curb (with or without a grade level storm sewer catch basin with a grating on top) which leads to a drain unit that directs stormwater into a storm sewer. While focused on use with a curb inlet type of drain, the instant invention may also be used with a combination type of drain which joins a curb inlet drain with a catch basin type of drain with a horizontal grate.  
         [0006]     The instant invention includes a frame and a filter cover formed on at least part of the frame. For example, such types of curb inlet filters are often used in and around construction sites where earthen materials have been moved around and under heavy rains become sediment suspended in runoff water. As the runoff water (with sediment or the like suspended therein) flow into a curb inlet type of storm drain, the instant invention covers the mouth of the curb inlet and filters out many of the sediment or solid particles suspended in the stormwater.  
         [0007]     A curb inlet filter, in accordance with the instant invention, is provided for filtering out sediments, solids and the like flowing into a curb inlet. The curb inlet filter has a filter body which includes a water permeable, substantially rigid, elongated frame having an upstream side and a downstream side thereof, and an elongated filter cover formed around at least one of the sides of the frame, wherein the filter cover is formed of a filtration material to filter out sediments and the like. Additionally, the curb inlet filter includes a weight support attached to the bottom of the filter body for supporting a weight, and a support strap connecting the weight support to an upper portion of the filter body. The support strap helps to pull the top of the filter body snug with the top of the curb inlet. It is contemplated that the weight support can be attached rigidly or flexibly to the filer body. It is then possible that the support straps could be connected to different portions of the filer body, rather than just the upper portion, although the upper portion is preferable. It is also possible that there are no support straps. For example, a weight support may be attached more rigidly to filter body, so that support straps are not necessary.  
         [0008]     Additionally, the curb inlet filter may include a plurality of spacers, wherein at least one spacer is formed at each end of the frame. Spacers are formed on the downstream side thereof, in order to form a gap between the spacers and the downstream side of the frame. This allows the water to flow over the top of the frame, through the gap formed between the spacers, and into the curb inlet.  
         [0009]     The filter cover of the filter body preferably entirely surrounds the frame. However, it is possible to mount the filter cover on only one side of the frame. While the filter cover is preferably a woven fabric, it may also be formed of a non-woven material. This non-woven material could be a mat-type material, or it may be some type of metal grill or other type of filter. The preferred woven fabric is multidimensional, and even more preferably a three dimensional fabric. A preferable fabric is Pyramat® manufactured by SI Geosolutions. For the same size of frame, a three dimension fabric has a larger surface area than a conventional two dimensional fabric. Accordingly, a filter using a three dimensional fabric will be able to filter more sediment than a conventional two dimensional fabric. Another reason a three-dimensional fabric is preferable is that flowing water tends to bounce off of a two-dimensional fabric easier than a three-dimensional fabric. Additionally, when the filter cover entirely surrounds the frame, in envelop fashion, it presents two surfaces for filtering, one on the upstream side and one on the downstream side of the frame.  
         [0010]     The weight support may be removably attached or fixedly attached to a bottom portion of the filter body. In other words, it may be located in a lower area of the filter body for pulling the filter snug against the curb. More specifically, the weight support may be removably attached to a bottom portion of the filter body by using connectors to make the connection. Furthermore, the weight support may be a bag for receiving a weight therein. When in use, it is easy for the user to put a portion of a steel or other type of weight in the bag. Additionally, the bag may be waterproof with a closable filling hole therein. A user could simply fill the bag with water and close the filing hole in order to provide the weight for the curb inlet filter.  
         [0011]     The filter cover may be formed of a cylindrical sleeve, into which the frame is axially inserted, wherein the sleeve is closed up at opposing ends thereof. Alternately, the filter cover may have a closeable seem running along a longitudinal side thereof. The frame may be inserted into the filter cover and the seam simply closed up. Any other appropriate arrangement for covering the sleeve is also appropriate.  
         [0012]     The frame may be a single unit, or it may be made of a plurality of individual units attached together. They may be permanently attached at they may be detachably attached to one another. Using a plurality of individual elements, the frame may be built up in modules for use with different sized curb inlets. Also, when a frame is composed of a plurality of individual elements (each one shorter than the total length of the frame) the frame may be broken down for easier shipping. Preferably, each of the individual elements of the frame would include one or more spacers. A frame element, whether it is one or a plurality of elements, may also be formed to be snapped together for easy assembly. Thus, the frame elements could be interlocking with one another. For example, each end of a frame element may have a dovetail or other equivalent type joint. In other words, one end of the frame would have a dovetail projection, and the opposite end of the frame element would have a dovetail recess, such that a frame may be formed of the plurality of individual elements in which the dovetail portions are nested with one another. Also, a key/keyway combination (or any other conventional means) may be used to join individual frame elements together.  
         [0013]     The frame may also be a collapsible type of frame. The plurality of individual elements may be connected together by hinges, or the like, to provide an easily collapsible frame for ready transportation. Additionally, the frame may have a telescoping structure that makes for easy storage or shipping when in a collapsed state.  
         [0014]     Additionally, the frame (whether a single unit or a plurality of individual elements) may also include a flexible insert formed on a bottom portion thereof, in order to adjust to the contours of the road surface on which the filter sets. The flexible insert may simply be a type of foam or foam rubber formed on the bottom of the frame. Additionally, the flexible insert may be an extruded rubber insert of any type which is fixed to the bottom of the frame or inserted into a groove or keyway.  
         [0015]     For ease of transporting, a handle may also be formed on an upper portion of the curb inlet filter. Tieback straps may also be formed on the upper portion of the filter body in order to stabilize the curb inlet filter when in position in front of a curb inlet.  
         [0016]     Furthermore, the curb inlet filter according to the instant invention may include an additional layer to absorb metals, oils and other containments. For example a coconut mat or organic layer may be added to absorb contaminants or other undesirable substances.  
         [0017]     Also, the curb inlet according to the instant invention is easy to clean and reuse. It may simply be washed off and repositioned for subsequent use. As such, it provides great labor savings for a user, such as a contractor. It is reusable and, may be easily replaced if damaged. The frame may be easily replaced if it is damaged, while retaining the filer cover. Conversely, if the filter cover is damaged, it may easily be replaced while retaining the frame.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]     The advantages of the invention will become apparent in the following description taken in conjunction with the drawings, wherein:  
         [0019]      FIG. 1  is a perspective view of a downstream side of the curb inlet filter in accordance with the instant invention;  
         [0020]     FIGS.  2 ( a )- 2 ( c ) are views of a curb inlet filter;  
         [0021]      FIG. 3  is a perspective view of a curb inlet;  
         [0022]      FIG. 4  is a perspective view of the curb inlet of  FIG. 3 , with the curb inlet filter in position;  
         [0023]      FIG. 5  is a cross-sectional view of a curb inlet and storm sewer drain with a curb inlet filter in position;  
         [0024]      FIG. 6  is a top plan view showing a curb inlet filter in position in front of a curb inlet;  
         [0025]      FIG. 7  is a partial cutaway view of a curb inlet filter showing the frame thereof;  
         [0026]     FIGS.  8 ( a )- 8 ( b ) illustrate insertion of the frame into filter covers;  
         [0027]      FIG. 9  illustrates different weight bags for attaching to the filter body;  
         [0028]     FIGS.  10 ( a ) and  10 ( b ) illustrate flexible inserts usable with the curb inlet filter;  
         [0029]      FIG. 11  is an illustration of the curb inlet filter, demonstrating woven and non-woven fabrics thereon;  
         [0030]      FIG. 12  is a perspective view of a single frame structure;  
         [0031]      FIG. 13  is an illustration of a plurality of individual elements which make up a single elongated frame; and  
         [0032]      FIG. 14  is an illustration of dovetail type connectors between individual elements. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0033]      FIG. 1  is a perspective view of a downstream side of the curb inlet filter in accordance with the instant invention. FIGS.  2 ( a )- 2 ( c ) are additional views of the stormwater filer. As illustrated in  FIGS. 1 and 2 , curb inlet filter  10  includes a filter body  12 , a weight support  16 , and support straps  18 . A handle  20  is attached to the top of filter body  12  for ease of transportation from one location to another. Tieback straps  22  may or may not be used. They may be used to tie the upper portion of filter body  12  back to keep it snug with the curb inlet. Arrow  24  represents the inflow of water toward the curb inlet filter  10 . Arrow  26  represents the outflow of water after it has passed through stormwater filter  10 . Accordingly, arrow  24  represents the upstream side of curb inlet filter  10 , while arrow  26  represents the downstream side of curb inlet filter  10 .  
         [0034]      FIG. 3  is a perspective view of a typical curb inlet. Specifically, curb inlet  28  is formed in a curb  36 , adjacent a road surface  30 . Normally, such curb inlets have a top portion  32  with a manhole (or access) cover  34  located therein, in order to provide access to the drain below. A curb inlet opening  40  provides a passage for the inflow of water, represented by arrow  24 , into the storm drain itself.  
         [0035]      FIG. 4  illustrates the curb inlet filter  10  in place, in front of a curb inlet.  FIG. 5  illustrates a cross-section of the curb inlet with the curb inlet filter  10  in place. In  FIG. 4 , filter body  12  is in place in front of curb inlet opening  40 . In this illustration, tieback straps  22  extend rearwardly to the ground surface behind curb  36 . The tieback straps  22  are staked into the ground by stakes  42 .  
         [0036]      FIG. 5  is a cross-section of the curb inlet  28  of  FIG. 4 , with the curb inlet filter  10  in place. As illustrated in  FIG. 5 , the structure of the curb inlet  28  includes a curb inlet housing  48  formed in the ground and adjacent to road surface  30 . Curb inlet  28  has a top portion  32  formed on top of the curb inlet housing  48 . An access opening  35  is formed in top cover  32  for allowing access to the curb inlet  28  for removing clogs and the like. An access cover  34  covers the access opening  35 . A curb inlet opening  40  is formed for allowing stormwater to enter the curb inlet. Drain pipe  46  is formed on the lower portion of the curb inlet housing  48  for directing the stormwater down to the storm sewer.  
         [0037]     Curb inlet filter  10  is shown in place in front of curb inlet opening  40 . Filter body  12  sets on the road surface  30  with weight support  16  extending in the downstream direction into curb inlet housing  48 . As illustrated in  FIG. 5 , weight support  16  also contains a weight  17  therein. Furthermore, support strap  18  extends from weight support  16  to an upper portion of filter body  12 . Furthermore, filter body  12  includes a water permeable, substantially rigid, elongated frame  50  and an elongated filter cover  54 . Frame  50  also includes a spacer  52  formed on a downstream side thereof. Because the thickness of the filter body  12  is substantially less than the width, this filter does not project very far from the curb, and thus does not extend substantially out into the road.  
         [0038]      FIG. 6  is a plan view showing the curb inlet filter  10  in place against curb inlet  28 . As illustrated in  FIGS. 5 and 6 , arrow  24  represents the inflow of stormwater. This inflow of stormwater is normally laden with suspended solids such as sediment, debris and the like. As the stormwater or sediment laden water impinges on the upstream side of curb inlet filter  10 , suspended solids such as sediment and the like are trapped by the filter material of filter cover  54 . The water flows through filter cover  54 , and the water permeable frame  50 . The outflow of water on the downstream side of the curb inlet filter  10  is represented by arrow  26 . This outflow has been filtered by the curb inlet filter  10  and flows through curb inlet housing  48  into drain pipe  46  and down into the storm sewer system.  
         [0039]     When the curb inlet filter  10  becomes clogged, or if the water level rises above the top of the curb inlet filter  10 , overflow water, represented by arrows  44 , flows over the top of stormwater  10  and into curb inlet opening  40 . This is possible because spacers  52  space the frame  50  apart from the front of curb inlet  28 . Frame  50  and spacers  52  form a gap therebetween in order to allow the overflow water to flow into opening  40  of inlet  28 . The overflow capability is often specified by engineers when specifying requirements for filters for curb inlets.  
         [0040]      FIG. 7  illustrates a partial cutaway view of the curb inlet filter  10 . As illustrated, filter body  12  includes a frame  50 . The frame  50  is a water permeable, substantially rigid, elongated structure. A spacer  52  is formed near an end thereof on a downstream side thereof. As illustrated in  FIG. 7 , the frame is made of elongated rails  58  connected together by cross members  60 . This forms openings  56  which allow water to flow therethrough. It should be noted that the frame  50  disclosed in  FIG. 7  is only one example of such a frame. Frame  50  may be made of plastic, metal, wood, recycled material or any other suitable material that provides the necessary water permeability, and the rigidity necessary to support the filter cover  14 . It is even possible that the frame may be made of a substance such as coconut mat, so long as it has sufficient rigidity and water permeability. Frame  50  is formed as an elongated structure, and generally has a long and thin shape. The shape may be board like so that it does not take up a great deal of space in front of the curb inlet.  
         [0041]     Filter cover  14 , as illustrated in  FIG. 7 , entirely surrounds frame  50 . Although it is possible for the filter cover to be formed on only a single side of frame  50 . Preferably, however, filter cover  14  entirely surrounds frame  50 .  
         [0042]     While filter cover  14  is preferably formed by a fabric, it may also be formed by a grill or grating. Preferably though, a fabric is used for the filter cover. The fabric may be a woven fabric, a non-woven fabric, or another type of non-woven material. It is also preferable to use a multidimensional, woven fabric such as a three dimensional fabric, as illustrated in  FIG. 7 . A three dimensional fabric used as a filter cover is found to be efficient in filtering out solids, such as sediment and the like. Because a three dimensional fabric has a greater surface area than a two dimensional fabric, more sediment may be filtered out of the stormwater flowing through the filter.  
         [0043]      FIGS. 8A and 8B  illustrate different forms of filter covers  14 . In  FIG. 8A , filter cover  14  is formed of a tubular shape of fabric  62 . In assembling curb inlet filter  10  in  FIG. 8A , frame  50  is inserted into tubular fabric  62  and ends  64 ,  64  are closed.  FIG. 8B  illustrates an alternate version of how curb inlet filter  10  is assembled. Flat fabric  66  is provided with seams  68  along the edges thereof. For assembly, frame  50  is positioned in the fold of fabric  66  and seams  68 ,  68  are closed-up by way of zipper, velcro, thread, or any other conventional way.  
         [0044]      FIG. 9  illustrates different weight bags for removably attaching the weight bag to the weight support of the storm filter. In  FIG. 9 , weight support  16  is attached to a lower portion of filter body  12  of curb inlet filter  10 . Weight bags may also be considered to be part of the weight support  16 . Weight bag  76  or waterproof weight bag  78  may alternately be attached to the weight support  16 . The detachability of the weight bags increases adaptability and convenience for the user. For ease of attaching and detaching a weight, weight support  16 , as illustrated in  FIG. 9 , includes male clips  70 ,  70 , attached to weight support  16  by way of straps,  72 ,  72 . Male clips  72 ,  72  are attachable with female clips  74   a ,  74   a  of weight bag  76 , or female clips  74   b ,  74   b  of waterproof weight bag  78 .  
         [0045]     Weight bag  76  is attached to female clips  74   a ,  74   a  by way of straps  86 ,  86 . Weight bag  76  includes a front flap  82  folded over front panel  88  and secured on the edges. Accordingly, this allows a weight such as weight  17  to be inserted under front flap  82  and behind front panel  88  and thus to securely remain there in order to serve as a weight for curb inlet filter  10 . Weight  17  may be a steel bar, or any other suitable material for weighing down the stormwater filer. Weight bag  76  may also be part of weight support  16 , since weight bag  76  also supports weight  17 . Additional clips  90 ,  90  are attached to a lower portion of weight bag  6  in order to connect with cooperative male clips (not shown) attached to support straps  18 .  
         [0046]     Waterproof weight bag  78 , as illustrated in  FIG. 9 , also attaches to weight support  16  by way of female clips  74   b ,  74   b  cooperatively engaging male clips  70 ,  70 . Female clip  74   b ,  74   b  are attached to waterproof weight bag  78  by way of straps  86 ,  86 . A closeable filling hole  80  is formed in a front panel  92  of waterproof weight bag  78 . Closeable filling hole  80  may have a screw top or any other type of closable filling hole suitable for enabling waterproof bag  78  to be filled with water, and then closed-up, in order to provide the sufficient weight for curb inlet filter  10 . As with weight bag  76 , waterproof weight bag  78  may be part of weight support  16 , since waterproof weight bag  78  supports the water therein for providing weight to hold the curb inlet filter  10  in place. Also, waterproof weight bag  78  may include female clips  94 ,  94  to cooperatively engage with male clips (not shown) of support straps  18 . While clips are illustrated in  FIG. 9 , any suitable type of connecting device may be employed to connect a bag to the weight support  16 .  
         [0047]     FIGS.  10 ( a ) and  10 ( b ) illustrate flexible inserts used with the curb inlet filter  10 . Specifically,  FIG. 10 ( a ) illustrates a flexible extruded rubber insert  96  attached to a lower portion of frame  50  by way of a slot  98  formed in the bottom of the frame  50 . A projection  100  formed axially along the length of extruded rubber insert  96  is engaged with slot  98  of frame  50  for securing the extruded rubber insert  96  to the bottom thereof. While it is preferable that extruded rubber insert  96  is located within filter cover  14 , other arrangements are also possible.  
         [0048]      FIG. 10 ( b ) illustrates another version of the flexible insert. In  FIG. 10 ( b ), a foam portion  102  is fixed to a lower part of frame  50 . Form portion  102  is affixed to the bottom of frame  50  by adhesives or any other appropriate method. As with extruded rubber insert  96 , foam portion  102  is preferably formed on the bottom of frame  50 , inside of filter cover  14 .  
         [0049]      FIG. 11  illustrates two type of fabrics used for filter cover  14  of filter body  12 . Filter cover  14  is split into two different types of covers for illustration purposes only. On the left side of  FIG. 11 , a woven fabric  104  is illustrated, while a non-woven fabric  106  is illustrated on the right side of  FIG. 11 . Woven fabric  104  is illustrated as a multidimensional fabric. Specifically, woven fabric  104  is a three dimensional fabric. While a two dimensional fabric may be used for filter cover  14 , a three dimensional fabric is preferable because it presents a larger surface area to filter the sediment laden stormwater. With a greater surface area, the three dimensional woven fabric takes longer to clog up than a similar two dimensional fabric. Non-woven fabric  106  may be a water permeable matt fabric. A perforated sheet may also be used as a filter cover.  
         [0050]      FIG. 12  illustrates a single frame structure with elongated frame  50  having spacers  52  formed on the downstream side thereof, one each positioned at opposite ends thereof. As illustrated, frame  50  contains generally parallel rails  58  which are connected together by cross members  60 . Frame  50  provides substantial rigidity and is water permeable, so that the substantially rigid frame supports filter cover  14  and allows water to pass therethrough.  
         [0051]      FIG. 13  is an illustration of a plurality of individual elements which make up a single elongated frame. In  FIG. 13 , frame portions  50   a ,  50   b  and  50   c  can be detachably attached to one another. In  FIG. 13 , each individual frame element has a male and female connector. For example, frame element  50   a  has a male connector projection  108  and a female connector recess  110 . Furthermore, each individual frame element  50   a  may be supplied with individual spacers  52   a ,  52   a  on a downstream side thereof. Thus, frames of different length may be assembled by connecting individual frame elements together. While any number of individual frame elements may be combined to result in a desired length frame, individual elements are often easier and less expensive to ship.  
         [0052]      FIG. 14  illustrates a different style of connector compared with male and female connectors  108 ,  110  of  FIG. 13 . In  FIG. 14 , a male dovetail projection  112  is formed on an end of frame element  50   d . Male dovetail projection  112  enables frame element  50   d  to be attached to frame element  50   e  by being coupled with female dovetail recess  114 . Additionally, individual frame elements may be detachably attached to one another by screwing individual elements together.  
         [0053]     Although a specific form of embodiment of the instant invention has been described above and illustrated in the accompanying drawings in order to be more clearly understood, the above description is made by way of example and not as a limitation to the scope of the instant invention. It is contemplated that various modifications apparent to one of ordinary skill in the art could be made without departing from the scope of the invention which is to be determined by the following claims.