Abstract:
A restrictor plate assembly is disclosed. The assembly is adapted for being positioned within a catch basin throat so that the throat extends rearward of the assembly. The assembly has a longitudinally extending restrictor plate and a restrictor plate securing system, which includes a first clamp arm, pivotally positioned against the restrictor plate, for engaging a first throat surface of the catch basin; a second clamp arm pivotally positioned against the restrictor plate, for engaging a second throat surface of the catch basin, the second throat surface opposing the first throat surface; and an urging member which simultaneously urges the first and second clamp arms against the first and second throat surfaces, respectively.

Description:
BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The invention relates to a system for positioning a restrictor plate within a catch basin throat. 
     2. Background of the Related Art 
     Private groups and government bodies, such as the United States Environmental Protection Agency (U.S.E.P.A.), have sought to control unregulated sources of storm water discharge that have the greatest likelihood of causing continued environmental degradation. Such sources include storm water runoff, which picks up and transports harmful pollutants and discharges them, untreated, to waterways via sewer systems. Sediment-laden, contaminated runoff can overwhelm local water bodies, particularly small streams, resulting in streambed scour, stream bank erosion, and destruction of near-stream vegetative cover. The further result is the loss of in-stream habitats for fish and other aquatic species, an increased difficulty in filtering drinking water, the loss of drinking water reservoir storage capacity, and negative impacts on the navigational capacity of waterways. 
     Introduced regulations limit the size of runoff access points in storm drains to a maximum of seven square inches. Openings defining such access points must be not more than two inches across the smallest dimension. For example, a rectangular opening of two inches by three and a half inches would conform to such regulations. Such regulations have left state and local governments, who have curbside storm water catch basins with large inlets, searching for a solution. 
     Accordingly, there is a need to provide a novel structure for enabling drain water and allowable sized sediment to enter the sewer system while preventing the access to larger sediment. 
     SUMMARY OF THE EMBODIMENTS 
     A restrictor plate assembly is disclosed. The assembly is adapted for being positioned within a catch basin throat so that the throat extends rearward of the assembly. The assembly has a longitudinally extending restrictor plate and a restrictor plate securing system, which includes a first clamp arm, pivotally positioned against the restrictor plate, for engaging a first throat surface of the catch basin; a second clamp arm pivotally positioned against the restrictor plate, for engaging a second throat surface of the catch basin, the second throat surface opposing the first throat surface; and an urging member which simultaneously urges the first and second clamp arms against the first and second throat surfaces, respectively. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       It is to be understood that the following drawings depict details of only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, and in particular: 
         FIG. 1  illustrates a catch basin fitted with a restrictor plate according to an embodiment of the invention; 
         FIG. 2  illustrates details of a restrictor plate provided in  FIG. 1 ; 
         FIG. 3  illustrates details of a second restrictor plate provided in  FIG. 1 ; 
         FIG. 4  illustrates details of a splice plate provided in  FIG. 1 ; 
         FIG. 5  illustrates an alternative embodiment, utilizing three restrictor plates; 
         FIG. 6  illustrates details of a clamp arm provided in  FIG. 2 ; and 
         FIG. 7  illustrates details of a wedge provided in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The Catch Basin 
       FIG. 1  is a prospective/front view of a restrictor plate  10 , according to an embodiment of the invention, fitted within a Type Five (5) Catch Basin, utilized by the Department of Transportation for the state of Florida, U.S.A. This catch basin  11  is provided herein for illustration purposes only. The catch basin  11  includes a rectangular inlet  12 , in which the restrictor plate  10  is positioned. Further details of the catch basin  11  will be disclosed for providing context for the shape and function of the restrictor plate  10 . 
     The catch basin  11 , is formed from reinforced concrete and has a rectangular inlet  12 . As illustrated, the width is substantially greater than the height. Specifically, the height is about five inches while the width is almost eleven feet. 
     With further reference to  FIG. 1 , the height of the inlet  12  is defined by opposing top and bottom edges  14 ,  16  and the width is defined by opposing side edges  18 ,  20 . The top and side inlet edges are chamfered in the location where the edges lead into the basin throat  22 . 
     Top and bottom throat surfaces  24 ,  26  extend rearward from top and bottom inlet edges  14 ,  16 , and both pitch downwardly towards the rear  28  of the throat  22 . Similarly, opposing side throat surfaces  32 ,  34  extend reward from opposing side inlet edges  18 ,  20  and taper inwardly towards the rear of the throat  28 . 
     In the area of the drain  30 , the catch basin includes a grate  36 . As illustrated, the grate  36  is on one side  38  of the catch basin  11 . The grate  36  allows sediment to drop into a basin cavity  40 , and pass into the drain  30 . Furthermore, the grate  36  is flush with the surface of the basin  11 . 
     The grate has opposing side edges  42 ,  44  defining a width of the grate  36 . The side edges are spaced about five feet from each other. In the illustrated basin  11 , this spacing is less than a half of the width of the inlet  12 . 
     On the other hand, the grate  36  has a depth defined by opposing front and rear grate edges  46 ,  48 . The grate front edge  46  is forward of the inlet  12 . On the other hand, the grate rear edge  48  is rearward of the inlet  12 . In the illustrated basin  11 , the grate rear edge  48  is about a half a foot rear of the basin inlet  12 . 
     The Restrictor Plate 
     Turning to  FIG. 2  the restrictor plate  10  is illustrated. The restrictor plate  10  is adapted for being retrofitted into the basin throat  22 , flush with or rear of the inlet  12 . The restrictor plate  10  can be manufactured from an appropriately rigid and durable material. One example is strength/low alloy, quarter-inch thick, Cor-Ten brand weathering steel, which is an ASTM A588 grade steel rated to 60,000 psi. 
     As indicated, the restrictor plate  10  can be positioned reward of the inlet  12  by a distance which allows clear access to the grate  36 . For example, the grate rear edge  48  is rearward by about a half of one foot from the inlet  12 . Accordingly, the restrictor plate  10  is similarly located to allow access to and removal of the grate  36  after the restrictor plate  10  is installed. 
     The illustrated restrictor plate  10  substantially as wide as the basin grate  36 , which is less than a half of the width of the illustrated basin inlet  12 . The height of the restrictor plate  10  is slightly less than the height of the basin inlet  12 . For example, in the illustration, the restrictor plate  10  has a height of about four and a half inches, which is about one half of an inch less than the height of the inlet  12 . 
     The height difference between the restrictor plate  10  and the inlet  12  enables floating the restrictor plate  10  above the bottom surface of the catch basin upon installation. Floating enables the restrictor plate  10  to fit within the basin throat  22 , despite random surface contour variations. It also allows small particles to pass under the restrictor plate  10  and into the drain  30 , which is acceptable by regulations. 
     The restrictor plate  10  includes a main body  52 , which has a bottom edge  54 . Attached to the bottom edge  54  is a stiffening flange  56 . The flange  56  is pitched downwardly to match the pitch of the basin throat  22 . This pitch provide an effective guide for proper insertion of the restrictor plate  10  into the basin throat  22 . The flange  52 , as illustrated, is about three inches deep. However, other depths which provide the proper stiffness are acceptable. 
     Regarding the guide function, if a job-site worker accidentally inverts the restrictor plate  10 , (e.g., flips the plate  10  about its center, depth-wise axis), the flange pitch will extend in the wrong direction. This would prevent the restrictor plate  10  from being installed in the basin throat  22 . The job-site worker would be required to flip the restrictor plate  10  to the proper orientation to complete instillation. 
     The flange  56  has opposing side edges  58 ,  60  which are cut or formed with a surface contour. This contour matches the inward pitch angle of the side surfaces  32 ,  34  of the basin throat  12 . This also enables a proper placement of the restrictor plate  10  within the basin throat  12 . 
     Along an upper edge  62  of the restrictor plate  10  are plural flanges  64 ,  66 , which have the same depth as the bottom flange  56 . The upper flanges  64 ,  66  are also parallel with the bottom flange  56 . The upper flanges  64 ,  66  are illustrated as being substantially less than the length of the restrictor plate  10 . The flanges  64 ,  66  provide additional stiffness in the area at which the securing system (discussed below) interacts with the restrictor plate  10 . As illustrated, the upper flanges  64 ,  66  are asymmetrical about their depth-wise centerline and the width of the flanges  64 ,  66  is approximately five inches. 
     Alternatively, if the restrictor plate  10  were longer than that illustrated in  FIG. 2 , additional securing system (discussed below) could be used for securing the restrictor plate  10  to the basin throat  22 . Such a longer restrictor plate  67  is illustrated in  FIG. 3 , and is provided with flanges  68 ,  70  which are offset from the center of the restrictor plate  67 . The flanges  68 ,  70  are symmetrical about their depth-wise center and are approximately six inches wide. The actual dimensions of each of the upper flanges  64 - 70  can be modified so long as structural integrity of the restrictor plates  10 ,  67  are maintained. 
     Furthermore, the asymmetric upper flanges  64 ,  68  have side edges  72 ,  74 , which have the same edge contours as the outer edges  58 ,  68  of the bottom flange  56 . The contours serve the same purpose as with the bottom flange, to guide the restrictor plate  10  when being set in a with-wise tapered basin throat  22 . 
     The restrictor plate  10  has plural drainage openings, e.g.,  76 , disposed along its length, which allow for continued drainage while restricting larger floatables. Based on design requirements, the size and shape of the openings is less than seven square inches and has a clear space no greater than two inches across the smallest dimension. It is to be noted that the design requirements for the opening size are identified for illustration purposes only and not to limit the scope of the invention. 
     According to  FIG. 2 , there are nine openings  76 . While eight of the openings are identical, the center opening  78  sized differently and is designed to display a stainless steel badge  80  ( FIG. 1 ), which has been stitch-welded to a rear face  81  of the main body  52  of the restrictor plate  10 . The badge  80  can be used to provide information, such as from a government or private entity which installed, or cause to be installed, the restrictor plate  10 . For example, the message could be from the U.S.E.P.A. It is to be noted that other shapes, sizes and locations for the badge can be implemented. 
     As illustrated in  FIG. 1 , a second restrictor plate  82  is positioned on the right side of the other (first) restrictor plate  10 . Depending on the width of the inlet  12  on the right side of the basin grate  36 , the second restrictor plate  82  may be shorter, longer or the same length as the first restrictor plate  10 . As indicated above, an example of a longer restrictor plate  82  is restrictor plate  67 , illustrated in  FIG. 3 . 
     It should be appreciated from the above discussion that the shape of the restrictor plates are symmetrically designed. This symmetry provides advantages, discussed below. 
     The second restrictor plate  82  is positioned forward of the first restrictor plate  10 , and is substantially flush with the inlet  12 . This is because the second restrictor plate  82  does not extend over the grate  36 . 
     The Splice Plate 
     The aggregate length of the first and second restrictor plates  10 ,  82  are intentionally less than the width of the inlet  12 . This enables the two restrictor plates  10 ,  82  to be connected by a splice plate  84 , providing end-to-end restricted coverage of the inlet  12 . 
     The splice plate  84  is formed from the same material as the restrictor plate  10 . As illustrated in  FIG. 4 , the splice plate  84  has the same height as the restrictor plate  10 . The splice  84  plate is formed with compound (i.e., two) offset angles  86 ,  88 , such as a shifted slide. 
     As illustrated in  FIG. 4 , based on the first offset angle  86 , one side  90  of the splice plate  84  is lower than the other side  92 . Based on the second offset angle  88 , one side  90  of the splice plate terminates rearward of the other side  92 . This compound offset matches the downward pitch of the throat  22  occupied between adjacent restrictor plates  10 ,  82 . As a result, the two restrictor plates  10 ,  82  engage in a linear connection, across the inlet  12 . 
     The splice plate  86  is formed with opposing end tabs  94 ,  96 . The tabs are parallel with each other and at an angle  99  to a main body portion  98  of the splice plate  86 . This relationship enables the tabs  94 ,  96  to be plumb against the main body portions (e.g.,  52 ) of adjacent restrictor plates  10 ,  82 . 
     The splice plate tabs  94 ,  96 , and connecting ends of at least one of the restrictor plates  10 ,  82  have plural mounting holes  98 ,  100 . More than one hole in each member is desirable, and two holes are illustrated, to prevent rotation of the splice plate  84  relative to the restrictor plate  82 . The type of bolts which can be used to match the splice plates to the restrictor plates include, e.g., ½-13 button head cap screw made of 10-18 steel which conforms with ASTM F835 standards. However, other such mounting bolts may be applied. 
     The splice plate  86  includes plural drain holes, e.g.,  102 , which are the same shape as the holes  76  in the restrictor plates  10 ,  82 . The drain holes  102  are stepped in the direction of the first angle  86  of the compound offset of the splice plate  84 . Stepping the drain holes in this fashion positions the holes in parallel with the holes  76  in the restrictor plate. 
     Turning to  FIG. 5 , another configuration is illustrated. In this configuration, the grate plate (not illustrated) is positioned in the center of a catch basin (not illustrated). In this embodiment, a third restrictor plate  104  can be utilized, along with a second splice plate  106 . In this configuration, the outer restrictor plates are flush with the basin inlet. The center restrictor plate is recessed, down the throat of the basin, to allow for grate access. 
     As illustrated in  FIG. 5 , the outer restrictor plates are longer than the center restrictor plate. This is suitable for a catch basin in which the center grate is smaller than one/third the width of the basin inlet. 
     The symmetric shape of each discussed restrictor plate allows the plate to be laterally shifted in the inlet opening. As such, in  FIG. 5 , the same restrictor plate formation can be used for each outer restrictor plate. The same restrictor plate formation could also serve as the outer plates and the center plate, if conditions warranted such a configuration. 
     The same formation for the splice plate can provide both splice plates  84 ,  106 . A splice plate needs only be flipped about its axis to suit its purpose. 
     The Clamp Arm of the Securing System 
     Attention will now be directed to structure for securing the restrictor plate within the throat of the catch basin, which is illustrated in  FIGS. 2 ,  6  and  7 . There are at least two such structures  108 ,  110 , one at each opposing end of the restrictor plate  10 . With reference to  FIG. 3 , more such structures, e.g., a total of four structures, can be added depending on the length of the restrictor plate. 
     The components of each of the securing systems  108  are identical. Each includes plural clamp arms  112 ,  114 . That is, a lower clamp arm and an upper clamp arm. 
     A front edge  116  of the lower clamp  112  arm extends outwardly from a rear face  81  of the main body  52  of the restrictor plate  10 . A fulcrum  118  is located at about the lengthwise midpoint of the clamp arm  112 , at which point the arm pitches downwardly, at an angle  119 , which is illustrated as being about sixty degrees. The angle  119  enables the clamp arm  112  to grip into the concrete surface of the basin throat  22 , but other angles may be substituted. 
     Rearward of the fulcrum  118 , the clamp extends through an opening  120  in the bottom flange  56 . The opening  120  is required due to the depth of the flanges and the size of the clamp arms. The opening  120  in the flange is illustrated as being just over two inches long (i.e., parallel to the length axis for the flange  56 ) and just over an inch in depth. Furthermore, the opening  120  is spaced by about a quarter of an inch from the depth-wise edge of the flange. However, these dimensions are only exemplarily and can be modified according to the design and placement of the clamp arms. 
     The upper clamp  114  arm also extends from the rear face  81  of the main body  52  of the restrictor plate  10 . The upper clamp  114  extends through an opening  121 , sized similarly to the other referenced opening  120 , in a respective upper flange  64 . 
     Each clamp arm includes a serrated end section  122 . The serrated sections are adapted to dig into the concrete basin throat  22 , securing the restrictor plate  10  to the basin. The serrated sections  122  are illustrated as being triangular, saw toothed serrations  124 , spanning the distance of the clamp edge. Further, as illustrated, each tooth is about a quarter of an inch tall and about a third of an inch wide. However, other serration configurations may be equally applicable. 
     In an unbent state, e.g., during the fabrication process, the clamp is illustrated as having a length of about four inches. The clamp is also illustrated as having a width of about two inches. However, these dimensions are not viewed as limiting the invention. 
     Each clamp has a compound tab  126  disposed at the front clamp edge  116 . A rearward part  128  of the tab  126  extends from the center of the front clamp edge  116 . The rearward part  128  of the tab  126  projects outwardly from the front clamp edge  116  by the thickness of the restrictor plate  10 . The tab  126  is designed to fit within a complementary positioning slot  132  in the restrictor plate  10 . 
     Extending from the rearward portion of the tab  126  is a half-moon shaped secondary tab  134 . The secondary tab  134  is connected to the rearward portion  128  of the  126  tab by a narrow connecting extension  136 . 
     With the compound tab  126  and matching slot  132 , the clamp  112  can be held in a proper configuration against the restrictor plate  10  before instillation is complete. This is done by inserting the tab  126  into the restrictor plate  10 , griping the secondary tab  134  with a wrench, and twisting about the narrow extension  136  by just a few degrees. After instillation is complete, the secondary tab  126  can be torn off by further twisting until the extension  136  factures. 
     The clamp  112  also has two side edge tabs  138 ,  140 , with associated extensions  139 ,  141 . This structure is similar in shape, though smaller, than the secondary tab  134  and connecting extension  136  in the compound tab  126 . The side edge tabs  138 ,  140  are connected via extensions  139 ,  141  directly to respective side edges  142 ,  144  of the clamp  112 , forward of the fulcrum  118 . 
     When the long axis of the restrictor plate is parallel with the horizontal, the positioned clamps  112 ,  114  have two pair of vertically aligned side edge tabs. Each pair is joined by a respective stabilizing spring  142 ,  144 , which helps prevent misalignment of the clamps during instillation. 
     The Wedge of the Securing System 
     A wedge  146  is illustrated in  FIG. 7 , which has opposing wedge surfaces  148 ,  150 . Each of the surfaces  148 ,  150  is double sided  152 ,  154 , and each extends substantially perpendicular to an intermediate surface  156 . The pitch angle  158  for each side  152 ,  154  of the wedge  146  is about forty degrees, but other suitable angles could be utilized. The wedge is fabricated from the same material as the restrictor plate  10 . 
     In use, the intermediate wedge surface  156  is pulled towards the rear face  81  of the main body  52  of the restrictor plate  10 . By this operation, the opposing pitched surfaces  152 ,  154  of the wedge  146  press against the clamp arms at, e.g., the fulcrum. The clamp arms are thereby advanced through respective upper and lower flange openings and forced to dig into the concrete in the basin throat  22 . 
     The intermediate wedge surface  156  is widthwise dimensioned to separate the wedge surfaces  148 ,  150  against the clamp arm  112  by substantially the width of the clamp arm. The intermediate wedge surface  156  is height-wise dimensioned to separate opposing, outermost tips  159 ,  160  of the wedge by about three inches, but other height-wise spacing may be substituted. 
     The intermediate surface is drawn to the restrictor plate, via a through hole  162 , by a mounting bolt  164 . As illustrated, the mounting bolt  164  is a ½-13 button head cap screw made of 10-18 steel which conforms with ASTM F835 standards. However, other such mounting bolts may be applied. The head of the bolt  166  rests against the front surface  168  of the main body  52  of the restrictor plate  10 . On the other side, a mounting nut  165  is positioned on a rear surface  170  of the intermediate surface  156 . 
     In use, the wedge is positioned against the clamp arms, which are urged together by the springs. The mounting bolt and nut are introduced and tightened by, e.g., 72+5−0 ft-lbs of torque. This causes the wedge to urge the clamp arms against the concrete basin, thereby centering the restrictor plate in the height of the opening. This also renders the system tamperproof at the completion of instillation. The secondary tabs can be removed, as indicated above, as may be required or desired. 
     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not as restrictive. The scope of the invention is, therefore, indicated by the appended claims and their combination in whole or in part rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.