Patent Publication Number: US-8522408-B2

Title: Catch basin clamp system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to mounting restrictor plates flush with and/or within a catch basin curb inlet. 
     2. Background 
     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. 
     In attempting to control unregulated sources of storm water discharge, specific-use plates, known as floatable restrictor plates, have been connected to the front opening of a catch basin curb inlet for preventing floatables from entering storm sewer systems through the curb inlet. However, the known method for connecting the restrictor plate to the curb inlet positions the restrictor plate past the front plane of the opening of the curb inlets. This placement positions the restrictor plate outside of the protection of the curb inlet and in the path of machinery which sweeps against the front face of the curb inlet, such as snow plows. The result is damage to the restrictor plate, the snow plow, or both. 
     The present inventors have conceived of one solution, which is to position the restrictor plate within or flush with an opening of a catch basin curb inlet. Curb type catch basins are manufactured in varying shapes and sizes designed to create a street level inlet for water at the curb line as well as a vertical opening for water through the curb face. The various shapes and sizes came about as different state and local agencies designed and developed their own storm water management solutions since the development of roadways for cars. 
     One example of a known curb inlet which could be fitted with a flush or internally mounted restrictor plate is curb inlet  10 , illustrated in  FIG. 3 . The height of the back of the illustrated curb inlet  10  is approximately one foot, though heights range from four inches to a foot, and are fixed or adjustable. The width of the illustrated curb inlet is approximately three feet, though widths range from two to four feet. The depth of the illustrated curb inlet is approximately six inches. The curb inlet  10  includes a plurality of strengthening gussets  12  (or ribs) molded integrally therein which are spaced along the length of the curb inlet  10 . 
     Plural clamps could be utilized, each one gripping a designated portion of the restrictor plate and a respective gusset  12  for proper positioning of the restrictor plate. However, a known manufacturing issue regarding the curb inlet  10  would prevent proper gripping of all gussets  12  in a curb inlet. That is, the curb inlet  10  is formed by pattern and/or sand casting. Normal variations from such formation methods cause the position of the gussets  12  to vary horizontally (i.e., lengthwise along the curb inlet) within a predetermined tolerance. Such a position variance would create a misalignment between the gussets any portion of the restrictor plate designated to be clamped, so as to prevent proper clamping. 
     Accordingly, what is needed is a clamp which is capable of positioning a restrictor plate within or flush with the front opening of the curb inlet. The clamp would be able to grip the gussets of the curb inlet and maintain proper alignment with designated portions of the restrictor plate despite manufacturing induced variations in gussets positioning within the curb inlet. 
     SUMMARY OF THE INVENTION 
     A clamp includes a base section, from which a pair of sidewalls and prongs extend, where the prongs are designed to grip gussets within the curb inlet and maintain proper alignment with designated portions of the restrictor plate despite manufacturing variations in gussets positioning within the curb inlet. The clamp is capable of securely positioning a floatable restrictor plate within or flush with an opening of the curb inlet so as to prevent floatables from entering storm sewer systems through the curb inlet. 
    
    
     
       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 clamp and a clamp adjusting bar; 
         FIG. 2  illustrates a restrictor plate; 
         FIG. 3  illustrates a top view of a curb inlet, plural clamps and a restrictor plate; 
         FIG. 4  illustrates a perspective view a curb inlet, plural clamps and a restrictor plate; 
         FIG. 5  illustrates connecting a restrictor plate to a curb inlet; 
         FIG. 6  further illustrates connecting a restrictor plate to a curb inlet; and 
         FIG. 7  yet further illustrates connecting a restrictor plate to a curb inlet. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Overview 
     A clamp  14  ( FIGS. 1 ,  3  and  4 ) includes a base section, from which a pair of sidewalls and prongs  20  extend, where the prongs  20  are designed to grip gussets  12  within the curb inlet  10  and maintain proper alignment with designated portions of the restrictor plate  30  despite manufacturing variations in gussets  12  positioning within the curb inlet  10 . The clamp  14  is capable of securely positioning a floatable restrictor plate  30  ( FIGS. 2 ,  3  and  4 ) within or flush with an opening of the curb inlet  10  so as to prevent floatables from entering storm sewer systems through the curb inlet  10 . 
     The Restrictor Plate Gripped by the Clamp 
     The outer perimeter of the restrictor plate  30  is sized so that the restrictor plate  30  can be positioned inside, or positioned to just touch, the front face opening of the curb inlet  10 . The restrictor plate  30  has an impact strengthening bend L ( FIGS. 2 and 4 ) along its upper and/or lower edge, though the lower bend is illustrated in the figures. The strengthening bend  32  spans the length of the edge of the restrictor plate  30  and is directed substantially perpendicularly away from the restrictor plate  30 , into the opening of the curb inlet  10 . The strengthening bend  32  creates connected intersecting planes, adding rigidity to the plate. The added rigidity helps the restrictor plate  30  absorb impacts from roadway clutter, trash, stones, etc. 
     The restrictor plate  30  has a stainless steel badge  36  stitch-welded to the back of the restrictor plate  30  ( FIG. 2 ). The badge can be used to provide information, such as from a government or private entity which installed, or cause to be installed, the restrictor plate. For example, the message could be from the U.S.E.P.A. The badge is illustrated as circular, having a diameter essentially the size of drain holes in the restrictor plate (discussed below) and is located near a side edge of the restrictor plate. However, other shapes, sizes and locations would be suitable. 
     As indicated, the restrictor plate  30  has plural drainage openings  34  ( FIG. 2 ) disposed along the length of the restrictor plate  30 , which allow for continued drainage while restricting larger floatables. The size and shape of the openings is governed by local government code to provide proper drainage and filtration. For example, under U.S.E.P.A. regulations, these openings are less than seven square inches, or, have a clear space no bigger than two inches across the smallest dimension, which, as illustrated, is along the length of the restrictor plate  30 . 
     Restrictor plate mounting slots  38  ( FIGS. 2 and 4 ) are spaced along the length of the restrictor plate  30 . The openings in the slots  38  extend long the width of the restrictor plate  30 , so that the slots  38  are vertically oriented. The number of vertical slots  38  is the same as the number of gussets  12  in the curb inlet  10 . Each vertical slot  38  is wide enough to allow an attachment bolt  40  ( FIGS. 3 and 4 ) to pass through and continue to a mounting nut  22  disposed adjacent to a mounting hole  28  in the base of the clamp  14 . However, each vertical slot  38  is narrow enough to prevent the head of the attachment bolt  40  from passing therethrough. This enables each vertical slot  38  to form a seat for tightening the head of the attachment bolt  40  against the restrictor plate  30  and thereby connect the restrictor plate  30  to the clamp  14 . 
     The opening span of the vertical slot  38  allows for height adjustment of the restrictor plate  30  against the curb inlet  10 . As illustrated, the height of the vertical slots  38  is the same as the height of the drainage openings  34  in the restrictor plate  30 . 
     The spacing between adjacent vertical slots  38 , i.e., the horizontal spacing, is approximately the same as the spacing provided in literature from the manufacturer for the design spacing for the gussets  12 . It is to be appreciated that the spacing between adjacent vertical slots  38  does not account for the manufacturing variations (tolerances) in the gusset spacing. 
     4. The Base Area of the Clamp and the Clamp Adjusting Bar 
     The base of the clamp  14  is defined by a flattened fulcrum surface. The flattened surface provides a plane for maintaining the stability of the restrictor plate  30 . 
     The fulcrum surface includes the mounting hole  28 , which is in the form of a slot. The slot  28  extends in a direction which is perpendicular to the width of the clamp  14  so that the slot is horizontally oriented. By allowing the attachment bolt  40  to travel along the horizontal slot  28 , the horizontal slot  28  enables each clamp  14  to remain fixed to a single gusset  12  while being aligned with the vertical slot  38  in the restrictor plate  30 . Accordingly, the horizontal slot  28  is long enough to allow for such adjustments. 
     A flattened clamp adjusting bar  16  is slidably positioned within the clamp  14 , against the fulcrum ( FIGS. 1 ,  3  and  4 ). The above referenced mounting nut  22 , which is coaxial with the horizontal slot  28 , is indirectly secured to the clamp  14  and, rather, directly connected to the clamp adjusting bar  16 . 
     The cross section of the clamp adjusting bar  16  is rectangular, having a smaller width than that of the clamp  14 . For example, the width of the clamp adjusting bar is roughly half of the width of the clamp  14 . The clamp adjusting bar  16  has a cross section which enables the adjusting bar  16  to slide through a pair of co-planar slots  18  in the clamp  14  sidewalls (discussed below). 
     The clamp adjusting bar  16  is longer than the outside dimension of the clamp  14 , in the direction in which the adjusting bar  16  slides, i.e., in the direction perpendicular to the width of the clamp  14 . This prevents the clamp adjusting bar  16  from falling out of the clamp  14  during adjustment. 
     The clamp adjusting bar  16  includes a centrally disposed guide hole, at which location the mounting nut  22  is welded ( FIG. 3 ). Furthermore, the mounting nut  22  is welded to the clamp adjusting bar  16  after the clamp adjusting bar  16  is positioned in the clamp C. The post-insertion welding of the mounting nut  22  serves to lock the adjusting bar  16  into the clamp  14  and prevents loss in shipping or installation. 
     The sidewalls of the clamp, which extend substantially perpendicularly from the fulcrum of the clamp, are spaced along the axis perpendicular to the width of the clamp  14 . Accordingly, the sidewalls are separated by a distance which is at least large enough to allow for full adjustment of the clamp adjusting bar  16  against the clamp  14 . It is to be appreciated that such spacing is larger than the thickness of gussets  12  in the curb inlet  10 . 
     According to the above configuration, each attachment bolt  40  passes through a vertical slot  38  in the restrictor plate  30 , through the horizontal fulcrum slot  28  in the clamp  14 , though the guide hole in the clamp adjusting bar  16  and into the mounting nut  22 . This configuration floats the restrictor plate  30  at the curb inlet opening and obviates problems which would otherwise exist due to misalignments between the gussets  12  and the restrictor plate slots  38 . 
     i. The Clamp Sidewalls and Prongs 
     As illustrated in  FIGS. 1 ,  3  and  4 , the length of each sidewall is approximately twice the width of the clamp fulcrum. The length is designed around proper seating of the resister plate against the front face of the curb inlet. 
     As indicated, above, each side wall has a slot  18 . The slots  18  are positioned adjacent to the clamp fulcrum so that the adjusting bar  16  may slide directly against the fulcrum surface. The slots  18  have the same shape as the cross section of the adjusting bar  16  and is larger for enabling the adjusting bar  16  to slide freely therein during adjustment. Clearly, the height of the slot  18 , while larger than the thickness of the adjusting bar  16 , is not larger than the combination of the adjusting bar  16  and the mounting nut  22 . 
     At the upper end of each sidewall, the clamp  14  includes prongs  20 . Each prong  20  includes a free edge, with a curve defining the upper half of a “V”. The prongs  20  are bent inwardly so as to close the distance about a gusset  12  to which the prongs  20  will connect. However, the bend angle is small enough to prevent excess shear forces from building up at upper end of the sidewalls. For example, the bend angle is approximately thirty degrees from the long axis of the sidewall. The inwardly angled prongs  20  make the clamping action against some or all of the gussets  12  when the clamp  14  is tightened. It is to be appreciated that opposing prongs  20  are utilized because gussets  12  are uneven due to inconsistencies in the sand molding/casting operation. Such a molding process creates a rough finish and such a process requires utilizing draft angles on patterns. The effect of such a process is the creation of odd slopes and angles on the gussets  12 . The individual points of the clamping prongs  20  allow for individual contact upon uneven gussets  12  to maximize the clamping effort. 
     Furthermore, the length of the prongs  20  is such that the prong ends  20  are separated by a distance which allows the prongs  20  to be freely positioned about the gussets  12  before being clamped against the gussets  12 . For example, the distance between the free ends of the opposing prongs  20  is twice the thickness of a gusset  12 . 
     Each sidewall in the clamp  14  has a guide hole  24  ( FIG. 1 ). The guide holes  24  are centered along the sidewall width. The guide holes  24  are axially aligned and are designed to receive a clamping bolt  26 . The guide holes  24  are positioned close to the prongs  20  to enable maximum deflection of the prongs when tightening the clamping bolt  1 . 
     A clamping nut  22  ( FIGS. 1 ,  3  and  4 ) is welded on the outside of one of the guide holes H. Accordingly, the clamping bolt  26  is capable of being passed through one guide hole, across the clamp  14 , through the opposing guide hole, and into the clamping nut  22 . As can be appreciated, as the clamping bolt  26  is tightened, the clamp  14  deforms under the clamping pressure and the prongs  20  individually clamp into the gusset  12  allowing for maximum clamp pressure on any uneven surfaces. 
     As illustrated in  FIGS. 5-7 , when a clamp  14  fully engages a gusset  12  in a curb inlet  10 , the shank of the clamping bolt  26  rests against the narrow edge of the gusset  12 . Each gusset  12  has a triangular profile at the location at which the clamp bolt  26  engages the gusset  12 . Accordingly, moving the clamp  14  upwardly and downwardly along the gusset  12 , while maintaining a contact between the gusset  12  and the clamp bolt  26 , will increase or decrease the distance between the back face of the curb inlet  10  and the fulcrum of the clamp  14 . As such, the guide holes  24  provide for both height and depth adjustment of the clamp  14 , and therefore the restrictor plate  30 , with respect to the curb inlet  10 . 
     It is noted that the depth positioning of the restrictor plate  30  with respect to the curb inlet  10  is dependant on maximum standard installed height of the catch basin. This positioning of the restrictor plate  30  protects the restrictor plate  30  from vehicular or snow plow impact. This positioning also prevents the restrictor plate  30  from impinging on the grate of the catch basin if the curb height needs to be adjusted, or if the grate is raised for paving overlay. 
     Materials 
     The inventors contemplated utilizing ¼″ thick, A588 grade, Cor-Ten (trademark held by United States Steel Corporation) weathering steel for all materials, including the clamp, the adjusting bar and the restrictor plate. Such material is designed to “weather” (i.e., oxidize over time) to the patina of the cast iron inlet of the curb inlet  10  in which the materials are installed. A588 Cor-Ten weathering steel shares the same rust inhibiting properties as cast iron to provide years of service with no need for painting. Furthermore, the clamp and adjusting bar were contemplated to be 2″ wide. Moreover, the type of bolt contemplated by the inventors, for all uses, was a 5/16″ hex socket bolt. 
     However, one of ordinary skill would understand that various material types, thickness and overall dimensions could be applied so long as the clamp  14  is capable of mounting on the gussets  12  of the curb inlet and anchoring the restrictor plate  30  to the curb inlet  10 . 
     In use, the method of installing the restrictor plate  30  to the curb inlet  10  is a two step process. The first step is securely installing the clamps  14  on the gussets  12 . The second step is installing the restrictor plate  30  to the clamps A. This two step installation makes the installation easier and allows for future replacement of the restrictor plate  30  without having to replace any clamp  14 . 
     In sum, the following features are provided by the invention: 
     1) A clamped plate system is provided which restricts the inflow of floatables into storm water systems through catch basin curb inlets. 
     2) The clamped plate system uses the integral parts of the catch basin curb inlet as anchors for the restrictor plate. 
     3) The clamped plate system allows curb and/or grate adjustment for paving or curb line reconstruction to not interfere with the restrictor plate installation. 
     4) The clamped plate system mounts the restrictor plate inside the plane created by the front wall of the curb and its front face opening. 
     5) This mounting position lessens the potential for damage from vehicle of snow plow impact. 
     6) The pronged clamp used in the clamped plate system uses the prongs at the clamping end to provide maximum clamping effort on uneven gusset surfaces. 
     7) The pronged clamp uses the deformation of its steel shape caused by the tightening of the clamping bolt to create the clamping pressure. 
     8) The restrictor plate has openings designed to allow continued inflow of water while restricting larger floatables per EPA Stormwater Control Act mandates and specifications. 
     9) The restrictor plate has a full length Bend along the upper and/or lower edge to create intersecting connected planes to add rigidity. This rigidity lessens the potential for incidental impact damage. 
     10) The restrictor plate has a stitch welded steel badge, viewable through an opening in the Plate. The steel badge carries an educational message per USEPA Stormwater Control Act mandates and specifications. 
     11) The restrictor plate is attached to the pronged clamp through slots which allow vertical adjustment. 
     12) The adjusting bar in conjunction with the clamp slot allows for horizontal adjustment between the restrictor plate and the pronged clamp to accommodate varying field conditions. 
     13) The pronged clamp can be installed on the gussets before the restrictor plate is attached. 
     14) The restrictor plate can be replaced without removing the pronged clamp. 
     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.