Abstract:
A two piece inflow dish assembly for installation in an enlarged manhole opening to prevent debris from entering the manhole to clog the sewer system and to permit the inflow dish assembly to be removed from the manhole in separate pieces.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a divisional of U.S. patent application Ser. No. 13/682,900, filed Nov. 21, 2012, which claims priority from U.S. Provisional Application Ser. No. 61/562,517, filed Nov. 22, 2011, which is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present invention is directed to an inflow dish for a sanitary sewer system and more particularly to a two-piece dish assembly designed to be used in enlarged manhole openings. 
       BACKGROUND 
       [0003]    For a number of reasons, including the obesity of some workmen and the necessity to move larger equipment and supplies through a manhole opening to gain access to the manhole, it has been necessary to increase the diameter of manholes. Inflow dishes are designed to fit below the manhole cover and to prevent rainfall and debris that may find its way past the manhole cover from entering the sanitary sewer system. 
         [0004]    Inflow dishes designed to fit standard manhole openings, of course, do not fit manholes with enlarged diameters. Providing an inflow dish enlarged to accommodate the larger size manhole openings has not proven to be a satisfactory solution. Using standard materials to construct a single piece enlarged inflow dish has provided an inflow dish that is either too weak to accommodate rain and debris without collapsing or too heavy to be easily handled. Also very often it would not be necessary to remove the entire inflow dish if it could be removed in sections. 
       SUMMARY 
       [0005]    The present invention provides a two-piece inflow dish assembly which includes an outside dish with a central opening and an insert dish which nests within the outside dish to completely close the manhole below the manhole cover. The outside dish has the diameter of an enlarged manhole opening so that the two-piece dish can fit within and close the enlarged manhole opening. The insert dish is substantially the diameter of a standard manhole opening so that it can be used by itself to serve as an inflow dish for a standard size manhole. 
         [0006]    The construction permits the inflow dish assembly to be removed in two pieces. It may only be necessary to remove the insert dish to dispose of debris captured by the inflow dish. Where access to the manhole is required, it may be necessary to remove both pieces. 
         [0007]    A problem with using commonly used materials, such as polyethylene, for inflow dishes is that such material is not sufficiently strong and, especially in the larger diameters required by the enlarged manholes, can result in sagging of the dish and the possibility of the dish, and the debris carried by the dish, falling into the manhole. A preferred construction, however, would be that, rather than being formed of polyethylene, either or both of the dishes of the inflow dish constructed is constructed of polycarbonate or a material having the characteristics of polycarbonate. Polycarbonate has the necessary strength to function as an inflow dish even with large diameter dishes. It has been found that acrylic is also sufficiently strong to support the dishes over the span of an enlarged manhole opening. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Reference will be made herein to various drawings, wherein like reference numerals refer to like parts throughout and wherein: 
           [0009]      FIG. 1  is a fragmentary cross sectional view of the upper part of a manhole with a two-piece inflow dish assembly of the present invention shown in place; 
           [0010]      FIG. 1 a    is an enlarged view of a portion of the structure shown in  FIG. 1 ; 
           [0011]      FIG. 2  is top perspective view of the outside dish of the present invention; and 
           [0012]      FIG. 3  is top perspective view of the two piece dish assembly of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Referring now to the drawings an inflow dish assembly  10  of the present invention is shown which includes an outside dish  14  having a central opening  13  which receives an insert dish  12  to provide the two-piece inflow dish assembly  10 . The inflow dish assembly  10 , as can best be seen in  FIG. 1 , is dimensioned to fit within a manhole opening  16  of a manhole  17  and below a manhole cover  18 . The manhole opening  16  is of a diameter which is larger than the diameter of a standard manhole opening and the cover  18  is therefore larger than the standard manhole cover to fit within and close the manhole opening  16 . Inflow dishes are commonly provided to be mounted below the manhole cover  18  in the manhole opening  16  to collect rainwater and debris passing the cover  18  and before the rainwater can make its way into the sanitary sewer system and thereby causing the system to overflow. 
         [0014]    The inflow dish assembly  10  of the present invention is of a diameter to fit within an enlarged manhole opening  18  of a manhole  19  and with the insert dish assembly  10  in place within the central opening  13  it is operable to fully block the manhole opening  16  below the manhole cover  18 . With the inflow dish assembly  10  in place as shown in  FIG. 1 , debris and rainwater that has made its way past the manhole cover  18  can, in many instances, be removed by removing the cover  18  and then removing only the insert dish  12 . 
         [0015]    The insert dish  12  is preferably dimensioned to fit within a standard manhole where it can be used without the outside dish  14 . 
         [0016]    As can best be seen in  FIGS. 1  and  FIG. 3  the insert dish  12  removably nests within the center of the outside dish  14  to close the central opening  13  ( FIG. 2 ) formed within outside dish  14  to form the inflow dish assembly  10 . As seen in  FIG. 1  the inflow dish assembly  10  is intended to be inserted in the manhole opening  16  with an outwardly extending flange  22  of the outside dish  14  supported by a flange  20  formed in the wall  17  of the manhole  19 . A slot  21  is preferably formed in the flange  20  to receive the flange  22  of the outside dish  14 . 
         [0017]    Still referring to  FIGS. 1, 2 and 3  the outside dish  14  is provided with an offset internal flange  23  formed about the central opening  13  which supports an outer rim  24  ( FIG. 3 ) of the insert dish  12  to receive a central portion  25  of the insert dish  12  within the central opening  13  to nest the insert dish  12  within the outside dish  14  to close the central opening  13 . 
         [0018]    It should be apparent that then an inflow dish assembly has been provided which includes an insert dish mounted within an outside dish to form an assembly which fits within a manhole that has been enlarged from the conventional size. 
         [0019]    If access to the enlarged manhole is required any debris and rainwater can be removed by removing the inflow dish assembly in sections. If access through the enlarged manhole is not required it may only be necessary to remove the insert dish to gain access. 
         [0020]    Inflow dishes have heretofore been commonly constructed of polyethylene or a similar plastic material. Applicant has found that polycarbonate and similar plastic material as well as acrylic possess the strength necessary to prevent the dish from sagging and thereby risking debris and rainwater and even the dish itself from falling into the manhole and into the sanitary system. 
         [0021]    Having thus described the disclosed two-piece inflow dish assembly of the present invention, other embodiments for the present invention that do not depart from the scope of the claims will become apparent to those of skill in the art.