Inflow dish

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

FIELD

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

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.

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

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.

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.

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

Reference will be made herein to various drawings, wherein like reference numerals refer to like parts throughout and wherein:

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;

FIG. 1a is an enlarged view of a portion of the structure shown in FIG. 1;

FIG. 2 is top perspective view of the outside dish of the present invention; and

FIG. 3 is top perspective view of the two piece dish assembly of the present invention.

DETAILED DESCRIPTION

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.

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.

The insert dish 12 is preferably dimensioned to fit within a standard manhole where it can be used without the outside dish 14.

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.

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.

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.

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.

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.

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.

Claims

1. A manhole system comprising: a manhole being formed with a cylindrical wall, a ledge extending interiorly from said cylindrical wall, said ledge having a slot extending radially along said ledge so as to form a ring and a manhole cover removably mounted to said ledge;an inflow dish assembly for mounting in said manhole, said inflow dish assembly comprising; an outside dish and an insert dish mounted within said outside dish, said outside dish having a circumferential flange, said circumferential flange removably disposed on said ring so as to be bound by said ledge and disposed within said manhole and below said cover, said outside dish having an offset central opening forming a second ledge surrounding said opening, said second ledge disposed on a plane beneath the circumferential flange and parallel to the circumferential flange, and said inside dish removably mounted within said opening and on said second ledge.

2. The manhole system as set forth in claim 1, wherein said circumferential flange having a planar surface and an outer edge, the planar surface resting upon said ring, the outer edge disposed within the slot.

3. The manhole system set forth in claim 1, wherein said insert dish is dimensioned to fit within a standard size manhole opening.

4. The manhole system as set forth in claim 3, wherein said outside dish is dimensioned to fit within an enlarged size manhole opening.

5. The manhole system as set forth in claim 1, wherein said insert dish and said outside dish are formed of polycarbonate.