Manhole cover seal

Abstract

A manhole sealing device to prevent environmental water from entering a manhole through the joint between the manhole casing, manhole cover, and cover frame. The device comprises a disc shaped inflatable seal for insertion into the upper portion of the manhole and inflated to provide a sealing means to prevent infiltration of water from the environment to the interior of the manhole. The disc shaped seal may include a first rigid stabilization portion surrounded by a flexible inflatable seal wherein the stabilization portion supports and assists in maintaining a seal to prevent water or other fluids from entering the manhole through the cover or the corbel joint thereof. The manhole sealing device can be installed in an existing manhole without replacing any of the structural parts thereof.

Claims

1. A manhole cover seal, comprising: a hollow body formed from an upper rigid shell, a lower rigid shell, spaced apart from said upper rigid shell and at least one stiffening rib extending between said upper and lower rigid shells, said hollow body having a cavity therein, and an outer periphery of said upper and lower rigid shells forming a rim on said body; an expandable bladder, received in said rim, said expandable bladder in fluid communication with said cavity within said body, wherein said expandable bladder forms a watertight seal against a manhole frame when inflated; a fill valve in fluid communication with said cavity; and a drain hole positioned within said body to allow for controlled removal of accumulated water from the top of the seal, said drain hole including a gravity-based drain plug, wherein fluid entering said fill valve increases a pressure within said cavity and causes said expandable bladder to expand to seal said manhole.

2. The manhole cover seal of claim 1, wherein said drain plug includes a lifting ring on a top thereof.

3. The manhole cover seal of claim 1, wherein removal of said drain plug allows water trapped on a top surface of said manhole cover seal to drain through said drain hole.

4. The manhole cover seal of claim 1, further comprising: at least one lifting strap extending from said body.

5. The manhole cover seal of claim 1, further comprising: a rigid core positioned within at least a portion of said hollow cavity within said body.

6. The manhole cover seal of claim 1, further comprising: a rigid shell material on a top and bottom of said body portion; and a rigid rim structure joining a periphery of said top and bottom shells, wherein said expandable bladder is affixed around said rigid rim structure.

7. The manhole cover seal of claim 6, wherein said expandable bladder is a tube received and retained in said rigid rim structure.

8. The manhole cover seal of claim 1, wherein said expandable bladder is a resilient material selected from the group consisting of neoprene, rubber, EPDM, PVC, urethane, and combinations thereof.

9. The manhole cover seal of claim 1, wherein said fluid entering said fill valve is selected from the group consisting of: a gas, compressed air, nitrogen, gel, foam, and combinations thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:

(2) FIG. 1 is a cross sectional view of a manhole assembly as known in the art;

(3) FIG. 2 is a cross sectional view of one illustrative embodiment of a manhole sealing insert in accordance with the teachings of the present disclosure;

(4) FIG. 3 is a cross sectional view of another illustrative embodiment of a manhole sealing insert in accordance with the teachings of the present disclosure;

(5) FIG. 4 is a cross sectional view of still another illustrative embodiment of a manhole sealing insert in accordance with the teachings of the present disclosure; and

(6) FIG. 5 is a cross sectional view of yet another illustrative embodiment of a manhole sealing insert in accordance with the teachings of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

(7) Disclosed herein is a watertight manhole sealing insert is provided for preventing rainwater from entering a sewer system through a manhole cover. In one embodiment, the insert includes a dish-shaped body member with an outwardly extending flange designed to engage with an inflatable bladder seal having a fully inflated diameter that corresponds approximately to the diameter of the access port of the manhole to be sealed. The seal is positioned with the bladder in a deflated state to allow its positioning and the opening and the bladder is inflated with air pressure causing it to expand to seal the manhole opening and serving to retain the seal in its installed position. In the preferred embodiment, the body is depressed about five to six inches below the plane defined by the manhole cover. The body limits the amount of water which can be accumulated on top of the insert to minimize the weight which it must support.

(8) Turning to FIG. 1, a manhole structure as typically found in the art is shown and illustrated. The manhole assembly 1010 includes an underground masonry casing 1020, a chimney 1030 extending up from the casing 1020 about a top opening 1040 therein, and a cover frame 1050 resting on the top of the chimney 1030 at a corbel joint and protruding through the pavement 1060 of a street or the like. A manhole cover 1070 is received in the cover frame 1050 that is removable or hinged to allow access to the manhole. The difficulty arises in that each of these joints is difficult to seal, providing numerous opportunities for water infiltration. As a result, it is important to seal these manholes to prevent such infiltration which can add significantly to the normally calculated flow thereby increasing the volume of waste water that must be processed by the system.

(9) Turning now to FIG. 2, the present disclosure provides for a manhole sealing insert 2000 that is sized and shaped to fit into a manhole access port that rests on the lip of the masonry casing 1020 as shown or on the base of the cover frame 1050. The manhole sealing insert 2000 has an inflatable feature that will be described in more detail below that allows inflation thereof causing it to expand and seal against the chimney 1030 walls or the cover frame walls 1050 thereby preventing water infiltration into the manhole. A drain opening 2010 is positioned within the manhole sealing insert 2000 with a plug 2020 positioned therein. The plug 2020 is gravity biased in a downward fashion to seal the drain opening 2010 and includes a lifting ring 2030 at the top thereof to allow the drain plug 202 to be lifted and any standing water on the top of the manhole sealing insert 2000 to be drained into the manhole when the manhole sealing insert 2000 must be removed for service. Further, lifting straps 2040 may also be provided to allow attachment of a hoist to assist in removing the manhole sealing insert 2000 from the manhole for servicing.

(10) Turning to FIG. 3, the manhole sealing insert 2000 in one embodiment is formed as a hollow body with rigid top shell 3010 and bottom shell 3020 with an inflatable seal 3030 at the opposite ends thereof. A fill valve 3040 provides a valved stem to which a source of compressed air is connected. When air pressure is applied to the fill valve 3040, the pressure on the interior of the manhole sealing insert 2000 increases causing expansion of the inflatable seals 3030 to expand against the manhole structure to form an effective water tight seal therein. In some embodiments, inflation may be done with any variety of compressed gasses including but not limited to nitrogen. Further, in some embodiments, inflation may be done using a gel or foam material. For removal, the fill valve 3040 can be opened to allow a release of the internal pressure causing the inflatable seal 3030 to shrink so that the manhole sealing insert can be removed.

(11) In some embodiments, as shown at FIG. 4, the shells 3010 and 3020 of the manhole sealing insert 2000 may be joined at their periphery by a rim structure 4040, wherein the inflatable seal 4030 is a tube that extends around the perimeter of the manhole sealing insert 2000 such that the inflatable seal 4030 is received and retained in the rim structure 4040. In a preferred embodiment, shown at FIG. 5, at least one rib 5040 may also be provided in the rim of the body portion for stiffening and strengthening purposes as well as to receive and retain the inflatable seal. The inflatable seal may be secured to the rim by glue or ultrasonic weld. It may further include downwardly-extending ribs for engaging or resting on the manhole structure.

(12) In other embodiments depicted at FIG. 5, the manhole sealing insert 2000 may have an expandable solid foam reinforcement 5010 between the shells 3010 and 3020 to provide additional rigidity and dimensional stability.

(13) In some embodiments, the lift strap 2040 may be riveted or connected at both ends to the body portion, in order to facilitate easy removal of the insert from the manhole.

(14) In all embodiments, when the sealing means, such as a tube or bladder of rubber or closed cell neoprene, is positioned on or in the rim of the body portion such that, when inflated, the sealing means forms an essentially watertight seal between the insert and the manhole frame to prevent water from seeping down around the edges. In addition, to neoprene and rubber, the sealing means may alternatively be any expandable resilient material including neoprene, rubber, EPDM, PVC, urethane and combinations thereof.

(15) In some embodiments, the manhole sealing insert may be entirely inflatable. In such cases, the entire insert may be formed as an inflatable bladder with stiffening regions formed in a top, bottom or, both surfaces thereof to assist the manhole sealing insert in maintaining its shape.

(16) In all embodiments, around the periphery of the manhole sealing insert is shown an inflatable rubber seal. The inflatable seal is affixed to the edge of the manhole sealing insert. When air pressure is applied, the seal inflates to engage with the wall of the manhole structure. The seal contours to the shape of the manhole wall to create a reliable seal as well as exerting pressure against the wall to assist in retaining the sealing insert in the installed location.

(17) It can therefore be seen that the present disclosure provides a manhole sealing insert that allows easy and reliable installation in an active manhole access port. It can further be seen that the present disclosure provides a manhole sealing insert that can easily be handled to facilitate installation in space restricted environments. Still further it can be seen that the present disclosure provides a manhole sealing insert that can be easily serviced on sit allowing installation and removal to facilitate the servicing of the system and reinstallation for a reliable seal against water infiltration. For these reasons, the present disclosure is believed to represent a significant advancement in the art, which has substantial commercial merit.

(18) Various other components may be included and called upon for providing for aspects of the teachings herein. For example, additional materials, combinations of materials and/or omission of materials may be used to provide for added embodiments that are within the scope of the teachings herein.

(19) In the present application a variety of embodiments are described. It is to be understood that any combination of any of these variables can define an embodiment of the invention. Other combinations of articles, components, conditions, and/or methods can also be specifically selected from among variables listed herein to define other embodiments, as would be apparent to those of ordinary skill in the art.

(20) While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.