Self-sealing internal manhole chimney seal

Abstract

An assembly internally seals a manhole against infiltration of water. A pleated sleeve, made of an resilient material, includes a first and second sealing sections at opposite ends. The first sealing section has a lip that forms a recess for receiving an inwardly projecting flange on a frame of the manhole to attach the sleeve in a watertight manner. A fastening device engages the second sealing section and presses an outer surface of the sleeve against a different portion of the manhole to form another watertight seal.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to articles for internally sealing a chimney of a manhole against ground water infiltration, and more particularly to mechanisms by which the seal is attached to the manhole.

2. Description of the Related Art

A typical manhole includes a main chamber or barrel section to which the sewer pipes connect. That section is topped with a conical riser in which the diameter reduces going upward to a size needed to fit a metal frame for the manhole surface opening. The metal frame receives the manhole cover and either sits directly on top of the riser or there may be one or more vertical adjusting rings there between, as needed to raise the top of the frame level with the surrounding surface. Adjusting rings usually are formed by annular precast concrete sections or courses of bricks or blocks. This combination of components is referred to as a “chimney”.

During construction of the manhole, the joints between the chimney components are sealed with mortar or other material to prevent surface water infiltration. Nevertheless, movement of the metal frame, resulting from expansion and contraction due to seasonal temperature changes and from vibration as vehicles pass over the manhole, causes cracks to form at those joints. As a result, ground water from rain and snow is able to enter the manhole through these cracks. Such ground water infiltration is undesirable for sanitary sewers, as it increases the volume of effluent which has to be processed by a sewage treatment plant. Municipalities go to great lengths to minimize the inflow and infiltration of ground water into sanitary sewers.

As a consequence, different external and internal sealing systems have been devised to prevent ground water infiltration into manholes. One type of an internal sealing system is described in U.S. Pat. No. 4,469,467 and utilizes a resilient sleeve that is inserted into the manhole chimney and held against the inside surface by upper and lower metal fastening bands.

SUMMARY OF THE INVENTION

An assembly is provided to internally seal a manhole against infiltration of water, wherein the manhole includes an inwardly projecting flange.

The assembly comprises a sleeve made of a resilient material which includes a first sealing section and a second sealing section. The first sealing section has a recess for receiving the flange to attach the sleeve to the manhole. In a preferred embodiment, the first sealing section is formed with a hook-like lip that creates the recess and the resiliency of the sleeve enables the lip to engage the flange in a manner that provides a watertight seal.

A fastening device engages the second sealing section of the sleeve and presses an outer surface of the sleeve against a surface of the manhole, thereby providing another watertight seal. The preferred embodiment of the fastening device comprises a fastening band that has first and second end portions which overlap and a mechanism that adjustably secures those end portions together to form a loop. For example, the first end portion has a tab and the second end portion has a plurality of slots that cooperate with the tab to connect the first and second end portions together in the loop.

Another aspect of the assembly provides a pleated section between the first and second sealing sections to allow the sleeve to expand and contract with movement of the parts of the manhole without breaking the watertight seals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of the upper section of a manhole having an internal chimney seal according to the present invention;

FIG. 2 is an enlarged portion of FIG. 1 showing details of how an upper end of the internal chimney seal is secured to the manhole;

FIG. 3 is another enlarged portion of FIG. 1 that illustrates how a lower end of the internal chimney seal engages the manhole;

FIG. 4 is a fastening band that secures the lower portion of the internal chimney seal to the manhole;

FIG. 5 is a cross section through the fastening band along line 5-5 FIG. 3; and

FIG. 6 shows an installation tool being used to expand the fastening band inside the manhole chimney.

DETAILED DESCRIPTION OF THE INVENTION

With initial reference to FIG. 1, a manhole 10 has a chimney 14 that comprises a conical riser 12 typically formed of precast concrete, but which may be laid bricks or blocks. Above the riser 12 are two precast concrete, plastic or rubber adjusting rings 16 on top of which is a metal manhole frame 18. The number of adjusting rings 16 varies so that the chimney 14 has a height that places the upper end of the frame 18 level with the ground surface 20. The conical riser 12, adjusting rings 16, and manhole frame 18 are held together by mortar 15 or a suitable adhesive.

The metal frame 18 has an opening 22 by which a person gains access to the interior of the manhole 10. An interior, annular flange 24 extends around the interior of the opening 22. A manhole cover 26 is shown closing the upper portion of the opening 22 above the annular flange 24. The cover 26 is dropped in place and the annular flange 24 prevents the cover from falling completely through the opening 22.

An internal chimney seal 30 is attached inside the manhole 10 to provide a watertight barrier at the joints between the manhole frame 18, the adjusting rings 16, and the riser 12, thereby blocking ground water infiltration. The seal 30 consists of a tubular sleeve 32 that preferably is constructed of rubber or a similar resilient material that is extruded as a strip. The extruded strip is cut to a length that corresponds to the circumference of the finished sleeve and the ends then are sealed together with a suitable adhesive, for example. The exemplary sleeve 32 has two central pleats 33 and 34 located in between cylindrical sealing sections 35 and 36 at opposite ends of the sleeve. The pleats 33 and 34 allow the sleeve to expand, thereby accommodating vertical movement of the manhole components. Additional pleats or a straight section may be placed between pleats 33 and 34 to provide a sleeve that is able to span taller manhole chimneys.

With reference to FIG. 2, the upper sealing section 35 of the sleeve 32 is adapted to engage the interior annular flange 24 of the manhole frame 18. Specifically a hook-like lip 40 extends around the upper end of the sleeve 32, thereby forming a recess 38 in the outer circumference of the upper sealing section 35. The resilient property of the sleeve 32 and the size of the recess 38 provide a tight engagement of the hook-like lip 40 with the annular flange 24 of the manhole frame 18, that secures the components together with a watertight seam.

In addition to providing a watertight seal to the manhole chimney frame 18, the lip 40 of the sleeve 32 also acts as gasket between the manhole cover 26 and the chimney frame to prevent water infiltration through that seam. As seen in FIG. 1, the lip 40 extends over the upper surface of the annular flange 24 in the opening 22 of the chimney frame 18. Therefore when the manhole cover 26 is dropped into the frame opening 22, the cover compresses the sleeve lip 40 providing a seal between the cover and the chimney frame 18. Thus the novel internal chimney seal 30 incorporates an integral cover gasket.

Referring to FIGS. 1 and 3, the lower sealing section 36 of the sleeve 32 has outer circumferential surface 42 that engages and conforms to the interior surface 44 at the upper portion of the conical riser 12. That outer circumferential surface 42 is formed by plurality of outwardly projecting annular fins 50 which extend around the sleeve 32 and engage the conical riser's interior surface 44. The fins 50 deform when the lower sealing section 36 is pressed against the inner surface of the manhole 10, thereby conforming to irregularities in that manhole surface to provide a watertight seal. Specifically, each fin 50 has an edge or tip that contacts the interior surface of the manhole and has a section spaced from that edge which is adapted to deform as the fin is pressed against the manhole.

The fins 50 of the lower sealing section 36 are held against the inner surface of the manhole 10 by a stainless steel fastening band 48 that is received in an annular groove on the inner circumferential surface 46 of the lower sealing section 36. The fastening band 48 has overlapping end portions 51 and 52 which are slidable with respect to each other, as shown in FIG. 4. After the resilient sleeve 32 is properly located within the manhole 10, the fastening band 48 is expanded within the sleeve to press the finned outer periphery of the lower sealing section 36 against the inner surface of the manhole riser 12. The resiliency of the sleeve 32 allows the lower sealing section to expand against the manhole wall and form an annular seal which prevents water flow there between.

Referring to FIGS. 1 and 6, expansion of the fastening band 48 is performed by a scissors type tool 65 that is placed into apertures 66 and 67 in the fastening band 48. As the fastening band 48 is expanded by the tool 65, an angled tab 68 (see FIG. 5) on one end portion 51 sequentially ratchets into a plurality of slots 70 spaced along the other end portion 52. Specifically a bolt 72 on the tool is turned by a wrench to spread part two legs 74 and 75 that pivot about pin 76 on the tool 65. The remote ends of the legs 74 and 75 have hooks that fit into the apertures 66 and 67 in the fastening band 48. After the fastening band 48 has expanded sufficiently to provide the water tight seal, the bolt 72 is turned in the opposite direction to draw the legs 74 and 75 together so that the tool 65 can be disengaged from the fastening band. The fastening band and the expansion tool are described more fully in U.S. Pat. No. 5,496,128, which description is incorporated herein by reference.

The foregoing description was primarily directed to a preferred embodiment of the invention. Although some attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure.

Claims

1. An assembly for internally sealing a manhole against infiltration of water, wherein the manhole includes an inwardly projecting flange, the assembly comprising:

a sleeve made of an resilient material and having a first sealing section and a second sealing section, the first sealing section having a recess for receiving the flange to attach the sleeve to the manhole, and the second sealing section having an outer surface; and

a fastening device engaging the second sealing section and pressing the outer surface against a surface of the manhole.

2. The assembly as recited in claim 1 wherein the first sealing section comprises an annular lip which forms the recess.

3. The assembly as recited in claim 2 wherein the annular lip provides a seal between a manhole cover and the flange.

4. The assembly as recited in claim 1 wherein the first sealing section comprises a hook-like lip which extends around the sleeve and forms the recess.

5. The assembly as recited in claim 1 wherein the flange is received in the recess of the first sealing section in a manner that provides a watertight seal.

6. The assembly as recited in claim 1 wherein the sleeve further comprises a plurality of pleats between the first sealing section and the second sealing section.

7. The assembly as recited in claim 1 wherein the outer surface of the second sealing section comprises a plurality of annular fins extending outwardly around the sleeve.

8. The assembly as recited in claim 7 wherein each of the plurality of fins has an edge for contacting the surface of the manhole and has a section spaced from the edge and adapted to deform as the fin is pressed against the surface of the manhole enabling the fin to conform to irregularities in the manhole.

9. The assembly as recited in claim 7 wherein the section of each of the plurality of fins is hollow.

10. The assembly as recited in claim 1 wherein fastening device comprises a fastening band engaging the second sealing section.

11. The assembly as recited in claim 10 wherein the fastening band has a first end portion and second end portion which overlap, and has a mechanism that adjustably secures the first and second end portions together to form a loop.

12. The assembly as recited in claim 10 wherein the fastening band has a first end portion with a tab projecting therefrom, and second end portion with a plurality of slots that cooperate with the tab to connect the first and second end portions together to form a loop.

13. An assembly for internally sealing a manhole against infiltration of water, wherein the manhole includes a frame with an opening for access to inside the manhole and an annular flange projecting inwardly around the opening, the assembly comprising:

a sleeve made of an resilient material and including a first sealing section and a second sealing section, the first sealing section having a lip that forms a recess for receiving the flange to attach the sleeve to the frame of the manhole, and the second sealing section having an inner surface and an outer surface; and

a single fastening band, wherein the single fastening band engages the inner surface of the second sealing section and presses the outer surface against a surface of the manhole.

14. The assembly as recited in claim 13 wherein first sealing section provides a watertight seal with respect to the frame when the flange is received in the recess.

15. The assembly as recited in claim 13 wherein the lip provides a seal between a manhole cover and the flange.

16. The assembly as recited in claim 13 wherein the sleeve further comprises a plurality of pleats between the first sealing section and the second sealing section.

17. The assembly as recited in claim 13 wherein the outer surface of the second sealing section comprises a plurality of annular fins extending outwardly around the sleeve.

18. The assembly as recited in claim 17 wherein each of the plurality of fins has an edge for contacting the surface of the manhole and has a section spaced from the edge and adapted to deform as the fin is pressed against the surface of the manhole enabling the fin to conform to irregularities in the manhole.

19. The assembly as recited in claim 17 wherein the section of each of the plurality of fins is hollow.

20. The assembly as recited in claim 13 wherein the fastening band has a first end portion and second end portion which overlap and further including a mechanism that adjustably secures the first and second end portions together to form a loop.

21. The assembly as recited in claim 13 wherein the fastening band has a first end portion with a tab projecting therefrom, and second end portion with a plurality of slots that cooperate with the tab to connect the first and second end portions together to form a loop.

22. The assembly as recited in claim 1 wherein the fastening device is the only fastening device that engages the sleeve.