Abstract:
A device for sealing the opening of a manhole. The device includes a seal coupled to a lid; a valve; and a compression inducing device. The lid is set within an existing manhole frame and operates without modification. The seal is coupled to a lower surface of the lid and contacts a lip within the frame. The seal is compressed to the lip and the compression inducing device is used to grip the frame below the lip to maintain the compressive state of the seal. The manhole cover is placed on top of the lid. Gases escape through the valve. Water or moisture is prevented from passing through the seal or valve. One or more grooves or ribs are optionally included to create a gap between the lid and the manhole cover for the routing of released gases.

Description:
BACKGROUND 
     1. Field of the Invention 
     The present application relates generally to sealing a manhole opening against ground water infiltration, and more particularly to an article to rest beneath the manhole cover in the existing opening. 
     2. Description of Related Art 
     In many urban areas, the growth and sprawl of towns and cities has decreased the amount of ground surface area which is available for absorbing moisture from rain and snow. Accordingly, this water must be drained off and disposed of through suitable means. In some instances where rainfall is minimal, it is possible to collect this water and dispose of it through the city sewer system. Sewer systems are constructed to accommodate a maximum level of influent to be expected at any one time. As long as the amount of water is minimal, conventional sewer systems may be able to process this without much risk. In areas where rainfall and snowfall is more extreme, conventional sewer systems are not capable of handling the runoff without a gross overdesigning of the system. 
     A basic fact is that rainfall disposed of through the sewer system has to be processed. Whether the sewer system is designed to accommodate runoff collection or not, the act of processing the runoff costs money. Where moisture is minimal, this cost is not significant. However, where moisture is more prevalent, this cost is non-trivial. Such costs can quickly rise and become a hindrance to city budgets. Therefore, costs associated with processing the moisture through a sewer system is not only costly at the time of building the system but also in the act of processing every gallon that passes through the system. Disadvantages of processing moisture through the sewer system include: higher costs, increased wear and tear on the system, and decreased efficiency to oversize the entire sewer system to accommodate rainfall and sewage. 
     Some towns or cities have developed a storm drain system to collect and route the moisture away through selected drain systems, away from sewer systems. These have done well but are not completely perfect. Localized flooding still occurs. Additionally, during rainy weather an average manhole in a sanitary sewer system can contribute from 3,000 to 12,000 gallons per day of rainwater to the sewer system for treatment. Although storm drain systems help, they are not enough to avoid the extra costs associated with processing runoff from moisture. 
     A device is needed that acts to seal or prevent the runoff from entering the manholes. Such a device would act to substantially reduce costs and wear to existing sewer treatment systems. A typical manhole includes a main chamber or barrel section to which the sewer pipes connect. That section is topped with a conical riser upward to a size needed to fit a metal frame for the manhole cover. The metal frame includes an internal lip to support the manhole cover. Water typically passes around the cover because the cover and frame are not sealed. 
     Many devices have been developed to try and seal manholes to prevent the undesired passing of storm water and other moisture. They can include dishes, bowls, and internally translating sealing sleeves to name a few. Such devices usually become quite complex and involve the reworking and construction of the manhole itself. Such work and cost, given the sheer number of manholes, is undesirable. 
     It is desirable to have a device that is configured to seal the opening of the manhole and operate with existing manhole frames to avoid the need to reconstruct the manhole assembly. Although some strides have been made, considerable shortcomings remain. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the application are set forth in the appended claims. However, the application itself, as well as a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a side view of a manhole cover sealing device according to the preferred embodiment of the present application; 
         FIG. 2  is a side view of the manhole cover sealing device of  FIG. 1  within a manhole; 
         FIG. 3  is a top view of the manhole cover sealing device of  FIG. 1 ; 
         FIG. 4  is a bottom view of the manhole cover sealing device of  FIG. 1 ; 
         FIG. 5  is a side view of an alternative embodiment of the manhole cover sealing device of  FIG. 1 ; 
         FIG. 6  is a side view of the manhole cover sealing device of  FIG. 5  within a manhole; 
         FIG. 7  is a top view of the manhole cover sealing device of  FIG. 5 ; and 
         FIG. 8  is a bottom view of the manhole cover sealing device of  FIG. 5 . 
     
    
    
     While the system and method of the present application is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the application to the particular embodiment disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the process of the present application as defined by the appended claims. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Illustrative embodiments of the preferred embodiment are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer&#39;s specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. 
     In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present application, the devices, members, apparatuses, etc. described herein may be positioned in any desired orientation. Thus, the use of terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the device described herein may be oriented in any desired direction. 
     The system in accordance with the present application overcomes one or more of the above-discussed problems commonly associated with conventional manhole covers. Specifically, the manhole cover sealing device of the present application is configured to be located between the manhole cover and the internal lip of the manhole frame. The device is configured to have a seal that seals along the lip around the full circumference of the lip. The device includes a valve to permit the escaping of gas from the sewer while preventing the passage of moisture into the sewer. Additionally, the device includes a plurality of compression inducing devices that extend into the throat of the manhole and act to initiate a compressive lock. This compressive lock secures device in place to ensure a compressed seal is maintained. This is important given the frequent miss-fitting nature of manhole covers in the frame wherein the cover rocks side to side or fails to actually provide a uniform seating along the lip. The compressive locking feature therefore maintains the seal in a compressed state independent of the fit and weight of the cover itself. These and other unique features of the device are discussed below and illustrated in the accompanying drawings. 
     The device and method will be understood, both as to its structure and operation, from the accompanying drawings, taken in conjunction with the accompanying description. Several embodiments of the system are presented herein. It should be understood that various components, parts, and features of the different embodiments may be combined together and/or interchanged with one another, all of which are within the scope of the present application, even though not all variations and particular embodiments are shown in the drawings. It should also be understood that the mixing and matching of features, elements, and/or functions between various embodiments is expressly contemplated herein so that one of ordinary skill in the art would appreciate from this disclosure that the features, elements, and/or functions of one embodiment may be incorporated into another embodiment as appropriate, unless otherwise described. 
     The manhole cover sealing device of the present application is illustrated in the associated drawings. The device includes seal and a plurality of compression inducing devices configured to maintain the seal in a compressed state. A one-way valve is also included to allow for the passage of sewage gas and restrict water entrance. 
     Referring now to the drawings wherein like reference characters identify corresponding or similar elements in form and function throughout the several views.  FIGS. 1-4  in the drawings illustrate manhole cover sealing device  101 . As stated previously, device  101  includes a seal  103 , a lid  105 , a valve  107 , and one or more compression inducing members  109 . Device  101  is configured to ideally operate within a manhole opening, however, it is understood that the functions and features of device  101  are not so limited. Device  101  may be used with any opening (i.e. a sleeve), whether of one or multiple internal diameters. Lid  105  may be compressed along the upper surface of an opening as opposed to an internal lip herein described. 
     As seen in  FIG. 2 , device  101  is shown in a manhole opening. A manhole opening is defined as the opening made for the acceptance of a conventional manhole cover  99 . It is typically relatively flush with street level and provides an access point for workers to enter the sewer system of a city. A frame  97  is defined in the street (or other surface location) to accept manhole cover  99 . An internal lip  95  is defined in the frame to prevent the falling of the manhole cover  99  through the opening. A throat area  93  of the frame  97  is the decreased diameter portion just below the lip  95  of the frame  97 . 
     As seen in  FIG. 1 , lid  105  is a relatively rigid member made from one or more materials and is configured to enter into the opening of frame  95 . Ideally, lid  105  is sized to be slightly smaller than the internal diameter of the opening. Lid  105  is constructed to support the weight of an individual standing at its center to prevent accidental injury from falling into the sewer. Seal  103  is configured to engage frame  97  and restrict passage of gases, solids, and liquids from passing through frame  97 . Seal  103  is coupled to a lower surface  111  of lid  104  and engages lip  95 . Seal  103  is operated by compressing lid  105  into lip  95 . As seen in  FIG. 2 , seal  103  is in a compressed state. Seal  103  is configured to be any type of flexible material that is resistant to absorption. Examples may include elastomeric materials, rubber, and so forth. Seal  103  is configured to wrap around the full circumference of lid  105  along lower surface  111 . 
     Valve  107  is coupled to lid  105  and is configured to restrict the passage of moisture through the manhole opening. One example of valve  107  is a one-way valve wherein it is designed to allow for gases within the sewer, below lid  105 , to pass upward and into the ambient air. This avoids dangers associated with potential build-up of methane and other gases in the sewer systems. However, as a one-way valve, valve  107  is configured to prevent the passage of moisture (i.e. water) back through lid  105  and into the sewer. Both seal  103  and valve  107  together operate to prevent the passage of moisture into the sewer. This has the advantage of minimizing the amount of water runoff or rain that enters the sewer system and therefore has to be processed and treated. 
     Device  101  further includes compression inducing device  109 . Device  109  is configured to locate lid  105  within frame  97  and to maintain seal  103  in a compressed state. Device  109  is composed of one or more members that act to engage and grip frame  97  in the throat area  93 , such that when lid  105  is pressed down into the manhole opening and against lip  95 , device  109  produces a sufficient outward force against throat  93  so as to maintain the relative compressive position of lid  105  within frame  97 . This position is independent of the placement of cover  99 . Device  101  does not rely upon the weight of cover  99  to compress seal  103 . 
     An example of compression inducing device  109  is that of a tang that is cantilevered from lower surface  111  of lid  105 . Tang  109   a  is configured to flex in relative position to that of lower surface  111 . Tang  109   a  includes a first surface  113 . When in a relaxed state, tang  109   a  is in a first position forming more of an acute angle relative to lower surface  111 . When installed in frame  97 , tang  109   a  flexes inward into a second position. The second position results in an increased angle relative to lower surface  111 . Additionally, the pressure or force to flex tang  109   a  is used to grip frame  97  and maintain the compressive state of seal  103 . Surface  113  is angled to allow tang  109   a  to flex inward as it contacts lip  95  when being installed. To remove device  101 , an upward force is applied to pull it out of frame  97 . 
     Referring in particular to  FIG. 3 , an optional groove  117  is formed into an upper surface  115  of lid  105 . Groove  117  is configured to provide a gap between the lid  105  and cover  99  to permit the escaping of gas through valve  107 . Depending on the design of cover  99 , additional space may be required to ensure exhausting gas has a route out of the volume of air defined by frame  97 . 
     Referring now also to  FIGS. 5-8  in the drawings, an alternative embodiment to device  101  is illustrated. Manhole cover sealing device  201  is similar in form and function to that of device  101  of  FIGS. 1-4 . Like reference characters identify corresponding or similar elements in form and function throughout the several views. The operation and function of the various features of device  201  are similar to that of device  101  except as noted herein. Device  201  is configured to use a different method of creating a gap of space between lid  105  and cover  99 . Device  201  uses a rib  119  to separate the bottom surface of cover  99  from upper surface  115  of lid  105 . The pattern of rib  119  may be varied for selected purposes. Additionally, the height can be chosen based upon design characteristics. Rib  119  is formed on upper surface  115  and configured to provide the gap between cover  99  and lid  105  to permit the escaping of gas through valve  107 . 
     In operation of either device  101  or device  201 , lid  105  is located relative to the frame of the manhole. The lid is rested within the frame adjacent lip  95 . Seal  103  contacts lip  95  around the full circumference of the frame. Pressure is applied to the top of lid  105  to compress seal  103 . Devices  109  are used to secure the lid in the compressed position by gripping the throat of the frame. The cover  99  is laid atop of lid  105 . Cover  99  may be laid atop before or after lid  105  is set and compressed. 
     Along with the spirit of the application, lid  105  may be applied to a hole or sleeve end wherein device  109  is used to grip the internal surfaces of the hole and the seal is applied to the outer upper surface of the hole. Interference fit is used to secure device  109  to the frame and/or surface of the hole. 
     The current application has many advantages over the prior art including at least the following: (1) water-tight seal around the fame of the manhole to prevent the passage of water into the sewer system; (2) a valve configured to permit the release of gas; (3) a compression inducing device configured to translate within the frame and maintain the compressed state of the seal; (4) simplistic operation and design; and (5) fits existing conventional manholes negating the need to reconstruct the manhole to use. 
     The particular embodiments disclosed above are illustrative only, as the application may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. It is therefore evident that the particular embodiments disclosed above may be altered or modified, and all such variations are considered within the scope and spirit of the application. Accordingly, the protection sought herein is as set forth in the description. It is apparent that an application with significant advantages has been described and illustrated. Although the present application is shown in a limited number of forms, it is not limited to just these forms, but is amenable to various changes and modifications without departing from the spirit thereof.