Abstract:
A manhole cover adapter system comprises an adapter assembly having a central passage and a wing structure which enables the system is to be embedded between pavement layers during installation. The manhole cover adapter further comprises an expansion joint assembly and, if required, an angular adjustment assembly for allowing uses in various construction scenarios upon various types of manholes.

Description:
RELATED APPLICATIONS 
     There are no current co-pending applications. 
     FIELD OF THE INVENTION 
     The presently disclosed subject matter is directed toward manholes. More particularly the present invention relates to manhole cover adapters for installing manholes and manhole covers in a variety of different construction scenarios. 
     BACKGROUND OF THE INVENTION 
     Almost every city has three (3) active levels. The two (2) most often viewed are the street level with its road, signs, and poles, and the upper level with its buildings, towers, and various superstructures. There is however a mostly hidden level, the subsurface level where subways, sewers, and underground utilities such as water, electrical power, communication lines, and the like reside. The number of structures and their scope in the subsurface level would likely be surprising to many. 
     Access to the subsurface level is usually by way of manholes that are located on paved surfaces such as roadways and parking lots. Such manholes provide ready access to underground features such as water, sewer, electrical power, communication lines, and the like to authorized personnel while restricting access to others. In addition, manholes and their covers provide safety to those operating on the street level. The weight of cars and trucks can easily be handled by a properly installed manhole and its manhole cover. Finally, manholes and their covers provide these features in a manner that is minimally disruptive to overall visual appearances. 
     In practice, manhole covers are usually located in frames that are set flush with a paved surface, such as a street or parking lot. This is beneficial in that the passage of vehicles, people, and the like can occur safely and with minimal intrusions. However, when such surfaces are repaved it is nearly impossible to adjust the height of the manhole cover frame to match the repaving. Drivers and pedestrians must then deal with sunken manhole covers. About the only practical alternative is a complete manhole cover frame overhaul, which can be very costly and time-consuming. 
     Accordingly, there exists a need for means by which manholes, their frames, and their covers can be easily adjusted in height to accommodate repaving activities or other actions which cause manholes to be improperly located. 
     SUMMARY OF THE INVENTION 
     The principles of the present invention provide a means by which manholes, their frames, and their covers can be easily adjusted in height to accommodate repaving activities or other actions which cause manholes to be improperly located. 
     A manhole cover adapter that is in accord with the present invention includes an adapter assembly having a cylinder with a center opening, an outward protruding rim, and a flat topped expansion joint housing located below the rim. The expansion joint housing has an inverted “U”-shape cross-section. The manhole cover adapter further includes a wing assembly having a plurality of arms that are attached at one (1) end to the top of the expansion joint housing and outer ends that are attached to a ring. An extending metal mesh is located over the wing assembly. The manhole cover adapter further includes an expansion joint having an inverted “T”-shaped cross-section with a leg that fits into the “U”-shape cross-section. The cylinder is dimensioned to support a manhole cover. 
     The expansion joint is dimensioned to provide gaps between its vertical surfaces and the expansion joint housing. A dust boot prevents debris from entering the “U”-shape cross-section. Beneficially a flexible rubber pad is disposed between the expansion joint housing and the expansion joint. The rubber pad may be secured to the expansion joint housing using a fastener that passes through a pad aperture. 
     Preferably the expanded metal layer and the arms are welded to the wing assembly, which maybe circular. In practice the expansion joint housing is beneficially approximately three inches (3 in.) beneath the rim, while the adapter assembly is comprised of a cast metal. If needed an angular adjustment assembly may be placed below the expansion joint. The angular adjustment assembly is beneficially attached to the expansion joint using fasteners and “L”-shaped brackets. If used, the angular adjustment assembly can be attached to an existing manhole structure using “L”-shaped brackets. If the angular adjustment assembly is not used the expansion joint housing may be attached an existing manhole structure using “L”-shaped brackets. 
     To improve stability at least one (1) brace member can extend between an arm and the expansion joint housing. The at least one (1) brace member may include a second bracket for holding the arm and/or have third bracket attached to the expansion joint housing. 
     An alternative manhole cover adapter includes an adapter assembly having a center opening that is dimensioned to fit around an existing cylinder. The adapter assembly includes an outward protruding rim and a flat topped expansion joint housing that is located below the rim. The expansion joint housing includes an outwardly protruding, inverted “U”-shape cross-section. The alternate embodiment further includes a wing assembly having a plurality of arms with inner ends attached to the top and outer ends attached to a ring. An extending metal mesh covers the wing assembly and an expansion joint having an inverted “T”-shaped cross-section with a leg that fits into the “U”-shape cross-section. Beneficially the alternative manhole cover adapter includes apertures through the joint housing to enable bolting to the existing cylinder. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
         FIG. 1  is a top perspective view of a manhole cover adapter  10  that is in accord with a preferred embodiment of the present invention; 
         FIG. 2  is a bottom perspective view of the manhole cover adapter  10  shown in  FIG. 1 ; 
         FIG. 3  is an exploded view of the manhole cover adapter  10  shown in  FIGS. 1 and 2 ; 
         FIG. 4   a  is a section view of the manhole cover adapter  10  shown in  FIGS. 1-3 ; 
         FIG. 4   b  is a close-up section view of the manhole cover adapter  10  shown in  FIGS. 1-4   a  depicting use on a height adjustment ring  90 ; 
         FIG. 5  is a section view of an alternate installation for the manhole cover adapter  10 ; and, 
         FIG. 6  is a close-up section view of an alternate embodiment  220  of the present invention. 
     
    
    
     DESCRIPTIVE KEY 
     
         
         
           
               10  manhole cover adapter 
               20  adapter assembly 
               22  cylinder 
               23  first center opening 
               24  rim feature 
               25  dust boot 
               26  first expansion joint housing 
               28  first bracket 
               40  wing assembly 
               42  ring member 
               44  arm member 
               46  brace member 
               47  second bracket 
               48  third bracket 
               50  expanded metal layer 
               60  expansion joint 
               61  mounting plate 
               62  support block 
               64  pad 
               65  pad aperture 
               66  pad fastener 
               80  fastening means 
               90  angular adjustment assembly 
               92  upper section 
               94  lower section 
               96  joining ring structure 
               97  second center opening 
               98  fourth bracket 
               150  first existing manhole structure 
               160  second existing manhole structure 
               165  existing grade ring 
               200  first pavement layer 
               210  second pavement layer 
               215  manhole cover 
               220  alternate embodiment 
               222  existing cylinder 
               224  second expansion joint housing 
               240  alternate wing assembly 
               244  alternate arm member 
               248  alternate third bracket 
           
         
       
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within  FIGS. 1 through 4   b , an alternate installation of that embodiment is shown in  FIG. 5 , and an alternate embodiment is shown in  FIG. 6 . However, the invention is not limited to the described embodiment, and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. 
       FIGS. 1 ,  2 , and  3  respectively present top, bottom, and exploded views of a manhole cover adapter  10  which is in accord with a preferred embodiment of the present invention. The manhole cover adapter  10  provides a manhole cover frame system having an inner adapter assembly  20  that supports a manhole cover  215  over re-paved or other road work. The manhole cover adapter  10  further includes a wing assembly  40  attached to the adapter assembly  20  and extending metal mesh  50  over the wing assembly  40 . The extending metal mesh  50  and the wing assembly  40  are configured to be positioned between first  200  and second  210  pavement layers during a construction project (see  FIGS. 4   a  and  4   b ). The manhole cover adapter  10  also incorporates an expansion joint  60 , and possibly an angular adjustment assembly  90 , both of which are described in more detail subsequently. 
     The adapter assembly  20  (illustrated in all FIGS.) is beneficially comprised of steel bar stock. It includes a cylinder  22  having a circularly-shaped first center opening  23  and an outwardly protruding rim  24  (see  FIGS. 1 and 3 ) along its top edge. This circular form is well-suited for use with round manhole covers  215 . However, it should be understood that other shapes may be used to support other shapes of manhole covers, such as rectangular. Thus the circular nature of the adapter assembly is not necessarily a factor of the manhole cover adapter  10 . 
     The rim  24  preferably has an inverted “L”-shape with one leg protruding outward from the upper edge of the cylinder  22 . This helps anchor and stabilize the manhole cover adapter  10  when placed on a second pavement layer  210  (see  FIGS. 4   a  and  4   b ). The cylinder  22  also includes an integral, external first expansion joint housing  26 . The first expansion joint housing  26  includes an inverted “U”-shaped cross-section which protrudes outward and down from the main body of the cylinder  22 . The inverted “U”-shaped cross-section is configured to receive the expansion joint  60  (as described in more detail subsequently, but see  FIGS. 4   a  and  4   b ). The first expansion joint housing  26  has a flat top surface over the inverted “U”-shaped cross-section. 
     The wing assembly  40  includes a plurality of equally spaced, radially extending arms  44  having inner ends that attach to the first expansion joint housing  26  via a plurality of fasteners  80 , such as bolts (again, see  FIGS. 4   a  and  4   b ). The outer ends of the extending arms  44  are welded to an outer ring  42 . In addition, the wing assembly  40  includes a plurality of brace members  46  that are disposed between the arms  44  near the ring  42  and the first expansion joint housing  26 . The arms  44  are held within a second bracket  47  of the end brace members  45 , while the brace members  46  also include a third bracket  48  for attaching the brace members  46  to the first expansion joint housing  26 . The brace members  46  provide height adjustment and support for the wing assembly  40 . The wing assembly  40  is thus a generally circularly shaped, well supported structure (but the shape may change depending on the specific application). 
     The wing assembly  40  and the first expansion joint housing  26  are configured to be positioned approximately three inches (3 in.) beneath the top of the rim  24  and with the inner ends of the arms  44  resting on the flat top of the first expansion joint housing  26 . When the manhole cover adapter  10  is installed the wing assembly  40  is beneficially embedded into position between the first pavement layer  200  and the second pavement layer  210  (see  FIGS. 4   a  and  4   b ). In practice the wing assembly  40  is preferably comprised of steel bar stock. 
     Referring now primarily to  FIGS. 4   a  and  4   b , section views of the manhole cover adapter  10 , the expansion joint  60  provides vertical load-bearing as well as compliant relative lateral motion between the remainder of the manhole cover adapter  10  and an existing subjacent manhole structure  150 . The vertical loading and lateral motion results from forces applied by traffic, as well as normally occurring thermal expansion and contraction. 
     The expansion joint  60  is a circular metal structure having an inverted “T”-shaped cross-section. That cross-section is configured such that the leg of the inverted “T” fits into the inverted “U” of the expansion joint housing  26 . The expansion joint  60  “T” shape is formed by a rectangular cross-sectioned upper support block  62  and an integral bottom mounting plate  61 . The upper support block  62  fits within the inverted “U” of the first expansion joint housing  26 . A flexible rubber pad  64  is beneficially positioned between the expansion joint  60  and the first expansion joint housing  26 . The rubber pad  64  assists in providing a compliant vertical load support. 
     The rubber pad  64  is a “donut-shaped,” compressible and flexible rubber ring with a rectangular cross-section. The pad  64  is dimensioned to cover the entire top of the support block  62  where it is secured via a plurality of fasteners  80 . The pad  64  includes recessed hemispherical pad apertures  65  that contain recessed the heads of the fasteners  80 . The fasteners  80  and pad apertures  65  are beneficially arranged in an equally-spaced circular pattern around the pad  64 . 
     As previously noted, in addition to supporting a vertical load the expansion joint  60  supports compliant lateral motion between the manhole cover adapter  10  and a subjacent first existing manhole structure  150 . To that end the support block  62  is dimensioned to form a gap between its vertical inner and outer side surfaces and the encompassing first expansion joint housing  26 . This allows limited lateral motion due to side-loading and thermal expansion and contraction. Additionally, the expansion joint  60  includes a rubber dust boot  25  which is affixed to the expansion joint  60  by a plurality of fasteners  80 . The dust boot  25  prevents debris from entering the interior of the first expansion joint housing  26  which might affect the expansion joint  60  functions. 
     The expansion joint  60  optionally attaches to an angular adjustment assembly  90 . The angular adjustment assembly  90  is envisioned as being similar to units protected under U.S. Pat. No. 5,564,855 (Anderson), and others. As such it has a cylindrical upper section  92 , a mating cylindrical lower section  94 , a joining ring structure  96 , and a second center opening  97  which matches the first center opening  23  of the adapter assembly  20 . When used in conjunction with the previously described portions of the manhole cover adapter  10  the angular adjustment assembly  90  supports tilting of the adapter assembly  20  and the expansion joint  60  via relative motion of the upper  92  and lower  94  sections. This beneficially enables the manhole cover adapter  10  to compensate for the slope of the pavement  210 . 
     The angular adjustment assembly  90  attaches at the bottom of the mounting plate  61  of the expansion joint  60  using a plurality of equally-spaced fasteners  80  and “L”-shaped first brackets  28 . The “L”-shaped first brackets  28  are attached along the inner vertical sides of the second center opening  97  and the bottom mounting plate  61  using the fasteners  80 . The bottom of the angular adjustment assembly  90  is beneficially fastened to a first existing manhole structure  150 , shown as a cone-shaped manhole structure. This is accomplished using a plurality of equally-spaced “L”-shaped second brackets  98  which are affixed inside the first existing manhole structure  150  using fasteners  80  to clamp the lower parts of the angular adjustment assembly  90 . 
       FIG. 5  is a section view of an alternate installation of the manhole cover adapter  10  depicting installation upon a second existing manhole structure  160 . In addition to the previously described preferred embodiment, the manhole cover adapter  10  may be reconfigured and applied to various manhole structures such as a conventional “flat-top” manhole having an existing concrete grade ring  165  assembly. This construction scenario is especially useful when used in conjunction with a level pavement installation since the angular adjustment assembly  90  is not required. This can reduce cost. Furthermore, it is understood that the teachings of the manhole cover adapter  10  may be utilized for use with various other manhole structures with equal benefit, and as such should not be interpreted as a limiting factor of the manhole cover adapter  10 . 
       FIG. 6  presents a close-up section view of an alternate embodiment  220  manhole adaptor. The alternate embodiment  220  installs a second expansion joint housing  224  and an alternate wing assembly  240  onto an existing manhole cover cylinder  222 . The existing cylinder  222  is first bolted to the second expansion joint housing  224  using a plurality of fasteners  80 . The alternate wing assembly  240  is then bolted to the outside of the existing cylinder  222 . Then the second pavement layer  210  is poured. 
     The alternate wing assembly  240  provides similar construction and function as the previously described preferred wing assembly  40 . However, the alternate wing assembly  240  supports adjustable positioning of the alternate wing assembly  240  based on the height of the existing cylinder  222 . The alternate embodiment  220  includes a plurality of alternate arm members  244  that respectively have alternate third brackets  248  that are welded to the ends of the side of the existing cylinder  22 . The alternate arms are fastened to the alternate embodiment  220  using fasteners  80 . Angular adjustment of the brace members  46  provides height adjustment and support of the alternate wing assembly  240  given different height existing cylinders  222 . 
     It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention. While only three particular configurations have been shown and described, that is for purposes of clarity and disclosure and not limitation of scope. 
     The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. After initial purchase or acquisition of the manhole cover adapter  10 , it would be installed as indicated in  FIG. 4   a.    
     The method of installing and utilizing the preferred embodiment of the manhole cover adapter  10  may be achieved by: procuring the manhole cover adapter  10 ; detaching and removing upper portions of the wing assembly  40 , including the ring  42 , the arms  44 , and the expanded metal layer  50 , from the brace members  46  by removing the respective fasteners  80 ; assembling the adapter assembly  20 , expansion joint  60 , and angular adjustment assembly  90  together, if not previously assembled; placing the assembly onto the top of the first existing manhole structure  150 ; loosening the fasteners  80  of the joining ring structure  96  and rotating the upper section  92  with respect to the lower section  94  until obtaining a desired angle and orientation of the manhole cover adapter  10  which corresponds to that of an anticipated slope of the pavement surface  210 ; securing the angle of the angular adjustment assembly  90  by tightening fasteners  80  of the joining ring structure  96 ; anchoring the angular adjustment assembly  90  to the first existing manhole structure  150  by installing the first brackets  28  and respective fasteners  80  along the second inner opening  97  of the angular adjustment assembly  90 ; adding foundational road materials around the first existing manhole structure  150 ; applying the first pavement layer  200 ; replacing and fastening the previously removed portions  42 ,  44 ,  50  of the wing assembly  40  to the brace members  46  using the fastening means  80 ; embedding the wing assembly  40  within the pavement by applying the second pavement layer  210  up to a level of the rim feature  24  of the adapter assembly  20 ; installing an appropriately sized manhole cover  215  onto the manhole cover adapter  10 ; and, benefiting from the combined stabilizing and angularly-adjustable features afforded a user of the manhole cover adapter  10 . 
     The method of installing and using the manhole cover adapter  10 , in conjunction with a level pavement scenario, such as upon a second existing manhole structure  160  having an existing grade ring  165  may be achieved in like manner as the preferred installation method; however, without inclusion of the angular adjustment assembly  90 . 
     The method of installing and utilizing the alternate embodiment of the system  220  may be achieved by performing the following additional steps: procuring the alternate embodiment  220 ; detaching and removing the alternate wing assembly  240 , if not previously removed; attaching the existing cylinder  222  to the top of the second expansion joint housing  224  using the fasteners  80 ; installing the brace member  46 , second bracket  47 , and third bracket  48  to the side of the second expansion joint housing  224 ; adjusting and tightening the brace member  46 , second bracket  47 , and third bracket  48  at a desired angle so as to result in correct positioning of the alternate wing assembly  240 ; applying the first pavement layer  200 ; replacing and fastening the previously removed alternate wing assembly  240  to the second brackets  47  using the fasteners  80 ; attaching the alternate third brackets  248  to the existing cylinder  222  using fasteners  80 ; applying the second pavement layer  210  up to a desired level embedding the alternate wing assembly  240  and a desired portion of the existing cylinder  222  into the pavement; and, installing an appropriately sized manhole cover  215  onto the existing cylinder  222 . 
     The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.