Patent Publication Number: US-2003235467-A1

Title: Adjustable manhole installation and method of adjustment

Description:
FIELD OF THE INVENTION  
       [0001] The present invention concerns a novel manhole installation that permits the easy adjustment of the relative height of the entrance to a manhole such that a manhole cover can be easily laid generally flush with the ground or the surface of a roadway. The present invention is generally directed towards new installations of manholes but can be easily adapted to be used with existing manhole installations.  
       BACKGROUND OF THE INVENTION  
       [0002] Access to subterranean conduits, such a storm sewers, sanitary sewers and others, is generally accomplished through manhole structures. Manhole structures are often found below roadways, as roadways generally correspond with municipal rights-of-way. The openings of such structures are, therefore, generally located on roadway surfaces.  
       [0003] Generally, manhole structures include a cast iron tube or a reinforced concrete cylindrical shell connecting a surface opening to a subterranean conduit. Additionally, a structure surrounding and supporting the connecting tube or cylinder is constructed to maintain an opening from the surface to the conduit despite movements and shifts (either due to surface pressures or tectonic forces) in the earth surface.  
       [0004] These manhole structures, therefore, are typically, imposing elements below the surface of the ground or roadway. The manhole structure is also constructed such that the load of vehicles, generally taken by the roadway, is supported by the manhole structure. As such, when new access to subterranean passageways is required, a new manhole installation is constructed, generally at great cost and effort. Further, because of their access at a road surface, when repairs to roads are required, existing manhole installations are often torn up and reconstructed. Such repairs and reconstructions can be very expensive and time consuming.  
       [0005] Further still, because of their location on roadway surfaces, the upper portion of the manhole structure must fit flush with the road surface so that vehicles are afforded a smooth ride. Because a manhole structure is not merely an opening in the roadway, but instead is often a complicated structure (as described above), adjusting the manhole entrance to be flush with the roadway surface, especially after road repair or resurfacing, can be difficult.  
       [0006] A device and method of using the device are discussed hereinafter that permit the surface level position of a manhole to be adjusted in response to surface level changes due to construction or reconstruction of roadways. Further, the device and method are an inexpensive, quick and easy way of repositioning an existing manhole entrance onto the surface of a roadway.  
       SUMMARY OF THE INVENTION  
       [0007] In accordance with the present invention, an adjustable manhole installation for use at and below the surface of the ground or a road surface is provided. The adjustable manhole installation comprises an inner generally tubular member having an exterior circumferential surface, and a first plurality of cooperative engagement elements spaced apart on that external circumferential surface and extending from and fixed on that exterior circumferential surface. Further, an outer generally tubular member, having an internal diameter greater than the overall diameter of the inner generally tubular member, such that the inner member fits concentrically within the outer member, is also provided. The outer tubular member defines an interior circumferential surface having a second plurality of complimentary cooperative engagement elements on its internal circumference.  
       [0008] In a preferred embodiment, the cooperative engagement elements are stair-shaped support members. The first plurality of stair-shaped support members are fixed on the external surface of the inner generally tubular member for cooperative engagement with the second plurality of stair-shaped elements on internal surface of the outer tubular member. The inner generally tubular member is then held concentrically within the outer generally tubular member by the engagement of the stair-shaped elements.  
       [0009] Further, the inner tubular member is subsequently adjustable, within the outer tubular member such that the inner member can be raised or lowered, within the outer member, relative to the ground or road surface, in graduated steps. By lifting the inner member, to a level equal to the height of a rise from one step to another in the stair-shaped structural element, and rotating the inner tubular member relative to the outer tubular member, the inner tubular member can be raised (by rotating one way) or lowered (by rotating the other way) relative to the ground surface  
       [0010] In a first embodiment, the height of adjustment is determinable by the height of the step risers in the stairs. Typically, the step height is determined by the thickness of road surfacing repair in a geographic area.  
       [0011] In another embodiment, the height-adjusting elements comprise rows of upwardly angled teeth-elements that interlock in the manner of gear teeth. Rotation of the inner tube member and engagement of teeth causes the inner member to be raised, or lowered, with respect to the outer tube member, and to the road surface.  
       [0012] In another embodiment, the height-adjusting elements comprise a series of block-shaped support elements, affixed to each tubular member, each block-shaped support element being set in a step pattern such that it resembles a stair. In this embodiment, the block height and placement is determined by the road surfacing repair practices in a geographic area. Such practices vary from one geographic area to another such that, for example, in colder climates thicker road surfaces may be used so as to prevent the formation of cold weather damage (such as those caused by freeze and thaw cycles) and in temperate climates, free of freeze and thaw cycles, thinner road surfaces may be used. In colder climate areas, therefore, the block heights can often be greater and in warmer climates, block heights can often be smaller.  
       [0013] The use of such blocks permits greater surface area for securing the support elements (such as by welding, adhesives or fasteners) to the tubular members. In this manner the support elements are strengthened, providing a stronger combination when the tubular elements are joined.  
       [0014] In another embodiment, the stair or block or tooth height-adjusting elements are cast into the tube members at the time of the casting of the tube members. In this embodiment, the thickness of the tube wall can be varied so as to form the stair elements. The height-adjusting elements being sculpted out of the thickness of the tubular member, thus provide a thickened and structurally stronger tube element with stronger height-adjusting members, that can be better capable of surviving sheering forces as a result of being formed integrally with the tube member.  
       [0015] In another embodiment, a series of concentric support ring segments, having spaced apart gaps, are provided on the interior surface of the inner tubular member and on the exterior surface of outer tubular member. The spaced apart gaps are of a length greater than or equal to the length of the ring segments, such that the ring segments of the inner tubular member can be raised or lowered through the ring gaps of the outer tubular member, the inner tubular member can then be rotated, such that its ring segments engage and bear on the ring segments of the outer tubular member thereby providing support for the inner tubular member.  
       [0016] In another embodiment, an existing manhole installation can be modified, to include some height-adjusting elements by, for example, welding such elements to the interior wall of an existing manhole installation, and inserting, into the existing manhole, a new tubular member element having cooperating height-adjusting elements. The combination can then be adjusted in the manner described above.  
       [0017] In all of the above examples, the support elements can define, on any one or more of the support element segments, an opening through which a bolt, cotter pin, key or other elongated element, can be inserted to lock one set of support elements of an inner tubular member to a support element of the outer tubular member.  
       [0018] A more detailed explanation of the invention is provided in the following description and claims and is illustrated in the accompanying drawings. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0019]FIG. 1 is a cut-away view of a typical manhole installation of the prior art.  
     [0020]FIG. 2 is an exploded cut-away view of a manhole installation of the present invention.  
     [0021]FIG. 3 is an exploded cut-away view of another embodiment of a manhole installation of the present invention.  
     [0022]FIG. 4 is an exploded cut-away view of still another embodiment of a manhole installation of the present invention.  
     [0023]FIG. 5 is an exploded cut-away view of another embodiment of the manhole invention of the present invention.  
     [0024]FIG. 6 is a perspective view of an embodiment of the manhole installation of FIG. 2, partially cut away to show a feature of the invention.  
     [0025]FIG. 7 is a perspective view of an embodiment of the manhole installation of FIG. 4, partially cut away to show a feature of the invention.  
     [0026]FIG. 8 is an exploded cut-away view of another embodiment of the manhole invention of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS  
     [0027] Although the present invention is susceptible of embodiment in various forms, there is shown in the drawings a number of presently preferred embodiments that are discussed in greater detail hereafter. It should be understood that the present disclosure is to be considered as an exemplification of the present invention, and is not intended to limit the invention to the specific embodiments illustrated. It should be further understood that the title of this section of this application (“Detailed Description of an Illustrative Embodiment”) relates to a requirement of the United States Patent Office, and should not be found to limit the subject matter disclosed herein.  
     [0028] Referring to the drawings, it can be seen that the present invention relates to openings permitting access to subterranean systems, such as sewers, drainpipes, deep tunnel systems, electrical installations and others. FIG. 1 shows a typical opening, known as a manhole installation  10 , giving access to a subterranean conduit  12 . The manhole installation  10  is generally comprised of a tubular member  14 , having a top rim  16  and an inner surface  18 . It can be seen that the surrounding area is comprised of the ground surface (or roadway)  2 , soil or roadway base  4 , concrete grouting  6  and a manhole casing  8 . It is to be understood that the subsurface installation shown in FIG. 1, and which forms the basis of FIGS. 2, 3,  4 ,  5  and  8 , is shown for illustrative purposes only and is not meant to be a limitation of the invention. The device of the present invention can be adapted and used in a number of different below surface installations without departing from the novel scope of the present invention.  
     [0029] Referring now to FIGS. 2, 3,  4 ,  5  and  8  manhole installations  20 ,  40 ,  60 ,  80  and  100  (respectively) of the present invention are shown. FIGS. 2, 3,  4 ,  5  and  8  further show, in phantom lines, a proposed new road way level  36 , which has been included to illustrate one of the reasons or uses for the device of the present invention. It can be seen, and will be understood as the present invention is disclosed, that the manhole installation  10  of the prior art can be interchanged, between the ground or road surface  2  and a subterranean conduit  22 , with a manhole installation of the present invention with very little modification.  
     [0030] Referring to FIG. 2, manhole installation  20  comprises a first tubular member  24 , having a top rim  26  and an inner surface  28 . Manhole installation  20  further comprises a second tubular member  30 , having a smaller diameter than the interior diameter of first tubular member  24 , and fitting concentrically within first tubular member  24 . Second tubular member  30 , further comprises an exterior surface  31  and a top rim  33 . A plurality of stair-shaped support elements  32  are provided on the inner surface  28  of first tubular member  24  and a second plurality of stair-shaped support elements  34  is provided on exterior surface  31  of second tubular member  30  for cooperation with the first plurality of stair shaped support member  32 .  
     [0031]FIG. 6 is a cut away view of a first tubular member  24  and a second tubular member  30  in an engaged position. As can be seen, the top rim  33  of second tubular member  30  is at new road surface  36 , whereas the top rim  26  of tubular member  24  is at the original road surface level  2 . It is to be understood, that although top rim  26  is shown at the original road level  2 , top rim  26  of the present invention can be located at any position below road level  36  without departing from the novel scope of the present invention. It is noted, that in the use of the present invention to make a modification of an existing manhole installation (as shown in FIG. 1, and described below), the existing manhole installation top rim can be at or above the original road level  2 .  
     [0032]FIG. 6, further, shows the interlacing of the stair-shaped support elements  32  and  34 , and the use of a locking bolt  35 , which can be inserted into any one or more openings (not shown) in run elements  32 R and  34 R. It is to be understood that different types of locking means can be used, including cotter pins, clamps, bolts, adhesives, and the like, that are preferably removable, without departing from the novel scope of the present invention. Further, locking means can also be used on adjacent riser elements of the stair supports of the present invention without departing from the novel scope of the present invention.  
     [0033] The use of locking nut  35 , or other locking means, provides an added means, besides the weight of the tubular members and any friction developed between the support elements, of maintaining the tubular manhole members locked together. The use of such locking means can help keep a second tubular member from sliding off of a first tubular member. Further, the use of such locking means can prove a deterrent to the theft of the second tubular member, particularly in situations, as explained below, where a smaller or lighter second tubular member is utilized.  
     [0034] In FIG. 3, manhole installation  40  comprises a first tubular member  44 , having a top rim  46  and an inner surface  48 . Manhole installation  40  further comprises a second tubular member  50 , having a smaller diameter than the interior diameter of first tubular member  44 , and fitting concentrically within first tubular member  44 . A plurality of stair-shaped (height-adjusting) support elements  52  is provided on the inner surface  48  of first tubular member  44  and a second plurality of stair-shaped (height-adjusting) support elements  54  is provided on the exterior surface  51  of second tubular member  50  for cooperation with the first plurality of stair shaped support member  52 . It can be seen, however, that second tubular member  50  of the present embodiment, is of a lesser overall length than second tubular member  30  shown in the previous embodiment.  
     [0035] As the proposed change in level in most street repairs amounts merely to generally no more than several inches, the device of the present embodiment of the invention is designed to span only slightly more than those several inches in increased relative height. It is to be understood that the size of the second tubular member can vary depending on need without departing from the novel scope of the present invention.  
     [0036] The stair-shaped support elements  34 ,  54  and support members  32 ,  52  can be made from any variety of members formed into stair-shaped elements and members, including thin flanged members formed of steel, plastic, concrete, iron or other resilient and strong materials that may be formed, molded or shaped into stair-shapes. It will be understood by persons having skill in the art that any material having desirable qualities can be used to form the stair-shaped elements and members without departing from the novel scope of the present invention.  
     [0037] In FIG. 4, manhole installation  60  comprises a first tubular member  64 , having a top rim  66  and an inner surface  68 . Manhole installation  60  further comprises a second tubular member  70 , having a smaller diameter than the interior diameter of first tubular member  64 , and fitting concentrically within first tubular member  64 . A plurality of height-adjusting block support elements  72 , arranged in a manner resembling a stair, are provided on the inner surface  68  of first tubular member  64  and a second plurality of block support elements  74 , cooperatively arranged in a stair-like shape, is provided on the exterior surface  71  of second tubular member  70  for interlocking cooperation with the first plurality of block support member  72 .  
     [0038] It can be seen in FIG. 4, that the overall length of second tubular member  70  is generally the same as that of second tubular member  30  of FIG. 2. However, it is to be understood that the overall length of second tubular member can be made to any desired length, as in second tubular member  50  of FIG. 3, without departing from the novel scope of the present invention.  
     [0039]FIG. 7 shows a cut away view of a first tubular member  64  and a second tubular member  70 , of FIG. 4, in an engaged position. As can be seen, the top rim  73  of second tubular member  70  is at new road surface  36 , whereas the top rim  66  of tubular member  64  is at the original road surface level  2 , in the manner described above, with respect to FIG. 6. FIG. 7, further, shows the interlocking of the block-shaped height-adjusting support elements  72  and  74 , and the use of a locking clamp  75 , which can be placed onto openings or indentations (not shown) in block elements  72 B and  74 B, so as to keep second tubular member  70  in place in manhole installation  60 .  
     [0040] In FIG. 5, manhole installation  80  comprises a first tubular member  84 , having a top rim  86  and an inner surface  88 . Manhole installation  80  further comprises a second tubular member  90 , having a smaller diameter than the interior diameter of first tubular member  84 , and fitting concentrically within first tubular member  84 . A series of platform support elements  92  is provided on both the inner surface of the first tubular member and on the outer surface of the second tubular member. Height-adjusting support elements  92  are comprised of concentric ring segments  94  having gaps  96  therein. The series of platform support elements  92  are cooperatively placed to engage each other, such that the ring segments  94  of one tubular member interlace with the ring segments  94  of the other. Interlacing of ring segments  94  is caused by rotation of second tubular member  90  such that the ring segments  94  of one tubular member are aligned with the gaps  96  of the other.  
     [0041] The second tubular member  90  can be lowered until a desired number of support elements  92  of both tubular members  84  and  90  are interlaced vertically. The second tubular member  90  can then be rotated to complete the interlacing of support members  92  and the locking of one tubular member with the other, at a desired level. It is preferred that in the present embodiment, supplemental locking means, such as bolt  35  of FIG. 6 or clamp  75  of FIG. 7, be utilized. Such locking means can provide additional restraint against unwanted rotation of the second tubular  90  member in relation to the first tubular member  84 .  
     [0042] Referring to FIG. 8, manhole installation  100  comprises a first tubular member  104 , having a top rim  106  and an inner surface  108 . Manhole installation  100  further comprises a second tubular member  110 , having a smaller diameter than the interior diameter of first tubular member  104 , and fitting concentrically within first tubular member  104 . Second tubular member  110 , further comprises an exterior surface  111  and a top rim  113 . A plurality of gear-teeth-shaped height-adjusting support elements  120  are provided on the inner surface  108  of first tubular member  104  and a second plurality of gear-teeth-shaped height-adjusting support elements  122  is provided on exterior surface  111  of second tubular member  110  for cooperation with the first plurality of gear-teeth-shaped support members  120 . It will be understood, by persons having skill in the art, that although the gear-teeth-shaped members  120 ,  122 , are shown as rows of gear teeth, any variety of tooth-shaped elements and cooperating tooth-shaped elements, having any number and size of “teeth”, can be used without departing from the novel scope of the present invention.  
     [0043] In the operation of a manhole structure of the present invention, referring to FIG. 2, first tubular member  24  is installed between ground level a subterranean pipe or other laterally situated opening or system  22  in a manner well known in the art. First tubular member  24  includes a first plurality of stair-shaped structural elements  32 , giving an appearance of a spiral stairs, on its interior face  28 . Second tubular member  30  is placed concentrically within first tubular member  24  and includes a plurality of complimentary second set of stair-shaped structural elements  34  for engagement with the first stair-shaped elements  32 .  
     [0044] Initially, first tubular member  24  and second tubular member  30  are adjusted, in the manner described above, so that top rim  33  of second tubular member  30  is at ground level  2 . When a change in ground surface level occurs, as a result of surface construction or repair, the second tubular member can be lifted, rotated and re-seated, such that the complementary stair-shaped structural elements  32  and  34  are re-engaged, and the top rim  33  of second tubular member  30  is set to the new surface level  36 .  
     [0045] In one embodiment of the present invention an existing manhole  10 , as shown in FIG. 1, can be modified to work with a device of the present invention. In such a modification, stair-shaped structural elements, such as those shown in FIGS. 2, 3, and  4 , are added to an existing manhole installation  10 , by bolting, welding or otherwise affixing the structural elements to the inner surface  18  of manhole installation  10 . It is to be understood that the device of the present invention can be adopted to existing manhole installations, which can have been constructed in shapes other than tubular. In such situations, provided that a segment near the top rim of the manhole opening has a circular cross-section stair-shaped structural elements, or at least one level of stair-shaped runners (similar to concentric rings  94  of FIG. 5), can be affixed thereto. Upon the attachment of such structural elements, a second tubular member (as shown in FIGS. 2, 3 and  4 ), having a smaller diameter than the existing manhole installation  10  and comprising cooperative stair-shaped support elements, can then be placed concentrically within the existing tubular member, and adjusted, as described above. In this manner, the existing manhole structure can be brought to a desired roadway or ground level. This embodiment of the present invention is useful in preserving current manhole installations and facilitating their continued use subsequent to surface construction and/or repair.  
     [0046] Further, modification of existing manhole installations can be accomplished using a second tubular member of smaller overall length, such as tubular member  50  of the embodiment shown in FIG. 3, thus preserving existing installations and saving materials and costs.  
     [0047] It is to be understood that modifications to existing manhole installations made of all types of materials, including reinforced concrete, cast iron, steel and others, can be made, by attaching stair-shaped support elements, or the like, using fasteners of various types known in the art, including bolts, adhesives and others, without departing from the novel scope of the present invention.  
     [0048] Although illustrative embodiments of the invention has been shown and described, it is to be understood that various modifications and substitutions can be made by those skilled in the art without departing from the novel spirit and scope of the invention.