Patent Application
20140250794
The present invention relates to a floating manhole frame assembly, and more particularly to a manhole frame assembly configured to move as the surrounding environment moves.
Manhole frame assemblies are well known. Generally, a manhole frame assembly covers an opening providing access to an underground area also known as a manhole that may include utilities, pipes, cables and passages. The manhole frame assembly may be fitted with a cover to, among other things, prevent someone from falling in and to keep unauthorized persons out. Conventional manhole frame assemblies include a frame capable of receiving a cover that limits access to the manhole. The cover is a removable plate forming the lid over an opening in the frame through which the underground area may be accessed. The manhole cover seats on the frame, sometimes flush with the surface of a road. And, the frame, often times, is secured to the underground area or surrounding structure, such as a concrete or asphalt concrete road surface, so that the manhole cover may be removed for access while the frame remains in place.
In many instances, the surrounding structure, including the ground, may shift or move after the manhole frame assembly has been installed. Thus, even if the manhole frame assembly, when fitted with a cover, is installed flush with the surrounding surface (e.g., the road surface), shifts in the surrounding structure may result in an uneven surface. For example, once such a shift occurs, portions of the manhole frame assembly may project significantly above or below the surrounding surface. There are a variety of events capable of causing shifts in the surrounding structure. One event, common to the climate of the Midwestern U.S., is freezing and thawing. As the ground freezes and thaws, the ground may shift resulting in movement in the roadway or the underground area. The surrounding surface or roadway, itself, may also shift when frozen and thawed. Another event, soil erosion, may cause movement in the surrounding structure as well. These are just two example events; there are many other events that may result in movement of surrounding structure or the ground in proximity to the manhole frame assembly.
As mentioned previously, many conventional manhole frame assemblies are unable to move in harmony with the ground or the surrounding structure. This inability to move is a common drawback of conventional manhole cover assemblies because it can result in a rough road surface or an abrupt transition between the surrounding surface and the manhole frame assembly. Uneven features in the roadway may increase wear on any vehicles traveling over the roadway. Smooth transitions on the road surface, on the other hand, may help to minimize wear on vehicles that travel over the manhole frame assembly.
The present invention provides a manhole frame assembly configured to seat about an opening of an underground area, and to be installed adjacent a surrounding structure. The manhole frame assembly may include a lower frame having a lower peripheral wall and a base, the base adapted to be fastened in place on the opening. The manhole frame assembly may also include an upper frame adapted to move with respect to the lower frame. Movement of the upper frame may occur in response to movements in the surrounding structure. In addition to or alternatively, movement of the upper frame may be conducted during installation to substantially match the upper frame height to the surface of the surrounding structure. By being capable of movement, the upper frame may provide a smooth transition between the surrounding surface and the manhole frame assembly.
The manhole frame assembly may also include a sleeve encircling at least part of the lower frame and capable of encircling at least part of the upper frame. The sleeve may prevent the surrounding structure from binding overlapping portions of the upper and lower frames so that the upper frame is capable of floating. And, the sleeve may be rigid such that it resists deflection in response to loading from the surrounding structure.
In one embodiment, the sleeve has a perimeter defining a gap between the sleeve and the lower peripheral wall, where the upper peripheral wall of the upper frame may fit within the gap. With this configuration, for example, portions of the upper frame may slide between the sleeve and the lower frame. The upper frame may displace vertically with respect to the lower frame, thereby extending and contracting within the gap. The upper frame may also tilt with respect to the lower frame. Because the upper frame may tilt, extend, and contract, the upper frame may float to maintain smooth transitions between a surface of the surrounding structure and the manhole frame assembly.
The gap formed by the sleeve may prevent the surrounding structure from binding the upper frame to the lower frame. For example, without the sleeve, the surrounding structure may sufficiently load the upper frame against the lower frame such that the upper frame is prevented from floating as intended. The sleeve may prevent such loading of the upper frame.
In one embodiment, the upper frame may include a projection extending from the upper peripheral wall that links with the surrounding structure. This link may enable movement in the surrounding structure to be translated to the upper frame, thereby resulting in the upper frame floating with respect to the lower frame to maintain appreciably smooth transitions between the surface of the surrounding structure and the frame assembly.
The present invention provides an effective manhole frame assembly that enables part of the frame assembly to move in response to movement in the surrounding structure. In this way, the manhole frame assembly may mitigate against abrupt transitions between the surface of the surrounding structure and the manhole frame assembly. These and other objects, advantages, and features of the present invention will be more fully understood and appreciated by reference to the description of the current embodiment and the drawings.
Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited to the details of operation or to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention may be implemented in various other embodiments and capable of being practiced or being carried out in alternative ways not expressly disclosed herein. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Further, enumeration may be used in the description of various embodiments. Unless otherwise expressly stated, the use of enumeration should not be construed as limiting the invention to any specific order or number of components. Nor should the use of enumeration be construed as excluding from the scope of the invention any additional steps or components that might be combined with or into the enumerated steps or components.
A manhole frame assembly according to one embodiment of the present invention is shown in
The described embodiment may be used as a manhole frame assembly 8 to cover an access opening 15 of an underground area and to provide access to an infrastructure, such as a drainage or sewer infrastructure system, underneath the opening. Although the manhole frame assembly 8 may be installed over any suitable hole, it will often be installed over a manhole in a street or sidewalk. As noted above, the manhole frame assembly 8 according to the current embodiment includes an upper frame 10, a lower frame 12, and a sleeve 14.
In the illustrated embodiments of
For purposes of disclosure, the described frame assembly 8 is annular and may be installed over an underground area, but it should be appreciated that the frame assembly 8 may be any shape, including for example rectangular or square. The upper frame 10 and lower frame 12 are constructed of cast iron in the current embodiment. However, that these components may be constructed of suitable materials other than iron or metal, and manufactured using established methods of manufacture other than casting. The sleeve 14 in the current embodiment is constructed of steel, but as with the upper frame 10 and lower frame 12, may be manufacture and constructed of other suitable materials.
The lower frame 12 in the current embodiment may also include one or more flanges 44 capable of coupling to an adjusting bolt 46 and a bracket 48. The flanges 44 may include a cast-in nut or may be drilled and tapped to receive the adjusting bolt 46. In this way, the height of the brackets 48 may be adjusted with respect to the lower frame 12 by turning the adjusting bolt 46. The brackets 48 in the current embodiment are capable of interfacing with and supporting the upper frame 10 at a desired height with respect to the lower frame 12. The brackets 48 and adjusting bolts 46 in practice are not permanent; rather, they allow the upper frame 10 and lower frame 12 to be positioned for installation. For example, because the thickness of the surrounding structure may be different from one installation site to another, enabling the upper frame 10 to move relative to the lower frame 12 allows the upper frame 10 to be installed such that a relatively smooth transition occurs between the surface of the surrounding structure and the frame assembly 8. Once the frame assembly 8 has been installed and the surrounding structure, such as concrete, has cured, the brackets 48 and adjusting bolts 46 may be removed.
In the current embodiment, the base 34 of lower frame 12 may be fastened to an upper portion of the underground area, often times referred to as a chimney (not shown). The lower frame 12 may be fastened to the chimney using anchor bolts or angled anchor rods fastened to either the chimney or the surrounding structure, such as the road. To mitigate against leaks in the joint between the chimney and the base 34, a seal (not shown) may be installed near the periphery of the joint, or disposed between (a) the chimney and base 34 and (b) the surrounding structure, or between the chimney and the base 34.
Turning now to the construction of the upper frame 10 according to the current embodiment, the upper frame 10, like the lower frame 12, includes an upper frame peripheral wall 50 having an inner surface 54 and an outer surface 52. The upper frame 10 may also include a top edge 58 and a cover receiving support 56 configured as a flange on the inner surface 54. The cover receiving support 56 supports the manhole cover (not shown) in a seated position. The construction of the top edge 58, inner surface 54, and cover receiving support 56 may be constructed to interface with the cover to cover the access opening 15. Although not shown, a gasket such as a neoprene gasket may be disposed between the cover and the cover receiving support 56, thereby potentially preventing debris from entering the access opening 15. The cover receiving support 56 may also interface with the brackets 48, as shown in
In an alternative embodiment, a supporting surface other than the cover receiving support 56 may support the manhole cover in a seated position to cover the access opening 15. For example, the cover may seat on the top edge 58 of the upper frame 10.
In the illustrated embodiment of
For example, as shown in the illustrated embodiment of
In addition to being capable of tilting, the upper frame 10 may displace vertically with respect to the upper surface of the lower frame 12. For example, as shown in the illustrated embodiment of
By enabling the upper frame 10 to both tilt and displace vertically, the frame assembly 8 may enable the upper frame 10 to move or float along with the surrounding structure, an effect that is sometimes referred to as self-leveling. Self-leveling of the frame assembly 8 may mitigate against abrupt transitions between the surface of the surrounding structure and the frame assembly 8. This self-leveling capability may be maintained through the use of a sleeve 14 around periphery portions of the upper frame 10 and the lower frame 12.
The sleeve 14, shown in the illustrated embodiments of
As shown in the illustrated embodiment of
Directional terms, such as “vertical,” “horizontal,” “top,” “bottom,” “upper,” “lower,” “inner,” “inwardly,” “outer” and “outwardly,” are used to assist in describing the invention based on the orientation of the embodiments shown in the illustrations. The use of directional terms should not be interpreted to limit the invention to any specific orientation(s).
The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.
