Abstract:
An apparatus that automatically levels a manhole upon placement of the manhole in the road. The preferred embodiment includes a support beam, two clamping units and two carrying handles. The clamping units contact the top of the manhole and clamp the manhole to the bottom of the support beam. The carrying handles assist in placing the manhole in the road and aligning the support beam on top of the road. The road surface forces the bottom of the support beam to align with the road. Since the top of the manhole is clamped to the bottom of the support beam, the manhole is also forced to align with the new road surface. The present manhole leveler works on roads with steep inclines and banking.

Description:
[0001]    The subject matter disclosed herein was originally disclosed in U.S. provisional patent application No. 60/926,495 filed on Apr. 27, 2007 and priority is claimed to the provisional application. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates generally to the field of road resurfacing and more specifically to a device for replacing and automatically leveling manholes. 
         [0003]    Most people are familiar with manhole covers, which dot the roadways and sidewalks of urban areas. However, they may be unaware that below each manhole cover is a preformed manhole structure that provides a connection to the sewer or other conduit below. When a road is re-paved, the height of the road is raised due to the addition of new asphalt or concrete. This increased height leaves manhole covers sunk below the level of the new road. In the past, the manhole would be removed and ring structures would be added under the manhole, until the top of the manhole reached the level of the new road. This method works well with roads that are flat and level. However, when the road was banked or had an inclining grade, using the ring structures made it extremely difficult, if not impossible to level the manhole cover with the sloping road. 
         [0004]    What is needed in the field is a device that can hold a manhole in place during replacement and allow the contour of the road to aid in leveling the manhole with the surface of a new road. 
       SUMMARY OF THE INVENTION 
       [0005]    An apparatus that is adapted for attachment to a manhole, wherein the apparatus is used to remove the manhole from a road during resurfacing, and to replace the manhole back into the road after resurfacing. The present manhole leveler provides for automatic leveling of the manhole with the road upon placement of the manhole in the road. The apparatus comprises a support beam and two clamping units. The support beam has a top and a bottom, and the support beam is capable of supporting the weight of the manhole. The first clamping unit is slideably attached to the support beam. The first clamping unit includes an attachment unit that is adapted to contact a first portion of the manhole. The first clamping unit is able to clamp the first portion of the manhole between the attachment unit and the bottom of the support beam. The second clamping unit is also slide-ably attached to the support beam. The second clamping unit includes a second attachment unit that is adapted to contact a second portion of the manhole. The second clamping unit is able to clamp the second portion of the manhole between the second attachment unit and the bottom of the support beam. 
         [0006]    The manhole leveler further comprises two carrying handles. The first carrying handle is attached to the top of the support beam at one end of the beam. The second carrying handle is attached to the top of the support beam at the opposite end of the beam. In the preferred embodiment, the attachment unit in each clamping unit comprises a curved prong that is complementary in shape and size to an outside of the manhole. Further, the attachment unit is release-ably attached the first clamping unit, and the second attachment unit is release-ably attached to the second clamping unit. 
         [0007]    Each clamping unit in the manhole leveler includes a screw handle that operates a specialized vice that allows a lip or edge of the manhole to be clamped between the attachment unit and the bottom of the support beam. Each clamping unit further includes a tubular housing through which the support beam passes, and that allows the clamping units to slide along the length of the beam. The housing also allows the specialized vice to be operated from two different locations. The clamping units are preferably made of metal, and the support beam is preferably made of aluminum. 
         [0008]    It is an object of the present invention to provide an apparatus that makes the job of leveling a manhole with the surface of a new road easy. 
         [0009]    If is another object of the present invention to provide a manhole leveler that is easy to produce and easy to use. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The invention of the present application will be described in detail with reference to the accompanying drawing(s), given only by way of example, in which: 
           [0011]      FIG. 1  is a frontal view of a clamping unit in the preferred embodiment; 
           [0012]      FIG. 2  shows a side view of the preferred clamping unit; 
           [0013]      FIG. 3  is a side view of the preferred embodiment of the present manhole leveler; and, 
           [0014]      FIG. 4  is a bottom view of the lower portion of the preferred clamping unit. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]      FIG. 1  is a frontal view of a clamping unit  100  that is an integral part of the preferred embodiment of the present Manhole Leveler. The present apparatus can be used to lift a manhole out of a road, in order to resurface the road, and replace the manhole in the road after resurfacing has been completed. The clamping unit  100  shown in  FIG. 1  is used to clamp one side of the manhole, and the preferred embodiment includes a second clamping unit that clamps on to the opposite side of the manhole to secure the manhole in operational position. The preferred embodiment, with two clamping units, is shown in  FIG. 3 . 
         [0016]    The clamping unit  100  includes a screw handle  105  that is used to raise and lower an attachment unit  130 , which preferably is a curved prong that contours to the shape of the outside of the manhole. In the preferred mode of operation, the attachment unit  130  is placed underneath the outside lip of the manhole and the curved prong is raised until the lip is clamped between the prong and the bottom of a support beam (shown in  FIG. 3 ) that is used to carry the manhole. The present Manhole Leveler advantageously uses the grade of the road being resurfaced to automatically level the top of the manhole with the new road. Since the top of the manhole is aligned with the bottom of the support beam, and the support beam is placed on top of the resurfaced road, the top of the manhole is automatically aligned, in all directions, with the new road. 
         [0017]    Turning the screw handle  105  in the clockwise direction causes the screw  110  to traverse through a nut that is held within the upper horizontal support arm  155 , which causes the support arm  155  to travel upward toward the screw handle  105 . The upper horizontal support arm  155  is mechanically attached to a lower horizontal support arm  125 , which is attached to the curved prong, or attachment unit  130 . When the screw handle  105  is turned clockwise, the attachment unit  130  is raised toward the bottom of the housing  145  of the clamping unit. Two vertical attachment arms  115  &amp;  120  that are attach to the lower horizontal support arm  125  traverse through housing sleeves  135  &amp;  140  while moving upward and downward. The support beam that is used to carry the clamping units and the manhole, extends through the middle  150  of the clamping unit housing  145 . The vertical attachment arms  115  &amp;  120  are release-ably attached to the upper horizontal support arm  155  by pins  160  &amp;  165 , in the preferred embodiment. This feature allows the attachment arms  115  &amp;  120 , and most importantly the attachment unit  130 , to be removed from the clamping unit  100 , rotated  180  degrees and reattached to the unit. When the attachment unit  130  is reversed, the clamping unit  100  can clamp onto the interior portion of a manhole, wherein the attachment unit extends into the interior of the manhole. 
         [0018]      FIG. 2  is a side view of the preferred clamping unit  100 . Two housing sleeves  140  &amp;  200  are provided on each side of the housing  145 . This allows the attachment unit  130  to be removed, reversed, and placed into operational position without having to remove the clamping unit housing  145  from the support beam. Sometimes it is better to secure a manhole to the present leveler by going through the opening at the top of the manhole, instead of grasping the manhole from the outside. The clamping unit  100  allows for insertion through the opening in the manhole by making the curved prong reversible. The clamping unit  100  includes locking pins, including pin  165 , that allow the curved prong to be removed, reversed and reattached to the housing  145 . The attachment unit  130  is designed to fit inside the opening in the top of a manhole. The attachment unit  130  can then be slid outward until the prong extends under the interior lip of the manhole. The screw handle  105  is then turned until the top of the manhole is pulled against the bottom of the support beam. While the preferred embodiment uses prongs with a circular shape, other embodiments can be provided with other shaped prongs. 
         [0019]      FIG. 3  shows the preferred embodiment of the present Manhole Leveler with a manhole  350  clamped to the support beam and ready for movement. The Manhole Leveler includes two clamping units  100  &amp;  300 , a support beam  360 , and two carrying handles  375  &amp;  380  at opposite ends of the support beam. The two clamping units  100  &amp;  300  are slide-ably attached the support beam. The clamping units are designed to engage with the bottom  355  of the lip of the manhole  350  and secure the manhole to the bottom  365  of the support beam. The present Leveler can be used to remove the manhole from a road during resurfacing, and to replace, and automatically level, the manhole after resurfacing. The bottom  370  of the support beam  360  rests on the top of the road&#39;s new surface when the manhole  350  is placed into the road. This action forces the manhole to take on the alignment and orientation of the new road, thus leveling the top of the manhole with the surface of the re-paved road, even when the new road is banked or has a steep grade. Preferably, the carrying handles  375  &amp;  380  are used to position the support beam  360  so that, after the manhole  350  has been placed in the road, the support beam is aligned with the steepest angle in the road. So, if the road is not banked and only has an incline, then the beam  360  is positioned so that it is parallel with the direction of the road. And, if the road is banked, and without an incline, then the support beam  360  is positioned perpendicular to the road. This alignment method optimizes the leveling ability of the present apparatus. 
         [0020]      FIG. 4  is a bottom view of the lower portion of the preferred clamping unit. The lower portion, which can be detached from the rest of the clamping unit, includes vertical attachment arms  115  &amp;  120 , lower horizontal support arm  125  and attachment unit  130 . During operation, the curved prong of attachment unit  130  is slid under the outer lip of the manhole and used to pull the manhole upward until the lip is clamped between the attachment unit  130  and the bottom of the support beam. The curved prong is designed to be complementary in shape to the outer portion of the manhole below the manhole&#39;s lip. In the preferred attachment method, both clamping units are simultaneously positioned and tightened, thereby securing the manhole to the bottom of the present leveler. After the manhole is carried to the hole in the newly re-surfaced road, the manhole is lowered into the hole and onto the connecting section of the sewer, or other pipe, under the road. The manhole is lowered until the bottom of the support beam contacts the top of the re-surfaced road. Since the top of the manhole is pulled tight against the bottom of the support beam, the top of the manhole is forced to take the level, including any banking, of the re-surfaced road. Metal shims are placed between the manhole and the sewer to fill in the empty space. The manhole is removed and cement, or other bonding material, is added around the shims and the manhole is replaced on top of the shims and cement. The attachment units are then detached from the manhole, by unscrewing the screws and sliding the units away from the manhole along the support beam. The area around the manhole is filled in and paved, and the new road is ready for vehicular traffic. Best of all, the manhole cover will not cause any unwanted bumps or dips to the vehicles passing over it. 
         [0021]    The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept. For example, the support beam could be made wider thereby providing greater contact and stability with the road. Therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology of terminology employed herein is for the purpose of description and not of limitation.