Inclined manhole cover riser assembly

Abstract

A riser assembly and method for engaging the same to raise a manhole cover to be flush with an inclined paved surface after the application of an additional layer of paving material thereto. The riser assembly includes a first and second riser frame with a plurality of specially manufactured spacer blocks fixedly secured between them. The spacer blocks have progressively different height dimensions and sloped upper surfaces so as to create an angle between the first and second riser frames. The angle is complementary to the slope of the paved surface. The riser assembly includes an expansion device for adjusting the diameter of the second riser frame so that it frictionally engages the existing manhole frame. The fixed securement of the spacer blocks prevents relative movement between the first and second riser frames even when the diameter of the second riser frame is changed.

Description

BACKGROUND OF THE INVENTION[0001]1. Technical Field[0002]This invention relates generally to manhole cover supports. More particularly, this invention relates to a separate riser assembly that is placed within an existing manhole frame to raise the height of the manhole cover to compensate for added roadway pavement. Specifically, this invention is directed to a riser assembly for use with a manhole frame positioned on an incline. The riser assembly comprises a first riser frame and second riser frame having spacer blocks fixedly engaged between them in a manner that retains the first riser frame at an angle relative to the second riser frame. The inclined first riser frame supports the full circumference of the manhole cover at an angle complementary to the sloped road surface.[0003]2. Background Information[0004]Most underground facilities such as sanitary and storm sewers, utility conduits, and the like have manhole openings to provide access thereto. These manholes usually are l...

AI Technical Summary

Benefits of technology

The patent describes a riser assembly and a method to use it to raise a manhole cover on a paved surface. The assembly includes two riser frames with special blocks in between them that have different heights and sloping surfaces to match the slope of the phed surface. The assembly also has an expansion device to adjust the size of the second riser frame so it fits snugly around the existing manhole frame. The special blocks prevent the two frames from moving relative to each other, even if the second frame is adjusted. The technical effect of this invention is the ability to raise manhole covers to be flush with the paved surface, while avoiding any movement between the two riser frames.

Problems solved by technology

Problems arise in the resurfacing of the roadways when a layer of pavement is placed on top of the existing pavement.

This results in the manhole cover being positioned a distance below the top surface of the new pavement, causing a depression in the roadway.

It is quite difficult and expensive to raise the existing manhole frame sufficiently to compensate for the added pavement.

However, when the pavement surface is inclined, as would be the case if the manhole were located on a hill or in a valley, for example, then the riser assembly disclosed in U.S. Pat. No. 7,165,911 is not entirely adequate for the job.

Either of this situations leads to early degradation of the new pavement surface and simultaneously tends to be hazardous for vehicles traveling over the road.

One of the issues with this device is that it requires the road crew installing it to make a series of calculations and adjustments to the device while they are busy installing the same.

This need for doing calculations in the field tends to slow the installation process down.

The device is therefore limited to riser heights that are greater than the thickness of the manhole cover plus the thickness of the top ring.

This arrangement is impractical in many instances because the average manhole cover thickness in the United States is 1¾″ to 3½″ thick and most asphalt overlays are around 1½″ thick.

Consequently, Bowman's device is only useful in very specific instances.

Additionally, when the turnbuckles on the device are expanded or contracted, Bowman's riser will not provide a flat surface upon which the manhole cover can rest.

In each of the expanded or contracted positions, the riser will present an uneven surface upon which the cover will have to rest, leading to rocking of the cover as vehicles travel over the same.

However, many manhole frames do not include these lips and then the Bowman device cannot be used with these existing manhole frames.

This device is problematic for a number of reasons.

Consequently, both the uppermost edge of the manhole frame and the seat of the frame where the bottom ring sits will tend to wear and corrode.

Consequently, as traffic moves over the cover, the cover will tend to rock on the spanners.

Additionally, because the top ring is disposed above the uppermost edge of the existing manhole frame, this riser assembly can only be used in specific applications because the riser heights have to be greater than the lid thickness plush the thickness of the base of the top ring.

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