| 摘要 |
An improved temporary manhole insert for securing a manhole passageway having a generally cylindrical structure with an inflatable, ring like tube encompassing the outer rim of the rigid portion of the insert. The insert with the inflatable ring is placed within the manhole aperture and then inflated to expand until the insert is secured in position. The manhole insert of the present invention prevents debris such as rocks, dust, asphalt and other debris from falling into the manhole during adjustments to the casting and also prevents debris from going into the sewer system such as pipes and pumps.
|
