| 摘要 |
PROBLEM TO BE SOLVED: To provide the uncovering tool and uncovering method of a manhole, in which a structure is simplified, labor is not required for an operation preparatory plan at a site and an asphalt surface and a concrete surface in the periphery of the manhole are not damaged, regarding the tool and the uncovering method used for opening a cover plate for the manhole. SOLUTION: In the uncovering operation of the manhole utilizing the power assisting work of a lever, the fulcrum of the lever is set at the upper edge of a manhole frame, and the balance of force of the setting of the point of application and the point of application of force by cover plate itself is used. That is, upward force as well as downward force are worked to cover plate itself, and upward force corresponding to the difference of upward force and downward force by the power multiply ratio of the lever is given to the cover plate and the cover plate is opened in the uncovering tool.
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