ALEXANDRIA, Va., Dec. 2 -- United States Patent no. 12,486,656, issued on Dec. 2.
"Manhole cover seal" was invented by Danny Warren (Carver, Mass.) and Scott Kraihanzel (Barnstable, Mass.).
According to the abstract* released by the U.S. Patent & Trademark Office: "A manhole sealing device to prevent environmental water from entering a manhole through the joint between the manhole casing, manhole cover, and cover frame. The device comprises a disc shaped inflatable seal for insertion into the upper portion of the manhole and inflated to provide a sealing means to prevent infiltration of water from the environment to the interior of the manhole. The disc shaped seal may include a first rigid stabilization portion surrounded by a flexible i...