Granted Patent
Utility
US 4,993,722 · App. 07/410,585
Apparatus and method for improved pipe to manhole sealing
Inventor:
William P. Gundy
Patented Case
View Patent ↗
Granted: Feb 19, 1991
Filed: Sep 21, 1989
Inventor
William P. Gundy
Assignee (at issue)
NPC CO., LTD.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.