Granted Patent
Utility
US 4,723,866 · App. 06/746,273
Manhole cover locking bolt construction
Inventor:
Durham S. McCauley
Patented Case
View Patent ↗
Granted: Feb 9, 1988
Filed: Jun 19, 1985
Inventor
Durham S. McCauley
Assignee (at issue)
McGard LLC
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.