Granted Patent
Utility
US 4,279,356 · App. 06/090,287
Quick opening manhole cover assembly
Inventors:
Franklyn J. Amorese, Vincent J. Piarulli
Patented Case
View Patent ↗
Granted: Jul 21, 1981
Filed: Nov 1, 1979
Inventors
Franklyn J. Amorese
Vincent J. Piarulli
Assignee (at issue)
Sybron Corporation
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.