Granted Patent
Utility
US 4,252,352 · App. 06/143,071
Sealing ring
Inventor:
John Scannell
Patented Case
View Patent ↗
Granted: Feb 24, 1981
Filed: Apr 24, 1980
Inventor
John Scannell
Assignee (at issue)
Parker-Hannifin 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.