Granted Patent
Utility
US 4,261,581 · App. 06/140,388
Mechanical seal with improved face ring mounting
Inventor:
Lowell E. Hershey
Patented Case
View Patent ↗
Granted: Apr 14, 1981
Filed: Apr 14, 1980
Inventor
Lowell E. Hershey
Assignee (at issue)
Durametallic 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.