Granted Patent
Utility
US 4,328,972 · App. 06/214,922
Seal ring and method of manufacture
Inventors:
Kenneth R. Albertson, Ralph Peterson
Patented Case
View Patent ↗
Granted: May 11, 1982
Filed: Dec 10, 1980
Inventors
Kenneth R. Albertson
Ralph Peterson
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.