Granted Patent
Utility
US 4,300,775 · App. 06/093,071
Liquid-filled radial seal
Inventor:
Reginald K. Ringel
Patented Case
View Patent ↗
Granted: Nov 17, 1981
Filed: Aug 13, 1979
Inventor
Reginald K. Ringel
Assignee (at issue)
Caterpillar Tractor Co.
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.