Granted Patent
Utility
US 4,240,642 · App. 06/133,632
Belleville spring-loaded crescent seal
Inventor:
Michael A. Roussin
Patented Case
View Patent ↗
Granted: Dec 23, 1980
Filed: Jan 11, 1980
Inventor
Michael A. Roussin
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.