Granted Patent
Utility
US 4,275,938 · App. 06/096,344
Tandem thrust bearing
Inventor:
Leo L. Roberts
Patented Case
View Patent ↗
Granted: Jun 30, 1981
Filed: Nov 21, 1979
Inventor
Leo L. Roberts
Assignee (at issue)
Centrilift-Hughes, Inc.
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.