Granted Patent
Utility
US 4,998,448 · App. 07/457,376
Aluminum driveshaft with balancing composition
Inventor:
William Paul ELLIS
Patented Case
View Patent ↗
Granted: Mar 12, 1991
Filed: Jul 3, 1990
Inventor
William Paul ELLIS
Assignee (at issue)
DANA LIMITED
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.