Granted Patent
Utility
US 4,847,064 · App. 07/137,159
Economical process for alpha alumina production
Inventor:
Alan Pearson
Patented Case
View Patent ↗
Granted: Jul 11, 1989
Filed: Dec 23, 1987
Inventor
Alan Pearson
Assignee (at issue)
Aluminum Company of America
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.