Granted Patent
Utility
US 4,278,513 · App. 06/164,650
Two-stage differential anodization process
Inventors:
Richard J. Millard, Walter J. Bernard, Alfred J. Whitman
Patented Case
View Patent ↗
Granted: Jul 14, 1981
Filed: Jun 30, 1980
Inventors
Richard J. Millard
Walter J. Bernard
Alfred J. Whitman
Assignee (at issue)
Sprague Electric Company
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.