Granted Patent
Utility
US 5,909,742 · App. 08/038,588
Metal cleaning method
Inventors:
Jiangbo Ouyang, Philip D. Deck, William L. Harpel
Patented Case
View Patent ↗
Granted: Jun 8, 1999
Filed: Mar 26, 1993
Inventors
Jiangbo Ouyang
Philip D. Deck
William L. Harpel
Assignee (at issue)
Betzdearborn, 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.