Granted Patent
Utility
US 4,325,921 · App. 06/147,459
Waste gas purification systems and methods
Inventors:
John Edward Aiken, William J. Didycz
Patented Case
View Patent ↗
Granted: Apr 20, 1982
Filed: May 7, 1980
Inventors
John Edward Aiken
William J. Didycz
Assignee (at issue)
United States Steel Corporation
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.