Granted Patent
Utility
US 4,303,552 · App. 06/153,502
Diesel exhaust catalyst
Inventors:
Michael V. Ernest, William A. Welsh
Patented Case
View Patent ↗
Granted: Dec 1, 1981
Filed: May 27, 1980
Inventors
Michael V. Ernest
William A. Welsh
Assignee (at issue)
W. R. Grace & Co.
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.