Granted Patent
Utility
US 6,238,446 · App. 08/149,042
Unleaded aviation gasoline
Inventor:
Douglas H. Henderson
Patented Case
View Patent ↗
Granted: May 29, 2001
Filed: Nov 8, 1993
Inventor
Douglas H. Henderson
Assignee (at issue)
Ethyl Petroleum Additives, 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.