Granted Patent
Utility
US 5,060,271 · App. 07/519,389
Active muffler with dynamic tuning
Inventor:
Earl R. Geddes
Patented Case
View Patent ↗
Granted: Oct 22, 1991
Filed: May 4, 1990
Inventor
Earl R. Geddes
Assignee (at issue)
Ford Motor 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.