Granted Patent
Utility
US 4,719,752 · App. 06/909,000
Exhaust pipe system
Inventor:
Andrew Hall
Patented Case
View Patent ↗
Granted: Jan 19, 1988
Filed: Sep 18, 1986
Inventor
Andrew Hall
Assignee (at issue)
General Motors LLC
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.