Granted Patent
Utility
US 4,646,575 · App. 06/882,437
Ultrasonic flowmeter
Inventors:
John G. O'Hair, Michael Nolan
Patented Case
View Patent ↗
Granted: Mar 3, 1987
Filed: Jul 7, 1986
Inventors
John G. O'Hair
Michael Nolan
Assignee (at issue)
British Gas
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.