Granted Patent
Utility
US 4,447,777 · App. 06/216,499
Magnetic pipeline inspection vehicle with metallic foil and bristle contacts supporting the vehicle
Inventors:
Michael R. G. Sharp, John C. Braithwaite
Patented Case
View Patent ↗
Granted: May 8, 1984
Filed: Dec 15, 1980
Inventors
Michael R. G. Sharp
John C. Braithwaite
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.