Granted Patent
Utility
US 4,274,054 · App. 05/962,945
Dual channel apparatus for detecting surface defects in elongate metallic members with liftoff compensation
Inventors:
David H. Savidge, Eric Wadsworth
Patented Case
View Patent ↗
Granted: Jun 16, 1981
Filed: Nov 22, 1978
Inventors
David H. Savidge
Eric Wadsworth
Assignee (at issue)
British Steel Corporation
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.