Granted Patent
Utility
US 5,199,304 · App. 07/839,339
Apparatus for optically measuring specimen deformation during material testing
Inventor:
Hugo S. Ferguson
Patented Case
View Patent ↗
Granted: Apr 6, 1993
Filed: Feb 20, 1992
Inventor
Hugo S. Ferguson
Assignee (at issue)
Duffers Scientific, Inc.
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.