Granted Patent
Utility
US 5,837,880 · App. 08/915,401
Compact ultrasonic calibration block
Inventors:
Michael L. Shakinovsky, Robert E. Lucas
Patented Case
View Patent ↗
Granted: Nov 17, 1998
Filed: Aug 20, 1997
Inventors
Michael L. Shakinovsky
Robert E. Lucas
Assignee (at issue)
Sperry Rail Service
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.