Granted Patent
Utility
US 4,944,593 · App. 07/153,840
Volume-measuring method for surface depressions
Inventors:
Reiner Kalstroem, Erich Schulz-DuBois
Patented Case
View Patent ↗
Granted: Jul 31, 1990
Filed: Dec 30, 1987
Inventors
Reiner Kalstroem
Erich Schulz-DuBois
Assignee (at issue)
Dr. Ing. Rudolf Hell GmbH
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.