Granted Patent
Utility
US 4,885,933 · App. 07/197,841
Hardness impact tester
Inventors:
Everett N. Hiestand, Stephen Balog
Patented Case
View Patent ↗
Granted: Dec 12, 1989
Filed: May 24, 1988
Inventors
Everett N. Hiestand
Stephen Balog
Assignee (at issue)
The Upjohn Co.
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.