Granted Patent
Utility
US 5,063,791 · App. 07/326,549
Sampling of material
Inventor:
William J. Martin
Patented Case
View Patent ↗
Granted: Nov 12, 1991
Filed: Mar 13, 1989
Inventor
William J. Martin
Assignee (at issue)
NATIONAL RESEARCH DEVELOPMENT 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.