Granted Patent
Utility
US 4,446,362 · App. 06/041,092
Workpiece with abraded machine-readable marking therein and method of making
Inventor:
Philip M. Heyman
Patented Case
View Patent ↗
Granted: May 1, 1984
Filed: May 21, 1979
Inventor
Philip M. Heyman
Assignee (at issue)
RCA 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.