Granted Patent
Utility
US 4,321,772 · App. 06/145,050
Levelable lapping machine
Inventor:
Douglas H. Ziegel
Patented Case
View Patent ↗
Granted: Mar 30, 1982
Filed: Apr 30, 1980
Inventor
Douglas H. Ziegel
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.