Granted Patent
Utility
US 4,820,109 · App. 06/851,008
Bidirectional transfer mechanism
Inventor:
William F. Witt
Patented Case
View Patent ↗
Granted: Apr 11, 1989
Filed: Apr 11, 1986
Inventor
William F. Witt
Assignee (at issue)
Ampex 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.