Granted Patent
Utility
US 4,283,178 · App. 06/053,991
Electromechanical braille cell
Inventor:
James F. Tetzlaff
Patented Case
View Patent ↗
Granted: Aug 11, 1981
Filed: Jul 2, 1979
Inventor
James F. Tetzlaff
Assignee (at issue)
Telesensory Systems, Inc.
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.