Granted Patent
Utility
US 4,112,261 · App. 05/797,490
Key telephone system and method
Inventor:
Milo B. Shiff
Patented Case
View Patent ↗
Granted: Sep 5, 1978
Filed: May 16, 1977
Inventor
Milo B. Shiff
Assignee (at issue)
ANACONDA, 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.