Granted Patent
Utility
US 4,406,927 · App. 06/261,929
Electronic tone ringer
Inventor:
Karl E. Pommer, II
Patented Case
View Patent ↗
Granted: Sep 27, 1983
Filed: May 8, 1981
Inventor
Karl E. Pommer, II
Assignee (at issue)
International Telephone and Telegraph 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.