Granted Patent
Utility
US 4,528,675 · App. 06/528,357
FSK modem for bidirectional loop communications system
Inventors:
Robert J. Esterling, Clarence L. Freed, Edward L. Weiss, Simon Korowitz
Patented Case
View Patent ↗
Granted: Jul 9, 1985
Filed: Aug 31, 1983
Inventors
Robert J. Esterling
Clarence L. Freed
Edward L. Weiss
Simon Korowitz
Assignee (at issue)
Federal Signal 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.