Granted Patent
Utility
US 5,086,459 · App. 07/483,875
Timing circuit and a secure telephone jack utilizing this circuit
Inventor:
Steven B. Perry
Patented Case
View Patent ↗
Granted: Feb 4, 1992
Filed: Feb 23, 1990
Inventor
Steven B. Perry
Assignee (at issue)
Keptel, 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.