Granted Patent
Utility
US 5,151,935 · App. 07/609,083
Programmable universal signaling circuit for a telephone network
Inventors:
Jimmy D. Slife, David J. Farrell
Patented Case
View Patent ↗
Granted: Sep 29, 1992
Filed: Nov 2, 1990
Inventors
Jimmy D. Slife
David J. Farrell
Assignee (at issue)
XEL Communications, 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.