Granted Patent
Utility
US 4,488,294 · App. 06/363,424
Establishing and supporting data traffic in private branch exchanges
Inventors:
Tore Christensen, Gail L. Haygood, Douglas A. Spencer, Steven Szymanski
Patented Case
View Patent ↗
Granted: Dec 11, 1984
Filed: Mar 30, 1982
Inventors
Tore Christensen
Gail L. Haygood
Douglas A. Spencer
Steven Szymanski
Assignee (at issue)
AT&T Bell Laboratories
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.