Granted Patent
Utility
US 4,799,255 · App. 07/009,175
Communication facilities access control arrangement
Inventors:
Randy J. Billinger, Laurel K. Dotter, Tommy D. Gasaway
Patented Case
View Patent ↗
Granted: Jan 17, 1989
Filed: Jan 30, 1987
Inventors
Randy J. Billinger
Laurel K. Dotter
Tommy D. Gasaway
Assignee (at issue)
American Telephone and Telegraph Company, AT&T Information Systems
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.