Granted Patent
Utility
US 4,975,903 · App. 07/456,084
Digital timeslot and signaling bus in a digital PBX switch
Inventors:
John F. Wakerly, Samuel F. Wood
Patented Case
View Patent ↗
Granted: Dec 4, 1990
Filed: Dec 21, 1989
Inventors
John F. Wakerly
Samuel F. Wood
Assignee (at issue)
David Systems, 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.