Granted Patent
Utility
US 5,646,985 · App. 08/556,327
Hierarchical switch support of services for subscribers of independent private branch exchanges
Inventors:
Donald Lee Andruska, Liane Toy Tsai
Patented Case
View Patent ↗
Granted: Jul 8, 1997
Filed: Nov 16, 1995
Inventors
Donald Lee Andruska
Liane Toy Tsai
Assignee (at issue)
LUCENT TECHNOLOGIES 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.