Granted Patent
Utility
US 5,638,430 · App. 08/479,004
Call validation system
Inventors:
Steven J. Hogan, Kristi T. Feltz, Douglas R. Murdock, David J. Vercande, Michael R. Tangeman, Eric Busch
Patented Case
View Patent ↗
Granted: Jun 10, 1997
Filed: Jun 7, 1995
Inventors
Steven J. Hogan
Kristi T. Feltz
Douglas R. Murdock
David J. Vercande
Michael R. Tangeman
Eric Busch
Assignee (at issue)
Link USA Corp.
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.