Granted Patent
Utility
US 6,139,431 · App. 08/821,437
Free long distance calls on slot machines
Inventors:
Jay S. Walker, James A. Jorasch, Thomas M. Sparico
Patented Case
View Patent ↗
Granted: Oct 31, 2000
Filed: Mar 21, 1997
Inventors
Jay S. Walker
James A. Jorasch
Thomas M. Sparico
Assignee (at issue)
Walker Digital, LLC
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.