Granted Patent
Utility
US 5,988,509 · App. 08/906,735
Refundable prepaid telephone card
Inventor:
John M. Taskett
Patented Case
View Patent ↗
Granted: Nov 23, 1999
Filed: Aug 6, 1997
Inventor
John M. Taskett
Assignee (at issue)
American Express TRS
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.