Granted Patent
Utility
US 4,790,004 · App. 06/940,141
Implied principal busy status indicator for covered calls
Inventor:
Robert Daniel Nalbone
Patented Case
View Patent ↗
Granted: Dec 6, 1988
Filed: Dec 10, 1986
Inventor
Robert Daniel Nalbone
Assignee (at issue)
American Telephone and Telegraph Company, AT&T Information Systems
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.