Granted Patent
Utility
US 5,539,812 · App. 08/336,001
Method and apparatus for detecting an attempted three-way conference call on a remote telephone
Inventors:
Dwight W. Kitchin, Alan K. Schott, John C. Johnson, Clive Smith
Patented Case
View Patent ↗
Granted: Jul 23, 1996
Filed: Nov 8, 1994
Inventors
Dwight W. Kitchin
Alan K. Schott
John C. Johnson
Clive Smith
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.