Granted Patent
Utility
US 4,199,787 · App. 05/961,508
Intercarrier sound system
Inventor:
Jack Craft
Patented Case
View Patent ↗
Granted: Apr 22, 1980
Filed: Nov 17, 1978
Inventor
Jack Craft
Assignee (at issue)
RCA Corporation
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.