Granted Patent
Utility
US 4,243,840 · App. 05/972,248
Loudspeaker system
Inventor:
James M. Kates
Patented Case
View Patent ↗
Granted: Jan 6, 1981
Filed: Dec 22, 1978
Inventor
James M. Kates
Assignee (at issue)
Teledyne Industries, Inc.
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.