Granted Patent
Utility
US 4,813,271 · App. 07/033,806
Resonator device
Inventor:
John C. Greenwood
Patented Case
View Patent ↗
Granted: Mar 21, 1989
Filed: Apr 3, 1987
Inventor
John C. Greenwood
Assignee (at issue)
STC PLC
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.