Granted Patent
Utility
US 4,401,979 · App. 06/233,539
Electrical controls for ionization smoke detector
Inventor:
John J. Dobrzanski
Patented Case
View Patent ↗
Granted: Aug 30, 1983
Filed: Feb 11, 1981
Inventor
John J. Dobrzanski
Assignee (at issue)
Federal Signal 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.