Granted Patent
Utility
US 4,124,298 · App. 05/777,043
Optical smoke detector inlet screen
Inventor:
Donald F. Steele
Patented Case
View Patent ↗
Granted: Nov 7, 1978
Filed: Mar 14, 1977
Inventor
Donald F. Steele
Assignee (at issue)
Electro Signal Lab, 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.