Granted Patent
Utility
US 4,720,421 · App. 06/811,616
Poison resistant combustible gas sensor
Inventor:
Gul Khilnani
Patented Case
View Patent ↗
Granted: Jan 19, 1988
Filed: Dec 20, 1985
Inventor
Gul Khilnani
Assignee (at issue)
REXNORD GMBH
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.