Granted Patent
Utility
US 5,163,616 · App. 07/640,947
Air freshener device with visual signal means
Patented Case
View Patent ↗
Granted: Nov 17, 1992
Filed: Jan 14, 1991
Assignee (at issue)
BLOCK DRUG COMPANY 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.