Granted Patent
Utility
US 4,557,281 · App. 06/558,221
Filtered cigarette
Inventor:
Elmer F. Litzinger
Patented Case
View Patent ↗
Granted: Dec 10, 1985
Filed: Dec 5, 1983
Inventor
Elmer F. Litzinger
Assignee (at issue)
Brown & Williamson Tobacco 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.