Granted Patent
Utility
US 6,209,547 · App. 09/181,859
Cigarette filter
Inventors:
Kent B. Koller, Susan E. Wrenn, Willie G. Houck, Jr., John B. Paine, III
Patented Case
View Patent ↗
Granted: Apr 3, 2001
Filed: Oct 29, 1998
Inventors
Kent B. Koller
Susan E. Wrenn
Willie G. Houck, Jr.
John B. Paine, III
Assignee (at issue)
Philip Morris 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.