Granted Patent
Utility
US 5,108,474 · App. 07/637,233
Smoke filter
Inventors:
James A. Riedy, Ralph D. Zingle
Patented Case
View Patent ↗
Granted: Apr 28, 1992
Filed: Jan 3, 1991
Inventors
James A. Riedy
Ralph D. Zingle
Assignee (at issue)
W. L. Gore & Associates, 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.