Granted Patent
Utility
US 4,685,944 · App. 06/386,653
High efficiency particulate air filter
Inventors:
Thomas Allan, Robert V. Cramer
Patented Case
View Patent ↗
Granted: Aug 11, 1987
Filed: Jun 9, 1982
Inventors
Thomas Allan
Robert V. Cramer
Assignee (at issue)
FLANDERS FILTERS, 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.