Granted Patent
Utility
US 4,365,541 · App. 06/273,872
Filter arrangement for an air circulatory system
Inventors:
Jerry G. Marques, Robert D. Cruthis
Patented Case
View Patent ↗
Granted: Dec 28, 1982
Filed: Dec 12, 1980
Inventors
Jerry G. Marques
Robert D. Cruthis
Assignee (at issue)
Caterpillar Tractor Co.
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.