Granted Patent
Utility
US 4,300,927 · App. 06/202,568
Pocket filter arrangement
Inventor:
Charles E. Day
Patented Case
View Patent ↗
Granted: Nov 17, 1981
Filed: Oct 31, 1980
Inventor
Charles E. Day
Assignee (at issue)
AMERICAN AIR FILTER COMPANY, 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.