Granted Patent
Utility
US 4,389,315 · App. 06/286,563
Filter device with permeable corrugated grid panel
Inventor:
Frank Crocket
Patented Case
View Patent ↗
Granted: Jun 21, 1983
Filed: Jul 24, 1981
Inventor
Frank Crocket
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.