Granted Patent
Utility
US 4,540,625 · App. 06/569,432
Flexible air permeable non-woven fabric filters
Inventor:
Charles H. Sherwood
Patented Case
View Patent ↗
Granted: Sep 10, 1985
Filed: Jan 9, 1984
Inventor
Charles H. Sherwood
Assignee (at issue)
Hughes Aircraft Company
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.