Granted Patent
Utility
US 4,383,956 · App. 06/230,132
Method of a single element complete air filtering structure for a respirator filter cartridge
Inventors:
George T. Croft, Richard J. Hovey
Patented Case
View Patent ↗
Granted: May 17, 1983
Filed: Jan 30, 1981
Inventors
George T. Croft
Richard J. Hovey
Assignee (at issue)
American Optical Corporation
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.