Granted Patent
Utility
US 5,299,448 · App. 08/027,218
Positive pressure test apparatus for facepiece respirator
Inventors:
Richard D. Maryyanek, Joseph Z. Zdrok, Keith Simpson
Patented Case
View Patent ↗
Granted: Apr 5, 1994
Filed: Mar 5, 1993
Inventors
Richard D. Maryyanek
Joseph Z. Zdrok
Keith Simpson
Assignee (at issue)
Cabot Safety 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.