Granted Patent
Utility
US 5,492,882 · App. 08/097,423
Chromium-free impregnated activated universal respirator carbon for adsorption of toxic gases and/or vapors in industrial applications
Inventors:
David T. Doughty, William J. Knebel, John W. Cobes, III
Patented Case
View Patent ↗
Granted: Feb 20, 1996
Filed: Jul 26, 1993
Inventors
David T. Doughty
William J. Knebel
John W. Cobes, III
Assignee (at issue)
CALGON CARBON 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.