Granted Patent
Utility
US 5,000,858 · App. 07/381,095
Method for removing hexavalent chromium from water
Inventors:
Richard E. Manning, Ted H. Wells
Patented Case
View Patent ↗
Granted: Mar 19, 1991
Filed: Jul 17, 1989
Inventors
Richard E. Manning
Ted H. Wells
Assignee (at issue)
COLTEC INDUSTRIES, INC.
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.