Granted Patent
Utility
US 4,399,028 · App. 06/388,387
Froth flotation apparatus and method
Inventors:
Gregory D. Kile, Larry D. Markham, Ronald D. Cruea, Derald R. Hatton
Patented Case
View Patent ↗
Granted: Aug 16, 1983
Filed: Jun 14, 1982
Inventors
Gregory D. Kile
Larry D. Markham
Ronald D. Cruea
Derald R. Hatton
Assignee (at issue)
Black Clawson Company, 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.