Granted Patent
Utility
US 4,535,943 · App. 06/644,644
Pulping apparatus including a rotor and helical screw flights extending upwardly from the rotor
Inventor:
Joseph Couture
Patented Case
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Granted: Aug 20, 1985
Filed: Aug 24, 1984
Inventor
Joseph Couture
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.