Granted Patent
Utility
US 4,976,586 · App. 07/381,067
Pump with separate fluidizing vaned shaft adjacent impeller
Inventors:
Johan C. F. C. Richter, Ole J. Richter
Patented Case
View Patent ↗
Granted: Dec 11, 1990
Filed: Jul 18, 1989
Inventors
Johan C. F. C. Richter
Ole J. Richter
Assignee (at issue)
Kamyr AB
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.