Granted Patent
Utility
US 4,385,873 · App. 06/194,805
Rotary vane type pump or motor and the like with circular chamber portions
Inventor:
Hans Richter
Patented Case
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Granted: May 31, 1983
Filed: Oct 7, 1980
Inventor
Hans Richter
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.