Granted Patent
Utility
US 4,973,228 · App. 07/483,104
Rotor of a compression-wave engine
Inventors:
Rolf Althaus, Jakob Keller
Patented Case
View Patent ↗
Granted: Nov 27, 1990
Filed: Feb 22, 1990
Inventors
Rolf Althaus
Jakob Keller
Assignee (at issue)
Asea Brown Boveri, S.A.
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.