Granted Patent
Utility
US 4,900,224 · App. 07/323,342
Centrifugal pump structure
Inventors:
Jukka Timperi, Reijo Vesala
Patented Case
View Patent ↗
Granted: Feb 13, 1990
Filed: Mar 14, 1989
Inventors
Jukka Timperi
Reijo Vesala
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.