Granted Patent
Utility
US 4,867,633 · App. 07/156,759
Centrifugal pump with hydraulic thrust balance and tandem axial seals
Inventor:
Homer E. Gravelle
Patented Case
View Patent ↗
Granted: Sep 19, 1989
Filed: Feb 18, 1988
Inventor
Homer E. Gravelle
Assignee (at issue)
Sundstrand Corporation
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.