Granted Patent
Utility
US 4,694,213 · App. 06/933,485
Ferrofluid seal for a stationary shaft and a rotating hub
Inventors:
Hanumaiah L. Gowda, Charles J. Cheever, Frank Bloom
Patented Case
View Patent ↗
Granted: Sep 15, 1987
Filed: Nov 21, 1986
Inventors
Hanumaiah L. Gowda
Charles J. Cheever
Frank Bloom
Assignee (at issue)
Ferrofluidics 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.