Granted Patent
Utility
US 4,526,382 · App. 06/606,586
Radially polarized multiple-stage ferrofluid seal apparatus
Inventors:
Kuldip Raj, Hanumaiah L. Gowda
Patented Case
View Patent ↗
Granted: Jul 2, 1985
Filed: May 3, 1984
Inventors
Kuldip Raj
Hanumaiah L. Gowda
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.