Granted Patent
Utility
US 4,890,850 · App. 07/182,510
Tapered ferrofluid seal
Inventors:
Kuldip Raj, Ronald Moskowitz, Frank Bloom
Patented Case
View Patent ↗
Granted: Jan 2, 1990
Filed: Apr 18, 1988
Inventors
Kuldip Raj
Ronald Moskowitz
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.