Granted Patent
Utility
US 4,490,759 · App. 06/322,083
Rotary head assembly having fluid thrust and radial bearings
Inventor:
Teruo Maruyama
Patented Case
View Patent ↗
Granted: Dec 25, 1984
Filed: Nov 17, 1981
Inventor
Teruo Maruyama
Assignee (at issue)
SUMITOMO ELECTRIC INDUSTRIES, LTD.
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.