Granted Patent
Utility
US 4,873,594 · App. 07/182,675
Disk spacer ring having air pumps
Inventor:
Tsu-Fang Chen
Patented Case
View Patent ↗
Granted: Oct 10, 1989
Filed: Apr 18, 1988
Inventor
Tsu-Fang Chen
Assignee (at issue)
Magnetic Peripherals, Inc.
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.