Granted Patent
Utility
US 4,940,401 · App. 07/310,778
Lubrication fluid circulation using a piston valve pump with bi-directional flow
Inventor:
Hollis N. White, Jr.
Patented Case
View Patent ↗
Granted: Jul 10, 1990
Filed: Feb 14, 1989
Inventor
Hollis N. White, Jr.
Assignee (at issue)
White Hydraulics, 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.