Granted Patent
Utility
US 6,336,470 · App. 09/510,545
Directional seat valve
Inventor:
Friedrich Zapf
Patented Case
View Patent ↗
Granted: Jan 8, 2002
Filed: Feb 22, 2000
Inventor
Friedrich Zapf
Assignee (at issue)
Hydraulik-Ring GmbH
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.