Granted Patent
Utility
US 4,570,672 · App. 06/720,086
Hydraulic control valve with independently operable bypass valve
Inventor:
Raud A. Wilke
Patented Case
View Patent ↗
Granted: Feb 18, 1986
Filed: Apr 5, 1985
Inventor
Raud A. Wilke
Assignee (at issue)
Koehring Company
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.