Granted Patent
Utility
US 4,569,367 · App. 06/691,474
Hydraulic valve inlet unloaders
Inventor:
John D. Petro
Patented Case
View Patent ↗
Granted: Feb 11, 1986
Filed: Jan 14, 1985
Inventor
John D. Petro
Assignee (at issue)
Commercial Shearing, 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.