Granted Patent
Utility
US 4,239,061 · App. 05/810,657
Damper valve
Inventor:
Harley G. Peterson
Patented Case
View Patent ↗
Granted: Dec 16, 1980
Filed: Jun 27, 1977
Inventor
Harley G. Peterson
Assignee (at issue)
Joy Manufacturing 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.