Granted Patent
Utility
US 4,314,621 · App. 06/081,219
Fluidborne noise attenuator
Inventor:
Robert C. Hansen
Patented Case
View Patent ↗
Granted: Feb 9, 1982
Filed: Mar 7, 1979
Inventor
Robert C. Hansen
Assignee (at issue)
Caterpillar Tractor Co.
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.