Granted Patent
Utility
US 4,633,856 · App. 06/793,201
Percussor subassembly for generating gas bursts
Inventor:
Harold R. Havstad
Patented Case
View Patent ↗
Granted: Jan 6, 1987
Filed: Oct 31, 1985
Inventor
Harold R. Havstad
Assignee (at issue)
Hudson Oxygen Therapy Sales 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.