Granted Patent
Utility
US 4,325,163 · App. 06/138,166
Portable blower-vacuum unit
Inventors:
Charles A. Mattson, George M. Zink, Douglas A. Milliken
Patented Case
View Patent ↗
Granted: Apr 20, 1982
Filed: Apr 7, 1980
Inventors
Charles A. Mattson
George M. Zink
Douglas A. Milliken
Assignee (at issue)
Allegretti & 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.