Granted Patent
Utility
US 4,377,922 · App. 05/654,078
Portable apparatus for treating surfaces
Inventor:
John C. Bergh
Patented Case
View Patent ↗
Granted: Mar 29, 1983
Filed: Feb 2, 1976
Inventor
John C. Bergh
Assignee (at issue)
Wheelabrator-Frye 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.