Granted Patent
Utility
US 4,290,442 · App. 06/133,000
Mobile cleaning unit
Inventor:
Detmer B. Shaffer
Patented Case
View Patent ↗
Granted: Sep 22, 1981
Filed: Mar 24, 1980
Inventor
Detmer B. Shaffer
Assignee (at issue)
Sparkle Wash, 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.