Granted Patent
Utility
US 4,416,092 · App. 06/337,832
Cleaning apparatus
Inventor:
Robert T. Nelson
Patented Case
View Patent ↗
Granted: Nov 22, 1983
Filed: Jan 7, 1982
Inventor
Robert T. Nelson
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.