Granted Patent
Utility
US 4,255,906 · App. 05/963,689
Abrasive cleaning apparatus
Inventor:
Wayne B. Hockett
Patented Case
View Patent ↗
Granted: Mar 17, 1981
Filed: Nov 27, 1978
Inventor
Wayne B. Hockett
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.