Granted Patent
Utility
US 4,298,473 · App. 06/150,323
Drum filter apparatus
Inventor:
Floyd H. Wyman
Patented Case
View Patent ↗
Granted: Nov 3, 1981
Filed: May 16, 1980
Inventor
Floyd H. Wyman
Assignee (at issue)
Marshall and Williams 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.