Granted Patent
Utility
US 4,323,452 · App. 06/219,310
Pumpless flow system for a corrosive liquid
Inventor:
Marion J. Witzenburg
Patented Case
View Patent ↗
Granted: Apr 6, 1982
Filed: Nov 3, 1980
Inventor
Marion J. Witzenburg
Assignee (at issue)
Caterpillar Tractor Co.
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.