Granted Patent
Utility
US 4,296,592 · App. 06/203,084
Auger floatation limit
Inventor:
Irwin D. McIlwain
Patented Case
View Patent ↗
Granted: Oct 27, 1981
Filed: Nov 3, 1980
Inventor
Irwin D. McIlwain
Assignee (at issue)
Sperry Corp.
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.