Granted Patent
Utility
US 4,142,600 · App. 05/774,100
Control system for auxiliary front wheel drive
Inventor:
John J. Campbell
Patented Case
View Patent ↗
Granted: Mar 6, 1979
Filed: Mar 3, 1977
Inventor
John J. Campbell
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.