Granted Patent
Utility
US 4,056,989 · App. 05/691,053
Vehicle drive
Inventor:
Walter M. Shaffer
Patented Case
View Patent ↗
Granted: Nov 8, 1977
Filed: May 28, 1976
Inventor
Walter M. Shaffer
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.