Granted Patent
Utility
US 4,423,644 · App. 06/248,743
Multi-speed planetary differential
Inventor:
Alan R. Coutant
Patented Case
View Patent ↗
Granted: Jan 3, 1984
Filed: Apr 1, 1981
Inventor
Alan R. Coutant
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.