Granted Patent
Utility
US 4,474,080 · App. 05/872,535
Differential with variable torque means
Inventor:
Ralph R. Day
Patented Case
View Patent ↗
Granted: Oct 2, 1984
Filed: Jan 26, 1978
Inventor
Ralph R. Day
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.