Granted Patent
Utility
US 4,471,863 · App. 06/297,445
Multi-stage torsional damping device
Inventor:
Thaddeus Lech, Jr.
Patented Case
View Patent ↗
Granted: Sep 18, 1984
Filed: Aug 28, 1981
Inventor
Thaddeus Lech, Jr.
Assignee (at issue)
BorgWarner Inc.
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.