Granted Patent
Utility
US 6,427,983 · App. 09/689,382
Self-restoring highway crash attenuator
Inventors:
Patrick A. Leonhardt, James B. Welch
Patented Case
View Patent ↗
Granted: Aug 6, 2002
Filed: Oct 12, 2000
Inventors
Patrick A. Leonhardt
James B. Welch
Assignee (at issue)
ENERGY ABSORPTION SYSTEMS, 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.