Granted Patent
Utility
US 6,142,452 · App. 09/344,149
Highway barrier and guardrail
Inventors:
Owen S. Denman, Patrick A. Leonhardt, Michael H. Oberth, James B. Welch, Lincoln C. Cobb
Patented Case
View Patent ↗
Granted: Nov 7, 2000
Filed: Jun 24, 1999
Inventors
Owen S. Denman
Patrick A. Leonhardt
Michael H. Oberth
James B. Welch
Lincoln C. Cobb
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.