Granted Patent
Utility
US 4,324,412 · App. 06/132,757
Composite shield-step
Inventor:
Bernard J. Wulff
Patented Case
View Patent ↗
Granted: Apr 13, 1982
Filed: Mar 24, 1980
Inventor
Bernard J. Wulff
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.