Granted Patent
Utility
US 5,064,022 · App. 07/358,314
Ladder apparatus and method for large mobile equipment
Inventor:
George W. Graham
Patented Case
View Patent ↗
Granted: Nov 12, 1991
Filed: May 30, 1989
Inventor
George W. Graham
Assignee (at issue)
Marrowbone Development Company
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.