Granted Patent
Utility
US 4,608,743 · App. 06/747,836
Mining shovel ballast box connection method and apparatus
Inventor:
Paul Stewart
Patented Case
View Patent ↗
Granted: Sep 2, 1986
Filed: Jun 24, 1985
Inventor
Paul Stewart
Assignee (at issue)
Dresser Industries, 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.