Granted Patent
Utility
US 6,325,460 · App. 09/493,976
Machine used in connection with underground mining having an operator protective shield
Inventor:
John R. Frederick
Patented Case
View Patent ↗
Granted: Dec 4, 2001
Filed: Jan 28, 2000
Inventor
John R. Frederick
Assignee (at issue)
Joy MM Delaware, 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.