Granted Patent
Utility
US 5,653,297 · App. 08/423,657
Blasthole drill with improved automatic breakout wrench
Inventor:
H. Dewain Whisenhunt
Patented Case
View Patent ↗
Granted: Aug 5, 1997
Filed: Apr 14, 1995
Inventor
H. Dewain Whisenhunt
Assignee (at issue)
Harnischfeger Corporation
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.