Granted Patent
Utility
US 6,047,775 · App. 09/358,216
Blast hole drill pipe gripping mechanism
Inventor:
Erwin Mock
Patented Case
View Patent ↗
Granted: Apr 11, 2000
Filed: Jul 21, 1999
Inventor
Erwin Mock
Assignee (at issue)
Bucyrus Intl. 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.