Granted Patent
Utility
US 5,887,667 · App. 08/895,315
Method and means for drilling an earthen hole
Inventors:
William R. Van Zante, Craig A. Van Zante
Patented Case
View Patent ↗
Granted: Mar 30, 1999
Filed: Jul 16, 1997
Inventors
William R. Van Zante
Craig A. Van Zante
Assignee (at issue)
RING-O-MATIC MFG. CO., 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.