Granted Patent
Utility
US 4,660,651 · App. 06/749,827
Highly flexible, foldable drill for uniform depth seed deposit
Inventors:
Billy J. Pfenninger, David R. Smith, David H. Weast
Patented Case
View Patent ↗
Granted: Apr 28, 1987
Filed: Jun 28, 1985
Inventors
Billy J. Pfenninger
David R. Smith
David H. Weast
Assignee (at issue)
Krause Plow Corporation, 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.