Granted Patent
Utility
US 4,295,535 · App. 06/068,212
In-hole motor drill with locking bit clutch
Inventors:
Gary M. Crase, Kurt M. Trzeciak
Patented Case
View Patent ↗
Granted: Oct 20, 1981
Filed: Aug 20, 1979
Inventors
Gary M. Crase
Kurt M. Trzeciak
Assignee (at issue)
SMITH INTERNATIONAL, 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.