Granted Patent
Utility
US 4,538,690 · App. 06/468,668
PDC cutter and bit
Inventor:
Lot William Short, Jr.
Patented Case
View Patent ↗
Granted: Sep 3, 1985
Filed: Feb 22, 1983
Inventor
Lot William Short, Jr.
Assignee (at issue)
NL Industries, 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.