Granted Patent
Utility
US 4,816,637 · App. 07/057,729
Underwater and above-water plasma arc cutting torch and method
Inventors:
Nicholas A. Sanders, Richard W. Couch, Jr.
Patented Case
View Patent ↗
Granted: Mar 28, 1989
Filed: Jun 2, 1987
Inventors
Nicholas A. Sanders
Richard W. Couch, Jr.
Assignee (at issue)
Hypertherm, 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.