Granted Patent
Utility
US 4,421,970 · App. 06/365,466
Height sensing system for a plasma arc cutting tool
Inventor:
Richard W. Couch, Jr.
Patented Case
View Patent ↗
Granted: Dec 20, 1983
Filed: Apr 5, 1982
Inventor
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.