Granted Patent
Utility
US 5,994,663 · App. 08/727,028
Plasma arc torch and method using blow forward contact starting system
Inventor:
Zhipeng Lu
Patented Case
View Patent ↗
Granted: Nov 30, 1999
Filed: Oct 8, 1996
Inventor
Zhipeng Lu
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.