Granted Patent
Utility
US 4,564,735 · App. 06/595,059
Direct current pulse welder
Inventor:
Gerald Dufrenne
Patented Case
View Patent ↗
Granted: Jan 14, 1986
Filed: Mar 30, 1984
Inventor
Gerald Dufrenne
Assignee (at issue)
Unitek
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.