Granted Patent
Utility
US 5,115,111 · App. 07/563,014
Dual tip rotating welding electrode
Inventors:
William M. Fries, Thomas L. Ratledge, William H. Hill
Patented Case
View Patent ↗
Granted: May 19, 1992
Filed: Aug 6, 1990
Inventors
William M. Fries
Thomas L. Ratledge
William H. Hill
Assignee (at issue)
Hughes Aircraft Company
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.