Granted Patent
Utility
US 4,857,701 · App. 06/610,317
Internal welding head assembly
Inventor:
Clyde M. Slavens
Patented Case
View Patent ↗
Granted: Aug 15, 1989
Filed: May 14, 1984
Inventor
Clyde M. Slavens
Assignee (at issue)
CRC-EVANS PIPELINE INTERNATIONAL, 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.