Granted Patent
Utility
US 4,657,263 · App. 06/670,132
Annular packing unit and insert
Inventors:
Joseph H. Hynes, James A. Burton
Patented Case
View Patent ↗
Granted: Apr 14, 1987
Filed: Oct 19, 1984
Inventors
Joseph H. Hynes
James A. Burton
Assignee (at issue)
Hydril 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.