Granted Patent
Utility
US 4,521,042 · App. 06/510,881
Threaded connection
Inventors:
Jan W. Blackburn, Burl E. Baron
Patented Case
View Patent ↗
Granted: Jun 4, 1985
Filed: Jul 5, 1983
Inventors
Jan W. Blackburn
Burl E. Baron
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.