Granted Patent
Utility
US 4,428,433 · App. 06/306,443
Telescopic joint upper tube retainer method
Inventor:
Bruce J. Watkins
Patented Case
View Patent ↗
Granted: Jan 31, 1984
Filed: Sep 28, 1981
Inventor
Bruce J. Watkins
Assignee (at issue)
Hughes Tool Company LLC
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.