Granted Patent
Utility
US 5,901,798 · App. 08/628,719
Drill pipe tubing and casing protectors
Inventors:
Derek Herrera, Alex Joseph Gerard Herrera, Gregory Herrera, John Philip Corkhill
Patented Case
View Patent ↗
Granted: May 11, 1999
Filed: Sep 9, 1996
Inventors
Derek Herrera
Alex Joseph Gerard Herrera
Gregory Herrera
John Philip Corkhill
Assignee (at issue)
Hydril U.K. Limited
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.