Granted Patent
Utility
US 4,828,293 · App. 07/153,224
Wellhead slip and seal assembly
Inventors:
Delbert Edwin Vanderford, Jerry D. Smith
Patented Case
View Patent ↗
Granted: May 9, 1989
Filed: Feb 8, 1988
Inventors
Delbert Edwin Vanderford
Jerry D. Smith
Assignee (at issue)
Cameron Iron Works USA, 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.