Granted Patent
Utility
US 4,984,636 · App. 07/313,688
Geothermal wellhead repair unit
Inventors:
Thomas F. Bailey, James N. Strickland
Patented Case
View Patent ↗
Granted: Jan 15, 1991
Filed: Feb 21, 1989
Inventors
Thomas F. Bailey
James N. Strickland
Assignee (at issue)
Drilex Systems, 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.