Granted Patent
Utility
US 4,460,039 · App. 06/439,082
Wellhead valve removal and installation tool
Inventor:
John Knight
Patented Case
View Patent ↗
Granted: Jul 17, 1984
Filed: Nov 4, 1982
Inventor
John Knight
Assignee (at issue)
W-K-M Wellhead 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.