Granted Patent
Utility
US 4,828,037 · App. 07/191,578
Liner hanger with retrievable ball valve seat
Inventors:
Hiram E. Lindsey, Jr., Roger P. Allwin, Richard Adams
Patented Case
View Patent ↗
Granted: May 9, 1989
Filed: May 9, 1988
Inventors
Hiram E. Lindsey, Jr.
Roger P. Allwin
Richard Adams
Assignee (at issue)
Lindsey Completion 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.