Granted Patent
Utility
US 4,441,519 · App. 06/346,811
Gas lift valve and method of presetting
Inventor:
Ben D. Terral
Patented Case
View Patent ↗
Granted: Apr 10, 1984
Filed: Feb 8, 1982
Inventor
Ben D. Terral
Assignee (at issue)
Schlumberger Technology Corporation
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.