Granted Patent
Utility
US 4,589,495 · App. 06/601,938
Apparatus and method for inserting flow control means into a well casing
Inventors:
Friedrich H. Langer, William D. Stringfellow
Patented Case
View Patent ↗
Granted: May 20, 1986
Filed: Apr 19, 1984
Inventors
Friedrich H. Langer
William D. Stringfellow
Assignee (at issue)
Weatherford Holding U.S., 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.