Granted Patent
Utility
US 4,787,458 · App. 07/056,488
Spring bow, centralizer, and related methods
Inventor:
Friederich H. Langer
Patented Case
View Patent ↗
Granted: Nov 29, 1988
Filed: May 29, 1987
Inventor
Friederich H. Langer
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.