Granted Patent
Utility
US 4,674,773 · App. 06/799,623
Insulating coupling for drill collars and method of manufacture thereof
Inventors:
Frederick A. Stone, Robert J. Maron
Patented Case
View Patent ↗
Granted: Jun 23, 1987
Filed: Nov 19, 1985
Inventors
Frederick A. Stone
Robert J. Maron
Assignee (at issue)
Teleco Oilfield Services 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.