Granted Patent
Utility
US 4,291,768 · App. 06/111,760
Packing assembly for wellheads
Inventor:
Robert J. Diehl
Patented Case
View Patent ↗
Granted: Sep 29, 1981
Filed: Jan 14, 1980
Inventor
Robert J. Diehl
Assignee (at issue)
W-K-M Wellhead 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.