Granted Patent
Utility
US 5,348,938 · App. 08/054,462
Oleophilic alcohols as a constituent of invert drilling fluids
Inventors:
Heinz Mueller, Claus-Peter Herold, Stephan von Tapavicza
Patented Case
View Patent ↗
Granted: Sep 20, 1994
Filed: Apr 28, 1993
Inventors
Heinz Mueller
Claus-Peter Herold
Stephan von Tapavicza
Assignee (at issue)
Henkel Kommanditgesellschaft auf Aktien
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.