Granted Patent
Utility
US 5,587,354 · App. 08/233,501
Drilling fluid and drilling fluid additive
Inventor:
William M. Duncan, Jr.
Patented Case
View Patent ↗
Granted: Dec 24, 1996
Filed: Apr 26, 1994
Inventor
William M. Duncan, Jr.
Assignee (at issue)
Integrity Industries, 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.