Granted Patent
Utility
US 4,925,497 · App. 07/319,793
Solvent for paraffin removal from oilfield equipment
Inventor:
Charles L. Thierheimer, Jr.
Patented Case
View Patent ↗
Granted: May 15, 1990
Filed: Mar 6, 1989
Inventor
Charles L. Thierheimer, Jr.
Assignee (at issue)
Petrolite Corporation
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.