Granted Patent
Utility
US 5,649,574 · App. 08/639,829
Engine coolant removal and refill method and device
Inventors:
David E. Turcotte, John J. Conville, Stephen M. Zeld, Daniel E. Coker, James T. Lyon
Patented Case
View Patent ↗
Granted: Jul 22, 1997
Filed: Apr 29, 1996
Inventors
David E. Turcotte
John J. Conville
Stephen M. Zeld
Daniel E. Coker
James T. Lyon
Assignee (at issue)
Ashland, 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.