Granted Patent
Utility
US 4,922,991 · App. 06/903,192
Composite core assembly for metal casting
Inventors:
Michael Pitcher, Albert L. Haugse, Richard L. Pelfrey, Gregory P. Sturtz
Patented Case
View Patent ↗
Granted: May 8, 1990
Filed: Sep 3, 1986
Inventors
Michael Pitcher
Albert L. Haugse
Richard L. Pelfrey
Gregory P. Sturtz
Assignee (at issue)
Ashland Oil, 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.