Granted Patent
Utility
US 4,294,303 · App. 06/195,719
Sand core pattern and method of forming a sand mold
Inventor:
Edward E. Flesburg
Patented Case
View Patent ↗
Granted: Oct 13, 1981
Filed: Mar 13, 1980
Inventor
Edward E. Flesburg
Assignee (at issue)
Caterpillar Tractor Co.
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.